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Cusack DF, Christoffersen B, Smith-Martin CM, Andersen KM, Cordeiro AL, Fleischer K, Wright SJ, Guerrero-Ramírez NR, Lugli LF, McCulloch LA, Sanchez-Julia M, Batterman SA, Dallstream C, Fortunel C, Toro L, Fuchslueger L, Wong MY, Yaffar D, Fisher JB, Arnaud M, Dietterich LH, Addo-Danso SD, Valverde-Barrantes OJ, Weemstra M, Ng JC, Norby RJ. Toward a coordinated understanding of hydro-biogeochemical root functions in tropical forests for application in vegetation models. New Phytol 2024; 242:351-371. [PMID: 38416367 DOI: 10.1111/nph.19561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 01/10/2024] [Indexed: 02/29/2024]
Abstract
Tropical forest root characteristics and resource acquisition strategies are underrepresented in vegetation and global models, hampering the prediction of forest-climate feedbacks for these carbon-rich ecosystems. Lowland tropical forests often have globally unique combinations of high taxonomic and functional biodiversity, rainfall seasonality, and strongly weathered infertile soils, giving rise to distinct patterns in root traits and functions compared with higher latitude ecosystems. We provide a roadmap for integrating recent advances in our understanding of tropical forest belowground function into vegetation models, focusing on water and nutrient acquisition. We offer comparisons of recent advances in empirical and model understanding of root characteristics that represent important functional processes in tropical forests. We focus on: (1) fine-root strategies for soil resource exploration, (2) coupling and trade-offs in fine-root water vs nutrient acquisition, and (3) aboveground-belowground linkages in plant resource acquisition and use. We suggest avenues for representing these extremely diverse plant communities in computationally manageable and ecologically meaningful groups in models for linked aboveground-belowground hydro-nutrient functions. Tropical forests are undergoing warming, shifting rainfall regimes, and exacerbation of soil nutrient scarcity caused by elevated atmospheric CO2. The accurate model representation of tropical forest functions is crucial for understanding the interactions of this biome with the climate.
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Affiliation(s)
- Daniela F Cusack
- Department of Ecosystem Science and Sustainability, Warner College of Natural Resources, Colorado State University, 1231 Libbie Coy Way, A104, Fort Collins, CO, 80523-1476, USA
- Smithsonian Tropical Research Institute, Apartado, Balboa, 0843-03092, Panama
| | - Bradley Christoffersen
- School of Integrative Biological and Chemical Sciences, The University of Texas Rio Grande Valley, Edinburg, TX, 78539, USA
| | - Chris M Smith-Martin
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, 55108, USA
| | | | - Amanda L Cordeiro
- Department of Ecosystem Science and Sustainability, Warner College of Natural Resources, Colorado State University, 1231 Libbie Coy Way, A104, Fort Collins, CO, 80523-1476, USA
- Smithsonian Tropical Research Institute, Apartado, Balboa, 0843-03092, Panama
| | - Katrin Fleischer
- Department Biogeochemical Signals, Max-Planck-Institute for Biogeochemistry, Hans-Knöll-Straße 10, Jena, 07745, Germany
| | - S Joseph Wright
- Smithsonian Tropical Research Institute, Apartado, Balboa, 0843-03092, Panama
| | - Nathaly R Guerrero-Ramírez
- Silviculture and Forest Ecology of Temperate Zones, Faculty of Forest Sciences and Forest Ecology, University of Göttingen, Gottingen, 37077, Germany
- Centre of Biodiversity and Sustainable Land Use (CBL), University of Göttingen, Gottingen, 37077, Germany
| | - Laynara F Lugli
- School of Life Sciences, Technical University of Munich, Freising, 85354, Germany
| | - Lindsay A McCulloch
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford St., Cambridge, MA, 02138, USA
- National Center for Atmospheric Research, National Oceanographic and Atmospheric Agency, 1850 Table Mesa Dr., Boulder, CO, 80305, USA
| | - Mareli Sanchez-Julia
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, 70118, USA
| | - Sarah A Batterman
- Smithsonian Tropical Research Institute, Apartado, Balboa, 0843-03092, Panama
- Cary Institute of Ecosystem Studies, Millbrook, NY, 12545, USA
- School of Geography, University of Leeds, Leeds, LS2 9JT, UK
| | - Caroline Dallstream
- Department of Biology, McGill University, 1205 Av. du Docteur-Penfield, Montreal, QC, H3A 1B1, Canada
| | - Claire Fortunel
- AMAP (Botanique et Modélisation de l'Architecture des Plantes et des Végétations), Université de Montpellier, CIRAD, CNRS, INRAE, IRD, Montpellier, 34398, France
| | - Laura Toro
- Yale Applied Science Synthesis Program, The Forest School at the Yale School of the Environment, Yale University, New Haven, CT, 06511, USA
| | - Lucia Fuchslueger
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, 1030, Austria
| | - Michelle Y Wong
- Cary Institute of Ecosystem Studies, Millbrook, NY, 12545, USA
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06511, USA
| | - Daniela Yaffar
- Functional Forest Ecology, Universität Hamburg, Barsbüttel, 22885, Germany
| | - Joshua B Fisher
- Schmid College of Science and Technology, Chapman University, 1 University Drive, Orange, CA, 92866, USA
| | - Marie Arnaud
- Institute of Ecology and Environmental Sciences (IEES), UMR 7618, CNRS-Sorbonne University-INRAE-UPEC-IRD, Paris, 75005, France
- School of Geography, Earth and Environmental Sciences & BIFOR, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Lee H Dietterich
- Department of Ecosystem Science and Sustainability, Warner College of Natural Resources, Colorado State University, 1231 Libbie Coy Way, A104, Fort Collins, CO, 80523-1476, USA
- U.S. Army Engineer Research and Development Center, Environmental Laboratory, Vicksburg, MS, 39180, USA
- Department of Biology, Haverford College, Haverford, PA, 19003, USA
| | - Shalom D Addo-Danso
- Forests and Climate Change Division, CSIR-Forestry Research Institute of Ghana, P.O Box UP 63 KNUST, Kumasi, Ghana
| | - Oscar J Valverde-Barrantes
- Department of Biological Sciences, International Center for Tropical Biodiversity, Florida International University, Miami, FL, 33199, USA
| | - Monique Weemstra
- Department of Biological Sciences, International Center for Tropical Biodiversity, Florida International University, Miami, FL, 33199, USA
| | - Jing Cheng Ng
- Nanyang Technological University, Singapore, 639798, Singapore
| | - Richard J Norby
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA
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Hunziker S, Nazarova T, Kather M, Hartmann M, Brunner I, Schaub M, Rigling A, Hug C, Schönbeck L, Bose AK, Kammerer B, Gessler A. The metabolic fingerprint of Scots pine - root and needle metabolites show different patterns in dying trees. Tree Physiol 2024:tpae036. [PMID: 38526975 DOI: 10.1093/treephys/tpae036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Accepted: 03/19/2024] [Indexed: 03/27/2024]
Abstract
The loss of leaves and needles in tree crowns and tree mortality are increasing worldwide, mostly as a result of more frequent and severe drought stress. Scots pine (Pinus sylvestris L.) is a tree species that is strongly affected by these developments in many regions of Europe and Asia. So far, changes in metabolic pathways and metabolite profiles in needles and roots on the trajectory towards mortality are unknown, although they could contribute to a better understanding of the mortality mechanisms. Therefore, we linked long-term observations of canopy defoliation and tree mortality with the characterization of the primary metabolite profile in needles and fine roots of Scots pines from a forest site in the Swiss Rhone valley. Our results show that Scots pines are able to maintain metabolic homeostasis in needles over a wide range of canopy defoliation levels. However, there is a metabolic tipping point at around 80-85% needle loss. Above this threshold, many stress-related metabolites (particularly osmoprotectants, defense compounds and antioxidants) increase in the needles, whereas they decrease in the fine roots. If this defoliation tipping point is exceeded, the trees are very likely to die within a few years. The different patterns between needles and roots indicate that mainly belowground carbon starvation impairs key functions for tree survival and suggests that this is an important factor explaining the increasing mortality of Scots pines.
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Affiliation(s)
- Stefan Hunziker
- Forest Dynamics, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
| | - Tatiana Nazarova
- Forest Dynamics, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
| | - Michel Kather
- Core Facility Metabolomics, Albert-Ludwigs-University Freiburg, 79014 Freiburg, Germany
| | - Martin Hartmann
- Institute of Agricultural Sciences, ETH Zurich, 8092 Zurich, Switzerland
| | - Ivano Brunner
- Forest Soils and Biogeochemistry, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
| | - Marcus Schaub
- Forest Dynamics, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
| | - Andreas Rigling
- Forest Dynamics, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
- Institute of Terrestrial Ecosystems, ETH Zurich, 8092 Zurich, Switzerland
| | - Christian Hug
- Forest Dynamics, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
| | - Leonie Schönbeck
- Forest Dynamics, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
- Department of Botany and Plant Sciences, University of California, Riverside, CA 9252, USA
| | - Arun K Bose
- Forest Dynamics, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
- Forestry and Wood Technology Discipline, Khulna University, Khulna-9208, Bangladesh
| | - Bernd Kammerer
- Core Facility Metabolomics, Albert-Ludwigs-University Freiburg, 79014 Freiburg, Germany
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
- Institute of Terrestrial Ecosystems, ETH Zurich, 8092 Zurich, Switzerland
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Argiroff WA, Carrell AA, Klingeman DM, Dove NC, Muchero W, Veach AM, Wahl T, Lebreux SJ, Webb AB, Peyton K, Schadt CW, Cregger MA. Seasonality and longer-term development generate temporal dynamics in the Populus microbiome. mSystems 2024; 9:e0088623. [PMID: 38421171 PMCID: PMC10949431 DOI: 10.1128/msystems.00886-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 02/08/2024] [Indexed: 03/02/2024] Open
Abstract
Temporal variation in community composition is central to our understanding of the assembly and functioning of microbial communities, yet the controls over temporal dynamics for microbiomes of long-lived plants, such as trees, remain unclear. Temporal variation in tree microbiomes could arise primarily from seasonal (i.e., intra-annual) fluctuations in community composition or from longer-term changes across years as host plants age. To test these alternatives, we experimentally isolated temporal variation in plant microbiome composition using a common garden and clonally propagated plants, and we used amplicon sequencing to characterize bacterial/archaeal and fungal communities in the leaf endosphere, root endosphere, and rhizosphere of two Populus spp. over four seasons across two consecutive years. Microbial community composition differed among seasons and years (which accounted for up to 21% of the variation in microbial community composition) and was correlated with seasonal dissimilarity in climatic conditions. However, microbial community dissimilarity was also positively correlated with time, reflecting longer-term compositional shifts as host trees aged. Together, our findings demonstrate that temporal patterns in tree microbiomes arise from both seasonal fluctuations and longer-term changes, which interact to generate unique seasonal patterns each year. In addition to shedding light on two important controls over the assembly of plant microbiomes, our results also suggest future studies of tree microbiomes should account for background temporal dynamics when testing the drivers of spatial patterns in microbial community composition and temporal responses of plant microbiomes to environmental change.IMPORTANCEMicrobiomes are integral to the health of host plants, but we have a limited understanding of the factors that control how the composition of plant microbiomes changes over time. Especially little is known about the microbiome of long-lived trees, relative to annual and non-woody plants. We tested how tree microbiomes changed between seasons and years in poplar (genus Populus), which are widespread and ecologically important tree species that also serve as important biofuel feedstocks. We found the composition of bacterial, archaeal, and fungal communities differed among seasons, but these seasonal differences depended on year. This dependence was driven by longer-term changes in microbial composition as host trees developed across consecutive years. Our findings suggest that temporal variation in tree microbiomes is driven by both seasonal fluctuations and longer-term (i.e., multiyear) development.
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Affiliation(s)
- William A. Argiroff
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Alyssa A. Carrell
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Dawn M. Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Nicholas C. Dove
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Wellington Muchero
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Allison M. Veach
- Department of Integrative Biology, The University of Texas, San Antonio, Texas, USA
| | - Toni Wahl
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Steven J. Lebreux
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Amber B. Webb
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Kellie Peyton
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Christopher W. Schadt
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Melissa A. Cregger
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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Bhattarai B, Sigurdsson BD, Sigurdsson P, Leblans N, Janssens I, Meynzer W, Devarajan AK, Truu J, Truu M, Ostonen I. Soil warming duration and magnitude affect the dynamics of fine roots and rhizomes and associated C and N pools in subarctic grasslands. Ann Bot 2023; 132:269-279. [PMID: 37471454 PMCID: PMC10583211 DOI: 10.1093/aob/mcad102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 07/18/2023] [Indexed: 07/22/2023]
Abstract
BACKGROUND AND AIMS The response of subarctic grassland's below-ground to soil warming is key to understanding this ecosystem's adaptation to future climate. Functionally different below-ground plant organs can respond differently to changes in soil temperature (Ts). We aimed to understand the below-ground adaptation mechanisms by analysing the dynamics and chemistry of fine roots and rhizomes in relation to plant community composition and soil chemistry, along with the duration and magnitude of soil warming. METHODS We investigated the effects of the duration [medium-term warming (MTW; 11 years) and long-term warming (LTW; > 60 years)] and magnitude (0-8.4 °C) of soil warming on below-ground plant biomass (BPB), fine root biomass (FRB) and rhizome biomass (RHB) in geothermally warmed subarctic grasslands. We evaluated the changes in BPB, FRB and RHB and the corresponding carbon (C) and nitrogen (N) pools in the context of ambient, Ts < +2 °C and Ts > +2 °C scenarios. KEY RESULTS BPB decreased exponentially in response to an increase in Ts under MTW, whereas FRB declined under both MTW and LTW. The proportion of rhizomes increased and the C-N ratio in rhizomes decreased under LTW. The C and N pools in BPB in highly warmed plots under MTW were 50 % less than in the ambient plots, whereas under LTW, C and N pools in warmed plots were similar to those in non-warmed plots. Approximately 78 % of the variation in FRB, RHB, and C and N concentration and pools in fine roots and rhizomes was explained by the duration and magnitude of soil warming, soil chemistry, plant community functional composition, and above-ground biomass. Plant's below-ground biomass, chemistry and pools were related to a shift in the grassland's plant community composition - the abundance of ferns increased and BPB decreased towards higher Ts under MTW, while the recovery of below-ground C and N pools under LTW was related to a higher plant diversity. CONCLUSION Our results indicate that plant community-level adaptation of below ground to soil warming occurs over long periods. We provide insight into the potential adaptation phases of subarctic grasslands.
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Affiliation(s)
- Biplabi Bhattarai
- Institute of Ecology and Earth Sciences, University of Tartu, Estonia
| | - Bjarni D Sigurdsson
- Faculty of Environmental and Forest Sciences, The Agricultural University of Iceland, Iceland
| | - Páll Sigurdsson
- Faculty of Environmental and Forest Sciences, The Agricultural University of Iceland, Iceland
| | - Niki Leblans
- Climate Impact Research Centre, Umeå University, Sweden
| | - Ivan Janssens
- Department of Biology, University of Antwerp, Belgium
| | | | | | - Jaak Truu
- Institute of Molecular and Cell Biology, University of Tartu, Estonia
| | - Marika Truu
- Institute of Molecular and Cell Biology, University of Tartu, Estonia
| | - Ivika Ostonen
- Institute of Ecology and Earth Sciences, University of Tartu, Estonia
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Krokene P, Børja I, Carneros E, Eldhuset TD, Nagy NE, Volařík D, Gebauer R. Effects of combined drought and pathogen stress on growth, resistance and gene expression in young Norway spruce trees. Tree Physiol 2023; 43:1603-1618. [PMID: 37171580 DOI: 10.1093/treephys/tpad062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 04/20/2023] [Accepted: 05/08/2023] [Indexed: 05/13/2023]
Abstract
Drought-induced mortality is a major direct effect of climate change on tree health, but drought can also affect trees indirectly by altering their susceptibility to pathogens. Here, we report how a combination of mild or severe drought and pathogen infection affected the growth, pathogen resistance and gene expression in potted 5-year-old Norway spruce trees [Picea abies (L.) Karst.]. After 5 weeks of drought, trees were inoculated with the fungal pathogen Endoconidiophora polonica. Combined drought-pathogen stress over the next 8 weeks led to significant reductions in the growth of drought-treated trees relative to well-watered trees and more so in trees subjected to severe drought. Belowground, growth of the smallest fine roots was most affected. Aboveground, shoot diameter change was most sensitive to the combined stress, followed by shoot length growth and twig biomass. Both drought-related and some resistance-related genes were upregulated in bark samples collected after 5 weeks of drought (but before pathogen infection), and gene expression levels scaled with the intensity of drought stress. Trees subjected to severe drought were much more susceptible to pathogen infection than well-watered trees or trees subjected to mild drought. Overall, our results show that mild drought stress may increase the tree resistance to pathogen infection by upregulating resistance-related genes. Severe drought stress, on the other hand, decreased tree resistance. Because drought episodes are expected to become more frequent with climate change, combined effects of drought and pathogen stress should be studied in more detail to understand how these stressors interactively influence tree susceptibility to pests and pathogens.
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Affiliation(s)
- P Krokene
- Division of Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research, P.O. Box 115, Ås, 1431, Norway
| | - I Børja
- Division of Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research, P.O. Box 115, Ås, 1431, Norway
| | - E Carneros
- Division of Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research, P.O. Box 115, Ås, 1431, Norway
- Center for Biological Research Margarita Salas-Spanish National Research Council (CSIC), Madrid, Spain
| | - T D Eldhuset
- Division of Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research, P.O. Box 115, Ås, 1431, Norway
- Sagveien 17, 1414, Trollåsen, Norway
| | - N E Nagy
- Division of Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research, P.O. Box 115, Ås, 1431, Norway
| | - D Volařík
- Department of Forest Botany, Dendrology and Geobicoenology, Mendel University in Brno, Zemědělská 3, Brno, 61300, Czech Republic
| | - R Gebauer
- Department of Forest Botany, Dendrology and Geobicoenology, Mendel University in Brno, Zemědělská 3, Brno, 61300, Czech Republic
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You C, Li J, Yang K, Tan B, Yin R, Li H, Zhang L, Cui X, Liu S, Wang L, Liu Y, Chen L, Yuan Y, Li J, Sardans J, Zhang J, Xu Z, Peñuelas J. Variations and patterns of C and N stoichiometry in the first five root branch orders across 218 woody plant species. New Phytol 2023; 238:1838-1848. [PMID: 36891665 DOI: 10.1111/nph.18870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 02/27/2023] [Indexed: 05/04/2023]
Abstract
Despite the vital role in carbon (C) sequestration and nutrient retention, variations and patterns in root C and nitrogen (N) stoichiometry of the first five root orders across woody plant species remains unclear. We compiled a dataset to explore variations and patterns of root C and N stoichiometry in the first five orders of 218 woody plant species. Across the five orders, root N concentrations were greater in deciduous, broadleaf, and arbuscular mycorrhizal species than in evergreen, coniferous species, and ectomycorrhizal association species, respectively. Contrasting trends were found for root C : N ratios. Most root branch orders showed clear latitudinal and altitudinal trends in root C and N stoichiometry. There were opposite patterns in N concentrations between latitude and altitude. Such variations were mainly driven by plant species, and climatic factors together. Our results indicate divergent C and N use strategies among plant types and convergence and divergence in the patterns of C and N stoichiometry between latitude and altitude across the first five root orders. These findings provide important data on the root economics spectrum and biogeochemical models to improve understanding and prediction of climate change effects on C and nutrient dynamics in terrestrial ecosystems.
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Affiliation(s)
- Chengming You
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jihong Li
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Kaijun Yang
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
- Global Ecology Unit CREAF-CSIC-UAB, CSIC, Bellaterra, 08193, Barcelona, Catalonia, Spain
| | - Bo Tan
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Rui Yin
- Department of Community Ecology, Helmholtz-Centre for Environmental Research-UFZ, Theodor-Lieser-Strasse 4, 06110, Halle (Saale), Germany
| | - Han Li
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Li Zhang
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xinglei Cui
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Sining Liu
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Lixia Wang
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yang Liu
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Lianghua Chen
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yaling Yuan
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jiao Li
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jordi Sardans
- Global Ecology Unit CREAF-CSIC-UAB, CSIC, Bellaterra, 08193, Barcelona, Catalonia, Spain
- CREAF, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain
| | - Jian Zhang
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Zhenfeng Xu
- Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China
| | - Josep Peñuelas
- Global Ecology Unit CREAF-CSIC-UAB, CSIC, Bellaterra, 08193, Barcelona, Catalonia, Spain
- CREAF, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain
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7
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Watson SJ, Aguirre BA, Wright AJ. Soil versus atmospheric drought: A test case of plant functional trait responses. Ecology 2023:e4109. [PMID: 37232406 DOI: 10.1002/ecy.4109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 04/27/2023] [Accepted: 05/18/2023] [Indexed: 05/27/2023]
Abstract
Climate change alters mean global surface temperatures, precipitation regimes, and atmospheric moisture. Resultant drought affects the composition and diversity of terrestrial ecosystems worldwide. To date, there are no assessments of the combined impacts of reduced precipitation and atmospheric drying on functional trait distributions of any species in an outdoor experiment. Here, we examined whether soil and atmospheric drought affect the functional traits of a focal grass species (Poa secunda) growing in monoculture and 8-species grass communities in outdoor mesocosms. We focused on specific leaf area (SLA), leaf area, stomatal density, root:shoot ratio, and fine root:coarse root ratio responses. Leaf area and overall growth were reduced with soil drying. Root:shoot ratio only increased for P. secunda growing in monoculture under combined atmospheric and soil drought. Plant energy allocation strategy (measured using principal components) differed when P. secunda was grown in combined soil and atmospheric drought conditions compared with soil drought alone. Given a lack of outdoor manipulations of this kind, our results emphasize the importance of atmospheric drying on functional trait responses more broadly. We suggest that drought methods focused purely on soil water inputs may be imprecisely predicting drought effects on other terrestrial organisms as well (other plants, arthropods, and higher trophic levels). This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Samantha J Watson
- Department of Biological Sciences, California State University Los Angeles, Los Angeles, CA, USA
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
- The Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Beatriz A Aguirre
- Department of Biological Sciences, California State University Los Angeles, Los Angeles, CA, USA
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| | - Alexandra J Wright
- Department of Biological Sciences, California State University Los Angeles, Los Angeles, CA, USA
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8
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Xia M, Valverde‐Barrantes OJ, Suseela V, Blackwood CB, Tharayil N. Characterizing natural variability of lignin abundance and composition in fine roots across temperate trees: a comparison of analytical methods. New Phytol 2022; 236:2358-2373. [PMID: 36168143 PMCID: PMC9828118 DOI: 10.1111/nph.18515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 08/27/2022] [Indexed: 06/16/2023]
Abstract
Lignin is an important root chemical component that is widely used in biogeochemical models to predict root decomposition. Across ecological studies, lignin abundance has been characterized using both proximate and lignin-specific methods, without much understanding of their comparability. This uncertainty in estimating lignin limits our ability to comprehend the mechanisms regulating root decomposition and to integrate lignin data for large-scale syntheses. We compared five methods of estimating lignin abundance and composition in fine roots across 34 phylogenetically diverse tree species. We also assessed the feasibility of high-throughput techniques for fast-screening of root lignin. Although acid-insoluble fraction (AIF) has been used to infer root lignin and decomposition, AIF-defined lignin content was disconnected from the lignin abundance estimated by techniques that specifically measure lignin-derived monomers. While lignin-specific techniques indicated lignin contents of 2-10% (w/w) in roots, AIF-defined lignin contents were c. 5-10-fold higher, and their interspecific variation was found to be largely unrelated to that determined using lignin-specific techniques. High-throughput pyrolysis-gas chromatography-mass spectrometry, when combined with quantitative modeling, accurately predicted lignin abundance and composition, highlighting its feasibility for quicker assessment of lignin in roots. We demonstrate that AIF should be interpreted separately from lignin in fine roots as its abundance is unrelated to that of lignin polymers. This study provides the basis for informed decision-making with respect to lignin methodology in ecology.
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Affiliation(s)
- Mengxue Xia
- Department of Plant & Environmental SciencesClemson UniversityClemsonSC29634USA
| | - Oscar J. Valverde‐Barrantes
- International Center for Tropical Biodiversity, Institute of EnvironmentFlorida International UniversityMiamiFL33199USA
| | - Vidya Suseela
- Department of Plant & Environmental SciencesClemson UniversityClemsonSC29634USA
| | | | - Nishanth Tharayil
- Department of Plant & Environmental SciencesClemson UniversityClemsonSC29634USA
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9
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Tullus A, Rusalepp L, Lutter R, Rosenvald K, Kaasik A, Rytter L, Kontunen-Soppela S, Oksanen E. Climate and Competitive Status Modulate the Variation in Secondary Metabolites More in Leaves Than in Fine Roots of Betula pendula. Front Plant Sci 2021; 12:746165. [PMID: 34899775 PMCID: PMC8655902 DOI: 10.3389/fpls.2021.746165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 11/04/2021] [Indexed: 06/01/2023]
Abstract
Plant secondary metabolites have many important functions; they also determine the productivity and resilience of trees under climate change. The effects of environmental factors on secondary metabolites are much better understood in above-ground than in below-ground part of the tree. Competition is a crucial biotic stress factor, but little is known about the interaction effect of climate and competition on the secondary chemistry of trees. Moreover, competition effect is usually overlooked when analyzing the sources of variation in the secondary chemistry. Our aim was to clarify the effects of competitive status, within-crown light environment, and climate on the secondary chemistry of silver birch (Betula pendula Roth). We sampled leaves (from upper and lower crown) and fine roots from competitively dominant and suppressed B. pendula trees in plantations along a latitudinal gradient (56-67° N) in Fennoscandia, with mean annual temperature (MAT) range: -1 to 8°C. Secondary metabolites in leaves (SML) and fine roots (SMFR) were determined with an HPLC-qTOF mass spectrometer. We found that SML content increased significantly with MAT. The effect of competitive stress on SML strengthened in colder climates (MAT<4°C). Competition and shade initiated a few similar responses in SML. SMFR varied less with MAT. Suppressed trees allocated relatively more resources to SML in warmer climates and to SMFR in colder ones. Our study revealed that the content and profile of secondary metabolites (mostly phenolic defense compounds and growth regulators) in leaves of B. pendula varied with climate and reflected the trees' defense requirements against herbivory, exposure to irradiance, and competitive status (resource supply). The metabolic profile of fine roots reflected, besides defense requirements, also different below-ground competition strategies in warmer and colder climates. An increase in carbon assimilation to secondary compounds can be expected at northern latitudes due to climate change.
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Affiliation(s)
- Arvo Tullus
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Linda Rusalepp
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
- Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Tartu, Estonia
| | - Reimo Lutter
- Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Tartu, Estonia
| | - Katrin Rosenvald
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Ants Kaasik
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | | | - Sari Kontunen-Soppela
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Elina Oksanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
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10
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Argiroff WA, Zak DR, Pellitier PT, Upchurch RA, Belke JP. Decay by ectomycorrhizal fungi couples soil organic matter to nitrogen availability. Ecol Lett 2021; 25:391-404. [PMID: 34787356 DOI: 10.1111/ele.13923] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 10/21/2021] [Accepted: 10/30/2021] [Indexed: 01/04/2023]
Abstract
Interactions between soil nitrogen (N) availability, fungal community composition, and soil organic matter (SOM) regulate soil carbon (C) dynamics in many forest ecosystems, but context dependency in these relationships has precluded general predictive theory. We found that ectomycorrhizal (ECM) fungi with peroxidases decreased with increasing inorganic N availability across a natural inorganic N gradient in northern temperate forests, whereas ligninolytic fungal saprotrophs exhibited no response. Lignin-derived SOM and soil C were negatively correlated with ECM fungi with peroxidases and were positively correlated with inorganic N availability, suggesting decay of lignin-derived SOM by these ECM fungi reduced soil C storage. The correlations we observed link SOM decay in temperate forests to tradeoffs in tree N nutrition and ECM composition, and we propose SOM varies along a single continuum across temperate and boreal ecosystems depending upon how tree allocation to functionally distinct ECM taxa and environmental stress covary with soil N availability.
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Affiliation(s)
- William A Argiroff
- School for Environment and Sustainability, University of Michigan, Ann Arbor, Michigan, USA
| | - Donald R Zak
- School for Environment and Sustainability, University of Michigan, Ann Arbor, Michigan, USA.,Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Peter T Pellitier
- School for Environment and Sustainability, University of Michigan, Ann Arbor, Michigan, USA
| | - Rima A Upchurch
- School for Environment and Sustainability, University of Michigan, Ann Arbor, Michigan, USA
| | - Julia P Belke
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan, USA
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11
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Xia M, Valverde-Barrantes OJ, Suseela V, Blackwood CB, Tharayil N. Coordination between compound-specific chemistry and morphology in plant roots aligns with ancestral mycorrhizal association in woody angiosperms. New Phytol 2021; 232:1259-1271. [PMID: 34137048 DOI: 10.1111/nph.17561] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/31/2021] [Indexed: 06/12/2023]
Abstract
Recent studies on fine root functional traits proposed a root economics hypothesis where adaptations associated with mycorrhizal dependency strongly influence the organization of root traits, forming a dominant axis of trait covariation unique to roots. This conclusion, however, is based on tradeoffs of a few widely studied root traits. It is unknown how other functional traits fit into this mycorrhizal-collaboration gradient. Here, we provide a significant extension to the field of root ecology by examining how fine root secondary compounds coordinate with other root traits. We analyzed a dataset integrating compound-specific chemistry, morphology and anatomy of fine roots and leaves from 34 temperate tree species spanning major angiosperm lineages. Our data uncovered previously undocumented coordination where root chemistry, morphology and anatomy covary with each other. This coordination, aligned with mycorrhizal colonization, reflects tradeoffs between chemical protection and mycorrhizal dependency, and provides mechanistic support for the mycorrhizal-collaboration gradient. We also found remarkable phylogenetic structuring in root chemistry. These patterns were not mirrored by leaves. Furthermore, chemical protection was largely decoupled from the leaf economics spectrum. Our results unveil broad organization of root chemistry, demonstrate unique belowground adaptions, and suggest that root strategies and phylogeny could impact biogeochemical cycles through their links with root chemistry.
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Affiliation(s)
- Mengxue Xia
- Department of Plant & Environmental Sciences, Clemson University, Clemson, SC, 29634, USA
| | - Oscar J Valverde-Barrantes
- Department of Biological Sciences, International Center for Tropical Biodiversity, Florida International University, Miami, FL, 33199, USA
| | - Vidya Suseela
- Department of Plant & Environmental Sciences, Clemson University, Clemson, SC, 29634, USA
| | | | - Nishanth Tharayil
- Department of Plant & Environmental Sciences, Clemson University, Clemson, SC, 29634, USA
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12
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Frimpong F, Anokye M, Windt CW, Naz AA, Frei M, Dusschoten DV, Fiorani F. Proline-Mediated Drought Tolerance in the Barley ( Hordeum vulgare L.) Isogenic Line Is Associated with Lateral Root Growth at the Early Seedling Stage. Plants (Basel) 2021; 10:2177. [PMID: 34685984 DOI: 10.3390/plants10102177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/11/2021] [Accepted: 10/11/2021] [Indexed: 12/02/2022]
Abstract
A vigorous root system in barley promotes water uptake from the soil under water-limited conditions. We investigated three spring barley genotypes with varying water stress responses using rhizoboxes at the seedling stage. The genotypes comprised two elite German cultivars, Barke and Scarlett, and a near-isogenic line, NIL 143. The isogenic line harbors the wild allele pyrroline-5-carboxylate synthase1-P5cs1. Root growth in rhizoboxes under reduced water availability conditions caused a significant reduction in total root length, rooting depth, root maximum width, and root length density. On average, root growth was reduced by more than 20% due to water stress. Differences in organ proline concentrations were observed for all genotypes, with shoots grown under water stress exhibiting at least a 30% higher concentration than the roots. Drought induced higher leaf and root proline concentrations in NIL 143 compared with any of the other genotypes. Under reduced water availability conditions, NIL 143 showed less severe symptoms of drought, higher lateral root length, rooting depth, maximum root width, root length density, and convex hull area compared with Barke and Scarlett. Within the same comparison, under water stress, NIL 143 had a higher proportion of lateral roots (+30%), which were also placed at deeper substrate horizons. NIL 143 had a less negative plant water potential and higher relative leaf water content and stomatal conductance compared with the other genotypes under water stress. Under these conditions, this genotype also maintained an enhanced net photosynthetic rate and exhibited considerable fine root growth (diameter class 0.05–0.35 mm). These results show that water stress induces increased shoot and root proline accumulation in the NIL 143 barley genotype at the seedling stage and that this effect is associated with increased lateral root growth.
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13
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Hilman B, Muhr J, Helm J, Kuhlmann I, Schulze ED, Trumbore S. The size and the age of the metabolically active carbon in tree roots. Plant Cell Environ 2021; 44:2522-2535. [PMID: 34096615 DOI: 10.1111/pce.14124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/31/2021] [Accepted: 06/01/2021] [Indexed: 06/12/2023]
Abstract
Little is known about the sources and age of C respired by tree roots. Previous research in stems identified two functional pools of non-structural carbohydrates (NSC): an "active" pool supplied directly from canopy photo-assimilates supporting metabolism and a "stored" pool used when fresh C supplies are limited. We compared the C isotope composition of water-soluble NSC and respired CO2 for aspen roots (Populus tremula hybrids) cut off from fresh C supply after stem-girdling or prolonged incubation of excised roots. We used bomb radiocarbon to estimate the time elapsed since C fixation for respired CO2 , water-soluble NSC and structural α-cellulose. While freshly excised roots (mostly <2.9 mm in diameter) respired CO2 fixed <1 year previously, the age increased to 1.6-2.9 year within a week after root excision. Freshly excised roots from trees girdled ~3 months ago had respiration rates and NSC stocks similar to un-girdled trees but respired older C (~1.2 year). We estimate that over 3 months NSC in girdled roots must be replaced 5-7 times by reserves remobilized from root-external sources. Using a mixing model and observed correlations between Δ14 C of water-soluble C and α-cellulose, we estimate ~30% of C is "active" (~5 mg C g-1 ).
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Affiliation(s)
- Boaz Hilman
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
| | - Jan Muhr
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
- Department of Bioclimatology, Georg-August University Göttingen, Göttingen, Germany
| | - Juliane Helm
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
| | - Iris Kuhlmann
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
| | - Ernst-Detlef Schulze
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
| | - Susan Trumbore
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
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14
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Huaraca Huasco W, Riutta T, Girardin CAJ, Hancco Pacha F, Puma Vilca BL, Moore S, Rifai SW, Del Aguila-Pasquel J, Araujo Murakami A, Freitag R, Morel AC, Demissie S, Doughty CE, Oliveras I, Galiano Cabrera DF, Durand Baca L, Farfán Amézquita F, Silva Espejo JE, da Costa ACL, Oblitas Mendoza E, Quesada CA, Evouna Ondo F, Edzang Ndong J, Jeffery KJ, Mihindou V, White LJT, N'ssi Bengone N, Ibrahim F, Addo-Danso SD, Duah-Gyamfi A, Djaney Djagbletey G, Owusu-Afriyie K, Amissah L, Mbou AT, Marthews TR, Metcalfe DB, Aragão LEO, Marimon-Junior BH, Marimon BS, Majalap N, Adu-Bredu S, Abernethy KA, Silman M, Ewers RM, Meir P, Malhi Y. Fine root dynamics across pantropical rainforest ecosystems. Glob Chang Biol 2021; 27:3657-3680. [PMID: 33982340 DOI: 10.1111/gcb.15677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 02/27/2021] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
Fine roots constitute a significant component of the net primary productivity (NPP) of forest ecosystems but are much less studied than aboveground NPP. Comparisons across sites and regions are also hampered by inconsistent methodologies, especially in tropical areas. Here, we present a novel dataset of fine root biomass, productivity, residence time, and allocation in tropical old-growth rainforest sites worldwide, measured using consistent methods, and examine how these variables are related to consistently determined soil and climatic characteristics. Our pantropical dataset spans intensive monitoring plots in lowland (wet, semi-deciduous, and deciduous) and montane tropical forests in South America, Africa, and Southeast Asia (n = 47). Large spatial variation in fine root dynamics was observed across montane and lowland forest types. In lowland forests, we found a strong positive linear relationship between fine root productivity and sand content, this relationship was even stronger when we considered the fractional allocation of total NPP to fine roots, demonstrating that understanding allocation adds explanatory power to understanding fine root productivity and total NPP. Fine root residence time was a function of multiple factors: soil sand content, soil pH, and maximum water deficit, with longest residence times in acidic, sandy, and water-stressed soils. In tropical montane forests, on the other hand, a different set of relationships prevailed, highlighting the very different nature of montane and lowland forest biomes. Root productivity was a strong positive linear function of mean annual temperature, root residence time was a strong positive function of soil nitrogen content in montane forests, and lastly decreasing soil P content increased allocation of productivity to fine roots. In contrast to the lowlands, environmental conditions were a better predictor for fine root productivity than for fractional allocation of total NPP to fine roots, suggesting that root productivity is a particularly strong driver of NPP allocation in tropical mountain regions.
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Affiliation(s)
- Walter Huaraca Huasco
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | - Terhi Riutta
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | - Cécile A J Girardin
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | | | | | - Sam Moore
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | - Sami W Rifai
- ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, Australia
| | | | - Alejandro Araujo Murakami
- Museo de Historia Natural Noel Kempff Mercado Universidad Autónoma Gabriel Rene Moreno, Santa Cruz, Bolivia
| | - Renata Freitag
- Programa de Pós-graduação em Ecologia e Conservação, Universidade do Estado de Mato Grosso, Nova Xavantina, MT, Brazil
| | - Alexandra C Morel
- Department of Geography and Environmental Science, University of Dundee, Dundee, UK
| | | | - Christopher E Doughty
- School of Informatics, Computing and Cyber systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Imma Oliveras
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | | | | | | | | | | | | | | | | | | | | | - Vianet Mihindou
- Ministère de la Foret, de la Mer, de l'Environnement, Chargé Du Plan Climat, Libreville, Gabon
| | - Lee J T White
- Ministère de la Foret, de la Mer, de l'Environnement, Chargé Du Plan Climat, Libreville, Gabon
| | - Natacha N'ssi Bengone
- Ministère de la Foret, de la Mer, de l'Environnement, Chargé Du Plan Climat, Libreville, Gabon
| | - Forzia Ibrahim
- Forestry Research Institute of Ghana, Council for Scientific and Industrial Research, University, Kumasi, Ghana
| | - Shalom D Addo-Danso
- Forestry Research Institute of Ghana, Council for Scientific and Industrial Research, University, Kumasi, Ghana
| | - Akwasi Duah-Gyamfi
- Forestry Research Institute of Ghana, Council for Scientific and Industrial Research, University, Kumasi, Ghana
| | - Gloria Djaney Djagbletey
- Forestry Research Institute of Ghana, Council for Scientific and Industrial Research, University, Kumasi, Ghana
| | - Kennedy Owusu-Afriyie
- Forestry Research Institute of Ghana, Council for Scientific and Industrial Research, University, Kumasi, Ghana
| | - Lucy Amissah
- Forestry Research Institute of Ghana, Council for Scientific and Industrial Research, University, Kumasi, Ghana
| | - Armel T Mbou
- Centro Euro-Mediterraneo sui Cambiamenti Climatici, Leece, Italy
| | | | - Daniel B Metcalfe
- Department of Ecology and Environment Science, Umeå University, Umeå, Sweden
| | - Luiz E O Aragão
- Divisão de Sensoriamento Remoto-DIDSR, Instituto Nacional de Pesquisas Espaciais, São Jose dos Campos, SP, Brazil
| | - Ben H Marimon-Junior
- Programa de Pós-graduação em Ecologia e Conservação, Universidade do Estado de Mato Grosso, Nova Xavantina, MT, Brazil
| | - Beatriz S Marimon
- Programa de Pós-graduação em Ecologia e Conservação, Universidade do Estado de Mato Grosso, Nova Xavantina, MT, Brazil
| | - Noreen Majalap
- Sabah Forestry Department, Forest Research Centre, Sabah, Malaysia
| | - Stephen Adu-Bredu
- Forestry Research Institute of Ghana, Council for Scientific and Industrial Research, University, Kumasi, Ghana
| | | | - Miles Silman
- Department of Biology, Wake Forest University, Winston-Salem, NC, USA
| | - Robert M Ewers
- Department of Life Science, Imperial College London, Ascot, UK
| | - Patrick Meir
- Research School of Biology, Australian National University, Canberra, ACT, Australia
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | - Yadvinder Malhi
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
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15
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Li X, Zhang C, Zhang B, Wu D, Shi Y, Zhang W, Ye Q, Yan J, Fu J, Fang C, Ha D, Fu S. Canopy and understory nitrogen addition have different effects on fine root dynamics in a temperate forest: implications for soil carbon storage. New Phytol 2021; 231:1377-1386. [PMID: 33993502 DOI: 10.1111/nph.17460] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/03/2021] [Indexed: 05/28/2023]
Abstract
Elucidating the effects of atmospheric nitrogen (N) deposition on fine root dynamics and the potential underlying mechanisms is required to understand the changes in belowground and aboveground carbon storage. However, research on these effects in forests has mostly involved direct understory addition of N and has ignored canopy interception and processing of N. Here, we conducted a field experiment comparing the effects of canopy addition of N (CAN) with those of understory addition of N (UAN) at three N-addition rates (0, 25 and 50 kg N ha-1 yr-1 ) on fine root dynamics in a temperate deciduous forest. Fine root production and biomass were significantly higher with CAN than with UAN. At the same N-addition rate, increases in fine root production with CAN were at least two-fold greater than with UAN. At the high N-addition rate and relative to the control, fine root biomass was significantly increased by CAN (by 23.5%) but was significantly decreased by UAN (by 12.2%). Our results indicate that traditional UAN may underestimate the responses of fine root dynamics to atmospheric N deposition in forest ecosystems. Canopy N processes should be considered for more realistic assessments of the effects of atmospheric N deposition in forests.
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Affiliation(s)
- Xiaowei Li
- College of Environment and Planning, Henan University, Kaifeng, 475004, China
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions (Henan University), Ministry of Education, Kaifeng, 475004, China
- Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security, Henan University, Kaifeng, 475004, China
| | - Chenlu Zhang
- College of Environment and Planning, Henan University, Kaifeng, 475004, China
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions (Henan University), Ministry of Education, Kaifeng, 475004, China
- Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security, Henan University, Kaifeng, 475004, China
| | - Beibei Zhang
- College of Environment and Planning, Henan University, Kaifeng, 475004, China
| | - Di Wu
- College of Environment and Planning, Henan University, Kaifeng, 475004, China
| | - Yifei Shi
- College of Environment and Planning, Henan University, Kaifeng, 475004, China
| | - Wei Zhang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Junhua Yan
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Juemin Fu
- Jigongshan National Nature Reserve, Xinyang, 464039, China
| | | | - Denglong Ha
- Jigongshan National Nature Reserve, Xinyang, 464039, China
| | - Shenglei Fu
- College of Environment and Planning, Henan University, Kaifeng, 475004, China
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions (Henan University), Ministry of Education, Kaifeng, 475004, China
- Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security, Henan University, Kaifeng, 475004, China
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16
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Jovani-Sancho AJ, Cummins T, Byrne KA. Soil carbon balance of afforested peatlands in the maritime temperate climatic zone. Glob Chang Biol 2021; 27:3681-3698. [PMID: 33949752 DOI: 10.1111/gcb.15654] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/20/2021] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
Drainage and conversion of natural peatlands to forestry increases soil CO2 emissions through decomposition of peat and modifies the quantity and quality of litter inputs and therefore the soil carbon balance. In organic soils, CO2 net emissions and removals are reported using carbon emission factors (EF). The choice of specific default Tier 1 EF values from the IPCC 2013 Wetlands supplement depends on land-use categories and climate zones. However, Tier 1 EF for afforested peatlands in the temperate maritime climate zone are based on data from eight sites, mainly located in the hemiboreal zone, and the uncertainty associated with these default values is a concern. In addition, moving from Tier 1 to higher-Tier carbon reporting values is highly desirable when large areas are affected by land-use changes. In this study, we estimated site-specific soil carbon balance for the development of Tier 2 soil CO2 -C EFs for afforested peatlands. Soil heterotrophic respiration and aboveground tree litterfall were measured during two years at eight afforested peatland sites in Ireland. In addition, fine-root turnover rate and site-specific fine-root biomass were used to quantify belowground litter inputs. We found that drainage of peatlands and planting them with either Sitka spruce or lodgepole pine, resulted in soils being net carbon sources. The soil carbon balance at multi-year sites varied between 63 ± 92 and 309 ± 67 g C m-2 year-1 . Mean CO2 -C EF for afforested peatlands was 1.68 ± 0.33 t CO2 -C ha-1 year-1 . The improved CO2 -C EFs presented here for afforested peatlands are proposed as a basis to update national CO2 -C emissions from this land-use class in Ireland. Furthermore, new data from these sites will significantly contribute to the development of more reliable IPCC default Tier 1 CO2 -C EFs for afforested peatlands in the maritime temperate climate zone.
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Affiliation(s)
| | - Thomas Cummins
- UCD School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Kenneth A Byrne
- Department of Biological Sciences, School of Natural Sciences, University of Limerick, Limerick, Ireland
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Endo I, Kobatake M, Tanikawa N, Nakaji T, Ohashi M, Makita N. Anatomical patterns of condensed tannin in fine roots of tree species from a cool-temperate forest. Ann Bot 2021; 128:59-71. [PMID: 33608716 PMCID: PMC8318258 DOI: 10.1093/aob/mcab022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/13/2021] [Indexed: 05/27/2023]
Abstract
BACKGROUND AND AIMS Condensed tannin (CT) is an important compound in plant biological structural defence and for tolerance of herbivory and environmental stress. However, little is known of the role and location of CT within the fine roots of woody plants. To understand the role of CT in fine roots across diverse species of woody dicot, we evaluated the localization of CT that accumulated in root tissue, and examined its relationships with the stele and cortex tissue in cross-sections of roots in 20 tree species forming different microbial symbiotic groups (ectomycorrhiza and arbuscular mycorrhiza). METHODS In a cool-temperate forest in Japan, cross-sections of sampled roots in different branching order classes, namely, first order, second to third order, fourth order, and higher than fourth order (higher order), were measured in terms of the length-based ratios of stele diameter and cortex thickness to root diameter. All root samples were then stained with ρ-dimethylaminocinnamaldehyde solution and we determined the ratio of localized CT accumulation area to the root cross-section area (CT ratio). KEY RESULTS Stele ratio tended to increase with increasing root order, whereas cortex ratio either remained unchanged or decreased with increasing order in all species. The CT ratio was significantly positively correlated to the stele ratio and negatively correlated to the cortex ratio in second- to fourth-order roots across species during the shift from primary to secondary root growth. Ectomycorrhiza-associated species mostly had a higher stele ratio and lower cortex ratio than arbuscular mycorrhiza-associated species across root orders. Compared with arbuscular mycorrhiza species, there was greater accumulation of CT in response to changes in the root order of ectomycorrhiza species. CONCLUSIONS Different development patterns of the stele, cortex and CT accumulation along the transition from root tip to secondary roots could be distinguished between different mycorrhizal associations. The CT in tissues in different mycorrhizal associations could help with root protection in specific branching orders during shifts in stele and cortex development before and during cork layer formation.
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Affiliation(s)
- Izuki Endo
- School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan
| | - Miwa Kobatake
- Faculty of Science, Shinshu University, Matsumoto, Nagano, Japan
| | - Natsuko Tanikawa
- Faculty of Science, Shinshu University, Matsumoto, Nagano, Japan
| | - Tatsuro Nakaji
- Uryu Experimental Forest, Hokkaido University, Moshiri, Hokkaido, Japan
| | - Mizue Ohashi
- School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan
| | - Naoki Makita
- Faculty of Science, Shinshu University, Matsumoto, Nagano, Japan
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18
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Hu YK, Pan X, Liu XY, Fu ZX, Zhang MY. Above- and Belowground Plant Functional Composition Show Similar Changes During Temperate Forest Swamp Succession. Front Plant Sci 2021; 12:658883. [PMID: 34262575 PMCID: PMC8274568 DOI: 10.3389/fpls.2021.658883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/21/2021] [Indexed: 06/13/2023]
Abstract
Plant functional composition, defined by both community-weighted mean (CWM) traits and functional diversity, can provide insights into plant ecological strategies and community assembly. However, our understanding of plant functional composition during succession is largely based on aboveground traits. Here we investigated community-level traits and functional diversity for six pairs of analogous leaf and fine root traits of understory plants in a temperate forest swamp during succession with a decrease in soil pH and nutrient availability. CWMs of traits related to resource acquisition (including specific leaf area, specific root length, leaf N, leaf P, root N, and root P) decreased with succession, whereas those related to resource conservation (leaf dry matter content, root dry matter content, leaf tissue density, leaf C, and root C) increased along the forest swamp successional gradient. Multi-trait functional dispersion (FDis) of both leaf and fine root traits tended to decrease along the successional gradient, but functional richness and evenness were highest at the middle successional stage. Moreover, FDis of individual plant traits except N showed the same pattern as multi-trait FDis. Soil pH and nutrient availability were the main drivers of successional changes in both CWM traits and FDis. The changes of community-level traits along succession indicated a shift from acquisitive to conservative strategy of understory plants during forest swamp succession. Similar trends in leaf and fine root functional diversity along succession may indicate above- and belowground functional diversity are coordinated during the processes of plant community assembly. These findings of linkages between above- and belowground plant functional composition have important implications for plant community dynamics and assembly rules.
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Affiliation(s)
- Yu-Kun Hu
- Beijing Key Laboratory of Wetland Services and Restoration, Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China
- Hengshuihu National Wetland Ecosystem Research Station, Hengshui, China
| | - Xu Pan
- Beijing Key Laboratory of Wetland Services and Restoration, Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China
| | - Xu-Yan Liu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Zhi-Xi Fu
- College of Life Sciences, Sichuan Normal University, Chengdu, China
| | - Man-Yin Zhang
- Beijing Key Laboratory of Wetland Services and Restoration, Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China
- Hengshuihu National Wetland Ecosystem Research Station, Hengshui, China
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19
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Reingwirtz I, Uretsky J, Cuneo IF, Knipfer T, Reyes C, Walker MA, McElrone AJ. Inherent and Stress-Induced Responses of Fine Root Morphology and Anatomy in Commercial Grapevine Rootstocks with Contrasting Drought Resistance. Plants (Basel) 2021; 10:1121. [PMID: 34205907 PMCID: PMC8227383 DOI: 10.3390/plants10061121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/24/2021] [Accepted: 05/24/2021] [Indexed: 11/16/2022]
Abstract
Some grapevine rootstocks perform better than others during and after drought events, yet it is not clear how inherent and stress-induced differences in root morphology and anatomy along the length of fine roots are involved in these responses. Using a variety of growing conditions and plant materials, we observed significant differences in root diameter, specific root length (SRL) and root diameter distribution between two commonly used commercial grapevine rootstocks: Richter 110 (110R; drought resistant) and Millardet et de Grasset 101-14 (101-14Mgt; drought sensitive). The 110R consistently showed greater root diameters with smaller SRL and proportion of root length comprised of fine lateral roots. The 110R also exhibited significantly greater distance from tip to nearest lateral, longer white root length, and larger proportion of root length that is white under drought stress. Mapping of fine root cortical lacunae showed similar patterns between the rootstocks; mechanical failure of cortical cells was common in the maturation zone, limited near the root tip, and increased with drought stress for both genotypes; however, lacuna formed under wetter soil conditions in 110R. Results suggest that drought resistance in grapevine rootstocks is associated with thick, limitedly branched roots with a larger proportion of white-functional roots that tend to form lacuna under more mild water deficit, all of which likely favor continued resource acquisition at depth.
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Affiliation(s)
- Idan Reingwirtz
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
| | - Jake Uretsky
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
| | - Italo F. Cuneo
- Faculty of Agriculture and Food Sciences, Pontificia Universidad Católica de Valparaíso, Valparaíso 2340025, Chile;
| | - Thorsten Knipfer
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
| | - Clarissa Reyes
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
| | - M. Andrew Walker
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
| | - Andrew J. McElrone
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
- Crops Pathology and Genetics Research Unit, United States Department of Agriculture, Agricultural Research Service, Davis, CA 95616, USA
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20
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Wang J, Defrenne C, McCormack ML, Yang L, Tian D, Luo Y, Hou E, Yan T, Li Z, Bu W, Chen Y, Niu S. Fine-root functional trait responses to experimental warming: a global meta-analysis. New Phytol 2021; 230:1856-1867. [PMID: 33586131 DOI: 10.1111/nph.17279] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 02/03/2021] [Indexed: 05/12/2023]
Abstract
Whether and how warming alters functional traits of absorptive plant roots remains to be answered across the globe. Tackling this question is crucial to better understanding terrestrial responses to climate change as fine-root traits drive many ecosystem processes. We carried out a detailed synthesis of fine-root trait responses to experimental warming by performing a meta-analysis of 964 paired observations from 177 publications. Warming increased fine-root biomass, production, respiration and nitrogen concentration as well as decreased root carbon : nitrogen ratio and nonstructural carbohydrates. Warming effects on fine-root biomass decreased with greater warming magnitude, especially in short-term experiments. Furthermore, the positive effect of warming on fine-root biomass was strongest in deeper soil horizons and in colder and drier regions. Total fine-root length, morphology, mortality, life span and turnover were unresponsive to warming. Our results highlight the significant changes in fine-root traits in response to warming as well as the importance of warming magnitude and duration in understanding fine-root responses. These changes have strong implications for global soil carbon stocks in a warmer world associated with increased root-derived carbon inputs into deeper soil horizons and increases in fine-root respiration.
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Affiliation(s)
- Jinsong Wang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- Department of Biological Sciences, Center for Ecosystem Sciences and Society, Northern Arizona University, Flagstaff, AZ, 86001, USA
| | - Camille Defrenne
- Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - M Luke McCormack
- Center for Tree Science, The Morton Arboretum, 4100 Illinois Rt. 53, Lisle, IL, 60532, USA
| | - Lu Yang
- Research Center of Forest Management Engineering of State Forestry and Grassland Administration, Beijing Forestry University, Beijing, 100083, China
| | - Dashuan Tian
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yiqi Luo
- Department of Biological Sciences, Center for Ecosystem Sciences and Society, Northern Arizona University, Flagstaff, AZ, 86001, USA
| | - Enqing Hou
- Department of Biological Sciences, Center for Ecosystem Sciences and Society, Northern Arizona University, Flagstaff, AZ, 86001, USA
| | - Tao Yan
- State Key Laboratory of Grassland and Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, China
| | - Zhaolei Li
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Key Laboratory of Agricultural Environment in Universities of Shandong, College of Resources and Environment, Shandong Agricultural University, Taian, 271018, China
| | - Wensheng Bu
- College of Forestry, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Ye Chen
- Department of Mathematics and Statistics, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Shuli Niu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
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21
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Lang AK, Jevon FV, Vietorisz CR, Ayres MP, Hatala Matthes J. Fine roots and mycorrhizal fungi accelerate leaf litter decomposition in a northern hardwood forest regardless of dominant tree mycorrhizal associations. New Phytol 2021; 230:316-326. [PMID: 33341954 DOI: 10.1111/nph.17155] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
●Fine roots and mycorrhizal fungi may either stimulate leaf litter decomposition by providing free-living decomposers with root-derived carbon, or may slow decomposition through nutrient competition between mycorrhizal and saprotrophic fungi. ●We reduced the presence of fine roots and their associated mycorrhizal fungi in a northern hardwood forest in New Hampshire, USA by soil trenching. Plots spanned a mycorrhizal gradient from 96% arbuscular mycorrhizal (AM) associations to 100% ectomycorrhizal (ECM)-associated tree basal area. We incubated four species of leaf litter within these plots in areas with reduced access to roots and mycorrhizal fungi and in adjacent areas with intact roots and mycorrhizal fungi. ●Over a period of 608 d, we found that litter decayed more rapidly in the presence of fine roots and mycorrhizal hyphae regardless of the dominant tree mycorrhizal association. Root and mycorrhizal exclusion reduced the activity of acid phosphatase on decomposing litter. ●Our results indicate that both AM- and ECM-associated fine roots stimulate litter decomposition in this system. These findings suggest that the effect of fine roots and mycorrhizal fungi on litter decay in a particular ecosystem likely depends on whether interactions between mycorrhizal roots and saprotrophic fungi are antagonistic or facilitative.
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Affiliation(s)
- Ashley K Lang
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Fiona V Jevon
- Yale School of the Environment, Yale University, New Haven, CT, 06511, USA
| | | | - Matthew P Ayres
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
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22
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Defrenne CE, Abs E, Longhi Cordeiro A, Dietterich L, Hough M, Jones JM, Kivlin SN, Chen W, Cusack D, Franco ALC, Khasanova A, Stover D, Romero‐Olivares AL. The Ecology Underground coalition: building a collaborative future of belowground ecology and ecologists. New Phytol 2021; 229:3058-3064. [PMID: 33616944 PMCID: PMC7986216 DOI: 10.1111/nph.17163] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Affiliation(s)
- Camille E. Defrenne
- Climate Change Science Institute and Environmental Sciences DivisionOak Ridge National LaboratoryOak RidgeTN37830USA
| | - Elsa Abs
- Department of Ecology and Evolutionary BiologyUniversity of California Irvine321 SteinhausIrvineCA92697USA
| | - Amanda Longhi Cordeiro
- Department of Ecosystem Science and SustainabilityColorado State UniversityCampus Delivery 1476Fort CollinsCO80523USA
| | - Lee Dietterich
- Department of Ecosystem Science and SustainabilityColorado State UniversityCampus Delivery 1476Fort CollinsCO80523USA
| | - Moira Hough
- Department of Ecology & Evolutionary BiologyUniversity of ArizonaTucsonAZ85721USA
| | - Jennifer M. Jones
- The Kellogg Biological StationMichigan State UniversityHickory CornersMI48824USA
| | - Stephanie N. Kivlin
- Department of Ecology and Evolutionary BiologyUniversity of TennesseeKnoxvilleTN37996USA
| | - Weile Chen
- College of Life SciencesZhejiang UniversityHangzhouZhejiang310027China
| | - Daniela Cusack
- Department of Ecosystem Science and SustainabilityColorado State UniversityCampus Delivery 1476Fort CollinsCO80523USA
| | | | - Albina Khasanova
- Department of Integrative BiologyUniversity of Texas at AustinAustinTX78712USA
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23
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Schwieger S, Blume-Werry G, Ciesiolka F, Anadon-Rosell A. Root biomass and root traits of Alnus glutinosa show size-dependent and opposite patterns in a drained and a rewetted forest peatland. Ann Bot 2021; 127:337-346. [PMID: 33211793 PMCID: PMC7872119 DOI: 10.1093/aob/mcaa195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 11/13/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND AND AIMS Forest peatlands represent 25 % of global peatlands and store large amounts of carbon (C) as peat. Traditionally they have been drained in order to increase forestry yield, which may cause large losses of C from the peat. Rewetting aims to stop these losses and to restore the initial storage function of the peatlands. As roots represent major peat-forming elements in these systems, we sampled roots with diameter <5 mm in a drained and a rewetted forest peatland in north-east Germany to evaluate differences in tree biomass investments below ground, root functional characteristics and root age. METHODS We cored soil next to Alnus glutinosa stems and sorted root biomass into <1, 1-2 and 2-5 mm diameter classes. We measured biomass distribution and specific root area (SRA) in 10-cm depth increments down to 50 cm, and estimated root age from annual growth rings. KEY RESULTS Root biomass in the rewetted site was more than double that in the drained site. This difference was mostly driven by very fine roots <1 mm, which accounted for 51 % of the total root biomass and were mostly (75 %) located in the upper 20 cm. For roots <1 mm, SRA did not differ between the sites. However, SRA of the 1-2 mm and 2-5 mm diameter roots was higher in the drained than in the rewetted site. Root age did not differ between sites. CONCLUSIONS The size-dependent opposite patterns between root biomass and their functional characteristics under contrasting water regimes indicate differences between fine and coarse roots in their response to environmental changes. Root age distribution points to similar root turnover rates between the sites, while higher root biomass in the rewetted site clearly indicates larger tree C stocks below ground under rewetting, supporting the C sink function of the ecosystem.
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Affiliation(s)
- Sarah Schwieger
- Experimental Plant Ecology, Institute of Botany and Landscape Ecology, Greifswald University, Greifswald, Germany
| | - Gesche Blume-Werry
- Experimental Plant Ecology, Institute of Botany and Landscape Ecology, Greifswald University, Greifswald, Germany
| | - Felix Ciesiolka
- Experimental Plant Ecology, Institute of Botany and Landscape Ecology, Greifswald University, Greifswald, Germany
- Landscape Ecology and Ecosystem Dynamics, Institute of Botany and Landscape Ecology, Greifswald University, Greifswald, Germany
| | - Alba Anadon-Rosell
- Landscape Ecology and Ecosystem Dynamics, Institute of Botany and Landscape Ecology, Greifswald University, Greifswald, Germany
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24
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Li P, Zhou HM, Feng ZZ. [Ozone Pollution, Nitrogen Addition, and Drought Stress Interact to Affect Non-structural Carbohydrates in the Leaves and Fine Roots of Poplar]. Huan Jing Ke Xue 2021; 42:1004-1012. [PMID: 33742897 DOI: 10.13227/j.hjkx.202007213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ground-level ozone (O3) pollution frequently co-occurs with drought and nitrogen (N) deposition during the growing season. It is important to understand how the carbon dynamics of plants respond to O3 pollution in drier and N-enriched environments. Here we present the patterns of non-structural carbohydrates and its components (soluble sugar and starch) in the leaves and fine roots in poplar clone 546 (Populus deltoides cv. '55/56'×P. deltoides cv. 'Imperial') for one growing season at two O3 concentrations (control, charcoal-filtered air, and elevated O3, non-filtered air+40 nmol·mol-1 of O3), two watering regimes (well-watered and reduced watering at 40% of well-watered irrigation), and two soil nitrogen addition treatments[no addition and the addition of 50 kg·(hm2·a)-1]. The results showed that O3 stress significantly increased the content of soluble sugar in leaves and starch in fine roots but decreased the content of starch and total non-structural carbohydrate (NSC) in leaves. Drought stress significantly reduced the content of starch and total NSC in leaves but increased the contents of soluble sugar and total NSC in fine roots. Nitrogen addition had no significant effect on NSC and its components in leaves and fine roots. NSC and its components in leaves and fine roots were positively correlated with photosynthetic rate and biomass. With an increase in the number of environmental stress factors, NSC in leaves showed a significant downward trend while NSC in fine roots showed a significant upward trend. The study demonstrates that environmental stress can promote the transformation of starch into soluble sugars in plant leaves and the transfer of NSC from leaves to roots for storage, which may be a coping strategy for plants exposed to environmental stress.
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Affiliation(s)
- Pin Li
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Hui-Min Zhou
- State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Zhao-Zhong Feng
- School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
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25
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Suseela V, Tharayil N, Orr G, Hu D. Chemical plasticity in the fine root construct of Quercus spp. varies with root order and drought. New Phytol 2020; 228:1835-1851. [PMID: 32750158 DOI: 10.1111/nph.16841] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 07/06/2020] [Indexed: 06/11/2023]
Abstract
Fine roots of trees exhibit varying degree of plasticity to adapt to environmental stress. Although the morphological and physiological plasticity of roots has been well studied, less known are the accompanying changes in the chemical composite (chemical plasticity) of fine roots, which regulates both root function and soil carbon sequestration. We investigated the changes in quantity, composition and localization of phenolic compounds in fine root orders of Quercus alba and Quercus rubra subjected to drought stress. In both species the total quantity of lignins varied only by root orders, where the distal (first and second) root orders had lower lignin compared to higher orders. Despite a lower lignin content, the distal root orders had higher content of guaiacyl lignin and bound phenolics that would provide a greater meshing of lignocellulosic matrix, and thus a higher tissue integrity. Unlike lignins, drought altered the quantity and composition of tannins. In Q. alba, the ellagitannins decreased in the distal root orders exposed to drought, while the fiber-bound condensed tannnins increased. The lower content of ellagitannins with antimicrobial properties under drought reveals an adaptive response by fine roots to promote symbiotic association, as evidenced by the higher colonization of ectomycorrhizal fungi. Our study revealed that, when exposed to drought, the composition of heteropolymers are strategically varied across fine root orders, so as to provide a greater root function without compromising the tissue protection.
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Affiliation(s)
- Vidya Suseela
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, 29624, USA
| | - Nishanth Tharayil
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, 29624, USA
| | - Galya Orr
- Environmental Molecular Sciences Laboratory - Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Dehong Hu
- Environmental Molecular Sciences Laboratory - Pacific Northwest National Laboratory, Richland, WA, 99354, USA
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Pierre S, Litton CM, Giardina CP, Sparks JP, Fahey TJ. Mean annual temperature influences local fine root proliferation and arbuscular mycorrhizal colonization in a tropical wet forest. Ecol Evol 2020; 10:9635-9646. [PMID: 33005336 PMCID: PMC7520179 DOI: 10.1002/ece3.6561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 05/11/2020] [Accepted: 05/21/2020] [Indexed: 11/25/2022] Open
Abstract
Mean annual temperature (MAT) is an influential climate factor affecting the bioavailability of growth-limiting nutrients nitrogen (N) and phosphorus (P). In tropical montane wet forests, warmer MAT drives higher N bioavailability, while patterns of P availability are inconsistent across MAT. Two important nutrient acquisition strategies, fine root proliferation into bulk soil and root association with arbuscular mycorrhizal fungi, are dependent on C availability to the plant via primary production. The case study presented here tests whether variation in bulk soil N bioavailability across a tropical montane wet forest elevation gradient (5.2°C MAT range) influences (a) morphology fine root proliferation into soil patches with elevated N, P, and N+P relative to background soil and (b) arbuscular mycorrhizal fungal (AMF) colonization of fine roots in patches. We created a fully factorial fertilized root ingrowth core design (N, P, N+P, unfertilized control) representing soil patches with elevated N and P bioavailability relative to background bulk soil. Our results show that percent AMF colonization of roots increased with MAT (r 2 = .19, p = .004), but did not respond to fertilization treatments. Fine root length (FRL), a proxy for root foraging, increased with MAT in N+P-fertilized patches only (p = .02), while other fine root morphological parameters did not respond to the gradient or fertilized patches. We conclude that in N-rich, fine root elongation into areas with elevated N and P declines while AMF abundance increases with MAT. These results indicate a tradeoff between P acquisition strategies occurring with changing N bioavailability, which may be influenced by higher C availability with warmer MAT.
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Affiliation(s)
- Suzanne Pierre
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York USA
- Department of Integrative Biology University of California, Berkeley Berkeley California USA
| | - Creighton M Litton
- Department of Natural Resources and Environmental Management University of Hawai'i at Manoa Honolulu Hawai'i USA
| | - Christian P Giardina
- Institute of Pacific Islands Forestry Pacific Southwest Research Station US Forest Service Hilo Hawaii USA
| | - Jed P Sparks
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York USA
| | - Timothy J Fahey
- Department of Natural Resources Cornell University Ithaca New York USA
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Lavely EK, Chen W, Peterson KA, Klodd AE, Volder A, Marini RP, Eissenstat DM. On characterizing root function in perennial horticultural crops. Am J Bot 2020; 107:1214-1224. [PMID: 32901939 DOI: 10.1002/ajb2.1530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 05/13/2020] [Indexed: 06/11/2023]
Abstract
PREMISE While root-order approaches to fine-root classification have shown wide utility among wild plants, they have seen limited use for perennial crop plants. Moreover, inadequate characterization of fine roots across species of domesticated perennial crops has led to a knowledge gap in the understanding of evolutionary and functional patterns associated with different fine-root orders. METHODS We examined fine-root traits of common horticultural fruit and nut crops: Malus ×domestica, Prunus persica, Vitus vinifera, Prunus dulcis, and Citrus ×clementina. Additional roots were sampled from 33 common perennial horticultural crops, native to tropical, subtropical, and temperate regions, to examine variation in 1st- and 2nd-order absorptive roots. RESULTS First-order roots of grape and 1st- and 2nd-order roots of apple and peach were consistently thin, nonwoody, mycorrhizal, and had high N:C ratios. In contrast, 4th- and 5th-order roots of grape and 5th-order roots of apple and peach were woody, nonmycorrhizal, had low N:C ratios, and were thicker than lower-order roots. Among the 33 horticultural species, diameter of 1st- and 2nd-order roots varied about 15-fold, ranging from 0.04 to 0.60 mm and 0.05 to 0.89 mm respectively. This variation generally was phylogenetically conserved across plant lineages. CONCLUSIONS Collectively, our research shows that root-order characterization has considerably more utility than an arbitrary diameter cutoff for identifying roots of different functions in perennial horticultural crops. In addition, much of the variation in root diameter among species can be predicted by evolutionary relationships.
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Affiliation(s)
- Emily K Lavely
- Department of Plant Science, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Weile Chen
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - K Aysha Peterson
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Annie E Klodd
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Astrid Volder
- Department of Plant Sciences, University of California Davis, Davis, CA, 95616, USA
| | - Richard P Marini
- Department of Plant Science, The Pennsylvania State University, University Park, PA, 16802, USA
| | - David M Eissenstat
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, 16802, USA
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28
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Magaña-Hernández E, Zuloaga-Aguilar S, Cuevas-Guzmán R, Pausas JG. Variation in plant belowground resource allocation across heterogeneous landscapes: implications for post-fire resprouting. Am J Bot 2020; 107:1114-1121. [PMID: 32830864 DOI: 10.1002/ajb2.1521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/05/2020] [Indexed: 06/11/2023]
Abstract
PREMISE Resource availability affects biomass allocation in ways that could influence plant responses to disturbance such as fire. This is important because fire also varies across landscapes in ways that are correlated to resource availability. We hypothesized that plants growing in landscape microsites with a shortage of nutrients and water allocate more biomass and resources to belowground structures (and thus promote traits that enhance post-fire resprouting ability) than plants in more mesic sites. METHODS We selected sites in three contrasting topographies (3 gullies, 3 midslopes, and 3 ridges) that supported different vegetation types and fire regimes, in Jalisco, Mexico. At each site, we measured soil nutrient and water content and light availability. Then we sampled biomass and root starch allocation in three post-fire resprouting shrubs that grow across a wide range of microenvironmental conditions. RESULTS The ridges showed the highest values of solar radiation and the lowest of soil N and water content. Overall, we found a significant tendency for higher root-to-shoot (R/S) ratios, greater fine root biomass, and higher root starch content, in individuals growing in ridges or midslopes compared to the values of the plants living in gullies. CONCLUSIONS Plants located in open canopy sites, characterized by a shortage of nutrients and water, tend to allocate more biomass belowground than plants in wet and fertile sites. Thus, plants in wet and fertile forests should be more vulnerable to increased disturbance such as wildfires.
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Affiliation(s)
- Esteban Magaña-Hernández
- Departamento de Ecología y Recursos Naturales, Centro Universitario de la Costa Sur, Universidad de Guadalajara, Av. Independencia Nacional 151, Autlán de Navarro, Jalisco, Mexico
| | - Susana Zuloaga-Aguilar
- Departamento de Ecología y Recursos Naturales, Centro Universitario de la Costa Sur, Universidad de Guadalajara, Av. Independencia Nacional 151, Autlán de Navarro, Jalisco, Mexico
| | - Ramón Cuevas-Guzmán
- Departamento de Ecología y Recursos Naturales, Centro Universitario de la Costa Sur, Universidad de Guadalajara, Av. Independencia Nacional 151, Autlán de Navarro, Jalisco, Mexico
| | - Juli G Pausas
- CIDE-CSIC, Ctra. Náquera km 4.5 (IVIA), Montcada, Valencia, 46113, Spain
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29
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Wojciechowska N, Marzec-Schmidt K, Kalemba EM, Ludwików A, Bagniewska-Zadworna A. Seasonal senescence of leaves and roots of Populus trichocarpa-is the scenario the same or different? Tree Physiol 2020; 40:987-1000. [PMID: 32091108 PMCID: PMC7392034 DOI: 10.1093/treephys/tpaa019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/22/2020] [Accepted: 01/31/2020] [Indexed: 05/26/2023]
Abstract
The remobilization and resorption of plant nutrients is considered as a crucial aspect of the seasonal senescence of plant organs. In leaves, the mechanisms responsible for the relocation of valuable compounds are well understood while the related processes in roots are still being debated. Some research indicates that remobilization in roots occurs, while other studies have not found evidence of this process. Considering that the total biomass of fine roots is equal to or greater than that of leaves, clarifying the conflicting reports and ambiguities may provide critical information on the circulation of chemical elements in forest ecosystems. This study provides new information concerning the basis for remobilization processes in roots by combining physiological data with gene expression and protein levels. We suggest that, as in leaves, molecular mechanisms involved in nitrogen (N) resorption are also activated in senescent roots. An analysis of N concentration indicated that N levels decreased during the senescence of both organs. The decrease was associated with an increase in the expression of a glutamine synthetase (GS) gene and a concomitant elevation in the amount of GS-one of the most important enzymes in N metabolism. In addition, significant accumulation of carbohydrates was observed in fine roots, which may represent an adaptation to unfavorable weather conditions that would allow remobilization to occur rather than a rapid death in response to ground frost or cold. Our results provide new insights into the senescence of plant organs and clarify contentious topics related to the remobilization process in fine roots.
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Affiliation(s)
- Natalia Wojciechowska
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland
| | - Katarzyna Marzec-Schmidt
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland
| | - Ewa M Kalemba
- Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland
| | - Agnieszka Ludwików
- Department of Biotechnology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland
| | - Agnieszka Bagniewska-Zadworna
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland
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30
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Malhotra A, Brice DJ, Childs J, Graham JD, Hobbie EA, Vander Stel H, Feron SC, Hanson PJ, Iversen CM. Peatland warming strongly increases fine-root growth. Proc Natl Acad Sci U S A 2020; 117:17627-17634. [PMID: 32661144 PMCID: PMC7395547 DOI: 10.1073/pnas.2003361117] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Belowground climate change responses remain a key unknown in the Earth system. Plant fine-root response is especially important to understand because fine roots respond quickly to environmental change, are responsible for nutrient and water uptake, and influence carbon cycling. However, fine-root responses to climate change are poorly constrained, especially in northern peatlands, which contain up to two-thirds of the world's soil carbon. We present fine-root responses to warming between +2 °C and 9 °C above ambient conditions in a whole-ecosystem peatland experiment. Warming strongly increased fine-root growth by over an order of magnitude in the warmest treatment, with stronger responses in shrubs than in trees or graminoids. In the first year of treatment, the control (+0 °C) shrub fine-root growth of 0.9 km m-2 y-1 increased linearly by 1.2 km m-2 y-1 (130%) for every degree increase in soil temperature. An extended belowground growing season accounted for 20% of this dramatic increase. In the second growing season of treatment, the shrub warming response rate increased to 2.54 km m-2 °C-1 Soil moisture was negatively correlated with fine-root growth, highlighting that drying of these typically water-saturated ecosystems can fuel a surprising burst in shrub belowground productivity, one possible mechanism explaining the "shrubification" of northern peatlands in response to global change. This previously unrecognized mechanism sheds light on how peatland fine-root response to warming and drying could be strong and rapid, with consequences for the belowground growing season duration, microtopography, vegetation composition, and ultimately, carbon function of these globally relevant carbon sinks.
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Affiliation(s)
- Avni Malhotra
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830;
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - Deanne J Brice
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - Joanne Childs
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - Jake D Graham
- Department of Geosciences, Boise State University, Boise, ID 83725
| | - Erik A Hobbie
- Earth Systems Research Center, University of New Hampshire, Durham, NH 03824
| | - Holly Vander Stel
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Kellogg Biological Station, Michigan State University, Hickory Corners, MI 49060
| | - Sarah C Feron
- Department of Physics, Universidad de Santiago de Chile, Santiago, 9170022, Chile
- School of Earth, Energy and Environmental Sciences, Department of Earth System Science, Stanford University, Stanford, CA 94305
| | - Paul J Hanson
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - Colleen M Iversen
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37830
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31
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Straková P, Larmola T, Andrés J, Ilola N, Launiainen P, Edwards K, Minkkinen K, Laiho R. Quantification of Plant Root Species Composition in Peatlands Using FTIR Spectroscopy. Front Plant Sci 2020; 11:597. [PMID: 32508861 PMCID: PMC7250167 DOI: 10.3389/fpls.2020.00597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 04/20/2020] [Indexed: 05/27/2023]
Abstract
Evidence of plant root biomass and production in peatlands at the level of species or plant functional type (PFT) is needed for defining ecosystem functioning and predicting its future development. However, such data are limited due to methodological difficulties and the toilsomeness of separating roots from peat. We developed Fourier transform infrared (FTIR) spectroscopy based calibration models for quantifying the mass proportions of several common peatland species, and alternatively, the PFTs that these species represented, in composite root samples. We further tested whether woody roots could be classified into diameter classes, and whether dead and living roots could be separated. We aimed to solve whether general models applicable in different studies can be developed, and what would be the best way to build such models. FTIR spectra were measured from dried and powdered roots: both "pure roots", original samples of 25 species collected in the field, and "root mixtures", artificial composite samples prepared by mixing known amounts of pure roots of different species. Partial least squares regression was used to build the calibration models. The general applicability of the models was tested using roots collected in different sites or times. Our main finding is that pure roots can replace complex mixtures as calibration data. Using pure roots, we constructed generally applicable models for quantification of roots of the main PFTs of northern peatlands. The models provided accurate estimates even for far distant sites, with root mean square error (RMSE) 1.4-6.6% for graminoids, forbs and ferns. For shrubs and trees the estimates were less accurate due to higher within-species heterogeneity, partly related to variation in root diameter. Still, we obtained RMSE 3.9-10.8% for total woody roots, but up to 20.1% for different woody-root types. Species-level and dead-root models performed well within the calibration dataset but provided unacceptable estimates for independent samples, limiting their routine application in field conditions. Our PFT-level models can be applied on roots separated from soil for biomass determination or from ingrowth cores for estimating root production. We present possibilities for further development of species-level or dead-root models using the pure-root approach.
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Affiliation(s)
- Petra Straková
- Natural Resources Institute Finland (LUKE), Helsinki, Finland
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Tuula Larmola
- Natural Resources Institute Finland (LUKE), Helsinki, Finland
| | - Javier Andrés
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland
| | - Noora Ilola
- Financial and Administrative Services, Education Department, City of Vantaa, Vantaa, Finland
| | - Piia Launiainen
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Keith Edwards
- Department of Ecosystem Biology, University of South Bohemia, ČeskéBudějovice, Czechia
| | - Kari Minkkinen
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Raija Laiho
- Natural Resources Institute Finland (LUKE), Helsinki, Finland
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32
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Ataka M, Sun L, Nakaji T, Katayama A, Hiura T. Five-year nitrogen addition affects fine root exudation and its correlation with root respiration in a dominant species, Quercus crispula, of a cool temperate forest, Japan. Tree Physiol 2020; 40:367-376. [PMID: 31976533 DOI: 10.1093/treephys/tpz143] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 08/22/2019] [Accepted: 12/18/2019] [Indexed: 06/10/2023]
Abstract
In forest ecosystems, fine root respiration directly contributes to belowground carbon (C) cycling. Exudation from fine roots indirectly affects C cycling via enhanced microbial decomposition of soil organic matter. Although these root-derived C fluxes are essential components of belowground C cycling, how nitrogen (N) addition affects these fluxes and their correlations remains unclear. In this study, fine root exudation, respiration and chemical/morphological traits were measured in a dominant canopy species, Quercus crispula Blume, found in a cool temperate forest, the Tomakomai Experimental Forest, Hokkaido University, which has undergone 5-year N addition. Soil-dissolved organic carbon (DOC) was also measured in both bulk and rhizosphere soils to evaluate the impact of fine root exudation on soil C cycling. Compared with a control plot with no N treatment, fine roots in the N addition plot exhibited larger diameters and higher N concentrations, but lower specific root lengths and areas. On a root-weight basis, respiration was not different between plots, but exudation was slightly higher under N addition. On a root-area basis, exudation was significantly higher in the N addition plot. Additionally, differences in DOC between rhizosphere and bulk soils were two times higher in the N addition plot than the control plot. Although fine root respiration was positively correlated with exudation in both the control and N addition plots, the ratio of exudation C to respiration C decreased after 5-year N addition. Nitrogen addition also affected absolute C allocation to fine root exudation and changed the C allocation strategy between exudation and respiration fluxes. These findings will help enhance predictions of belowground C allocation and C cycling under N-rich conditions in the future.
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Affiliation(s)
- Mioko Ataka
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake Cho, Sakyo District, Kyoto 6068502, Japan
| | - Lijuan Sun
- Institute of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, 5 Yiheyuan Road, Haidian District, Beijing 100871, China
| | - Tatsuro Nakaji
- Uryu Experimental Forest, Hokkaido University, Moshiri, Uryu 0740741, Japan
| | - Ayumi Katayama
- Kasuya Research Forest, Kyushu University, 394 Sasaguri, Kasuya 8112415, Japan
| | - Tsutom Hiura
- Field Science Center for Northern Biosphere, Hokkaido University, Kita 9, Nishi 9, Kita District, Sapporo 0600809, Japan
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33
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Klimešová J, Martínková J, Ottaviani G, Charles-Dominique T. Half of the (big) picture is missing! Am J Bot 2020; 107:385-389. [PMID: 32060893 DOI: 10.1002/ajb2.1438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 11/23/2019] [Indexed: 06/10/2023]
Affiliation(s)
- Jitka Klimešová
- Institute of Botany, The Czech Academy of Sciences, Dukelská 135, Třeboň, 37982, Czech Republic
- Department of Botany, Faculty of Science, Charles University, Benátská 2, Praha, 12801, Czech Republic
| | - Jana Martínková
- Institute of Botany, The Czech Academy of Sciences, Dukelská 135, Třeboň, 37982, Czech Republic
| | - Gianluigi Ottaviani
- Institute of Botany, The Czech Academy of Sciences, Dukelská 135, Třeboň, 37982, Czech Republic
| | - Tristan Charles-Dominique
- CNRS, UMR 7618, Sorbonne University, Institute of Ecology and Environmental Sciences, 4 Place Jussieu, 75005, Paris, France
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34
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Wang P, Huang K, Hu S. Distinct fine-root responses to precipitation changes in herbaceous and woody plants: a meta-analysis. New Phytol 2020; 225:1491-1499. [PMID: 31610024 DOI: 10.1111/nph.16266] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 10/08/2019] [Indexed: 06/10/2023]
Abstract
Precipitation is one of the most important factors that determine productivity of terrestrial ecosystems. Precipitation across the globe is predicted to change more intensively under future climate change scenarios, but the resulting impact on plant roots remains unclear. Based on 154 observations from experiments in which precipitation was manipulated in the field and root biomass was measured, we investigated responses in fine-root biomass of herbaceous and woody plants to alterations in precipitation. We found that root biomass of herbaceous and woody plants responded differently to precipitation change. In particular, precipitation increase consistently enhanced fine-root biomass of woody plants but had variable effects on herb roots in arid and semi-arid ecosystems. In contrast, precipitation decrease reduced root biomass of herbaceous plants but not woody plants. In addition, with precipitation alteration, the magnitude of root responses was greater in dry areas than in wet areas. Together, these results indicate that herbaceous and woody plants have different rooting strategies to cope with altered precipitation regimes, particularly in water-limited ecosystems. These findings suggest that root responses to precipitation change may critically influence root productivity and soil carbon dynamics under future climate change scenarios.
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Affiliation(s)
- Peng Wang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Kailing Huang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Shuijin Hu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
- Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, NC, 27695, USA
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35
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Santiago LS. Going underground: new approaches to assess dynamic root behaviour during drought. New Phytol 2020; 225:599-600. [PMID: 31721227 DOI: 10.1111/nph.16278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Louis S Santiago
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA, 92521, USA
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36
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Mackay DS, Savoy PR, Grossiord C, Tai X, Pleban JR, Wang DR, McDowell NG, Adams HD, Sperry JS. Conifers depend on established roots during drought: results from a coupled model of carbon allocation and hydraulics. New Phytol 2020; 225:679-692. [PMID: 31276231 DOI: 10.1111/nph.16043] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 07/01/2019] [Indexed: 06/09/2023]
Abstract
Trees may survive prolonged droughts by shifting water uptake to reliable water sources, but it is unknown if the dominant mechanism involves activating existing roots or growing new roots during drought, or some combination of the two. To gain mechanistic insights on this unknown, a dynamic root-hydraulic modeling framework was developed that set up a feedback between hydraulic controls over carbon allocation and the role of root growth on soil-plant hydraulics. The new model was tested using a 5 yr drought/heat field experiment on an established piñon-juniper stand with root access to bedrock groundwater. Owing to the high carbon cost per unit root area, modeled trees initialized without adequate bedrock groundwater access experienced potentially lethal declines in water potential, while all of the experimental trees maintained nonlethal water potentials. Simulated trees were unable to grow roots rapidly enough to mediate the hydraulic stress, particularly during warm droughts. Alternatively, modeled trees initiated with root access to bedrock groundwater matched the hydraulics of the experimental trees by increasing their water uptake from bedrock groundwater when soil layers dried out. Therefore, the modeling framework identified a critical mechanism for drought response that required trees to shift water uptake among existing roots rather than growing new roots.
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Affiliation(s)
- D Scott Mackay
- Department of Geography, University at Buffalo, Buffalo, NY, 14261, USA
| | - Philip R Savoy
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - Charlotte Grossiord
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903, Birmensdorf, Switzerland
| | - Xiaonan Tai
- Department of Geography, University at Buffalo, Buffalo, NY, 14261, USA
| | - Jonathan R Pleban
- Department of Geography, University at Buffalo, Buffalo, NY, 14261, USA
| | - Diane R Wang
- Department of Geography, University at Buffalo, Buffalo, NY, 14261, USA
| | | | - Henry D Adams
- Department of Plant Biology, Ecology, and Evolution, Oklahoma State University, Stillwater, OK, 74078, USA
| | - John S Sperry
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA
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37
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Klamer F, Vogel F, Li X, Bremer H, Neumann G, Neuhäuser B, Hochholdinger F, Ludewig U. Estimating the importance of maize root hairs in low phosphorus conditions and under drought. Ann Bot 2019; 124:961-968. [PMID: 30759179 PMCID: PMC6881218 DOI: 10.1093/aob/mcz011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 01/24/2019] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Root hairs are single-cell extensions of the epidermis that face into the soil and increase the root-soil contact surface. Root hairs enlarge the rhizosphere radially and are very important for taking up water and sparingly soluble nutrients, such as the poorly soil-mobile phosphate. In order to quantify the importance of root hairs for maize, a mutant and the corresponding wild type were compared. METHODS The rth2 maize mutant with very short root hairs was assayed for growth and phosphorus (P) acquisition in a slightly alkaline soil with low P and limited water supply in the absence of mycorrhization and with ample P supply. KEY RESULTS Root and shoot growth was additively impaired under P deficiency and drought. Internal P concentrations declined with reduced water and P supply, whereas micronutrients (iron, zinc) were little affected. The very short root hairs in rth2 did not affect internal P concentrations, but the P content of juvenile plants was halved under combined stress. The rth2 plants had more fine roots and increased specific root length, but P mobilization traits (root organic carbon and phosphatase exudation) differed little. CONCLUSIONS The results confirm the importance of root hairs for maize P uptake and content, but not for internal P concentrations. Furthermore, the performance of root hair mutants may be biased by secondary effects, such as altered root growth.
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Affiliation(s)
- Florian Klamer
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Stuttgart, Germany
| | - Florian Vogel
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Stuttgart, Germany
| | - Xuelian Li
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Stuttgart, Germany
| | - Hinrich Bremer
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Stuttgart, Germany
| | - Günter Neumann
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Stuttgart, Germany
| | - Benjamin Neuhäuser
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Stuttgart, Germany
| | | | - Uwe Ludewig
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Stuttgart, Germany
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Liu L, Yang F, Wang Y, Shen X, Janssens IA, Guenet B, Xiao C. Fine-Root Turnover, Litterfall, and Soil Microbial Community of Three Mixed Coniferous-Deciduous Forests Dominated by Korean Pine ( Pinus koraiensis) Along a Latitudinal Gradient. Front Plant Sci 2019; 10:1298. [PMID: 31708942 PMCID: PMC6821785 DOI: 10.3389/fpls.2019.01298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/18/2019] [Indexed: 06/10/2023]
Abstract
Carbon dynamics in forests and in particular in soils are of primary importance in the context of climate change. A better understanding of the drivers controlling carbon storage is needed to improve climate mitigation strategies. Carbon storage is the result of a balance between inputs and outputs. Carbon inputs in the soil come from plant residues and root exudates, which are further transformed by microorganisms and stored in the long term. Here, we measured litter and fine-root production in three mixed forests dominated by Pinus koraiensis along a latitudinal gradient and performed a litterbag experiment to better understand the driving factors of decomposition. We found that over the three sites litter production was controlled by climatic factors, soil properties, and forest stand characteristics, whereas decay rates were mainly controlled by microbial community structure and soil stoichiometry. For fine roots, production differed among sites, and higher production was consistently observed in the top soil layers compared to deep soil, although the root distribution along the soil profile differed among sites. Fine-root decay rates were mainly controlled by fine-root stoichiometric characteristics. This article emphasizes the complexity of fine-root dynamics even for a single species. Environmental drivers impact on both production and decay, and we suggest performing manipulative field experiments to better identify the mechanisms involved in soil carbon cycling.
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Affiliation(s)
- Lu Liu
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
- Hulun Lake Reserve Grassland Ecology Research Station, Minzu University of China, Beijing, China
| | - Fan Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - YuJue Wang
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
- Hulun Lake Reserve Grassland Ecology Research Station, Minzu University of China, Beijing, China
| | - Xing Shen
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
- Hulun Lake Reserve Grassland Ecology Research Station, Minzu University of China, Beijing, China
| | - Ivan A. Janssens
- Department of Biology, Research Group of Plants and Ecosystems, University of Antwerp, Wilrijk, Belgium
| | - Bertrand Guenet
- Laboratoire des Sciences du Climat et de l’Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Chunwang Xiao
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
- Hulun Lake Reserve Grassland Ecology Research Station, Minzu University of China, Beijing, China
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Abstract
The combination of individual-based selection with shared access to resources drives individuals to invest more than necessary in taking up their share of resources due to the threat of other individuals doing the same (competitive overinvestments). This evolutionary escalation of investment is common, from deer antlers and peacock feathers to tree height and plant roots. Because plant roots seem to be well intermingled belowground, the simplifying assumption that belowground resources are perfectly well mixed is often made in models-a condition that favours maximal fine-root overinvestments. Here, I develop simple models to investigate the role of space in determining the overlap among individuals belowground and resulting fine-root biomass. Without costs of growing roots through space, evolutionary optimization leads individuals to intermingle their fine roots perfectly and to invest just as much in these roots, whether there are two individuals competing or many. However, if there are any costs of sending roots through soil, investment in fine roots is constrained in amount and spatial extent. Dominant individuals are those that keep their roots in the soil closest to their own stem and the stems of their closest neighbours. These results highlight the importance of space in determining individual strategies as well as competitive networks.
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Affiliation(s)
- Caroline E Farrior
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
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Hu Y, Pan X, Yang X, Liu G, Liu X, Song Y, Zhang M, Cui L, Dong M. Is there coordination of leaf and fine root traits at local scales? A test in temperate forest swamps. Ecol Evol 2019; 9:8714-8723. [PMID: 31410274 PMCID: PMC6686282 DOI: 10.1002/ece3.5421] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 05/14/2019] [Accepted: 06/08/2019] [Indexed: 11/09/2022] Open
Abstract
Examining the coordination of leaf and fine root traits not only aids a better understanding of plant ecological strategies from a whole-plant perspective, but also helps improve the prediction of belowground properties from aboveground traits. The relationships between leaf and fine root traits have been extensively explored at global and regional scales, but remain unclear at local scales. Here, we measured six pairs of analogous leaf and fine root traits related to resource economy and organ size for coexisting dominant and subordinate vascular plants at three successional stages of temperate forest swamps in Lingfeng National Nature Reserve in the Greater Hinggan Mountains, NE China. Leaf and fine root traits related to resource acquisition (e.g., specific leaf area [SLA], leaf N, leaf P, root water content, and root P) decreased with succession. Overall, we found strong linear relationships between leaf dry matter content (LDMC) and root water content, and between leaf and root C, N, and P concentrations, but only weak correlations were observed between leaf area and root diameter, and between SLA and specific root length (SRL). The strong relationships between LDMC and root water content and between leaf and root C, N, and P held at the early and late stages, but disappeared at the middle stage. Besides, C and P of leaves were significantly correlated with those of roots for woody plants, while strong linkages existed between LDMC and root water content and between leaf N and root N for herbaceous species. These results provided evidence for the existence of strong coordination between leaf and root traits at the local scale. Meanwhile, the leaf-root trait relationships could be modulated by successional stage and growth form, indicating the complexity of coordination of aboveground and belowground traits at the local scale.
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Affiliation(s)
- Yu‐Kun Hu
- Institute of Wetland ResearchChinese Academy of ForestryBeijingChina
- Beijing Key Laboratory of Wetland Services and RestorationBeijingChina
| | - Xu Pan
- Institute of Wetland ResearchChinese Academy of ForestryBeijingChina
- Beijing Key Laboratory of Wetland Services and RestorationBeijingChina
| | - Xue‐Jun Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of BotanyChinese Academy of SciencesBeijingChina
| | - Guo‐Fang Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of BotanyChinese Academy of SciencesBeijingChina
| | - Xu‐Yan Liu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingChina
| | - Yao‐Bin Song
- Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, College of Life and Environmental SciencesHangzhou Normal UniversityHangzhouChina
| | - Man‐Yin Zhang
- Institute of Wetland ResearchChinese Academy of ForestryBeijingChina
- Beijing Key Laboratory of Wetland Services and RestorationBeijingChina
| | - Li‐Juan Cui
- Institute of Wetland ResearchChinese Academy of ForestryBeijingChina
- Beijing Key Laboratory of Wetland Services and RestorationBeijingChina
| | - Ming Dong
- Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, College of Life and Environmental SciencesHangzhou Normal UniversityHangzhouChina
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Blume-Werry G, Milbau A, Teuber LM, Johansson M, Dorrepaal E. Dwelling in the deep - strongly increased root growth and rooting depth enhance plant interactions with thawing permafrost soil. New Phytol 2019; 223:1328-1339. [PMID: 31074867 DOI: 10.1111/nph.15903] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Accepted: 04/12/2019] [Indexed: 05/27/2023]
Abstract
Climate-warming-induced permafrost thaw exposes large amounts of carbon and nitrogen in soil at considerable depths, below the seasonally thawing active layer. The extent to which plant roots can reach and interact with these hitherto detached, deep carbon and nitrogen stores remains unknown. We aimed to quantify how permafrost thaw affects root dynamics across soil depths and plant functional types compared with above-ground abundance, and potential consequences for plant-soil interactions. A decade of experimental permafrost thaw strongly increased total root length and growth in the active layer, and deep roots invaded the newly thawed permafrost underneath. Root litter input to soil across all depths was 10 times greater with permafrost thaw. Root growth timing was unaffected by experimental permafrost thaw but peaked later in deeper soil, reflecting the seasonally receding thaw front. Deep-rooting species could sequester 15 N added at the base of the ambient active layer in October, which was after root growth had ceased. Deep soil organic matter that has long been locked up in permafrost is thus no longer detached from plant processes upon thaw. Whether via nutrient uptake, carbon storage, or rhizosphere priming, plant root interactions with thawing permafrost soils may feed back on our climate both positively and negatively.
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Affiliation(s)
- Gesche Blume-Werry
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, 981 07, Abisko, Sweden
- Experimental Plant Ecology, Institute of Botany and Landscape Ecology, Greifswald University, 17487, Greifswald, Germany
| | - Ann Milbau
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, 981 07, Abisko, Sweden
- Research Institute for Nature and Forest INBO, Havenlaan 88, Bus 73, 1000, Brussels, Belgium
| | - Laurenz M Teuber
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, 981 07, Abisko, Sweden
- Experimental Plant Ecology, Institute of Botany and Landscape Ecology, Greifswald University, 17487, Greifswald, Germany
| | - Margareta Johansson
- Department of Physical Geography and Ecosystem Science, Lund University, Solvegatan 12, 223 62, Lund, Sweden
| | - Ellen Dorrepaal
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, 981 07, Abisko, Sweden
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42
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Colleen M. Iversen. New Phytol 2019; 223:530-1. [PMID: 31231871 DOI: 10.1111/nph.15830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
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Dybzinski R, Kelvakis A, McCabe J, Panock S, Anuchitlertchon K, Vasarhelyi L, McCormack ML, McNickle GG, Poorter H, Trinder C, Farrior CE. How are nitrogen availability, fine-root mass, and nitrogen uptake related empirically? Implications for models and theory. Glob Chang Biol 2019; 25:885-899. [PMID: 30536492 DOI: 10.1111/gcb.14541] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 11/22/2018] [Accepted: 11/27/2018] [Indexed: 06/09/2023]
Abstract
Understanding the effects of global change in terrestrial communities requires an understanding of how limiting resources interact with plant traits to affect productivity. Here, we focus on nitrogen and ask whether plant community nitrogen uptake rate is determined (a) by nitrogen availability alone or (b) by the product of nitrogen availability and fine-root mass. Surprisingly, this is not empirically resolved. We performed controlled microcosm experiments and reanalyzed published pot experiments and field data to determine the relationship between community-level nitrogen uptake rate, nitrogen availability, and fine-root mass for 46 unique combinations of species, nitrogen levels, and growing conditions. We found that plant community nitrogen uptake rate was unaffected by fine-root mass in 63% of cases and saturated with fine-root mass in 29% of cases (92% in total). In contrast, plant community nitrogen uptake rate was clearly affected by nitrogen availability. The results support the idea that although plants may over-proliferate fine roots for individual-level competition, it comes without an increase in community-level nitrogen uptake. The results have implications for the mechanisms included in coupled carbon-nitrogen terrestrial biosphere models (CN-TBMs) and are consistent with CN-TBMs that operate above the individual scale and omit fine-root mass in equations of nitrogen uptake rate but inconsistent with the majority of CN-TBMs, which operate above the individual scale and include fine-root mass in equations of nitrogen uptake rate. For the much smaller number of CN-TBMs that explicitly model individual-based belowground competition for nitrogen, the results suggest that the relative (not absolute) fine-root mass of competing individuals should be included in the equations that determine individual-level nitrogen uptake rates. By providing empirical data to support the assumptions used in CN-TBMs, we put their global climate change predictions on firmer ground.
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Affiliation(s)
- Ray Dybzinski
- Institute of Environmental Sustainability, Loyola University Chicago, Chicago, Illinois
| | - Angelo Kelvakis
- Institute of Environmental Sustainability, Loyola University Chicago, Chicago, Illinois
| | - John McCabe
- Institute of Environmental Sustainability, Loyola University Chicago, Chicago, Illinois
| | - Samantha Panock
- Institute of Environmental Sustainability, Loyola University Chicago, Chicago, Illinois
| | | | - Leah Vasarhelyi
- Institute of Environmental Sustainability, Loyola University Chicago, Chicago, Illinois
| | - M Luke McCormack
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, Minnesota
| | - Gordon G McNickle
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana
- Purdue Center for Plant Biology, Purdue University, West Lafayette, Indiana
| | - Hendrik Poorter
- Plant Sciences (IBG2), Forschungszentrum Jülich GmbH, Jülich, Germany
- Department of Biological Sciences, Macquarie University, North Ryde, New South Wales, Australia
| | - Clare Trinder
- School of Biological Sciences, Cruickshank Building, University of Aberdeen, Aberdeen, UK
| | - Caroline E Farrior
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas
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McCormack ML, Iversen CM. Physical and Functional Constraints on Viable Belowground Acquisition Strategies. Front Plant Sci 2019; 10:1215. [PMID: 31681355 PMCID: PMC6797606 DOI: 10.3389/fpls.2019.01215] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 09/03/2019] [Indexed: 05/19/2023]
Abstract
Since their emergence onto land, terrestrial plants have developed diverse strategies to acquire soil resources. However, we lack a framework that adequately captures how these strategies vary among species. Observations from around the world now allow us to quantify the variation observed in commonly-measured fine-root traits but it is unclear how root traits are interrelated and whether they fall along an "economic" spectrum of acquisitive to conservative strategies. We assessed root trait variation and mycorrhizal colonization rates by leveraging the largest global database of fine-root traits (the Fine-Root Ecology Database; FRED). We also developed a heuristic model to explore the role of mycorrhizal fungi in defining belowground exploration efficiency across a gradient of thin- to thick-diameter roots. In support of the expectations of the "root economic spectrum," we found that root diameter was negatively related to specific root length (Pearson's r=-0.76). However, we found an unexpected negative relationship between root diameter and root tissue density (Pearson's r = -0.40), and we further observed that root nitrogen content was largely unrelated to other economic traits. Mycorrhizal colonization was most closely associated with root diameter (Pearson's r = 0.62) and was unrelated to root tissue density and root nitrogen. The heuristic model demonstrated that while thinner roots have inherently greater capacity to encounter soil resources based on higher surface area per unit mass, the potential for increased associations with mycorrhizal fungi in thicker roots, combined with greater hyphal growth, can result in equally acquisitive strategies for both thin- and thick roots. Taken together, our assessments of root trait variation, trade-offs with mycorrhizal fungi, and broader connections to root longevity allowed us to propose a series of fundamental constraints on belowground resource acquisition strategies. Physical tradeoffs based on root construction (i.e., economic traits) and functional limitations related to the capacity of a root to encounter and acquire soil resources combine to limit the two-dimensional belowground trait space. Within this trait space there remains a diversity of additional variation in root traits that facilitates a wide range of belowground resource acquisition strategies.
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Affiliation(s)
- M. Luke McCormack
- Center for Tree Science, The Morton Arboretum. Lisle, IL, United States
- *Correspondence: M. Luke McCormack,
| | - Colleen M. Iversen
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory. Oak Ridge, TN, United States
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Mao Z, Wang Y, McCormack ML, Rowe N, Deng X, Yang X, Xia S, Nespoulous J, Sidle RC, Guo D, Stokes A. Mechanical traits of fine roots as a function of topology and anatomy. Ann Bot 2018; 122:1103-1116. [PMID: 29846521 PMCID: PMC6324743 DOI: 10.1093/aob/mcy076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/19/2018] [Indexed: 05/17/2023]
Abstract
Background and Aims Root mechanical traits, including tensile strength (Tr), tensile strain (εr) and modulus of elasticity (Er), are key functional traits that help characterize plant anchorage and the physical contribution of vegetation to landslides and erosion. The variability in these traits is high among tree fine roots and is poorly understood. Here, we explore the variation in root mechanical traits as well as their underlying links with morphological (diameter), architectural (topological order) and anatomical (stele and cortex sizes) traits. Methods We investigated the four tropical tree species Pometia tomentosa, Barringtonia fusicarpa, Baccaurea ramiflora and Pittosporopsis kerrii in Xishuangbanna, Yunnan, China. For each species, we excavated intact, fresh, fine roots and measured mechanical and anatomical traits for each branching order. Key Results Mechanical traits varied enormously among the four species within a narrow range of diameters (<2 mm): <0.1-65 MPa for Tr, 4-1135 MPa for Er and 0.4-37 % for εr. Across species, Tr and Er were strongly correlated with stele area ratio, which was also better correlated with topological order than with root diameter, especially at interspecific levels. Conclusions Root topological order plays an important role in explaining variability in fine-root mechanical traits due to its reflection of root tissue development. Accounting for topological order when measuring fine-root traits therefore leads to greater empirical understanding of plant functions (e.g. anchorage) within and across species.
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Affiliation(s)
- Zhun Mao
- AMAP, INRA, CNRS, IRD, CIRAD, University of Montpellier, Montpellier, France
| | - Yan Wang
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - M Luke McCormack
- Center of Forest Ecosystem Studies and Qianyanzhou Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research (IGSNRR), Chinese Academy of Sciences (CAS), Beijing, China
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, USA
| | - Nick Rowe
- AMAP, INRA, CNRS, IRD, CIRAD, University of Montpellier, Montpellier, France
| | - Xiaobao Deng
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
- Xishuangbanna Station for Tropical Rain Forest Ecosystem Studies, Chinese Ecosystem Research Net, Mengla, Yunnan, China
| | - Xiaodong Yang
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Shangwen Xia
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Jérôme Nespoulous
- AMAP, INRA, CNRS, IRD, CIRAD, University of Montpellier, Montpellier, France
| | - Roy C Sidle
- Sustainability Research Centre, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Dali Guo
- Center of Forest Ecosystem Studies and Qianyanzhou Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research (IGSNRR), Chinese Academy of Sciences (CAS), Beijing, China
| | - Alexia Stokes
- AMAP, INRA, CNRS, IRD, CIRAD, University of Montpellier, Montpellier, France
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Chen G, Hobbie SE, Reich PB, Yang Y, Robinson D. Allometry of fine roots in forest ecosystems. Ecol Lett 2018; 22:322-331. [PMID: 30488519 DOI: 10.1111/ele.13193] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 05/26/2018] [Accepted: 10/31/2018] [Indexed: 01/28/2023]
Abstract
Theoretical predictions regarding fine root production are needed in many ecosystem models but are lacking. Here, we expand the classic pipe model to fine roots and predict isometric scaling relationships between leaf and fine root biomass and among all major biomass production components of individual trees. We also predict that fine root production scales more slowly against increases in leaf production across global forest ecosystems at the stand level. Using meta-analysis, we show fine root biomass scales isometrically against leaf biomass both at the individual tree and stand level. However, despite isometric scaling between stem and coarse root production, fine root production scales against leaf production with a slope of about 0.8 at the stand level, which probably results from more rapid increase of turnover rate in leaves than in fine roots. These analyses help to improve our understandings of allometric theory and controls of belowground C processes.
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Affiliation(s)
- Guangshui Chen
- Key Laboratory for Subtropical Mountain Ecology, Ministry of Science and Technology and Fujian Province Funded, School of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
| | - Sarah E Hobbie
- Department of Ecology, Evolution & Behavior, University of Minnesota, St. Paul, MN, 55108, USA
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, MN, 55108, USA.,Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, 2753, Australia
| | - Yusheng Yang
- Key Laboratory for Subtropical Mountain Ecology, Ministry of Science and Technology and Fujian Province Funded, School of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
| | - David Robinson
- Institute of Biological & Environmental Sciences, School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK
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Forstner SJ, Wechselberger V, Müller S, Keibinger KM, Díaz-Pinés E, Wanek W, Scheppi P, Hagedorn F, Gundersen P, Tatzber M, Gerzabek MH, Zechmeister-Boltenstern S. Vertical Redistribution of Soil Organic Carbon Pools After Twenty Years of Nitrogen Addition in Two Temperate Coniferous Forests. Ecosystems 2018; 22:379-400. [PMID: 30956544 PMCID: PMC6423314 DOI: 10.1007/s10021-018-0275-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 06/07/2018] [Indexed: 11/26/2022]
Abstract
Nitrogen (N) inputs from atmospheric deposition can increase soil organic carbon (SOC) storage in temperate and boreal forests, thereby mitigating the adverse effects of anthropogenic CO2 emissions on global climate. However, direct evidence of N-induced SOC sequestration from low-dose, long-term N addition experiments (that is, addition of < 50 kg N ha-1 y-1 for > 10 years) is scarce worldwide and virtually absent for European temperate forests. Here, we examine how tree growth, fine roots, physicochemical soil properties as well as pools of SOC and soil total N responded to 20 years of regular, low-dose N addition in two European coniferous forests in Switzerland and Denmark. At the Swiss site, the addition of 22 kg N ha-1 y-1 (or 1.3 times throughfall deposition) stimulated tree growth, but decreased soil pH and exchangeable calcium. At the Danish site, the addition of 35 kg N ha-1 y-1 (1.5 times throughfall deposition) impaired tree growth, increased fine root biomass and led to an accumulation of N in several belowground pools. At both sites, elevated N inputs increased SOC pools in the moderately decomposed organic horizons, but decreased them in the mineral topsoil. Hence, long-term N addition led to a vertical redistribution of SOC pools, whereas overall SOC storage within 30 cm depth was unaffected. Our results imply that an N-induced shift of SOC from older, mineral-associated pools to younger, unprotected pools might foster the vulnerability of SOC in temperate coniferous forest soils.
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Affiliation(s)
- Stefan J. Forstner
- Institute of Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria
| | - Viktoria Wechselberger
- Institute of Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria
| | - Stefanie Müller
- Institute of Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria
| | - Katharina M. Keibinger
- Institute of Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria
| | - Eugenio Díaz-Pinés
- Institute of Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria
| | - Wolfgang Wanek
- Department of Microbiology and Ecosystem Science, University of Vienna, 1090 Vienna, Austria
| | - Patrick Scheppi
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903 Birmensdorf, Switzerland
| | - Frank Hagedorn
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903 Birmensdorf, Switzerland
| | - Per Gundersen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, 1958 Frederiksberg C, Denmark
| | - Michael Tatzber
- Institute of Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria
- Division of Radiation Protection, Department of Radiation Protection and Radiochemistry, Austrian Agency for Health and Food Safety (AGES), 1220 Vienna, Austria
| | - Martin H. Gerzabek
- Institute of Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria
| | - Sophie Zechmeister-Boltenstern
- Institute of Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria
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Wojciechowska N, Sobieszczuk-Nowicka E, Bagniewska-Zadworna A. Plant organ senescence - regulation by manifold pathways. Plant Biol (Stuttg) 2018; 20:167-181. [PMID: 29178615 DOI: 10.1111/plb.12672] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 11/21/2017] [Indexed: 05/20/2023]
Abstract
Senescence is the final stage of plant ontogeny before death. Senescence may occur naturally because of age or may be induced by various endogenous and exogenous factors. Despite its destructive character, senescence is a precisely controlled process that follows a well-defined order. It is often inseparable from programmed cell death (PCD), and a correlation between these processes has been confirmed during the senescence of leaves and petals. Despite suggestions that senescence and PCD are two separate processes, with PCD occurring after senescence, cell death responsible for senescence is accompanied by numerous changes at the cytological, physiological and molecular levels, similar to other types of PCD. Independent of the plant organ analysed, these changes are focused on initiating the processes of cellular structural degradation via fluctuations in phytohormone levels and the activation of specific genes. Cellular structural degradation is genetically programmed and dependent on autophagy. Phytohormones/plant regulators are heavily involved in regulating the senescence of plant organs and can either promote [ethylene, abscisic acid (ABA), jasmonic acid (JA), and polyamines (PAs)] or inhibit [cytokinins (CKs)] this process. Auxins and carbohydrates have been assigned a dual role in the regulation of senescence, and can both inhibit and stimulate the senescence process. In this review, we introduce the basic pathways that regulate senescence in plants and identify mechanisms involved in controlling senescence in ephemeral plant organs. Moreover, we demonstrate a universal nature of this process in different plant organs; despite this process occurring in organs that have completely different functions, it is very similar. Progress in this area is providing opportunities to revisit how, when and which way senescence is coordinated or decoupled by plant regulators in different organs and will provide a powerful tool for plant physiology research.
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Affiliation(s)
- N Wojciechowska
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - E Sobieszczuk-Nowicka
- Department of Plant Physiology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - A Bagniewska-Zadworna
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
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Abstract
Atmospheric nitrogen deposition increases forest carbon sequestration across broad parts of the Northern Hemisphere. Slower organic matter decomposition and greater soil carbon accumulation could contribute to this increase in carbon sequestration. We investigated the effects of chronic simulated nitrogen deposition on leaf litter and fine root decomposition at four sugar maple (Acer saccharum)- dominated northern hardwood forests. At these sites, we previously observed that nitrogen additions increased soil organic carbon and altered litter chemistry. We conducted a 3-year decomposition study with litter bags. Litter production of leaves and fine roots were combined with decomposition dynamics to estimate how fine roots and leaf litter contribute to soil organic carbon. We found that nitrogen additions marginally stimulated early-stage decomposition of leaf litter, an effect associated with previously documented changes in litter chemistry. In contrast, nitrogen additions inhibited the later stages of fine root decomposition, which is consistent with observed decreases in lignin-degrading enzyme activities with nitrogen additions at these sites. At the ecosystem scale, slower fine root decomposition led to additional root mass retention (g m-2), and this greater retention of root residues was estimated to explain 5-51% of previously documented carbon accumulation in the surface soil due to nitrogen additions. Our results demonstrated that simulated nitrogen deposition created contrasting effects on the decomposition of leaf litter and fine roots. Although previous nitrogen deposition studies have focused on leaf litter, this work suggests that slower fine root decomposition is a major driver of soil organic carbon accumulation under elevated nitrogen deposition.
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50
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Comas LH. Exploring plant root traits and fungal interactions governing plant community structure: re-focusing long standing questions. New Phytol 2017; 216:963-964. [PMID: 29110308 DOI: 10.1111/nph.14881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Louise H Comas
- USDA-ARS, Water Management and Systems Research Unit, Fort Collins, CO, 80526, USA
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