101
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Slot M, Winter K. High tolerance of tropical sapling growth and gas exchange to moderate warming. Funct Ecol 2017. [DOI: 10.1111/1365-2435.13001] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Martijn Slot
- Smithsonian Tropical Research Institute Balboa, Ancón Republic of Panama
| | - Klaus Winter
- Smithsonian Tropical Research Institute Balboa, Ancón Republic of Panama
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102
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Eloy C, Fournier M, Lacointe A, Moulia B. Wind loads and competition for light sculpt trees into self-similar structures. Nat Commun 2017; 8:1014. [PMID: 29044122 PMCID: PMC5715076 DOI: 10.1038/s41467-017-00995-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 08/08/2017] [Indexed: 11/30/2022] Open
Abstract
Trees are self-similar structures: their branch lengths and diameters vary allometrically within the tree architecture, with longer and thicker branches near the ground. These tree allometries are often attributed to optimisation of hydraulic sap transport and safety against elastic buckling. Here, we show that these allometries also emerge from a model that includes competition for light, wind biomechanics and no hydraulics. We have developed MECHATREE, a numerical model of trees growing and evolving on a virtual island. With this model, we identify the fittest growth strategy when trees compete for light and allocate their photosynthates to grow seeds, create new branches or reinforce existing ones in response to wind-induced loads. Strikingly, we find that selected trees species are self-similar and follow allometric scalings similar to those observed on dicots and conifers. This result suggests that resistance to wind and competition for light play an essential role in determining tree allometries. Tree branches follow allometric scalings between length, thickness and dry mass. Here, Eloy and colleagues develop a functional-structural model that shows how such allometries in tree architecture can emerge through evolution as a result of competition for light, wind biomechanics, and wind sensing.
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Affiliation(s)
- Christophe Eloy
- Aix Marseille Univ, CNRS, Centrale Marseille, F-13013 IRPHE, Marseille, France.
| | | | | | - Bruno Moulia
- UCA, INRA, UMR PIAF, F-63000, Clermont-Ferrand, France
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103
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Lang M, Hanslin HM, Kollmann J, Wagner T. Suppression of an invasive legume by a native grass — High impact of priority effects. Basic Appl Ecol 2017. [DOI: 10.1016/j.baae.2017.06.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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104
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Norby RJ, Iversen CM. Introduction to a Virtual Issue on root traits. THE NEW PHYTOLOGIST 2017; 215:5-8. [PMID: 28560788 DOI: 10.1111/nph.14522] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Richard J Norby
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37830-6301, USA
| | - Colleen M Iversen
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37830-6301, USA
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105
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McCormack ML, Guo D, Iversen CM, Chen W, Eissenstat DM, Fernandez CW, Li L, Ma C, Ma Z, Poorter H, Reich PB, Zadworny M, Zanne A. Building a better foundation: improving root-trait measurements to understand and model plant and ecosystem processes. THE NEW PHYTOLOGIST 2017; 215:27-37. [PMID: 28295373 DOI: 10.1111/nph.14459] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Trait-based approaches provide a useful framework to investigate plant strategies for resource acquisition, growth, and competition, as well as plant impacts on ecosystem processes. Despite significant progress capturing trait variation within and among stems and leaves, identification of trait syndromes within fine-root systems and between fine roots and other plant organs is limited. Here we discuss three underappreciated areas where focused measurements of fine-root traits can make significant contributions to ecosystem science. These include assessment of spatiotemporal variation in fine-root traits, integration of mycorrhizal fungi into fine-root-trait frameworks, and the need for improved scaling of traits measured on individual roots to ecosystem-level processes. Progress in each of these areas is providing opportunities to revisit how below-ground processes are represented in terrestrial biosphere models. Targeted measurements of fine-root traits with clear linkages to ecosystem processes and plant responses to environmental change are strongly needed to reduce empirical and model uncertainties. Further identifying how and when suites of root and whole-plant traits are coordinated or decoupled will ultimately provide a powerful tool for modeling plant form and function at local and global scales.
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Affiliation(s)
- M Luke McCormack
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, 55108, USA
| | - 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, Chinese Academy of Sciences, Beijing, 100101, China
| | - Colleen M Iversen
- Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Weile Chen
- Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - David M Eissenstat
- Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, 16802, USA
| | | | - Le Li
- Center of Forest Ecosystem Studies and Qianyanzhou Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- University of the Chinese Academy of Sciences, Beijing, 100101, China
| | - Chengen Ma
- Center of Forest Ecosystem Studies and Qianyanzhou Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- University of the Chinese Academy of Sciences, Beijing, 100101, China
| | - Zeqing Ma
- Center of Forest Ecosystem Studies and Qianyanzhou Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hendrik Poorter
- Plant Sciences (IBG-2), Forschungszentrum Jülich GmbH, Jülich, D-52425, Germany
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St Paul, MN, 55108, USA
- Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, NSW, 2751, Australia
| | - Marcin Zadworny
- Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, Kórnik, 62-035, Poland
| | - Amy Zanne
- Department of Biological Sciences, George Washington University, Washington, DC, 20052, USA
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106
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Mason CM, Goolsby EW, Davis KE, Bullock DV, Donovan LA. Importance of whole-plant biomass allocation and reproductive timing to habitat differentiation across the North American sunflowers. ANNALS OF BOTANY 2017; 119:1131-1142. [PMID: 28203721 PMCID: PMC5604586 DOI: 10.1093/aob/mcx002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 01/21/2017] [Indexed: 05/24/2023]
Abstract
BACKGROUND AND AIMS Trait-based plant ecology attempts to use small numbers of functional traits to predict plant ecological strategies. However, a major gap exists between our understanding of organ-level ecophysiological traits and our understanding of whole-plant fitness and environmental adaptation. In this gap lie whole-plant organizational traits, including those that describe how plant biomass is allocated among organs and the timing of plant reproduction. This study explores the role of whole-plant organizational traits in adaptation to diverse environments in the context of life history, growth form and leaf economic strategy in a well-studied herbaceous system. METHODS A phylogenetic comparative approach was used in conjunction with common garden phenotyping to assess the evolution of biomass allocation and reproductive timing across 83 populations of 27 species of the diverse genus Helianthus (the sunflowers). KEY RESULTS Broad diversity exists among species in both relative biomass allocation and reproductive timing. Early reproduction is strongly associated with resource-acquisitive leaf economic strategy, while biomass allocation is less integrated with either reproductive timing or leaf economics. Both biomass allocation and reproductive timing are strongly related to source site environmental characteristics, including length of the growing season, temperature, precipitation and soil fertility. CONCLUSIONS Herbaceous taxa can adapt to diverse environments in many ways, including modulation of phenology, plant architecture and organ-level ecophysiology. Although leaf economic strategy captures one key aspect of plant physiology, on their own leaf traits are not particularly predictive of ecological strategies in Helianthus outside of the context of growth form, life history and whole-plant organization. These results highlight the importance of including data on whole-plant organization alongside organ-level ecophysiological traits when attempting to bridge the gap between functional traits and plant fitness and environmental adaptation.
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Affiliation(s)
- Chase M. Mason
- University of Central Florida, Orlando, FL 32816, USA
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Eric W. Goolsby
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912, USA
| | - Kaleigh E. Davis
- University of Central Florida, Orlando, FL 32816, USA
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Devon V. Bullock
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Lisa A. Donovan
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
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107
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Milla R, Matesanz S. Growing larger with domestication: a matter of physiology, morphology or allocation? PLANT BIOLOGY (STUTTGART, GERMANY) 2017; 19:475-483. [PMID: 28075047 DOI: 10.1111/plb.12545] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 01/09/2017] [Indexed: 06/06/2023]
Abstract
Domestication might affect plant size. We investigated whether herbaceous crops are larger than their wild progenitors, and the traits that influence size variation. We grew six crop plants and their wild progenitors under common garden conditions. We measured the aboveground biomass gain by individual plants during the vegetative stage. We then tested whether photosynthesis rate, biomass allocation to leaves, leaf size and specific leaf area (SLA) accounted for variations in whole-plant photosynthesis, and ultimately in aboveground biomass. Despite variations among crops, domestication generally increased the aboveground biomass (average effect +1.38, Cohen's d effect size). Domesticated plants invested less in leaves and more in stems than their wild progenitors. Photosynthesis rates remained similar after domestication. Variations in whole-plant C gains could not be explained by changes in leaf photosynthesis. Leaves were larger after domestication, which provided the main contribution to increases in leaf area per plant and plant-level C gain, and ultimately to larger aboveground biomass. In general, cultivated plants have become larger since domestication. In our six crops, this occurred despite lower investment in leaves, comparable leaf-level photosynthesis and similar biomass costs of leaf area (i.e. SLA) than their wild progenitors. Increased leaf size was the main driver of increases in aboveground size. Thus, we suggest that large seeds, which are also typical of crops, might produce individuals with larger organs (i.e. leaves) via cascading effects throughout ontogeny. Larger leaves would then scale into larger whole plants, which might partly explain the increases in size that accompanied domestication.
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Affiliation(s)
- R Milla
- Departamento de Biología y Geología, Física y Química Inorgánica, Área de Biodiversidad y Conservación, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Móstoles, Spain
| | - S Matesanz
- Departamento de Biología y Geología, Física y Química Inorgánica, Área de Biodiversidad y Conservación, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Móstoles, Spain
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108
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Sun H, Wang X, Fan Y, Liu C, Wu P, Li Q, Yin W. Effects of biophysical constraints, climate and phylogeny on forest shrub allometries along an altitudinal gradient in Northeast China. Sci Rep 2017; 7:43769. [PMID: 28266604 PMCID: PMC5339776 DOI: 10.1038/srep43769] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 01/27/2017] [Indexed: 11/08/2022] Open
Abstract
Whether there is a general allometry law across plant species with different sizes and under different environment has long been controversial and shrubs are particularly useful to examine these questions. Here we sampled 939 individuals from 50 forest shrub species along a large altitudinal gradient. We tested several allometry models with four relationships simultaneously (between stem diameter, height, leaf, stem and aboveground biomass), including geometric, elastic and stress similarity, and metabolic scaling theory's predictions on small plants (MSTs) and trees (MSTt). We also tested if allometric exponents change markedly with climate and phylogeny. The predicted exponents of MSTt, elastic similarity and stress similarity (models for trees) were not supported by our data, while MSTs and geometric similarity gained more support, suggesting the finite size effect is more important for shrub allometries than being a woody plant. The influence of climate and phylogeny on allometric exponents were not significant or very weak, again suggesting strong biophysical constraints on shrub allometries. Our results reveal clear differences of shrub allometries from previous findings on trees (e.g. much weaker climatic and phylogenic control). Comparisons of herbs, shrubs and trees along a same climatic gradient are needed for better understanding of plant allometries.
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Affiliation(s)
- Han Sun
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Xiangping Wang
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Yanwen Fan
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Chao Liu
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Peng Wu
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Qiaoyan Li
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Weilun Yin
- College of Forestry, Beijing Forestry University, Beijing 100083, China
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109
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Chmura DJ, Modrzyński J, Chmielarz P, Tjoelker MG. Plasticity in seedling morphology, biomass allocation and physiology among ten temperate tree species in response to shade is related to shade tolerance and not leaf habit. PLANT BIOLOGY (STUTTGART, GERMANY) 2017; 19:172-182. [PMID: 27981788 DOI: 10.1111/plb.12531] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 12/08/2016] [Indexed: 06/06/2023]
Abstract
Mechanisms of shade tolerance in tree seedlings, and thus growth in shade, may differ by leaf habit and vary with ontogeny following seed germination. To examine early responses of seedlings to shade in relation to morphological, physiological and biomass allocation traits, we compared seedlings of 10 temperate species, varying in their leaf habit (broadleaved versus needle-leaved) and observed tolerance to shade, when growing in two contrasting light treatments - open (about 20% of full sunlight) and shade (about 5% of full sunlight). We analyzed biomass allocation and its response to shade using allometric relationships. We also measured leaf gas exchange rates and leaf N in the two light treatments. Compared to the open treatment, shading significantly increased traits typically associated with high relative growth rate (RGR) - leaf area ratio (LAR), specific leaf area (SLA), and allocation of biomass into leaves, and reduced seedling mass and allocation to roots, and net assimilation rate (NAR). Interestingly, RGR was not affected by light treatment, likely because of morphological and physiological adjustments in shaded plants that offset reductions of in situ net assimilation of carbon in shade. Leaf area-based rates of light-saturated leaf gas exchange differed among species groups, but not between light treatments, as leaf N concentration increased in concert with increased SLA in shade. We found little evidence to support the hypothesis of a increased plasticity of broadleaved species compared to needle-leaved conifers in response to shade. However, an expectation of higher plasticity in shade-intolerant species than in shade-tolerant ones, and in leaf and plant morphology than in biomass allocation was supported across species of contrasting leaf habit.
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Affiliation(s)
- D J Chmura
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
- Department of Ecosystem Science and Management, Texas A&M University, College Station, TX, USA
| | - J Modrzyński
- Department of Ecosystem Science and Management, Texas A&M University, College Station, TX, USA
- Department of Forest Sites and Ecology, Faculty of Forestry, Poznań University of Life Sciences, Poznań, Poland
| | - P Chmielarz
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
| | - M G Tjoelker
- Department of Ecosystem Science and Management, Texas A&M University, College Station, TX, USA
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
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110
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Weidlich EWA, von Gillhaussen P, Delory BM, Blossfeld S, Poorter H, Temperton VM. The Importance of Being First: Exploring Priority and Diversity Effects in a Grassland Field Experiment. FRONTIERS IN PLANT SCIENCE 2017; 7:2008. [PMID: 28119707 PMCID: PMC5221677 DOI: 10.3389/fpls.2016.02008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 12/19/2016] [Indexed: 06/06/2023]
Abstract
Diversity of species and order of arrival can have strong effects on ecosystem functioning and community composition, but these two have rarely been explicitly combined in experimental setups. We measured the effects of both species diversity and order of arrival on ecosystem function and community composition in a grassland field experiment, thus combining biodiversity and assembly approaches. We studied the effect of order of arrival of three plant functional groups (PFGs: grasses, legumes, and non-leguminous forbs) and of sowing low and high diversity seed mixtures (9 or 21 species) on species composition and aboveground biomass. The experiment was set up in two different soil types. Differences in PFG order of arrival affected the biomass, the number of species and community composition. As expected, we found higher aboveground biomass when sowing legumes before the other PFGs, but this effect was not continuous over time. We did not find a positive effect of sown diversity on aboveground biomass (even if it influenced species richness as expected). No interaction were found between the two studied factors. We found that sowing legumes first may be a good method for increasing productivity whilst maintaining diversity of central European grasslands, although the potential for long-lasting effects needs further study. In addition, the mechanisms behind the non-continuous priority effects we found need to be further researched, taking weather and plant-soil feedbacks into account.
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Affiliation(s)
- Emanuela W. A. Weidlich
- Plant Sciences, Institute for Bio- and Geosciences-2, Forschungszentrum Jülich GmbHJülich, Germany
- Ecosystem Functioning and Services, Institute of Ecology, Leuphana UniversityLüneburg, Germany
| | - Philipp von Gillhaussen
- Plant Sciences, Institute for Bio- and Geosciences-2, Forschungszentrum Jülich GmbHJülich, Germany
| | - Benjamin M. Delory
- Ecosystem Functioning and Services, Institute of Ecology, Leuphana UniversityLüneburg, Germany
| | - Stephan Blossfeld
- Plant Sciences, Institute for Bio- and Geosciences-2, Forschungszentrum Jülich GmbHJülich, Germany
| | - Hendrik Poorter
- Plant Sciences, Institute for Bio- and Geosciences-2, Forschungszentrum Jülich GmbHJülich, Germany
| | - Vicky M. Temperton
- Plant Sciences, Institute for Bio- and Geosciences-2, Forschungszentrum Jülich GmbHJülich, Germany
- Ecosystem Functioning and Services, Institute of Ecology, Leuphana UniversityLüneburg, Germany
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111
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Zhao J, Bodner G, Rewald B. Phenotyping: Using Machine Learning for Improved Pairwise Genotype Classification Based on Root Traits. FRONTIERS IN PLANT SCIENCE 2016; 7:1864. [PMID: 27999587 PMCID: PMC5138212 DOI: 10.3389/fpls.2016.01864] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 11/25/2016] [Indexed: 05/29/2023]
Abstract
Phenotyping local crop cultivars is becoming more and more important, as they are an important genetic source for breeding - especially in regard to inherent root system architectures. Machine learning algorithms are promising tools to assist in the analysis of complex data sets; novel approaches are need to apply them on root phenotyping data of mature plants. A greenhouse experiment was conducted in large, sand-filled columns to differentiate 16 European Pisum sativum cultivars based on 36 manually derived root traits. Through combining random forest and support vector machine models, machine learning algorithms were successfully used for unbiased identification of most distinguishing root traits and subsequent pairwise cultivar differentiation. Up to 86% of pea cultivar pairs could be distinguished based on top five important root traits (Timp5) - Timp5 differed widely between cultivar pairs. Selecting top important root traits (Timp) provided a significant improved classification compared to using all available traits or randomly selected trait sets. The most frequent Timp of mature pea cultivars was total surface area of lateral roots originating from tap root segments at 0-5 cm depth. The high classification rate implies that culturing did not lead to a major loss of variability in root system architecture in the studied pea cultivars. Our results illustrate the potential of machine learning approaches for unbiased (root) trait selection and cultivar classification based on rather small, complex phenotypic data sets derived from pot experiments. Powerful statistical approaches are essential to make use of the increasing amount of (root) phenotyping information, integrating the complex trait sets describing crop cultivars.
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Affiliation(s)
- Jiangsan Zhao
- Department of Forest and Soil Sciences, University of Natural Resources and Life SciencesVienna, Austria
| | - Gernot Bodner
- Division of Agronomy, Department of Crop Sciences, University of Natural Resources and Life SciencesVienna, Austria
| | - Boris Rewald
- Department of Forest and Soil Sciences, University of Natural Resources and Life SciencesVienna, Austria
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112
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Plant Responses to Brief Touching: A Mechanism for Early Neighbour Detection? PLoS One 2016; 11:e0165742. [PMID: 27828995 PMCID: PMC5102373 DOI: 10.1371/journal.pone.0165742] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 10/17/2016] [Indexed: 12/14/2022] Open
Abstract
In natural habitats plants can be exposed to brief and light contact with neighbouring plants. This mechanical stimulus may represent a cue that induces responses to nearby plants. However, little is known about the effect of touching on plant growth and interaction with insect herbivores. To simulate contact between plants, a soft brush was used to apply light and brief mechanical stimuli to terminal leaves of potato Solanum tuberosum L. The number of non-glandular trichomes on the leaf surface was counted on images made by light microscope while glandular trichomes and pavement cells were counted on images made under scanning electronic microscope. Volatile compounds were identified and quantified using coupled gas chromatography–mass spectrometry (GC-MS). Treated plants changed their pattern of biomass distribution; they had lower stem mass fraction and higher branch and leaf mass fraction than untouched plants. Size, weight and number of tubers were not significantly affected. Touching did not cause trichome damage nor change their total number on touched terminal leaves. However, on primary leaves the number of glandular trichomes and pavement cells was significantly increased. Touching altered the volatile emission of treated plants; they released higher quantities of the sesquiterpenes (E)-β-caryophyllene, germacrene D-4-ol and (E)-nerolidol, and lower quantities of the terpenes (E)-ocimene and linalool, indicating a systemic effect of the treatment. The odour of touched plants was significantly less preferred by the aphids Macrosiphum euphorbiae and Myzus persicae compared to odour of untouched plants. The results suggest that light contact may have a potential role in the detection of neighbouring plants and may affect plant-insect interactions.
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113
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Starko S, Martone PT. An empirical test of 'universal' biomass scaling relationships in kelps: evidence of convergence with seed plants. THE NEW PHYTOLOGIST 2016; 212:719-729. [PMID: 27479188 DOI: 10.1111/nph.14120] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 06/16/2016] [Indexed: 06/06/2023]
Abstract
Biomass allocation patterns have received substantial consideration, leading to the recognition of several 'universal' interspecific trends. Despite efforts to understand biomass partitioning among embryophytes, few studies have examined macroalgae that evolved independently, yet function ecologically in much the same ways as plants. Kelps allocate photosynthate among three organs (the blade(s), stipe(s) and holdfast) that are superficially convergent with organs of land plants, providing a unique opportunity to test the limits of 'universal' trends. In this study, we used an allometric approach to quantify interspecific biomass partitioning patterns in kelps and assess whether embryophyte-based predictions of biomass scaling can be applied to marine macrophytes that lack root-to-leaf hydraulic transport. Photosynthetic area and dry mass were found to scale to approximately the ¾ power and kelp biomass allocation patterns were shown to match closely to empirical measures of allometric scaling among woody plants. Larger kelp species were found to have increased relative stipe and holdfast mass than smaller species, highlighting important consequences of size for marine macroalgae. Our study provides insights into the evolution of size in the largest marine macrophytes and corroborates previous work suggesting that the morphology of divergent lineages of photoautotrophs may reflect similar selective pressures.
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Affiliation(s)
- Samuel Starko
- Department of Botany and Beaty Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada.
- Bamfield Marine Sciences Centre, 100 Pachena Rd, Bamfield, BC, V0R 1B0, Canada.
- Hakai Institute, Pruth Harbour, Calvert Island, BC, V0P 1H0, Canada.
| | - Patrick T Martone
- Department of Botany and Beaty Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
- Bamfield Marine Sciences Centre, 100 Pachena Rd, Bamfield, BC, V0R 1B0, Canada
- Hakai Institute, Pruth Harbour, Calvert Island, BC, V0P 1H0, Canada
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114
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Duursma RA, Falster DS. Leaf mass per area, not total leaf area, drives differences in above-ground biomass distribution among woody plant functional types. THE NEW PHYTOLOGIST 2016; 212:368-376. [PMID: 27241462 DOI: 10.1111/nph.14033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 04/28/2016] [Indexed: 06/05/2023]
Abstract
Here, we aim to understand differences in biomass distribution between major woody plant functional types (PFTs) (deciduous vs evergreen and gymnosperm vs angiosperm) in terms of underlying traits, in particular the leaf mass per area (LMA) and leaf area per unit stem basal area. We used a large compilation of plant biomass and size observations, including observations of 21 084 individuals on 656 species. We used a combination of semiparametric methods and variance partitioning to test the influence of PFT, plant height, LMA, total leaf area, stem basal area and climate on above-ground biomass distribution. The ratio of leaf mass to above-ground woody mass (MF /MS ) varied strongly among PFTs. We found that MF /MS at a given plant height was proportional to LMA across PFTs. As a result, the PFTs did not differ in the amount of leaf area supported per unit above-ground biomass or per unit stem basal area. Climate consistently explained very little additional variation in biomass distribution at a given plant size. Combined, these results demonstrate consistent patterns in above-ground biomass distribution and leaf area relationships among major woody PFTs, which can be used to further constrain global vegetation models.
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Affiliation(s)
- Remko A Duursma
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
| | - Daniel S Falster
- Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
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Jiang Y, Xu Z, Zhou G, Liu T. Elevated CO2 can modify the response to a water status gradient in a steppe grass: from cell organelles to photosynthetic capacity to plant growth. BMC PLANT BIOLOGY 2016; 16:157. [PMID: 27405416 PMCID: PMC4942890 DOI: 10.1186/s12870-016-0846-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 07/06/2016] [Indexed: 05/14/2023]
Abstract
BACKGROUND The atmospheric CO2 concentration is rising continuously, and abnormal precipitation may occur more frequently in the future. Although the effects of elevated CO2 and drought on plants have been well reported individually, little is known about their interaction, particularly over a water status gradient. Here, we aimed to characterize the effects of elevated CO2 and a water status gradient on the growth, photosynthetic capacity, and mesophyll cell ultrastructure of a dominant grass from a degraded grassland. RESULTS Elevated CO2 stimulated plant biomass to a greater extent under moderate changes in water status than under either extreme drought or over-watering conditions. Photosynthetic capacity and stomatal conductance were also enhanced by elevated CO2 under moderate drought, but inhibited with over-watering. Severe drought distorted mesophyll cell organelles, but CO2 enrichment partly alleviated this effect. Intrinsic water use efficiency (WUEi) and total biomass water use efficiency (WUEt) were increased by elevated CO2, regardless of water status. Plant structural traits were also found to be tightly associated with photosynthetic potentials. CONCLUSION The results indicated that CO2 enrichment alleviated severe and moderate drought stress, and highlighted that CO2 fertilization's dependency on water status should be considered when projecting key species' responses to climate change in dry ecosystems.
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Affiliation(s)
- Yanling Jiang
- />State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Haidian Beijing, 100093 China
| | - Zhenzhu Xu
- />State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Haidian Beijing, 100093 China
| | - Guangsheng Zhou
- />State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Haidian Beijing, 100093 China
- />Chinese Academy of Meteorological Sciences, China Meteorological Administration, 46 Zhongguancun South Street, Haidian Beijing, 100081 China
| | - Tao Liu
- />State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Haidian Beijing, 100093 China
- />Chinese Academy of Meteorological Sciences, China Meteorological Administration, 46 Zhongguancun South Street, Haidian Beijing, 100081 China
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Fajardo A. Are trait-scaling relationships invariant across contrasting elevations in the widely distributed treeline species Nothofagus pumilio? AMERICAN JOURNAL OF BOTANY 2016; 103:821-829. [PMID: 27208350 DOI: 10.3732/ajb.1500439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/28/2016] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY The study of scaling examines the relative dimensions of diverse organismal traits. Understanding whether global scaling patterns are paralleled within species is key to identify causal factors of universal scaling. I examined whether the foliage-stem (Corner's rules), the leaf size-number, and the leaf mass-leaf area scaling relationships remained invariant and isometric with elevation in a wide-distributed treeline species in the southern Chilean Andes. METHODS Mean leaf area, leaf mass, leafing intensity, and twig cross-sectional area were determined for 1-2 twigs of 8-15 Nothofagus pumilio individuals across four elevations (including treeline elevation) and four locations (from central Chile at 36°S to Tierra del Fuego at 54°S). Mixed effects models were fitted to test whether the interaction term between traits and elevation was nonsignificant (invariant). KEY RESULTS The leaf-twig cross-sectional area and the leaf mass-leaf area scaling relationships were isometric (slope = 1) and remained invariant with elevation, whereas the leaf size-number (i.e., leafing intensity) scaling was allometric (slope ≠ -1) and showed no variation with elevation. Leaf area and leaf number were consistently negatively correlated across elevation. CONCLUSIONS The scaling relationships examined in the current study parallel those seen across species. It is plausible that the explanation of intraspecific scaling relationships, as trait combinations favored by natural selection, is the same as those invoked to explain across species patterns. Thus, it is very likely that the global interspecific Corner's rules and other leaf-leaf scaling relationships emerge as the aggregate of largely parallel intraspecific patterns.
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Affiliation(s)
- Alex Fajardo
- Centro de Investigación en Ecosistemas de la Patagonia (CIEP) CONICYT-Regional R10C1003, Universidad Austral de Chile, Camino Baguales s/n, Coyhaique 5951601, Chile
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Biomass resilience of Neotropical secondary forests. Nature 2016; 530:211-4. [PMID: 26840632 DOI: 10.1038/nature16512] [Citation(s) in RCA: 305] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 12/02/2015] [Indexed: 01/28/2023]
Abstract
Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha(-1)), corresponding to a net carbon uptake of 3.05 Mg C ha(-1) yr(-1), 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha(-1)) across sites, and this recovery increased with water availability (higher local rainfall and lower climatic water deficit). We present a biomass recovery map of Latin America, which illustrates geographical and climatic variation in carbon sequestration potential during forest regrowth. The map will support policies to minimize forest loss in areas where biomass resilience is naturally low (such as seasonally dry forest regions) and promote forest regeneration and restoration in humid tropical lowland areas with high biomass resilience.
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