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Xu Q, Dong X, Huang W, Li Z, Huang T, Song Z, Yang Y, Chen J. Evaluating the Effect of Deficit Irrigation on Yield and Water Use Efficiency of Drip Irrigation Cotton under Film in Xinjiang Based on Meta-Analysis. PLANTS (BASEL, SWITZERLAND) 2024; 13:640. [PMID: 38475485 DOI: 10.3390/plants13050640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 02/19/2024] [Accepted: 02/22/2024] [Indexed: 03/14/2024]
Abstract
Water scarcity constrains the sustainable development of Chinese agriculture, and deficit irrigation as a new irrigation technology can effectively alleviate the problems of water scarcity and water use inefficiency in agriculture. In this study, the drip irrigation cotton field under film in Xinjiang was taken as the research object. Meta-analysis and machine learning were used to quantitatively analyze the effects of different farm management practices, climate, and soil conditions on cotton yield and water use efficiency under deficit irrigation, to investigate the importance of the effects of different factors on cotton yield and water use efficiency, and to formulate appropriate optimization strategies. The results showed that deficit irrigation significantly increased cotton water use efficiency (7.39%) but decreased cotton yield (-15.00%) compared with full irrigation. All three deficit irrigation levels (80~100% FI, 60~80% FI, and 40~60% FI; FI: full irrigation) showed a significant decrease in cotton yield and a significant increase in water use efficiency. Under deficit irrigation, cotton yield reduction was the smallest and cotton water use efficiency increased the most when planted with one film, two tubes, a six-row cropping pattern, an irrigation frequency ≥10 times, a nitrogen application of 300~400 kg·ha-1, and a crop density ≥240,000 per hectare, and planted with the Xinluzhong series of cotton varieties; deficit irrigation in areas with average annual temperature >10 °C, annual evapotranspiration >2000 mm, annual precipitation <60 mm, and with loam, sandy soil had the least inhibition of cotton yield and the greatest increase in cotton water use efficiency. The results of the random forest showed that the irrigation amount and nitrogen application had the greatest influence on cotton yield and water use efficiency. Rational irrigation based on optimal management practices under conditions of irrigation not less than 90% FI is expected to achieve a win-win situation for both cotton yield and water use efficiency. The above results can provide the best strategy for deficit irrigation and efficient water use in drip irrigation cotton under film in arid areas.
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Affiliation(s)
- Qi Xu
- College of Water Conservancy and Architectural Engineering, Tarim University, Alar 843300, China
- Key Laboratory of Modern Agricultural Engineering, Tarim University, Alar 843300, China
| | - Xiaomei Dong
- College of Water Conservancy and Architectural Engineering, Tarim University, Alar 843300, China
| | - Weixiong Huang
- College of Water Conservancy and Architectural Engineering, Tarim University, Alar 843300, China
- MOE Key Laboratory of Groundwater Quality and Health, School of Environmental Studies, China University of Geosciences, Wuhan 430078, China
| | - Zhaoyang Li
- College of Water Conservancy and Architectural Engineering, Tarim University, Alar 843300, China
- Key Laboratory of Modern Agricultural Engineering, Tarim University, Alar 843300, China
| | - Tongtong Huang
- College of Water Conservancy and Architectural Engineering, Tarim University, Alar 843300, China
| | - Zaijin Song
- Research Office, Beijing City University, Beijing 100193, China
| | - Yuhui Yang
- College of Water Conservancy and Architectural Engineering, Tarim University, Alar 843300, China
- Key Laboratory of Modern Agricultural Engineering, Tarim University, Alar 843300, China
| | - Jinsai Chen
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
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Chen J, Hao S, Bañuelos G, Zhou X. A quantitative review of the effects of Se application on the reduction of Hg concentration in plant: a meta-analysis. FRONTIERS IN PLANT SCIENCE 2023; 14:1199721. [PMID: 37409302 PMCID: PMC10318138 DOI: 10.3389/fpls.2023.1199721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 05/30/2023] [Indexed: 07/07/2023]
Abstract
Mercury (Hg) is a highly toxic heavy metal entering the human body through the food chain after absorption by plant. Exogenous selenium (Se) has been suggested as a potential solution to reduce Hg concentration in plants. However, the literature does not provide a consistent picture of the performance of Se on the accumulation of Hg in plant. To obtain a more conclusive answer on the interactions of Se and Hg, 1,193 data records were collected from 38 publications for this meta-analysis, and we tested the effects of different factors on Hg accumulation by meta-subgroup analysis and meta-regression model. The results highlighted a significant dose-dependent effect of Se/Hg molar ratio on the reduction of Hg concentration in plants, and the optimum condition for inhibiting Hg accumulation in plants is at a Se/Hg ratio of 1-3. Exogenous Se significantly reduced Hg concentrations in the overall plant species, rice grains, and non-rice species by 24.22%, 25.26%, and 28.04%, respectively. Both Se(IV) and Se(VI) significantly reduced Hg accumulation in plants, but Se(VI) had a stronger inhibiting effect than Se(IV). Se significantly decreased the BAFGrain in rice, which indicated that other physiological processes in rice may be involved in restricting uptake from soil to rice grain. Therefore, Se can effectively reduce Hg accumulation in rice grain, which provides a strategy for effectively alleviating the transfer of Hg to the human body through the food chain.
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Affiliation(s)
- Jiefei Chen
- College of Resources and Environment, Southwest University, Chongqing, China
- Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shangyan Hao
- College of Resources and Environment, Southwest University, Chongqing, China
| | - Gary Bañuelos
- United States Department of Agriculture-Agricultural Research Service, Parlier, CA, United States
| | - Xinbin Zhou
- College of Resources and Environment, Southwest University, Chongqing, China
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Ofori-Amanfo KK, Klem K, Veselá B, Holub P, Agyei T, Juráň S, Grace J, Marek MV, Urban O. The effect of elevated CO2 on photosynthesis is modulated by nitrogen supply and reduced water availability in Picea abies. TREE PHYSIOLOGY 2023; 43:925-937. [PMID: 36864576 DOI: 10.1093/treephys/tpad024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 02/22/2023] [Indexed: 06/11/2023]
Abstract
It is assumed that the stimulatory effects of elevated CO2 concentration ([CO2]) on photosynthesis and growth may be substantially reduced by co-occurring environmental factors and the length of CO2 treatment. Here, we present the study exploring the interactive effects of three manipulated factors ([CO2], nitrogen supply and water availability) on physiological (gas-exchange and chlorophyll fluorescence), morphological and stoichiometric traits of Norway spruce (Picea abies) saplings after 2 and 3 years of the treatment under natural field conditions. Such multifactorial studies, going beyond two-way interactions, have received only limited attention until now. Our findings imply a significant reduction of [CO2]-enhanced rate of CO2 assimilation under reduced water availability which deepens with the severity of water depletion. Similarly, insufficient nitrogen availability leads to a down-regulation of photosynthesis under elevated [CO2] being particularly associated with reduced carboxylation efficiency of the Rubisco enzyme. Such adjustments in the photosynthesis machinery result in the stimulation of water-use efficiency under elevated [CO2] only when it is combined with a high nitrogen supply and reduced water availability. These findings indicate limited effects of elevated [CO2] on carbon uptake in temperate coniferous forests when combined with naturally low nitrogen availability and intensifying droughts during the summer periods. Such interactions have to be incorporated into the mechanistic models predicting changes in terrestrial carbon sequestration and forest growth in the future.
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Affiliation(s)
- Kojo Kwakye Ofori-Amanfo
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic
- Department of Agrosystems and Bioclimatology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1665/1, 613 00 Brno, Czech Republic
| | - Karel Klem
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic
- Department of Agrosystems and Bioclimatology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1665/1, 613 00 Brno, Czech Republic
| | - Barbora Veselá
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic
| | - Petr Holub
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic
| | - Thomas Agyei
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic
- Department of Agrosystems and Bioclimatology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1665/1, 613 00 Brno, Czech Republic
- Department of Biological Science, School of Sciences, University of Energy and Natural Resources, Post Office Box 214, Sunyani, Ghana
| | - Stanislav Juráň
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic
| | - John Grace
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic
- School of GeoSciences, University of Edinburgh, Crew Bldg, Kings Bldgs, Alexander Crum Brown Rd, Edinburgh EH9 3FF, UK
| | - Michal V Marek
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic
- Institute of Management, Slovak Technical University Bratislava, Vazovova 5, 812 43 Bratislava, Slovakia
| | - Otmar Urban
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic
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Van Sundert K, Leuzinger S, Bader MKF, Chang SX, De Kauwe MG, Dukes JS, Langley JA, Ma Z, Mariën B, Reynaert S, Ru J, Song J, Stocker B, Terrer C, Thoresen J, Vanuytrecht E, Wan S, Yue K, Vicca S. When things get MESI: The Manipulation Experiments Synthesis Initiative-A coordinated effort to synthesize terrestrial global change experiments. GLOBAL CHANGE BIOLOGY 2023; 29:1922-1938. [PMID: 36607160 DOI: 10.1111/gcb.16585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/22/2022] [Accepted: 12/30/2022] [Indexed: 05/28/2023]
Abstract
Responses of the terrestrial biosphere to rapidly changing environmental conditions are a major source of uncertainty in climate projections. In an effort to reduce this uncertainty, a wide range of global change experiments have been conducted that mimic future conditions in terrestrial ecosystems, manipulating CO2 , temperature, and nutrient and water availability. Syntheses of results across experiments provide a more general sense of ecosystem responses to global change, and help to discern the influence of background conditions such as climate and vegetation type in determining global change responses. Several independent syntheses of published data have yielded distinct databases for specific objectives. Such parallel, uncoordinated initiatives carry the risk of producing redundant data collection efforts and have led to contrasting outcomes without clarifying the underlying reason for divergence. These problems could be avoided by creating a publicly available, updatable, curated database. Here, we report on a global effort to collect and curate 57,089 treatment responses across 3644 manipulation experiments at 1145 sites, simulating elevated CO2 , warming, nutrient addition, and precipitation changes. In the resulting Manipulation Experiments Synthesis Initiative (MESI) database, effects of experimental global change drivers on carbon and nutrient cycles are included, as well as ancillary data such as background climate, vegetation type, treatment magnitude, duration, and, unique to our database, measured soil properties. Our analysis of the database indicates that most experiments are short term (one or few growing seasons), conducted in the USA, Europe, or China, and that the most abundantly reported variable is aboveground biomass. We provide the most comprehensive multifactor global change database to date, enabling the research community to tackle open research questions, vital to global policymaking. The MESI database, freely accessible at doi.org/10.5281/zenodo.7153253, opens new avenues for model evaluation and synthesis-based understanding of how global change affects terrestrial biomes. We welcome contributions to the database on GitHub.
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Affiliation(s)
- Kevin Van Sundert
- Research Group PLECO (Plants and Ecosystems), Global Change Ecology Centre of Excellence, Biology Department, University of Antwerp, Wilrijk, Belgium
- Climate and Ecological Synthesis Lab, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Earth System Science, Doerr School of Sustainability, Stanford University, Stanford, California, USA
- Ecological Synthesis Lab, School of Informatics, Computing and Cyber Systems, Northern Arizona University, Flagstaff, Arizona, USA
| | | | - Martin K-F Bader
- Department of Forestry and Wood Technology, Linnaeus University, Växjö, Sweden
| | - Scott X Chang
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | | | - Jeffrey S Dukes
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California, USA
| | - J Adam Langley
- Department of Biology and Center for Biodiversity and Ecosystem Stewardship, Villanova University, Villanova, Pennsylvania, USA
| | - Zilong Ma
- State Key Laboratory of Biocontrol, School of Ecology, Sun Yat-sen University, Guangzhou, China
| | - Bertold Mariën
- Research Group PLECO (Plants and Ecosystems), Global Change Ecology Centre of Excellence, Biology Department, University of Antwerp, Wilrijk, Belgium
| | - Simon Reynaert
- Research Group PLECO (Plants and Ecosystems), Global Change Ecology Centre of Excellence, Biology Department, University of Antwerp, Wilrijk, Belgium
| | - Jingyi Ru
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, China
| | - Jian Song
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, China
| | - Benjamin Stocker
- Institute of Geography, University of Bern, Bern, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - César Terrer
- Climate and Ecological Synthesis Lab, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Joshua Thoresen
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
- Wildland Consultants, Auckland, New Zealand
| | - Eline Vanuytrecht
- Division of Soil & Water Management, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium
- Climate Change Adaptation, European Environment Agency, Copenhagen, Denmark
| | - Shiqiang Wan
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, China
| | - Kai Yue
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian, China
- Fujian Sanming Forest Ecosystem National Observation and Research Station, Sanming, Fujian, China
| | - Sara Vicca
- Research Group PLECO (Plants and Ecosystems), Global Change Ecology Centre of Excellence, Biology Department, University of Antwerp, Wilrijk, Belgium
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Zhang Z, Li Y, Williams RA, Chen Y, Peng R, Liu X, Qi Y, Wang Z. Responses of soil respiration and its sensitivities to temperature and precipitation: A meta-analysis. ECOL INFORM 2023. [DOI: 10.1016/j.ecoinf.2023.102057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
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Zou J, Zhang W, Zhang Y, Wu J. Global patterns of plant and microbial biomass in response to CO 2 fumigation. Front Microbiol 2023; 14:1175854. [PMID: 37152733 PMCID: PMC10156983 DOI: 10.3389/fmicb.2023.1175854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/03/2023] [Indexed: 05/09/2023] Open
Abstract
Introduction The stimulation of plant and microbial growth has been widely observed as a result of elevated CO2 concentrations (eCO2), however, this stimulation could be influenced by various factors and their relative importance remains unclear. Methods A global meta-analysis was performed using 884 lines of observations collected from published papers, which analyzed the eCO2 impact on plant and microbial biomass. Results A significant positive impact of eCO2 was observed on various biomass measures, including aboveground biomass (20.5%), belowground biomass (42.6%), soil microbial biomass (10.4%), fungal biomass (11.0%), and bacterial biomass (9.2%). It was found that eCO2 levels above 200 ppm had a greater impact on plant biomass compared to concentrations at or below 200 ppm. On the other hand, studies showed that positive effects on microbial biomass were more prominent at lower eCO2 levels (≤200 ppm) than at higher levels (>200 ppm), which could be explained by soil nitrogen limitations. Importantly, our results indicated that aboveground biomass was controlled more by climatic and experimental conditions, while soil properties strongly impacted the stimulation of belowground and microbial biomass. Discussion Our results provided evidence of the eCO2 fertilization effect across various ecosystem types, experimental methods, and climates, and provided a quantitative estimate of plant and soil microbial biomass sensitivity to eCO2. The results obtained in this study suggest that ecosystem models should consider climatic and edaphic factors to more accurately predict the effects of global climate change and their impact on ecosystem functions.
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Arsić J, Stojanović M, Petrovičová L, Noyer E, Milanović S, Světlík J, Horáček P, Krejza J. Increased wood biomass growth is associated with lower wood density in Quercus petraea (Matt.) Liebl. saplings growing under elevated CO2. PLoS One 2021; 16:e0259054. [PMID: 34679119 PMCID: PMC8535391 DOI: 10.1371/journal.pone.0259054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 10/11/2021] [Indexed: 11/19/2022] Open
Abstract
Atmospheric carbon dioxide (CO2) has increased substantially since the industrial revolution began, and physiological responses to elevated atmospheric CO2 concentrations reportedly alter the biometry and wood structure of trees. Additionally, soil nutrient availability may play an important role in regulating these responses. Therefore, in this study, we grew 288 two-year-old saplings of sessile oak (Quercus petraea (Matt.) Liebl.) in lamellar glass domes for three years to evaluate the effects of CO2 concentrations and nutrient supply on above- and belowground biomass, wood density, and wood structure. Elevated CO2 increased above- and belowground biomass by 44.3% and 46.9%, respectively. However, under elevated CO2 treatment, sapling wood density was markedly lower (approximately 1.7%), and notably wider growth rings-and larger, more efficient conduits leading to increased hydraulic conductance-were observed. Moreover, despite the vessels being larger in saplings under elevated CO2, the vessels were significantly fewer (p = 0.023). No direct effects of nutrient supply were observed on biomass growth, wood density, or wood structure, except for a notable decrease in specific leaf area. These results suggest that, although fewer and larger conduits may render the xylem more vulnerable to embolism formation under drought conditions, the high growth rate in sessile oak saplings under elevated CO2 is supported by an efficient vascular system and may increase biomass production in this tree species. Nevertheless, the decreased mechanical strength, indicated by low density and xylem vulnerability to drought, may lead to earlier mortality, offsetting the positive effects of elevated CO2 levels in the future.
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Affiliation(s)
- Janko Arsić
- Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
- Department of Forest Ecology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic
| | - Marko Stojanović
- Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
| | - Lucia Petrovičová
- Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
- Department of Forest Ecology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic
| | - Estelle Noyer
- Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
| | - Slobodan Milanović
- Faculty of Forestry, University of Belgrade, Belgrade, Serbia
- Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic
| | - Jan Světlík
- Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
- Department of Forest Ecology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic
| | - Petr Horáček
- Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
- Department of Wood Science and Technology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic
| | - Jan Krejza
- Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
- Department of Forest Ecology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic
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8
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Plant productivity is a key driver of soil respiration response to climate change in a nutrient-limited soil. Basic Appl Ecol 2021. [DOI: 10.1016/j.baae.2020.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Interactive Effect of Elevated CO2 and Reduced Summer Precipitation on Photosynthesis is Species-Specific: The Case Study with Soil-Planted Norway Spruce and Sessile Oak in a Mountainous Forest Plot. FORESTS 2020. [DOI: 10.3390/f12010042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We investigated how reduced summer precipitation modifies photosynthetic responses of two model tree species—coniferous Norway spruce and broadleaved sessile oak—to changes in atmospheric CO2 concentration. Saplings were grown under mountainous conditions for two growing seasons at ambient (400 μmol CO2 mol–1) and elevated (700 μmol CO2 mol–1) CO2 concentration. Half were not exposed to precipitation during the summer (June–August). After two seasons of cultivation under modified conditions, basic photosynthetic characteristics including light-saturated rate of CO2 assimilation (Amax), stomatal conductance (GSmax), and water use efficiency (WUE) were measured under their growth CO2 concentrations together with in vivo carboxylation rate (VC) and electron transport rate (J) derived from CO2-response curves at saturating light. An increase in Amax under elevated CO2 was observed in oak saplings, whereas it remained unchanged or slightly declined in Norway spruce, indicating a down-regulation of photosynthesis. Such acclimation was associated with an acclimation of both J and VC. Both species had increased WUE under elevated CO2 although, in well-watered oaks, WUE remained unchanged. Significant interactive effects of tree species, CO2 concentration, and water availability on gas-exchange parameters (Amax, GSmax, WUE) were observed, while there was no effect on biochemical (VC, J) and chlorophyll fluorescence parameters. The assimilation capacity (Asat; CO2 assimilation rate at saturating light intensity and CO2 concentration) was substantially reduced in spruce under the combined conditions of water deficiency and elevated CO2, but not in oak. In addition, the stimulatory effect of elevated CO2 on Amax persisted in oak, but completely diminished in water-limited spruce saplings. Our results suggest a strong species-specific response of trees to reduced summer precipitation under future conditions of elevated CO2 and a limited compensatory effect of elevated CO2 on CO2 uptake under water-limited conditions in coniferous spruce.
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10
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Multiple constraints cause positive and negative feedbacks limiting grassland soil CO 2 efflux under CO 2 enrichment. Proc Natl Acad Sci U S A 2020; 118:2008284117. [PMID: 33419921 DOI: 10.1073/pnas.2008284117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Terrestrial ecosystems are increasingly enriched with resources such as atmospheric CO2 that limit ecosystem processes. The consequences for ecosystem carbon cycling depend on the feedbacks from other limiting resources and plant community change, which remain poorly understood for soil CO2 efflux, JCO2, a primary carbon flux from the biosphere to the atmosphere. We applied a unique CO2 enrichment gradient (250 to 500 µL L-1) for eight years to grassland plant communities on soils from different landscape positions. We identified the trajectory of JCO2 responses and feedbacks from other resources, plant diversity [effective species richness, exp(H)], and community change (plant species turnover). We found linear increases in JCO2 on an alluvial sandy loam and a lowland clay soil, and an asymptotic increase on an upland silty clay soil. Structural equation modeling identified CO2 as the dominant limitation on JCO2 on the clay soil. In contrast with theory predicting limitation from a single limiting factor, the linear JCO2 response on the sandy loam was reinforced by positive feedbacks from aboveground net primary productivity and exp(H), while the asymptotic JCO2 response on the silty clay arose from a net negative feedback among exp(H), species turnover, and soil water potential. These findings support a multiple resource limitation view of the effects of global change drivers on grassland ecosystem carbon cycling and highlight a crucial role for positive or negative feedbacks between limiting resources and plant community structure. Incorporating these feedbacks will improve models of terrestrial carbon sequestration and ecosystem services.
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11
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Irrigation Combined with Aeration Promoted Soil Respiration through Increasing Soil Microbes, Enzymes, and Crop Growth in Tomato Fields. Catalysts 2019. [DOI: 10.3390/catal9110945] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Soil respiration (Rs) is one of the major components controlling the carbon budget of terrestrial ecosystems. Aerated irrigation has been proven to increase Rs compared with the control, but the mechanisms of CO2 release remain poorly understood. The objective of this study was (1) to test the effects of irrigation, aeration, and their interaction on Rs, soil physical and biotic properties (soil water-filled pore space, temperature, bacteria, fungi, actinomycetes, microbial biomass carbon, cellulose activity, dehydrogenase activity, root morphology, and dry biomass of tomato), and (2) to assess how soil physical and biotic variables control Rs. Therefore, three irrigation levels were included (60%, 80%, and 100% of full irrigation). Each irrigation level contained aeration and control. A total of six treatments were included. The results showed that aeration significantly increased total root length, dry biomass of leaf, stem, and fruit compared with the control (p < 0.05). The positive effect of irrigation on dry biomass of leaf, fruit, and root was significant (p < 0.05). With respect to the control, greater Rs under aeration (averaging 6.2% increase) was mainly driven by soil water-filled pore space, soil bacteria, and soil fungi. The results of this study are helpful for understanding the mechanisms of soil CO2 release under aerated subsurface drip irrigation.
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Camenzind T, Scheu S, Rillig MC. Expanding the toolbox of nutrient limitation studies: A novel method of soil microbial in‐growth bags to evaluate nutrient demands in tropical forests. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13352] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tessa Camenzind
- Institute of Biology, Plant Ecology Freie Universität Berlin Berlin Germany
- Berlin‐Brandenburg Institute of Advanced Biodiversity Research (BBIB) Berlin Germany
| | - Stefan Scheu
- J.F. Blumenbach Institute of Zoology and Anthropology, Animal Ecology University of Göttingen Göttingen Germany
- Centre of Biodiversity and Sustainable Land Use University of Göttingen Göttingen Germany
| | - Matthias C. Rillig
- Institute of Biology, Plant Ecology Freie Universität Berlin Berlin Germany
- Berlin‐Brandenburg Institute of Advanced Biodiversity Research (BBIB) Berlin Germany
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13
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Arsovski AA, Zemke JE, Haagen BD, Kim SH, Nemhauser JL. Phytochrome B regulates resource allocation in Brassica rapa. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69. [PMID: 29514292 PMCID: PMC5961229 DOI: 10.1093/jxb/ery080] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Crop biomass and yield are tightly linked to how the light signaling network translates information about the environment into allocation of resources, including photosynthates. Once activated, the phytochrome (phy) class of photoreceptors signal and re-deploy carbon resources to alter growth, plant architecture, and reproductive timing. Most of the previous characterization of the light-modulated growth program has been performed in the reference plant Arabidopsis thaliana. Here, we use Brassica rapa as a crop model to test for conservation of the phytochrome-carbon network. In response to elevated levels of CO2, B. rapa seedlings showed increases in hypocotyl length, shoot and root fresh weight, and the number of lateral roots. All of these responses were dependent on nitrogen and polar auxin transport. In addition, we identified putative B. rapa orthologs of PhyB and isolated two nonsense alleles. BrphyB mutants had significantly decreased or absent CO2-stimulated growth responses. Mutant seedlings also showed misregulation of auxin-dependent genes and genes involved in chloroplast development. Adult mutant plants had reduced chlorophyll levels, photosynthetic rate, stomatal index, and seed yield. These findings support a recently proposed holistic role for phytochromes in regulating resource allocation, biomass production, and metabolic state in the developing plant.
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Affiliation(s)
| | - Joseph E Zemke
- Department of Biology, University of Washington, Seattle, WA, USA
| | | | - Soo-Hyung Kim
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, USA
| | - Jennifer L Nemhauser
- Department of Biology, University of Washington, Seattle, WA, USA
- Correspondence:
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14
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Terrer C, Vicca S, Stocker BD, Hungate BA, Phillips RP, Reich PB, Finzi AC, Prentice IC. Ecosystem responses to elevated CO 2 governed by plant-soil interactions and the cost of nitrogen acquisition. THE NEW PHYTOLOGIST 2018; 217:507-522. [PMID: 29105765 DOI: 10.1111/nph.14872] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 09/05/2017] [Indexed: 05/11/2023]
Abstract
Contents Summary 507 I. Introduction 507 II. The return on investment approach 508 III. CO2 response spectrum 510 IV. Discussion 516 Acknowledgements 518 References 518 SUMMARY: Land ecosystems sequester on average about a quarter of anthropogenic CO2 emissions. It has been proposed that nitrogen (N) availability will exert an increasingly limiting effect on plants' ability to store additional carbon (C) under rising CO2 , but these mechanisms are not well understood. Here, we review findings from elevated CO2 experiments using a plant economics framework, highlighting how ecosystem responses to elevated CO2 may depend on the costs and benefits of plant interactions with mycorrhizal fungi and symbiotic N-fixing microbes. We found that N-acquisition efficiency is positively correlated with leaf-level photosynthetic capacity and plant growth, and negatively with soil C storage. Plants that associate with ectomycorrhizal fungi and N-fixers may acquire N at a lower cost than plants associated with arbuscular mycorrhizal fungi. However, the additional growth in ectomycorrhizal plants is partly offset by decreases in soil C pools via priming. Collectively, our results indicate that predictive models aimed at quantifying C cycle feedbacks to global change may be improved by treating N as a resource that can be acquired by plants in exchange for energy, with different costs depending on plant interactions with microbial symbionts.
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Affiliation(s)
- César Terrer
- AXA Chair Programme in Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
| | - Sara Vicca
- Centre of Excellence PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, Wilrijk, 2610, Belgium
| | - Benjamin D Stocker
- AXA Chair Programme in Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
- CREAF, Cerdanyola del Vallès, Catalonia, 08193, Spain
| | - Bruce A Hungate
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, 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, NSW, 2751, Australia
| | - Adrien C Finzi
- Department of Biology, Boston University, Boston, MA, 02215, USA
| | - I Colin Prentice
- AXA Chair Programme in Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
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15
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Piñeiro J, Ochoa-Hueso R, Delgado-Baquerizo M, Dobrick S, Reich PB, Pendall E, Power SA. Effects of elevated CO 2 on fine root biomass are reduced by aridity but enhanced by soil nitrogen: A global assessment. Sci Rep 2017; 7:15355. [PMID: 29127358 PMCID: PMC5681551 DOI: 10.1038/s41598-017-15728-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 10/31/2017] [Indexed: 11/08/2022] Open
Abstract
Plant roots play a crucial role in regulating key ecosystem processes such as carbon (C) sequestration and nutrient solubilisation. Elevated (e)CO2 is expected to alter the biomass of fine, coarse and total roots to meet increased demand for other resources such as water and nitrogen (N), however, the magnitude and direction of observed changes vary considerably between ecosystems. Here, we assessed how climate and soil properties mediate root responses to eCO2 by comparing 24 field-based CO2 experiments across the globe including a wide range of ecosystem types. We calculated response ratios (i.e. effect size) and used structural equation modelling (SEM) to achieve a system-level understanding of how aridity, mean annual temperature and total soil nitrogen simultaneously drive the response of total, coarse and fine root biomass to eCO2. Models indicated that increasing aridity limits the positive response of fine and total root biomass to eCO2, and that fine (but not coarse or total) root responses to eCO2 are positively related to soil total N. Our results provide evidence that consideration of factors such as aridity and soil N status is crucial for predicting plant and ecosystem-scale responses to future changes in atmospheric CO2 concentrations, and thus feedbacks to climate change.
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Affiliation(s)
- Juan Piñeiro
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, New South Wales, 2751, Australia.
| | - Raúl Ochoa-Hueso
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, New South Wales, 2751, Australia
| | - Manuel Delgado-Baquerizo
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, New South Wales, 2751, Australia
| | - Silvan Dobrick
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, New South Wales, 2751, Australia
| | - Peter B Reich
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, New South Wales, 2751, Australia
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota, USA
| | - Elise Pendall
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, New South Wales, 2751, Australia
| | - Sally A Power
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, New South Wales, 2751, Australia
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16
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van Groenigen KJ, Osenberg CW, Terrer C, Carrillo Y, Dijkstra FA, Heath J, Nie M, Pendall E, Phillips RP, Hungate BA. Faster turnover of new soil carbon inputs under increased atmospheric CO 2. GLOBAL CHANGE BIOLOGY 2017; 23:4420-4429. [PMID: 28480591 DOI: 10.1111/gcb.13752] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 04/13/2017] [Accepted: 05/01/2017] [Indexed: 06/07/2023]
Abstract
Rising levels of atmospheric CO2 frequently stimulate plant inputs to soil, but the consequences of these changes for soil carbon (C) dynamics are poorly understood. Plant-derived inputs can accumulate in the soil and become part of the soil C pool ("new soil C"), or accelerate losses of pre-existing ("old") soil C. The dynamics of the new and old pools will likely differ and alter the long-term fate of soil C, but these separate pools, which can be distinguished through isotopic labeling, have not been considered in past syntheses. Using meta-analysis, we found that while elevated CO2 (ranging from 550 to 800 parts per million by volume) stimulates the accumulation of new soil C in the short term (<1 year), these effects do not persist in the longer term (1-4 years). Elevated CO2 does not affect the decomposition or the size of the old soil C pool over either temporal scale. Our results are inconsistent with predictions of conventional soil C models and suggest that elevated CO2 might increase turnover rates of new soil C. Because increased turnover rates of new soil C limit the potential for additional soil C sequestration, the capacity of land ecosystems to slow the rise in atmospheric CO2 concentrations may be smaller than previously assumed.
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Affiliation(s)
- Kees Jan van Groenigen
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | | | - César Terrer
- AXA Chair Programme in Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, Ascot, UK
| | - Yolima Carrillo
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Feike A Dijkstra
- Centre for Carbon, Water and Food, School of Life and Environmental Sciences, The University of Sydney, Eveleigh, NSW, Australia
| | - James Heath
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Ming Nie
- Ministry of Education Key Lab for Biodiversity Science and Ecological Engineering, The Institute of Biodiversity Science, Fudan University, Shanghai, China
| | - Elise Pendall
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | | | - Bruce A Hungate
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
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17
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Matyssek R, Kozovits AR, Wieser G, King J, Rennenberg H. Woody-plant ecosystems under climate change and air pollution-response consistencies across zonobiomes? TREE PHYSIOLOGY 2017; 37:706-732. [PMID: 28338970 DOI: 10.1093/treephys/tpx009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 01/22/2017] [Indexed: 06/06/2023]
Abstract
Forests store the largest terrestrial pools of carbon (C), helping to stabilize the global climate system, yet are threatened by climate change (CC) and associated air pollution (AP, highlighting ozone (O3) and nitrogen oxides (NOx)). We adopt the perspective that CC-AP drivers and physiological impacts are universal, resulting in consistent stress responses of forest ecosystems across zonobiomes. Evidence supporting this viewpoint is presented from the literature on ecosystem gross/net primary productivity and water cycling. Responses to CC-AP are compared across evergreen/deciduous foliage types, discussing implications of nutrition and resource turnover at tree and ecosystem scales. The availability of data is extremely uneven across zonobiomes, yet unifying patterns of ecosystem response are discernable. Ecosystem warming results in trade-offs between respiration and biomass production, affecting high elevation forests more than in the lowland tropics and low-elevation temperate zone. Resilience to drought is modulated by tree size and species richness. Elevated O3 tends to counteract stimulation by elevated carbon dioxide (CO2). Biotic stress and genomic structure ultimately determine ecosystem responsiveness. Aggrading early- rather than mature late-successional communities respond to CO2 enhancement, whereas O3 affects North American and Eurasian tree species consistently under free-air fumigation. Insect herbivory is exacerbated by CC-AP in biome-specific ways. Rhizosphere responses reflect similar stand-level nutritional dynamics across zonobiomes, but are modulated by differences in tree-soil nutrient cycling between deciduous and evergreen systems, and natural versus anthropogenic nitrogen (N) oversupply. The hypothesis of consistency of forest responses to interacting CC-AP is supported by currently available data, establishing the precedent for a global network of long-term coordinated research sites across zonobiomes to simultaneously advance both bottom-up (e.g., mechanistic) and top-down (systems-level) understanding. This global, synthetic approach is needed because high biological plasticity and physiographic variation across individual ecosystems currently limit development of predictive models of forest responses to CC-AP. Integrated research on C and nutrient cycling, O3-vegetation interactions and water relations must target mechanisms' ecosystem responsiveness. Worldwide case studies must be subject to biostatistical exploration to elucidate overarching response patterns and synthesize the resulting empirical data through advanced modelling, in order to provide regionally coherent, yet globally integrated information in support of internationally coordinated decision-making and policy development.
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Affiliation(s)
- R Matyssek
- Technische Universität München, TUM School of Life Sciences Weihenstephan, Chair of Ecophysiology of Plants, Hans-Carl-von-Carlowitz-Platz 2, D-85354 Freising, Germany
| | - A R Kozovits
- Universidade Federal de Ouro Preto, Department of Biodiversity, Evolution and Environment, Campus Morro do Cruzeiro, Bauxita, 35.400-000 Ouro Preto, MG, Brazil
| | - G Wieser
- Department of Alpine Timberline Ecophysiology, Federal Office and Research Centre for Forests, Innsbruck, Austria
| | - J King
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, USA
| | - H Rennenberg
- Chair of Tree Physiology, Institute of Forest Sciences, University of Freiburg, Georges-Koehler-Allee 53/54, D79110 Freiburg, Germany
- King Saud University, PO Box 2454, Riyadh 11451, Saudi Arabia
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18
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Decades-long effects of high CO2 concentration on soil nitrogen dynamics at a natural CO2 spring. Ecol Res 2017. [DOI: 10.1007/s11284-016-1432-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Mills G, Harmens H, Wagg S, Sharps K, Hayes F, Fowler D, Sutton M, Davies B. Ozone impacts on vegetation in a nitrogen enriched and changing climate. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 208:898-908. [PMID: 26412200 DOI: 10.1016/j.envpol.2015.09.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 09/14/2015] [Indexed: 05/10/2023]
Abstract
This paper provides a process-oriented perspective on the combined effects of ozone (O3), climate change and/or nitrogen (N) on vegetation. Whereas increasing CO2 in controlled environments or open-top chambers often ameliorates effects of O3 on leaf physiology, growth and C allocation, this is less likely in the field. Combined responses to elevated temperature and O3 have rarely been studied even though some critical growth stages such as seed initiation are sensitive to both. Under O3 exposure, many species have smaller roots, thereby enhancing drought sensitivity. Of the 68 species assessed for stomatal responses to ozone, 22.5% were unaffected, 33.5% had sluggish or increased opening and 44% stomatal closure. The beneficial effect of N on root development was lost at higher O3 treatments whilst the effects of increasing O3 on root biomass became more pronounced as N increased. Both responses to gradual changes in pollutants and climate and those under extreme weather events require further study.
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Affiliation(s)
- Gina Mills
- Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor LL57 2UW, UK.
| | - Harry Harmens
- Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor LL57 2UW, UK
| | - Serena Wagg
- School of Biological Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK
| | - Katrina Sharps
- Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor LL57 2UW, UK
| | - Felicity Hayes
- Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor LL57 2UW, UK
| | - David Fowler
- Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB, UK
| | - Mark Sutton
- Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB, UK
| | - Bill Davies
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
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20
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Griepentrog M, Eglinton TI, Hagedorn F, Schmidt MWI, Wiesenberg GLB. Interactive effects of elevated CO2 and nitrogen deposition on fatty acid molecular and isotope composition of above- and belowground tree biomass and forest soil fractions. GLOBAL CHANGE BIOLOGY 2015; 21:473-486. [PMID: 24953725 DOI: 10.1111/gcb.12666] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 05/27/2014] [Indexed: 06/03/2023]
Abstract
Atmospheric carbon dioxide (CO2) and reactive nitrogen (N) concentrations have been increasing due to human activities and impact the global carbon (C) cycle by affecting plant photosynthesis and decomposition processes in soil. Large amounts of C are stored in plants and soils, but the mechanisms behind the stabilization of plant- and microbial-derived organic matter (OM) in soils are still under debate and it is not clear how N deposition affects soil OM dynamics. Here, we studied the effects of 4 years of elevated (13C-depleted) CO2 and N deposition in forest ecosystems established in open-top chambers on composition and turnover of fatty acids (FAs) in plants and soils. FAs served as biomarkers for plant- and microbial-derived OM in soil density fractions. We analyzed above- and belowground plant biomass of beech and spruce trees as well as soil density fractions for the total organic C and FA molecular and isotope (δ13C) composition. FAs did not accumulate relative to total organic C in fine mineral fractions, showing that FAs are not effectively stabilized by association with soil minerals. The δ13C values of FAs in plant biomass increased under high N deposition. However, the N effect was only apparent under elevated CO2 suggesting a N limitation of the system. In soil fractions, only isotope compositions of short-chain FAs (C16+18) were affected. Fractions of 'new' (experimental-derived) FAs were calculated using isotope depletion in elevated CO2 plots and decreased from free light to fine mineral fractions. 'New' FAs were higher in short-chain compared to long-chain FAs (C20-30), indicating a faster turnover of short-chain compared to long-chain FAs. Increased N deposition did not significantly affect the quantity of 'new' FAs in soil fractions, but showed a tendency of increased amounts of 'old' (pre-experimental) C suggesting that decomposition of 'old' C is retarded by high N inputs.
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Affiliation(s)
- Marco Griepentrog
- Department of Geography, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
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21
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Franklin O, Näsholm T, Högberg P, Högberg MN. Forests trapped in nitrogen limitation--an ecological market perspective on ectomycorrhizal symbiosis. THE NEW PHYTOLOGIST 2014; 203:657-666. [PMID: 24824576 PMCID: PMC4199275 DOI: 10.1111/nph.12840] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 04/02/2014] [Indexed: 05/20/2023]
Abstract
Ectomycorrhizal symbiosis is omnipresent in boreal forests, where it is assumed to benefit plant growth. However, experiments show inconsistent benefits for plants and volatility of individual partnerships, which calls for a re-evaluation of the presumed role of this symbiosis. We reconcile these inconsistencies by developing a model that demonstrates how mycorrhizal networking and market mechanisms shape the strategies of individual plants and fungi to promote symbiotic stability at the ecosystem level. The model predicts that plants switch abruptly from a mixed strategy with both mycorrhizal and nonmycorrhizal roots to a purely mycorrhizal strategy as soil nitrogen availability declines, in agreement with the frequency distribution of ectomycorrhizal colonization intensity across a wide-ranging data set. In line with observations in field-scale isotope labeling experiments, the model explains why ectomycorrhizal symbiosis does not alleviate plant nitrogen limitation. Instead, market mechanisms may generate self-stabilization of the mycorrhizal strategy via nitrogen depletion feedback, even if plant growth is ultimately reduced. We suggest that this feedback mechanism maintains the strong nitrogen limitation ubiquitous in boreal forests. The mechanism may also have the capacity to eliminate or even reverse the expected positive effect of rising CO2 on tree growth in strongly nitrogen-limited boreal forests.
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Affiliation(s)
- Oskar Franklin
- IIASA- International Institute for Applied Systems AnalysisA-2361, Laxenburg, Austria
| | - Torgny Näsholm
- Department of Forest Ecology and Management, Swedish University of Agricultural SciencesSE-901 83, Umeå, Sweden
| | - Peter Högberg
- Department of Forest Ecology and Management, Swedish University of Agricultural SciencesSE-901 83, Umeå, Sweden
| | - Mona N Högberg
- Department of Forest Ecology and Management, Swedish University of Agricultural SciencesSE-901 83, Umeå, Sweden
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22
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Qiao N, Schaefer D, Blagodatskaya E, Zou X, Xu X, Kuzyakov Y. Labile carbon retention compensates for CO2 released by priming in forest soils. GLOBAL CHANGE BIOLOGY 2014; 20:1943-1954. [PMID: 24293210 DOI: 10.1111/gcb.12458] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 10/17/2013] [Indexed: 06/02/2023]
Abstract
Increase of belowground C allocation by plants under global warming or elevated CO2 may promote decomposition of soil organic carbon (SOC) by priming and strongly affects SOC dynamics. The specific effects by priming of SOC depend on the amount and frequency of C inputs. Most previous priming studies have investigated single C additions, but they are not very representative for litterfall and root exudation in many terrestrial ecosystems. We evaluated effects of (13)C-labeled glucose added to soil in three temporal patterns: single, repeated, and continuous on dynamics of CO2 and priming of SOC decomposition over 6 months. Total and (13)C labeled CO2 were monitored to analyze priming dynamics and net C balance between SOC loss caused by priming and the retention of added glucose-C. Cumulative priming ranged from 1.3 to 5.5 mg C g(-1) SOC in the subtropical, and from -0.6 to 5.5 mg C g(-1) SOC in the tropical soils. Single addition induced more priming than repeated and continuous inputs. Therefore, single additions of high substrate amounts may overestimate priming effects over the short term. The amount of added glucose C remaining in soil after 6 months (subtropical: 8.1-11.2 mg C g(-1) SOC or 41-56% of added glucose; tropical: 8.7-15.0 mg C g(-1) SOC or 43-75% of glucose) was substantially higher than the net C loss due to SOC decomposition including priming effect. This overcompensation of C losses was highest with continuous inputs and lowest with single inputs. Therefore, raised labile organic C input to soils by higher plant productivity will increase SOC content even though priming accelerates decomposition of native SOC. Consequently, higher continuous input of C belowground by plants under warming or elevated CO2 can increase C stocks in soil despite accelerated C cycling by priming in soils.
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Affiliation(s)
- Na Qiao
- Key Laboratory of Tropical Forest Ecology, Chinese Academy of Sciences, Xishuangbanna Tropical Botanical Garden, Menglun, Mengla, Yunnan, 666303, China; Graduate School of the Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China
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23
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He Z, Xiong J, Kent AD, Deng Y, Xue K, Wang G, Wu L, Van Nostrand JD, Zhou J. Distinct responses of soil microbial communities to elevated CO2 and O3 in a soybean agro-ecosystem. THE ISME JOURNAL 2014; 8:714-726. [PMID: 24108327 PMCID: PMC3930317 DOI: 10.1038/ismej.2013.177] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 08/01/2013] [Accepted: 09/06/2013] [Indexed: 11/08/2022]
Abstract
The concentrations of atmospheric carbon dioxide (CO2) and tropospheric ozone (O3) have been rising due to human activities. However, little is known about how such increases influence soil microbial communities. We hypothesized that elevated CO2 (eCO2) and elevated O3 (eO3) would significantly affect the functional composition, structure and metabolic potential of soil microbial communities, and that various functional groups would respond to such atmospheric changes differentially. To test these hypotheses, we analyzed 96 soil samples from a soybean free-air CO2 enrichment (SoyFACE) experimental site using a comprehensive functional gene microarray (GeoChip 3.0). The results showed the overall functional composition and structure of soil microbial communities shifted under eCO2, eO3 or eCO2+eO3. Key functional genes involved in carbon fixation and degradation, nitrogen fixation, denitrification and methane metabolism were stimulated under eCO2, whereas those involved in N fixation, denitrification and N mineralization were suppressed under eO3, resulting in the fact that the abundance of some eO3-supressed genes was promoted to ambient, or eCO2-induced levels by the interaction of eCO2+eO3. Such effects appeared distinct for each treatment and significantly correlated with soil properties and soybean yield. Overall, our analysis suggests possible mechanisms of microbial responses to global atmospheric change factors through the stimulation of C and N cycling by eCO2, the inhibition of N functional processes by eO3 and the interaction by eCO2 and eO3. This study provides new insights into our understanding of microbial functional processes in response to global atmospheric change in soybean agro-ecosystems.
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Affiliation(s)
- Zhili He
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, the University of Oklahoma, Norman, OK, USA.
| | - Jinbo Xiong
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, the University of Oklahoma, Norman, OK, USA
- Faculty of Marine Sciences, Ningbo University, Ningbo, China
| | - Angela D Kent
- Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Ye Deng
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, the University of Oklahoma, Norman, OK, USA
| | - Kai Xue
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, the University of Oklahoma, Norman, OK, USA
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Liyou Wu
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, the University of Oklahoma, Norman, OK, USA
| | - Joy D Van Nostrand
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, the University of Oklahoma, Norman, OK, USA
| | - Jizhong Zhou
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, the University of Oklahoma, Norman, OK, USA.
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China.
- Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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24
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Cheng W, Parton WJ, Gonzalez-Meler MA, Phillips R, Asao S, McNickle GG, Brzostek E, Jastrow JD. Synthesis and modeling perspectives of rhizosphere priming. THE NEW PHYTOLOGIST 2014; 201:31-44. [PMID: 23952258 DOI: 10.1111/nph.12440] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 07/08/2013] [Indexed: 05/20/2023]
Abstract
The rhizosphere priming effect (RPE) is a mechanism by which plants interact with soil functions. The large impact of the RPE on soil organic matter decomposition rates (from 50% reduction to 380% increase) warrants similar attention to that being paid to climatic controls on ecosystem functions. Furthermore, global increases in atmospheric CO2 concentration and surface temperature can significantly alter the RPE. Our analysis using a game theoretic model suggests that the RPE may have resulted from an evolutionarily stable mutualistic association between plants and rhizosphere microbes. Through model simulations based on microbial physiology, we demonstrate that a shift in microbial metabolic response to different substrate inputs from plants is a plausible mechanism leading to positive or negative RPEs. In a case study of the Duke Free-Air CO2 Enrichment experiment, performance of the PhotoCent model was significantly improved by including an RPE-induced 40% increase in soil organic matter decomposition rate for the elevated CO2 treatment--demonstrating the value of incorporating the RPE into future ecosystem models. Overall, the RPE is emerging as a crucial mechanism in terrestrial ecosystems, which awaits substantial research and model development.
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Affiliation(s)
- Weixin Cheng
- Environmental Studies Department, University of California, Santa Cruz, CA, 95064, USA
- State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016, China
| | - William J Parton
- Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, 80523, USA
| | - Miquel A Gonzalez-Meler
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Richard Phillips
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Shinichi Asao
- Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, 80523, USA
| | - Gordon G McNickle
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Edward Brzostek
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Julie D Jastrow
- Biosciences Division, Argonne National Laboratory, Argonne, IL, 60439, USA
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25
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Sigurdsson BD, Medhurst JL, Wallin G, Eggertsson O, Linder S. Growth of mature boreal Norway spruce was not affected by elevated [CO(2)] and/or air temperature unless nutrient availability was improved. TREE PHYSIOLOGY 2013; 33:1192-1205. [PMID: 23878169 DOI: 10.1093/treephys/tpt043] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The growth responses of mature Norway spruce (Picea abies (L.) Karst.) trees exposed to elevated [CO(2)] (CE; 670-700 ppm) and long-term optimized nutrient availability or elevated air temperature (TE; ±3.9 °C) were studied in situ in northern Sweden in two 3 year field experiments using 12 whole-tree chambers in ca. 40-year-old forest. The first experiment (Exp. I) studied the interactions between CE and nutrient availability and the second (Exp. II) between CE and TE. It should be noted that only air temperature was elevated in Exp. II, while soil temperature was maintained close to ambient. In Exp. I, CE significantly increased the mean annual height increment, stem volume and biomass increment during the treatment period (25, 28, and 22%, respectively) when nutrients were supplied. There was, however, no significant positive CE effect found at the low natural nutrient availability. In Exp. II, which was conducted at the natural site fertility, neither CE nor TE significantly affected height or stem increment. It is concluded that the low nutrient availability (mainly nitrogen) in the boreal forests is likely to restrict their response to the continuous rise in [CO(2)] and/or TE.
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Hungate BA, Dijkstra P, Wu Z, Duval BD, Day FP, Johnson DW, Megonigal JP, Brown ALP, Garland JL. Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO₂ exposure in a subtropical oak woodland. THE NEW PHYTOLOGIST 2013; 200:753-766. [PMID: 23718224 PMCID: PMC4282374 DOI: 10.1111/nph.12333] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 04/10/2013] [Indexed: 05/05/2023]
Abstract
Rising atmospheric carbon dioxide (CO₂) could alter the carbon (C) and nitrogen (N) content of ecosystems, yet the magnitude of these effects are not well known. We examined C and N budgets of a subtropical woodland after 11 yr of exposure to elevated CO₂. We used open-top chambers to manipulate CO₂ during regrowth after fire, and measured C, N and tracer (15) N in ecosystem components throughout the experiment. Elevated CO₂ increased plant C and tended to increase plant N but did not significantly increase whole-system C or N. Elevated CO₂ increased soil microbial activity and labile soil C, but more slowly cycling soil C pools tended to decline. Recovery of a long-term (15) N tracer indicated that CO₂ exposure increased N losses and altered N distribution, with no effect on N inputs. Increased plant C accrual was accompanied by higher soil microbial activity and increased C losses from soil, yielding no statistically detectable effect of elevated CO₂ on net ecosystem C uptake. These findings challenge the treatment of terrestrial ecosystems responses to elevated CO₂ in current biogeochemical models, where the effect of elevated CO₂ on ecosystem C balance is described as enhanced photosynthesis and plant growth with decomposition as a first-order response.
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Affiliation(s)
- Bruce A Hungate
- Department of Biological Sciences and The Center for Ecosystem Science and Society, Northern Arizona UniversityFlagstaff, AZ, 86011, USA
| | - Paul Dijkstra
- Department of Biological Sciences and The Center for Ecosystem Science and Society, Northern Arizona UniversityFlagstaff, AZ, 86011, USA
| | - Zhuoting Wu
- Department of Biological Sciences and The Center for Ecosystem Science and Society, Northern Arizona UniversityFlagstaff, AZ, 86011, USA
- US Geological SurveyFlagstaff, AZ, 86001, USA
| | - Benjamin D Duval
- Department of Biological Sciences and The Center for Ecosystem Science and Society, Northern Arizona UniversityFlagstaff, AZ, 86011, USA
- US Dairy Forage Research Center, USDA-ARSMadison, WI, 53706, USA
| | - Frank P Day
- Department of Biological Sciences, Old Dominion UniversityNorfolk, VA, 23529, USA
| | - Dale W Johnson
- Department of Natural Resources and Environmental Science, University of NevadaReno, NV, 89557, USA
| | | | - Alisha L P Brown
- Department of Biological Sciences, Old Dominion UniversityNorfolk, VA, 23529, USA
| | - Jay L Garland
- Environmental Protection Agency, Microbiological and Chemical Exposure Assessment Research DivisionCincinnati, OH, 45268, USA
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Long SP. Virtual Special Issue (VSI) on mechanisms of plant response to global atmospheric change. PLANT, CELL & ENVIRONMENT 2012; 35:1705-6. [PMID: 22946457 DOI: 10.1111/j.1365-3040.2012.02589.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
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Dieleman WIJ, Vicca S, Dijkstra FA, Hagedorn F, Hovenden MJ, Larsen KS, Morgan JA, Volder A, Beier C, Dukes JS, King J, Leuzinger S, Linder S, Luo Y, Oren R, De Angelis P, Tingey D, Hoosbeek MR, Janssens IA. Simple additive effects are rare: a quantitative review of plant biomass and soil process responses to combined manipulations of CO2 and temperature. GLOBAL CHANGE BIOLOGY 2012; 18:2681-93. [PMID: 24501048 DOI: 10.1111/j.1365-2486.2012.02745.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 03/25/2012] [Indexed: 05/08/2023]
Abstract
In recent years, increased awareness of the potential interactions between rising atmospheric CO2 concentrations ([ CO2 ]) and temperature has illustrated the importance of multifactorial ecosystem manipulation experiments for validating Earth System models. To address the urgent need for increased understanding of responses in multifactorial experiments, this article synthesizes how ecosystem productivity and soil processes respond to combined warming and [ CO2 ] manipulation, and compares it with those obtained in single factor [ CO2 ] and temperature manipulation experiments. Across all combined elevated [ CO2 ] and warming experiments, biomass production and soil respiration were typically enhanced. Responses to the combined treatment were more similar to those in the [ CO2 ]-only treatment than to those in the warming-only treatment. In contrast to warming-only experiments, both the combined and the [ CO2 ]-only treatments elicited larger stimulation of fine root biomass than of aboveground biomass, consistently stimulated soil respiration, and decreased foliar nitrogen (N) concentration. Nonetheless, mineral N availability declined less in the combined treatment than in the [ CO2 ]-only treatment, possibly due to the warming-induced acceleration of decomposition, implying that progressive nitrogen limitation (PNL) may not occur as commonly as anticipated from single factor [ CO2 ] treatment studies. Responses of total plant biomass, especially of aboveground biomass, revealed antagonistic interactions between elevated [ CO2 ] and warming, i.e. the response to the combined treatment was usually less-than-additive. This implies that productivity projections might be overestimated when models are parameterized based on single factor responses. Our results highlight the need for more (and especially more long-term) multifactor manipulation experiments. Because single factor CO2 responses often dominated over warming responses in the combined treatments, our results also suggest that projected responses to future global warming in Earth System models should not be parameterized using single factor warming experiments.
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Affiliation(s)
- Wouter I J Dieleman
- Research Group of Plant and Vegetation Ecology, Department of Biology, University of Antwerp, Wilrijk, B-2610, Belgium; School of Earth and Environmental Sciences, Faculty of Science and Engineering, James Cook University, Smithfield, 4878, QLD, Australia
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Epron D, Bahn M, Derrien D, Lattanzi FA, Pumpanen J, Gessler A, Högberg P, Maillard P, Dannoura M, Gérant D, Buchmann N. Pulse-labelling trees to study carbon allocation dynamics: a review of methods, current knowledge and future prospects. TREE PHYSIOLOGY 2012; 32:776-98. [PMID: 22700544 DOI: 10.1093/treephys/tps057] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Pulse-labelling of trees with stable or radioactive carbon (C) isotopes offers the unique opportunity to trace the fate of labelled CO(2) into the tree and its release to the soil and the atmosphere. Thus, pulse-labelling enables the quantification of C partitioning in forests and the assessment of the role of partitioning in tree growth, resource acquisition and C sequestration. However, this is associated with challenges as regards the choice of a tracer, the methods of tracing labelled C in tree and soil compartments and the quantitative analysis of C dynamics. Based on data from 47 studies, the rate of transfer differs between broadleaved and coniferous species and decreases as temperature and soil water content decrease. Labelled C is rapidly transferred belowground-within a few days or less-and this transfer is slowed down by drought. Half-lives of labelled C in phloem sap (transfer pool) and in mature leaves (source organs) are short, while those of sink organs (growing tissues, seasonal storage) are longer. (13)C measurements in respiratory efflux at high temporal resolution provide the best estimate of the mean residence times of C in respiratory substrate pools, and the best basis for compartmental modelling. Seasonal C dynamics and allocation patterns indicate that sink strength variations are important drivers for C fluxes. We propose a conceptual model for temperate and boreal trees, which considers the use of recently assimilated C versus stored C. We recommend best practices for designing and analysing pulse-labelling experiments, and identify several topics which we consider of prime importance for future research on C allocation in trees: (i) whole-tree C source-sink relations, (ii) C allocation to secondary metabolism, (iii) responses to environmental change, (iv) effects of seasonality versus phenology in and across biomes, and (v) carbon-nitrogen interactions. Substantial progress is expected from emerging technologies, but the largest challenge remains to carry out in situ whole-tree labelling experiments on mature trees to improve our understanding of the environmental and physiological controls on C allocation.
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Affiliation(s)
- Daniel Epron
- Université de Lorraine, UMR 1137, Ecologie et Ecophysiologie Forestières, Faculté des Sciences, F-54500 Vandoeuvre-les-Nancy, France.
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Norby RJ, Zak DR. Ecological Lessons from Free-Air CO2 Enrichment (FACE) Experiments. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2011. [DOI: 10.1146/annurev-ecolsys-102209-144647] [Citation(s) in RCA: 482] [Impact Index Per Article: 37.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Richard J. Norby
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831;
| | - Donald R. Zak
- School of Natural Resources and Environment, Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan 48109
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Cheng L, Booker FL, Burkey KO, Tu C, Shew HD, Rufty TW, Fiscus EL, Deforest JL, Hu S. Soil microbial responses to elevated CO₂ and O₃ in a nitrogen-aggrading agroecosystem. PLoS One 2011; 6:e21377. [PMID: 21731722 PMCID: PMC3120872 DOI: 10.1371/journal.pone.0021377] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 05/26/2011] [Indexed: 11/19/2022] Open
Abstract
Climate change factors such as elevated atmospheric carbon dioxide (CO₂) and ozone (O₃) can exert significant impacts on soil microbes and the ecosystem level processes they mediate. However, the underlying mechanisms by which soil microbes respond to these environmental changes remain poorly understood. The prevailing hypothesis, which states that CO₂- or O₃-induced changes in carbon (C) availability dominate microbial responses, is primarily based on results from nitrogen (N)-limiting forests and grasslands. It remains largely unexplored how soil microbes respond to elevated CO₂ and O₃ in N-rich or N-aggrading systems, which severely hinders our ability to predict the long-term soil C dynamics in agroecosystems. Using a long-term field study conducted in a no-till wheat-soybean rotation system with open-top chambers, we showed that elevated CO₂ but not O₃ had a potent influence on soil microbes. Elevated CO₂(1.5×ambient) significantly increased, while O₃ (1.4×ambient) reduced, aboveground (and presumably belowground) plant residue C and N inputs to soil. However, only elevated CO₂ significantly affected soil microbial biomass, activities (namely heterotrophic respiration) and community composition. The enhancement of microbial biomass and activities by elevated CO₂ largely occurred in the third and fourth years of the experiment and coincided with increased soil N availability, likely due to CO₂-stimulation of symbiotic N₂ fixation in soybean. Fungal biomass and the fungi∶bacteria ratio decreased under both ambient and elevated CO₂ by the third year and also coincided with increased soil N availability; but they were significantly higher under elevated than ambient CO₂. These results suggest that more attention should be directed towards assessing the impact of N availability on microbial activities and decomposition in projections of soil organic C balance in N-rich systems under future CO₂ scenarios.
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Affiliation(s)
- Lei Cheng
- Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Fitzgerald L. Booker
- Plant Science Research Unit, United States Department of Agriculture, Agricultural Research Service, Raleigh, North Carolina, United States of America
- Department of Crop Science, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Kent O. Burkey
- Plant Science Research Unit, United States Department of Agriculture, Agricultural Research Service, Raleigh, North Carolina, United States of America
- Department of Crop Science, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Cong Tu
- Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America
| | - H. David Shew
- Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Thomas W. Rufty
- Department of Crop Science, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Edwin L. Fiscus
- Plant Science Research Unit, United States Department of Agriculture, Agricultural Research Service, Raleigh, North Carolina, United States of America
- Department of Crop Science, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Jared L. Deforest
- Department of Environmental and Plant Biology, Ohio University, Athens, Ohio, United States of America
| | - Shuijin Hu
- Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America
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Dieleman WIJ, Janssens IA. Can publication bias affect ecological research? A case study on soil respiration under elevated CO2. THE NEW PHYTOLOGIST 2011; 190:517-21. [PMID: 20874809 DOI: 10.1111/j.1469-8137.2010.03499.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
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