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Zhang H, Zhou Y, Hao Y, Yang Y, Lü Y, Lü XT, Yang Y, Pan Q, Han X, Wen L, Liu W. Interannual fluctuations in precipitation shape the trajectory of ecosystem respiration along a grazing exclusion chronosequence in a typical steppe in Inner Mongolia. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 366:121775. [PMID: 38991343 DOI: 10.1016/j.jenvman.2024.121775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 06/20/2024] [Accepted: 07/05/2024] [Indexed: 07/13/2024]
Abstract
Grazing exclusion (GE), as an effective strategy for revitalizing degraded grasslands, possesses the potential to increase ecosystem respiration (Re) and significantly influence the capacity of grassland soils to sequester carbon. However, our current grasp of Re dynamics in response to varying durations of GE, particularly in the context of precipitation fluctuations, remains incomplete. To fill this knowledge gap, we conducted a monitoring of Re over a 40-year GE chronosequence within Inner Mongolia temperate typical steppe across two distinct hydrologically years. Overall, Re exhibited a gradual saturation curve and an increasing trend with the duration of GE in the wet year of 2021 and the normal precipitation year of 2022, respectively. The variance primarily stemmed from relatively higher microbial biomass carbon observed in the short-term GE during 2022 in contrast to 2021. Moreover, the impacts of GE on the sensitivities of Re to moisture and temperature were intricately tied to precipitation patterns. increasing significantly with prolonged GE duration in 2022 but not in 2021. Our study highlights the intricate interplay between GE duration, precipitation variability, and Re dynamics. This deeper understanding enhances our ability to predict and manage carbon cycling within typical steppe in Inner Mongolia, offering invaluable insights for effective restoration strategies and climate change mitigation.
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Affiliation(s)
- Hao Zhang
- Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolia Plateau, Collaborative Innovation Center for Grassland Ecological Security, College of Ecology and Environment, Inner Mongolia University, Hohhot, China; State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Yong Zhou
- Department of Wildland Resources, Utah State University, Logan, UT, USA; Ecology Center, Utah State University, Logan, UT, USA
| | - Yiqing Hao
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yang Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yaxiang Lü
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China; University of Chinese Academy of Sciences, Beijing, China
| | - Xiao-Tao Lü
- Erguna Forest-Steppe Ecotone Research Station, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Yong Yang
- Inner Mongolia Key Laboratory of Remote Sensing of Grassland and Emergency Response Technic, Hohhot, China
| | - Qingmin Pan
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China; University of Chinese Academy of Sciences, Beijing, China
| | - Xingguo Han
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China; University of Chinese Academy of Sciences, Beijing, China
| | - Lu Wen
- Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolia Plateau, Collaborative Innovation Center for Grassland Ecological Security, College of Ecology and Environment, Inner Mongolia University, Hohhot, China.
| | - Wei Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China; Department of Wildland Resources, Utah State University, Logan, UT, USA.
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Legesse TG, Dong G, Dong X, Qu L, Chen B, Daba NA, Sorecha EM, Zhu W, Lei T, Shao C. The extreme wet and large precipitation size increase carbon uptake in Eurasian meadow steppes: Evidence from natural and manipulated precipitation experiments. ENVIRONMENTAL RESEARCH 2023; 237:117029. [PMID: 37659645 DOI: 10.1016/j.envres.2023.117029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/04/2023]
Abstract
The distribution of seasonal precipitation would profoundly affect the dynamics of carbon fluxes in terrestrial ecosystems. However, little is known about the impacts of extreme precipitation and size events on ecosystem carbon cycle when compared to the effects of average precipitation amount. The study involved an analysis of carbon fluxes and water exchange using the eddy covariance and chamber based techniques during the growing seasons of 2015-2017 in Bayan, Mongolia and 2019-2021 in Hulunbuir, Inner Mongolia, respectively. The components of carbon fluxes and water exchange at each site were normalized to evaluate of relative response among carbon fluxes and water exchange. The investigation delved into the relationship between carbon fluxes and extreme precipitation over five gradients (control, dry spring, dry summer, wet spring and wet summer) in Hulunbuir meadow steppe and distinct four precipitation sizes (0.1-2, 2-5, 5-10, and 10-25 mm d-1) in Bayan meadow steppe. The wet spring and summer showed the greatest ecosystem respiration (ER) relative response values, 76.2% and 73.5%, respectively, while the dry spring (-16.7%) and dry summer (14.2%) showed the lowest values. Gross primary production (GPP) relative response improved with wet precipitation gradients, and declined with dry precipitation gradients in Hulunbuir meadow steppe. The least value in net ecosystem CO2 exchange (NEE) was found at 10-25 mm d-1 precipitation size in Bayan meadow steppe. Similarly, the ER and GPP increased with size of precipitation events. The structural equation models (SEM) satisfactorily fitted the data (χ2 = 43.03, d.f. = 11, p = 0.215), with interactive linkages among soil microclimate, water exchange and carbon fluxes components regulating NEE. Overall, this study highlighted the importance of extreme precipitation and event size in influencing ecosystem carbon exchange, which is decisive to further understand the carbon cycle in meadow steppes.
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Affiliation(s)
- Tsegaye Gemechu Legesse
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Gang Dong
- School of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Xiaobing Dong
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems (SKLHIGA), College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Luping Qu
- Forest Ecology Stable Isotope Center, Forestry College, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Baorui Chen
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Nano Alemu Daba
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Eba Muluneh Sorecha
- State Engineering Laboratory of Efficient Water Use of Crops and Disaster Loss Mitigation/Key Laboratory of Dryland Agriculture, Ministry of Agriculture and Rural Affairs of China, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Wen Zhu
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Tinajie Lei
- State Engineering Laboratory of Efficient Water Use of Crops and Disaster Loss Mitigation/Key Laboratory of Dryland Agriculture, Ministry of Agriculture and Rural Affairs of China, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China.
| | - Changliang Shao
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
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3
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Xiao S, Wang C, Yu K, Liu G, Wu S, Wang J, Niu S, Zou J, Liu S. Enhanced CO 2 uptake is marginally offset by altered fluxes of non-CO 2 greenhouse gases in global forests and grasslands under N deposition. GLOBAL CHANGE BIOLOGY 2023; 29:5829-5849. [PMID: 37485988 DOI: 10.1111/gcb.16869] [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: 05/04/2023] [Accepted: 06/01/2023] [Indexed: 07/25/2023]
Abstract
Despite the increasing impact of atmospheric nitrogen (N) deposition on terrestrial greenhouse gas (GHG) budget, through driving both the net atmospheric CO2 exchange and the emission or uptake of non-CO2 GHGs (CH4 and N2 O), few studies have assessed the climatic impact of forests and grasslands under N deposition globally based on different bottom-up approaches. Here, we quantify the effects of N deposition on biomass C increment, soil organic C (SOC), CH4 and N2 O fluxes and, ultimately, the net ecosystem GHG balance of forests and grasslands using a global comprehensive dataset. We showed that N addition significantly increased plant C uptake (net primary production) in forests and grasslands, to a larger extent for the aboveground C (aboveground net primary production), whereas it only caused a small or insignificant enhancement of SOC pool in both upland systems. Nitrogen addition had no significant effect on soil heterotrophic respiration (RH ) in both forests and grasslands, while a significant N-induced increase in soil CO2 fluxes (RS , soil respiration) was observed in grasslands. Nitrogen addition significantly stimulated soil N2 O fluxes in forests (76%), to a larger extent in grasslands (87%), but showed a consistent trend to decrease soil uptake of CH4 , suggesting a declined sink capacity of forests and grasslands for atmospheric CH4 under N enrichment. Overall, the net GHG balance estimated by the net ecosystem production-based method (forest, 1.28 Pg CO2 -eq year-1 vs. grassland, 0.58 Pg CO2 -eq year-1 ) was greater than those estimated using the SOC-based method (forest, 0.32 Pg CO2 -eq year-1 vs. grassland, 0.18 Pg CO2 -eq year-1 ) caused by N addition. Our findings revealed that the enhanced soil C sequestration by N addition in global forests and grasslands could be only marginally offset (1.5%-4.8%) by the combined effects of its stimulation of N2 O emissions together with the reduced soil uptake of CH4 .
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Affiliation(s)
- Shuqi Xiao
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, Nanjing, China
| | - Chao Wang
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, Nanjing, China
| | - Kai Yu
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, Nanjing, China
| | - Genyuan Liu
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, Nanjing, China
| | - Shuang Wu
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, Nanjing, China
- Key Laboratory of Low-carbon and Green Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Jinyang Wang
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, Nanjing, China
- Key Laboratory of Low-carbon and Green Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Shuli Niu
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Jianwen Zou
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, Nanjing, China
- Key Laboratory of Low-carbon and Green Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
- Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Shuwei Liu
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, Nanjing, China
- Key Laboratory of Low-carbon and Green Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
- Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
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4
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Zhan T, Zhao H, Zhang J, Cheng C, Zhang Z. Differential effects of grazing intensity on carbon sequestration in arid versus humid grasslands across China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 881:163221. [PMID: 37019229 DOI: 10.1016/j.scitotenv.2023.163221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/23/2023] [Accepted: 03/28/2023] [Indexed: 06/01/2023]
Abstract
Livestock grazing, as a primary utilization practice for grasslands, plays a crucial role in carbon cycling process and its budget. Whether the impacts of different grazing intensities on carbon sequestration vary with precipitation over a broad geographic scales across China's grasslands remains unclear. In the context of striving for carbon neutrality, we carried out a meta-analysis based on 156 peer-reviewed journal articles to synthesize the general impacts of different grazing intensities on carbon sequestration with different precipitations. Our results showed that light, moderate, and heavy grazing dramatically reduced the soil organic carbon stocks by 3.43 %, 13.68 %, and 16.77 % in arid grasslands, respectively (P < 0.05), while light and moderate grazing did not alter soil organic carbon stocks in humid grasslands (P > 0.05). Moreover, the change rates of soil organic carbon stocks were all tightly positively associated with those of soil water content under different grazing intensities (P < 0.05). Further analysis revealed strong positive relationships between mean annual precipitation with the change rates of above- and belowground biomasses, soil microbial biomass carbon, and soil organic carbon stocks under moderate grazing intensity (P < 0.05). These findings imply that carbon sequestration is relatively less tolerant to grazing disturbance in arid grasslands than humid grasslands, which may be primary due to the grazing-intensified water limitation for plant growth and soil microbial activities under low precipitation. Our study is of implication to predict carbon budget of China's grasslands and help adopt sustainable management to strive for carbon neutrality.
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Affiliation(s)
- Tianyu Zhan
- Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao 266109, Shandong, China; State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Haotian Zhao
- Sichuan Engineering Technology Research Center of Geohazard Prevention, Chengdu 610081, China
| | - Jiaxi Zhang
- College of Tourism and Geographical Science, Leshan Normal University, Leshan 61400, China
| | - Chunyan Cheng
- College of Geography and Remote sensing Sciences, Xinjiang University, Urumqi 830046, China
| | - Zhenchao Zhang
- Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao 266109, Shandong, China.
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Zhang Z, Hua T, Zhao Y, Li Y, Wang Y, Wang F, Sun J, Sun J. Divergent effects of moderate grazing duration on carbon sequestration between temperate and alpine grasslands in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159621. [PMID: 36280069 DOI: 10.1016/j.scitotenv.2022.159621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/10/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
Moderate grazing has been widely proven to improve ecosystem functioning and have profound effects on the carbon cycling and storage in grassland ecosystems, which highly depend on grazing duration and grassland type. However, the effects of moderate grazing durations on carbon sequestration with different grassland types over broad geographic scales across China remain underexplored in the context of striving for carbon neutrality. Here, we explored the probably different responses of carbon sequestration to moderate grazing duration for temperate and alpine grasslands based on 129 published literatures regarding the China's grasslands. The results showed the soil organic carbon stocks were significantly increased during short-term (<5 years) grazing duration, while significantly decreased during medium- (5-10 years) and long-term (≥ 10 years) grazing durations in temperate grasslands. However, the soil organic carbon stocks were significantly decreased during short-term grazing duration, while showed no significant changes during medium- and long-term grazing durations in alpine grasslands. The changes in soil organic stock were significantly positively correlated with the changes in belowground biomass, root:shoot, and microbial biomass carbon (P < 0.05). These findings suggest that the temperate grasslands change from carbon sink to carbon source with moderate grazing duration increasing, while the alpine grasslands present an opposite change pattern from carbon source to carbon sink, regulated by grazing-altered carbon input and microbial activities. Our study might have significant implications for future sustainable management practices for carbon sequestration of China's grasslands.
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Affiliation(s)
- Zhenchao Zhang
- Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao 266109, Shandong, China
| | - Ting Hua
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Yanhua Zhao
- Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao 266109, Shandong, China
| | - Yanpeng Li
- School of Mapping and Geographic Information, Jiangxi College of Applied Technology, Ganzhou 341000, China
| | - Yi Wang
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Fei Wang
- Institute of Agricultural Information and Economics, Shandong Academy of Agricultural Sciences, No.23788, Industrial North Road, Jinan 250010, Shandong, China
| | - Juan Sun
- Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao 266109, Shandong, China.
| | - Jian Sun
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
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6
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Dynamic carbon-nitrogen coupling under global change. SCIENCE CHINA. LIFE SCIENCES 2023; 66:771-782. [PMID: 36680674 DOI: 10.1007/s11427-022-2245-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/21/2022] [Indexed: 01/22/2023]
Abstract
Carbon-nitrogen coupling is a fundamental principle in ecosystem ecology. However, how the coupling responds to global change has not yet been examined. Through a comprehensive and systematic literature review, we assessed how the dynamics of carbon processes change with increasing nitrogen input and how nitrogen processes change with increasing carbon input under global change. Our review shows that nitrogen input to the ecosystem mostly stimulates plant primary productivity but inconsistently decreases microbial activities or increases soil carbon sequestration, with nitrogen leaching and nitrogenous gas emission rapidly increasing. Nitrogen fixation increases and nitrogen leaching decreases to improve soil nitrogen availability and support plant growth and ecosystem carbon sequestration under elevated CO2 and temperature or along ecosystem succession. We conclude that soil nitrogen cycle processes continually adjust to change in response to either overload under nitrogen addition or deficiency under CO2 enrichment and ecosystem succession to couple with carbon cycling. Indeed, processes of both carbon and nitrogen cycles continually adjust under global change, leading to dynamic coupling in carbon and nitrogen cycles. The dynamic coupling framework reconciles previous debates on the "uncoupling" or "decoupling" of ecosystem carbon and nitrogen cycles under global change. Ecosystem models failing to simulate these dynamic adjustments cannot simulate carbon-nitrogen coupling nor predict ecosystem carbon sequestration well.
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Zhang Z, Zhao Y, Lin H, Li Y, Fu J, Wang Y, Sun J, Zhao Y. Comprehensive analysis of grazing intensity impacts alpine grasslands across the Qinghai-Tibetan Plateau: A meta-analysis. FRONTIERS IN PLANT SCIENCE 2023; 13:1083709. [PMID: 36733589 PMCID: PMC9887153 DOI: 10.3389/fpls.2022.1083709] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 12/29/2022] [Indexed: 06/18/2023]
Abstract
Livestock grazing is a dominant practice in alpine grasslands and plays a crucial role in the ecosystem service of the Qinghai-Tibetan Plateau. The effects of grazing on alpine grasslands highly depends on grazing intensity. Up to now, we still lack comprehensive understanding of the general responses of alpine grasslands to different grazing intensities over broad geographic scales across the Qinghai-Tibetan Plateau. Here, we conducted a meta-analysis to explore the responses of plant characteristics and soil properties to grazing intensity in alpine grasslands of the Qinghai-Tibetan Plateau based on 52 peer-reviewed literatures. The results showed that grazing did not change the belowground biomass, while significantly increased the ratio of root to shoot (P< 0.05). Light grazing exhibited no significant effects on the plant richness, Shannon-Wiener diversity, soil water content, soil bulk density, nutrients, microbial biomass carbon, and microbial biomass nitrogen (P > 0.05). Moderate grazing significantly increased the plant richness and Shannon-Wiener diversity, while significantly decreased the soil organic carbon and total nitrogen (P< 0.05). Heavy grazing significantly decreased the plant richness, Shannon-Wiener diversity, water content, soil organic carbon, total nitrogen, microbial biomass carbon, and microbial biomass nitrogen, and significantly increased the soil bulk density (P< 0.05). These findings suggest that overgrazing is closely associated with grassland degradation, and moderate grazing is a sustainable practice to provide animal production and simultaneously maintain ecological functions for alpine grasslands on the Qinghai-Tibetan Plateau.
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Affiliation(s)
- Zhenchao Zhang
- Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Yiran Zhao
- Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Hao Lin
- Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Yanpeng Li
- School of Mapping and Geographic Information, Jiangxi College of Applied Technology, Ganzhou, China
| | - Jinmin Fu
- Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Yingxin Wang
- Grassland Research Center of National Forestry and Grassland Administration, Research Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing, China
| | - Juan Sun
- Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Yanhua Zhao
- Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao, Shandong, China
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Song W, Ochoa-Hueso R, Li F, Cui H, Zhong S, Yang X, Zhao T, Sun W. Mowing enhances the positive effects of nitrogen addition on ecosystem carbon fluxes and water use efficiency in a semi-arid meadow steppe. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 320:115889. [PMID: 35932732 DOI: 10.1016/j.jenvman.2022.115889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 07/19/2022] [Accepted: 07/26/2022] [Indexed: 06/15/2023]
Abstract
Grasslands are now facing a continuously increasing supply of nitrogen (N) fertilizers, resulting in alterations in ecosystem functioning, including changes in carbon (C) and water cycling. Mowing, one of the most widely used grassland management techniques, has been shown to mitigate the negative impacts of increased N availability on species richness. However, knowledge of how N addition and mowing, alone and/or in combination, affect ecosystem-level C fluxes and water use efficiency (WN) is still limited. We experimentally manipulated N fertilization (0 and 10 g N m-2 yr-1) and mowing (once per year at the end of the growing season) following a randomized block design in a meadow steppe characterized by salinization and alkalinization in northeastern China. We found that, compared to the control plots, N addition, mowing, and their interaction increased net ecosystem CO2 exchange by 65.1%, 14.7%, and 133%, and WN by 40.7%, 18.5%, and 96.1%, respectively. Nitrogen enrichment also decreased soil pH, which resulted in greater aboveground biomass (AGB). Moreover, N addition indirectly increased AGB by inducing changes in species richness. Our results indicate that mowing enhances the positive effects of N addition on ecosystem C fluxes and WN. Therefore, appropriate grassland management practices are essential to improve ecosystem C sequestration, WN, and mitigate future species diversity declines due to ecosystem eutrophication.
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Affiliation(s)
- Wenzheng Song
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China; Department of Biology, IVAGRO, University of Cádiz, Campus de Excelencia Internacional Agroalimentario (ceiA3), Campus Del Rio San Pedro, 11510, Puerto Real, Cádiz, Spain
| | - Raúl Ochoa-Hueso
- Department of Biology, IVAGRO, University of Cádiz, Campus de Excelencia Internacional Agroalimentario (ceiA3), Campus Del Rio San Pedro, 11510, Puerto Real, Cádiz, Spain; Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700, AB, Wageningen, the Netherlands.
| | - Fei Li
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China
| | - Haiying Cui
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China
| | - Shangzhi Zhong
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China; Grassland Agri-Husbandry Research Center, College of Grassland Science, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xuechen Yang
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China; Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China
| | - Tianhang Zhao
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China
| | - Wei Sun
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China.
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9
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Li R, Yu D, Zhang Y, Han J, Zhang W, Yang Q, Gessler A, Li MH, Xu M, Guan X, Chen L, Wang Q, Wang S. Investment of needle nitrogen to photosynthesis controls the nonlinear productivity response of young Chinese fir trees to nitrogen deposition. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 840:156537. [PMID: 35679936 DOI: 10.1016/j.scitotenv.2022.156537] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/30/2022] [Accepted: 06/03/2022] [Indexed: 06/15/2023]
Abstract
Plant carbon (C) assimilation is expected to nonlinearly increase with continuously increasing nitrogen (N) deposition, causing a N saturation threshold for productivity. However, the response of plant productivity to N deposition rates and further the N saturation threshold still await comprehensive quantization for forest ecosystem. Here, we tested the effect of N addition on aboveground net primary productivity (ANPP) of three-year old Chinese fir (Cunninghamia lanceolata) trees by adding N at 0, 5.6, 11.2, 22.4, and 44.8 g N m-2 yr-1 for 2.5 years. The N saturation threshold was estimated based on a quadratic-plus-plateau model. Results showed that ANPP transitioned from an increasing stage with increasing N addition rate to a plateaued stage at an N rate of 16.3 g N m-2 yr-1. The response of ANPP to N addition rates was well explained by the net photosynthetic rates of needles. Results from the dual isotope measurement [simultaneous determination of needle stable carbon (δ13C) and oxygen (δ18O) isotopes] indicated that the photosynthetic capacity, rather than the stomatal conductance, mediated the response of photosynthesis and ANPP of the young Chinese fir trees to N addition. Accordingly, the amount of needle N partitioning to water-soluble fraction, which is associated with the photosynthetic capacity, also responded to N enrichment with a nonlinear increase. Our study will contribute to a more accurate prediction on the influence of N deposition on C cycles in Chinese fir plantations.
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Affiliation(s)
- Renshan Li
- Huitong Experimental Station of Forest Ecology, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Shenyang 110016, China; Life Science Department, Luoyang Normal University, Luoyang 471934, China
| | - Dan Yu
- Life Science Department, Luoyang Normal University, Luoyang 471934, China
| | - Yankuan Zhang
- Huitong Experimental Station of Forest Ecology, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Shenyang 110016, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianming Han
- Life Science Department, Luoyang Normal University, Luoyang 471934, China
| | - Weidong Zhang
- Huitong Experimental Station of Forest Ecology, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Shenyang 110016, China; Huitong National Research Station of Forest Ecosystem, Huitong 418307, China.
| | - Qingpeng Yang
- Huitong Experimental Station of Forest Ecology, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Shenyang 110016, China; Huitong National Research Station of Forest Ecosystem, Huitong 418307, China.
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Research Institute WSL, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Mai-He Li
- Huitong Experimental Station of Forest Ecology, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Shenyang 110016, China; Forest Dynamics, Swiss Federal Research Institute WSL, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Ming Xu
- BNU-HKUST Laboratory for Green Innovation, Beijing Normal University, Zhuhai 519085, China
| | - Xin Guan
- Huitong Experimental Station of Forest Ecology, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Shenyang 110016, China; Huitong National Research Station of Forest Ecosystem, Huitong 418307, China
| | - Longchi Chen
- Huitong Experimental Station of Forest Ecology, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Shenyang 110016, China; Huitong National Research Station of Forest Ecosystem, Huitong 418307, China
| | - Qingkui Wang
- Huitong Experimental Station of Forest Ecology, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Shenyang 110016, China; Huitong National Research Station of Forest Ecosystem, Huitong 418307, China
| | - Silong Wang
- Huitong Experimental Station of Forest Ecology, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Shenyang 110016, China; Huitong National Research Station of Forest Ecosystem, Huitong 418307, China
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10
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Liu Y, Men M, Peng Z, Houx JH, Peng Y. Nitrogen availability determines ecosystem productivity in response to climate warming. Ecology 2022; 103:e3823. [PMID: 35857189 DOI: 10.1002/ecy.3823] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/08/2022] [Indexed: 11/11/2022]
Abstract
One of the major uncertainties for carbon-climate feedback predictions is an inadequate understanding of the mechanisms governing variations in ecosystem productivity response to warming. Temperature and water availability are regarded as the primary controls over the direction and magnitude of warming effects, but some unexplained results signal that our understanding is incomplete. Using two complementary meta-analyses, we present evidence that soil nitrogen (N) availability drives the warming effects on ecosystem productivity more strongly than thermal and hydrological factors over a broad geographical scale. First, by synthesizing temperature manipulation experiments, meta-regression model analysis showed that the warming effect on productivity is mainly driven by its effect on soil N availability. Sites with higher warming-induced increase in N availability were characterized by stronger productivity enhancement and vice versa, suggesting that N is a limiting factor across sites. Second, a synthesis of full-factorial warming×N addition experiments demonstrated that N addition significantly weakened the positive warming effect, because the additional N induced by warming may not further benefit plant growth when N limitation is relieved, providing experimental evidence that N regulates the warming effect. Further, we demonstrated that warming effects on soil N availability were modulated by changes in dissolved organic N and soil microbes. Overall, our findings enrich a new mechanistic understanding of the varying magnitudes of observed productivity response to warming, and the N scaling of warming effects may help constrain climate projections.
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Affiliation(s)
- Yang Liu
- College of Resources and Environmental Sciences/Key Laboratory of Farmland Eco-Environment of Hebei, Hebei Agricultural University, Baoding, China.,State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Mingxin Men
- College of Resources and Environmental Sciences/Key Laboratory of Farmland Eco-Environment of Hebei, Hebei Agricultural University, Baoding, China
| | - Zhengping Peng
- College of Resources and Environmental Sciences/Key Laboratory of Farmland Eco-Environment of Hebei, Hebei Agricultural University, Baoding, China
| | - James H Houx
- Agriculture Research and Technology, National Crop Insurance Services, Overland Park, KS, USA
| | - Yunfeng Peng
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
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11
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Han L, Ganjurjav H, Hu G, Wu J, Yan Y, Danjiu L, He S, Xie W, Yan J, Gao Q. Nitrogen Addition Affects Ecosystem Carbon Exchange by Regulating Plant Community Assembly and Altering Soil Properties in an Alpine Meadow on the Qinghai-Tibetan Plateau. FRONTIERS IN PLANT SCIENCE 2022; 13:900722. [PMID: 35769289 PMCID: PMC9234307 DOI: 10.3389/fpls.2022.900722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 05/13/2022] [Indexed: 05/11/2023]
Abstract
Nitrogen (N) deposition can affect the global ecosystem carbon balance. However, how plant community assembly regulates the ecosystem carbon exchange in response to the N deposition remains largely unclear, especially in alpine meadows. In this study, we conducted a manipulative experiment to examine the impacts of N (ammonium nitrate) addition on ecosystem carbon dioxide (CO2) exchange by changing the plant community assembly and soil properties at an alpine meadow site on the Qinghai-Tibetan Plateau from 2014 to 2018. The N-addition treatments were N0, N7, N20, and N40 (0, 7, 20, and 40 kg N ha-1year-1) during the plant growing season. The net ecosystem CO2 exchange (NEE), gross ecosystem productivity (GEP), and ecosystem respiration (ER) were measured by a static chamber method. Our results showed that the growing-season NEE, ER and GEP increased gradually over time with increasing N-addition rates. On average, the NEE increased significantly by 55.6 and 65.2% in N20 and N40, respectively (p < 0.05). Nitrogen addition also increased forage grass biomass (GB, including sedge and Gramineae) by 74.3 and 122.9% and forb biomass (FB) by 73.4 and 51.4% in N20 and N40, respectively (p < 0.05). There were positive correlations between CO2 fluxes (NEE and GEP) and GB (p < 0.01), and the ER was positively correlated with functional group biomass (GB and FB) and soil available N content (NO3 --N and NH4 +-N) (p < 0.01). The N-induced shift in the plant community assembly was primarily responsible for the increase in NEE. The increase in GB mainly contributed to the N stimulation of NEE, and FB and the soil available N content had positive effects on ER in response to N addition. Our results highlight that the plant community assembly is critical in regulating the ecosystem carbon exchange response to the N deposition in alpine ecosystems.
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Affiliation(s)
- Ling Han
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hasbagan Ganjurjav
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
- National Agricultural Experimental Station for Agricultural Environment, Nagqu, China
| | - Guozheng Hu
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
- National Agricultural Experimental Station for Agricultural Environment, Nagqu, China
| | - Jianshuang Wu
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yulong Yan
- China New Era Group Corporation, Beijing, China
| | | | | | | | - Jun Yan
- Nagqu Grassland Station, Nagqu, China
| | - Qingzhu Gao
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
- National Agricultural Experimental Station for Agricultural Environment, Nagqu, China
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12
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Li Y, Ma J, Yu Y, Li Y, Shen X, Huo S, Xia X. Effects of multiple global change factors on soil microbial richness, diversity and functional gene abundances: A meta-analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 815:152737. [PMID: 34998753 DOI: 10.1016/j.scitotenv.2021.152737] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/23/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Soil microbial richness, diversity, and functional gene abundance are crucial factors affecting belowground ecosystem functions; however, there is still a lack of systematic understanding of their responses to global change. Here, we conducted a worldwide meta-analysis using 1071 observation data concerning the effects of global change factors (GCFs), including warming (W), increased precipitation (PPT+), decreased precipitation (PPT-), elevated CO2 concentration (eCO2), and nitrogen deposition (N), to evaluate their individual, combined, and interactive effects on soil microbial properties across different groups and ecosystems. Across the dataset, eCO2 increased microbial richness and diversity by 40.5% and 4.6%, respectively; warming and N addition decreased the abundance of denitrification functional genes (nirS, nirK, and nozS); N addition had a greater impact on soil C-cycling functional genes than on N-cycling ones. Long-term precipitation change was conducive to the increase in soil microbial richness, and fungal richness change was more sensitive than bacterial richness, but the sensitivity of bacteria richness to N addition was positively correlated with experimental duration. Soil microbial richness, diversity, and functional gene abundances could be significantly affected by individual or multiple GCF changes, and their interactions are mainly additive. W×eCO2 on microbial diversity, and N×PPT+ and W×N on N-cycling functional gene abundance showed synergistic interactions. Based on the limitations of the collected data and the findings, we suggest designing experiments with multiple GCFs and long experimental durations and incorporating the effects and interactions of multiple drivers into ecosystem models to accurately predict future soil microbial properties and functions under future global changes.
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Affiliation(s)
- Yuqian Li
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19 Xinjiekouwai Street, Haidian District, Beijing 100875, PR China.
| | - Junwei Ma
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19 Xinjiekouwai Street, Haidian District, Beijing 100875, PR China.
| | - Yi Yu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19 Xinjiekouwai Street, Haidian District, Beijing 100875, PR China
| | - Yijia Li
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19 Xinjiekouwai Street, Haidian District, Beijing 100875, PR China.
| | - Xinyi Shen
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19 Xinjiekouwai Street, Haidian District, Beijing 100875, PR China
| | - Shouliang Huo
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Xinghui Xia
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19 Xinjiekouwai Street, Haidian District, Beijing 100875, PR China.
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13
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Kompanizare M, Petrone RM, Macrae ML, De Haan K, Khomik M. Assessment of effective LAI and water use efficiency using Eddy Covariance data. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 802:149628. [PMID: 34454157 DOI: 10.1016/j.scitotenv.2021.149628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Globally, maize (Zea mays, a C4-plant) and alfalfa (Medicago sativa, a C3-plant) are common and economically important crops. Predicting the response of their water use efficiency, WUE, to changing hydrologic and climatic conditions is vital in helping farmers adapt to a changing climate. In this study, we assessed the effective leaf area index (eLAI - the leaf area most involved in CO2 and H2O exchange) and stomatal conductance in canopy scale in maize and alfalfa fields. In the process we used a theoretically-based photosynthesis C3-C4 model (C3C4PM) and carbon and water vapour fluxes measured by Eddy Covariance towers at our study sites. We found that in our study sites the eLAI was in the range of 25-32% of the observed total LAI in these crops. WUEs were in range of 8-9 mmol/mol. C3C4PM can be used in predictions of stomatal conductance and eLAI responses in C3 and C4 agricultural crops to elevated CO2 concentration and changes in precipitation and temperature under future climate scenarios.
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Affiliation(s)
- Mazda Kompanizare
- Department of Geography and Environmental Management, Hydrometeorology and Biogeochemistry Research Groups, University of Waterloo, 200 University Avenue W, Waterloo, ON N2L 3G1, Canada; Global Institute in Water Security, University of Saskatchewan, 11 Innovation Blvd, Saskatoon, SK S7N 3H5, Canada.
| | - Richard M Petrone
- Department of Geography and Environmental Management, Hydrometeorology and Biogeochemistry Research Groups, University of Waterloo, 200 University Avenue W, Waterloo, ON N2L 3G1, Canada
| | - Merrin L Macrae
- Department of Geography and Environmental Management, Hydrometeorology and Biogeochemistry Research Groups, University of Waterloo, 200 University Avenue W, Waterloo, ON N2L 3G1, Canada
| | - Kevin De Haan
- Department of Geography and Environmental Management, Hydrometeorology and Biogeochemistry Research Groups, University of Waterloo, 200 University Avenue W, Waterloo, ON N2L 3G1, Canada
| | - Myroslava Khomik
- Department of Geography and Environmental Management, Hydrometeorology and Biogeochemistry Research Groups, University of Waterloo, 200 University Avenue W, Waterloo, ON N2L 3G1, Canada
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14
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Wang F, Chen Y, Li T, Wang C, Wang D, Fu B, Lv Y, Wu X. Grazing Reduces the Soil-Atmosphere Exchange of Greenhouse Gases During Freeze-Thaw Cycles in Meadow Steppes in Inner Mongolia. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.795203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Both livestock grazing and soil freeze-thaw cycles (FTCs) can affect the soil-atmosphere exchange of greenhouse gases (GHGs) in grasslands. However, the combined effects of grazing and FTCs on GHG fluxes in meadow steppe soils remain unclear. In this study, we collected soils from paired grazing and enclosed sites and conducted an incubation experiment to investigate the effect of grazing on soil GHG fluxes in the meadow steppes of Inner Mongolia during three FTCs. Our results showed that FTCs substantially stimulated the emissions of soil N2O and CO2 and the uptake of CH4 in the meadow steppes. However, compared with enclosure treatments, grazing significantly reduced the cumulative N2O, CO2 and CH4 fluxes by 13.3, 14.6, and 26.8%, respectively, during the entire FTCs experiment. The soil dissolved organic carbon (DOC) and nitrogen (DON), NH4+-N and NO3–-N, significantly increased after three FTCs and showed close correlations with N2O and CO2 emissions. Structural equation modeling (SEM) revealed that the increase in NO3–-N induced by FTCs dominated the variance in N2O emissions and that DOC strongly affected CO2 emissions during thawing periods. However, long-term grazing reduced soil substrate availability and microbial activity and increased soil bulk density, which in turn decreased the cumulative GHG fluxes during FTCs. In addition, the interaction between grazing and FTCs significantly affected CO2 and CH4 fluxes but not N2O fluxes. Our results indicated that livestock grazing had an important effect on soil GHG fluxes during FTCs. The combined effect of grazing and FTCs should be taken into account in future estimations of GHG budgets in both modeling and experimental studies.
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15
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Zhu J, Wang Q, He N, Yu G. Effect of atmospheric nitrogen deposition and its components on carbon flux in terrestrial ecosystems in China. ENVIRONMENTAL RESEARCH 2021; 202:111787. [PMID: 34339690 DOI: 10.1016/j.envres.2021.111787] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 05/20/2023]
Abstract
Long-term atmospheric nitrogen (N) deposition increases bioavailable N in terrestrial ecosystems, thereby influencing ecosystem productivity. However, how N deposition and its components (i.e., NO3--N and NH4+-N) influence the spatial pattern of productivity in terrestrial ecosystems in China remains unknown. Here, we utilize published data including carbon (C) fluxes from eddy flux tower (gross ecosystem productivity, ecosystem respiration, and net ecosystem productivity) and the corresponding climate and N deposition data for 60 typical ecosystems in China. The objective was to investigate the effect of N deposition on ecosystem productivity and explore the variations of N use efficiency (NUE). Our results reveal that atmospheric total N deposition is significantly correlated with C fluxes of terrestrial ecosystems in China. Ecosystems respond variably to different components of N deposition. In detail, forest ecosystem marginally correlated with NO3--N and wet deposition, while grassland ecosystem significantly correlated with NH4+-N and dry deposition. NUE of productivity induced by N deposition in Chinese terrestrial ecosystems was 53.95 ± 40.30 g C g-1 N, and it was influenced by precipitation and aridity index. This study quantifies the contribution of total N deposition and its associated components to productivity in terrestrial ecosystems in China, offering vital information for regional C and N management.
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Affiliation(s)
- Jianxing Zhu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing, 100101, China.
| | - Qiufeng Wang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing, 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Nianpeng He
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing, 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Guirui Yu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing, 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China.
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16
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Peng Y, Chen HYH, Yang Y. Global pattern and drivers of nitrogen saturation threshold of grassland productivity. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13622] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yunfeng Peng
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing China
| | - Han Y. H. Chen
- Faculty of Natural Resources Management Lakehead University Thunder Bay ON Canada
| | - Yuanhe Yang
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing China
- University of Chinese Academy of Sciences Beijing China
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17
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Wang Y, Zhu Z, Ma Y, Yuan L. Carbon and water fluxes in an alpine steppe ecosystem in the Nam Co area of the Tibetan Plateau during two years with contrasting amounts of precipitation. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2020; 64:1183-1196. [PMID: 32146509 DOI: 10.1007/s00484-020-01892-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 02/28/2020] [Accepted: 03/02/2020] [Indexed: 06/10/2023]
Abstract
Carbon and water fluxes and their interactions with climate drivers in alpine grasslands on the Tibetan Plateau are poorly understood. This lack of understanding is particularly evident for the alpine steppe in the Nam Co area of the hinterland on the Tibetan Plateau, which is vulnerable and exceedingly sensitive to climate change. In this study, eddy covariance (EC) measurements of carbon dioxide (CO2) and water fluxes were carried out in this region during the growing season of 2008 and 2009, with contrasting hydrological conditions. The results show that (1) the monthly patterns of carbon and water fluxes differed markedly in the two years; the total respiration (Re), net ecosystem carbon dioxide exchange (NEE) and gross primary productivity (GPP) were 181.6 ± 11.5, - 62.6 ± 10.8, and 244.2 ± 9.6 and 144.6 ± 12.0, - 32.4 ± 11.7, and 176.9 ± 12.3 g C m-2 during the growing seasons in 2008 and 2009; meanwhile, the cumulative evapotranspiration (ET) values were 503.1 ± 13.5 and 387.3 ± 8.2 mm during the growing season in 2008 and 2009, respectively. The cumulative carbon fluxes and ET were both higher in the wetter 2008 than in the drier 2009, consistent with the precipitation results. (2) Soil water content (SWC) played a paramount role in the variations in carbon fluxes (NEE, GPP, and Re) and ET during the vegetative period over the two years. As a result, the alpine steppe ecosystem was water-limited. (3) Water stress caused by the low surface soil water content significantly depressed photosynthesis and ET during the daytime in July and August. (4) Water use efficiency (WUE) had a negative relationship with SWC during the growing season in these two years, and the WUE increased during drought.
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Affiliation(s)
- Yuyang Wang
- Chinese Academy of Sciences, Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhikun Zhu
- School of Science, Shandong Jianzhu University, Jinan, 250101, China
| | - Yaoming Ma
- Chinese Academy of Sciences, Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Chinese Academy of Sciences, CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China.
| | - Ling Yuan
- Chinese Academy of Sciences, Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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18
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Li J, Yang C, Zhou H, Shao X. Responses of plant diversity and soil microorganism diversity to water and nitrogen additions in the Qinghai-Tibetan Plateau. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2020.e01003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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19
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Liang X, Zhang T, Lu X, Ellsworth DS, BassiriRad H, You C, Wang D, He P, Deng Q, Liu H, Mo J, Ye Q. Global response patterns of plant photosynthesis to nitrogen addition: A meta-analysis. GLOBAL CHANGE BIOLOGY 2020; 26:3585-3600. [PMID: 32146723 DOI: 10.1111/gcb.15071] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 02/07/2020] [Indexed: 05/17/2023]
Abstract
A mechanistic understanding of plant photosynthetic response is needed to reliably predict changes in terrestrial carbon (C) gain under conditions of chronically elevated atmospheric nitrogen (N) deposition. Here, using 2,683 observations from 240 journal articles, we conducted a global meta-analysis to reveal effects of N addition on 14 photosynthesis-related traits and affecting moderators. We found that across 320 terrestrial plant species, leaf N was enhanced comparably on mass basis (Nmass , +18.4%) and area basis (Narea , +14.3%), with no changes in specific leaf area or leaf mass per area. Total leaf area (TLA) was increased significantly, as indicated by the increases in total leaf biomass (+46.5%), leaf area per plant (+29.7%), and leaf area index (LAI, +24.4%). To a lesser extent than for TLA, N addition significantly enhanced leaf photosynthetic rate per area (Aarea , +12.6%), stomatal conductance (gs , +7.5%), and transpiration rate (E, +10.5%). The responses of Aarea were positively related with that of gs , with no changes in instantaneous water-use efficiency and only slight increases in long-term water-use efficiency (+2.5%) inferred from 13 C composition. The responses of traits depended on biological, experimental, and environmental moderators. As experimental duration and N load increased, the responses of LAI and Aarea diminished while that of E increased significantly. The observed patterns of increases in both TLA and E indicate that N deposition will increase the amount of water used by plants. Taken together, N deposition will enhance gross photosynthetic C gain of the terrestrial plants while increasing their water loss to the atmosphere, but the effects on C gain might diminish over time and that on plant water use would be amplified if N deposition persists.
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Affiliation(s)
- Xingyun Liang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, and Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- College of Life Sciences, Gannan Normal University, Ganzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Tong Zhang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, and Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Xiankai Lu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, and Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
| | - David S Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Hormoz BassiriRad
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Chengming You
- Long-term Research Station of Alpine Forest Ecosystems, Provincial Key Laboratory of Ecological Forestry Engineering, Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, China
| | - Dong Wang
- School of Life Sciences, Henan University, Kaifeng, Henan, China
| | - Pengcheng He
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, and Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Qi Deng
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, and Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Hui Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, and Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Jiangming Mo
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, and Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, and Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- College of Life Sciences, Gannan Normal University, Ganzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
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20
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Comprehensive Grassland Degradation Monitoring by Remote Sensing in Xilinhot, Inner Mongolia, China. SUSTAINABILITY 2020. [DOI: 10.3390/su12093682] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Grassland degradation is a complex process and cannot be thoroughly measured by a single indicator, such as fractional vegetation cover (FVC), aboveground biomass (AGB), or net primary production (NPP), or by a simple combination of these indicators. In this research, we combined measured data with vegetation and soil characteristics to establish a set of standards applicable to the monitoring of regional grassland degradation by remote sensing. We selected indicators and set their thresholds with full consideration given to vegetation structure and function. We optimized the indicator simulation, based on which grassland degradation in the study area during 2014–2018 was comprehensively evaluated. We used the feeding intensity of herbivores to represent the grazing intensity. We analyzed the effects of climate and grazing activities on grassland degradation using the constraint line method. The results showed degradation in approximately 69% of the grassland in the study area and an overall continued recovery of the degraded grassland from 2014 to 2018. We did not identify any significant correlation between temperature and grassland degradation. The increase in precipitation promoted the recovery of degraded grassland, whereas increased grazing may have aggravated degradation. Our findings can not only improve the scientific quality and accuracy of grassland degradation monitoring by remote sensing but also provide clear spatial information and decision-making help in sustainable management of grassland regions.
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21
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Deng L, Huang C, Kim DG, Shangguan Z, Wang K, Song X, Peng C. Soil GHG fluxes are altered by N deposition: New data indicate lower N stimulation of the N 2 O flux and greater stimulation of the calculated C pools. GLOBAL CHANGE BIOLOGY 2020; 26:2613-2629. [PMID: 31863618 DOI: 10.1111/gcb.14970] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 12/11/2019] [Accepted: 12/12/2019] [Indexed: 05/18/2023]
Abstract
The effects of nitrogen (N) deposition on soil organic carbon (C) and greenhouse gas (GHG) emissions in terrestrial ecosystems are the main drivers affecting GHG budgets under global climate change. Although many studies have been conducted on this topic, we still have little understanding of how N deposition affects soil C pools and GHG budgets at the global scale. We synthesized a comprehensive dataset of 275 sites from multiple terrestrial ecosystems around the world and quantified the responses of the global soil C pool and GHG fluxes induced by N enrichment. The results showed that the soil organic C concentration and the soil CO2 , CH4 and N2 O emissions increased by an average of 3.7%, 0.3%, 24.3% and 91.3% under N enrichment, respectively, and that the soil CH4 uptake decreased by 6.0%. Furthermore, the percentage increase in N2 O emissions (91.3%) was two times lower than that (215%) reported by Liu and Greaver (Ecology Letters, 2009, 12:1103-1117). There was also greater stimulation of soil C pools (15.70 kg C ha-1 year-1 per kg N ha-1 year-1 ) than previously reported under N deposition globally. The global N deposition results showed that croplands were the largest GHG sources (calculated as CO2 equivalents), followed by wetlands. However, forests and grasslands were two important GHG sinks. Globally, N deposition increased the terrestrial soil C sink by 6.34 Pg CO2 /year. It also increased net soil GHG emissions by 10.20 Pg CO2 -Geq (CO2 equivalents)/year. Therefore, N deposition not only increased the size of the soil C pool but also increased global GHG emissions, as calculated by the global warming potential approach.
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Affiliation(s)
- Lei Deng
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, China
- Center of CEF/ESCER, Department of Biological Science, University of Quebec at Montreal, Montreal, QC, Canada
- Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi, China
| | - Chunbo Huang
- Center of CEF/ESCER, Department of Biological Science, University of Quebec at Montreal, Montreal, QC, Canada
- School of Geography and Information Engineering, China University of Geosciences, Wuhan, China
| | - Dong-Gill Kim
- Wondo Genet College of Forestry and Natural Resources, Hawassa University, Shashemene, Ethiopia
| | - Zhouping Shangguan
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, China
- Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi, China
| | - Kaibo Wang
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, Shaanxi, China
| | - Xinzhang Song
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, Zhejiang, China
| | - Changhui Peng
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, China
- Center of CEF/ESCER, Department of Biological Science, University of Quebec at Montreal, Montreal, QC, Canada
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22
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Britton AJ, Gibbs S, Fisher JM, Helliwell RC. Impacts of nitrogen deposition on carbon and nitrogen cycling in alpine Racomitrium heath in the UK and prospects for recovery. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 254:112986. [PMID: 31394340 DOI: 10.1016/j.envpol.2019.112986] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 07/24/2019] [Accepted: 07/30/2019] [Indexed: 06/10/2023]
Abstract
Deposition of reactive nitrogen (N) is a major threat to terrestrial ecosystems associated with impacts on ecosystem properties and functions including carbon (C) and nutrient stocks, soil water quality and nutrient retention. In the oceanic-alpine Racomitrium heath habitat, N deposition is associated with moss mat degradation and a shift from bryophyte to graminoid dominance. To investigate the effects of moss mat decline on C and N stocks and fluxes, we collected Racomitrium heath vegetation/soil cores from sites along a gradient of N deposition in the UK. Cores were maintained under controlled conditions and exposed to scenarios of current (8-40 kg N ha-1 y-1), reduced (8 kg N ha-1 y-1) and elevated (50 kg N ha-1 y-1) N deposition. Cores from high N deposition sites had smaller aboveground C and N stocks and, under current conditions, leached large amounts of inorganic N and had low soil water pH compared with low N deposition sites. With reduced N deposition there was evidence for rapid recovery of soil water quality in terms of reduced N leaching and small increases in pH. Under high N deposition, cores from low N deposition sites retained much of the applied N while those with a history of high N deposition leached large amounts of inorganic N. Carbon fluxes in soil water and net CO2 fluxes varied according to core source site but were not affected by the N deposition scenarios. We conclude that C and N stocks and cycling in Racomitrium heath are strongly affected by long-term exposure to N deposition but that soil water quality may improve rapidly, if N deposition rates are reduced. The legacy of N deposition impacts on moss mat cover and vegetation composition however, mean that the ecosystem remains sensitive to future pulses in N input.
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Affiliation(s)
- Andrea J Britton
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK.
| | - Sheila Gibbs
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - Julia M Fisher
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
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23
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Tang S, Wang K, Xiang Y, Tian D, Wang J, Liu Y, Cao B, Guo D, Niu S. Heavy grazing reduces grassland soil greenhouse gas fluxes: A global meta-analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 654:1218-1224. [PMID: 30841396 DOI: 10.1016/j.scitotenv.2018.11.082] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 11/06/2018] [Accepted: 11/06/2018] [Indexed: 05/12/2023]
Abstract
Grazing degrades worldwide grasslands and possibly suppresses soil greenhouse gas (GHG: CO2, CH4 and N2O) fluxes. However, the global patterns of these three gas fluxes in response to grazing and the general mechanisms remain poorly understood. Here, we performed a meta-analysis of 63 independent grazing studies that measured soil GHG fluxes across global grasslands. Our results revealed that light and moderate grazing had no significant effect on soil CH4 uptake, N2O and CO2 emission, but heavy grazing consistently reduced them. The magnitudes of their responses to grazing were regulated by grazing duration and precipitation. In comparison with CO2 emission, soil CH4 uptake and N2O emission were reduced much more under heavier grazing, longer grazing duration or less precipitation. The decrease in soil CO2 emission was possibly caused by grazing-induced reduction in root biomass and soil moisture, while the decline in soil CH4 uptake and N2O emission was due to decreased soil moisture and substrate availability. Overall, this study provides the first large-scale evaluation on three main soil GHG fluxes in response to grazing, highlighting grazing inhibition of GHG emission but at the cost of plant productivity and soil fertility. We call for future efforts to identify an appropriate grazing intensity that is optimal to balance these complicated impacts.
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Affiliation(s)
- Shiming Tang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China; Department of Ecology, School of Ecology and Environment, Inner Mongolia University, No. 235 West College Road, 010021 Hohhot, China
| | - Kun Wang
- Grassland Department of Animal Science and Technology College, China Agricultural University, Beijing 100193, China
| | - Yangzhou Xiang
- Guizhou Institute of Forest Inventory and Planning, Guiyang, Guizhou 550003, China
| | - Dashuan Tian
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China.
| | - Jinsong Wang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
| | - Yanshu Liu
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China
| | - Bo Cao
- Institute of Ecological Planning and Design, Orient Landscape Arts (Beijing) Co., Beijing 100015, China
| | - Ding Guo
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
| | - Shuli Niu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China; Department of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
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24
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Wu J, Li M, Fiedler S, Ma W, Wang X, Zhang X, Tietjen B. Impacts of grazing exclusion on productivity partitioning along regional plant diversity and climatic gradients in Tibetan alpine grasslands. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 231:635-645. [PMID: 30390448 DOI: 10.1016/j.jenvman.2018.10.097] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 09/20/2018] [Accepted: 10/26/2018] [Indexed: 06/08/2023]
Abstract
The biodiversity-productivity relationship is critical for better predicting ecosystem responses to climate change and human disturbance. However, it remains unclear about the effects of climate change, land use shifts, plant diversity, and their interactions on productivity partitioning above- and below-ground components in alpine grasslands on the Tibetan Plateau. To answer this question, we conducted field surveys at 33 grazed vs. fenced paired sites that are distributed across the alpine meadow, steppe, and desert-steppe zones on the northern Tibetan Plateau in early August of 2010-2013. Generalized additive models (GAMs) showed that aboveground net primary productivity (ANPP) linearly increased with growing season precipitation (GSP) while belowground net primary productivity (BNPP) decreased with growing season temperature (GST). Compared to grazed sites, short-term fencing did not alter the patterns of ANPP along climatic gradients but tended to decrease BNPP at moderate precipitation levels of 200 mm < GSP <450 mm. We also found that ANPP and BNPP linearly increased with species richness, ANPP decreased with Shannon diversity index, and BNPP did not correlate with the Shannon diversity index. Fencing did not alter the relationships between productivity components and plant diversity indices. Generalized additive mixed models furtherly confirmed that the interaction of localized plant diversity and climatic condition nonlinearly regulated productivity partitioning of alpine grasslands in this area. Finally, structural equation models (SEMs) revealed the direction and strength of causal links between biotic and abiotic variables within alpine grassland ecosystems. ANPP was controlled directly by GSP (0.53) and indirectly via species richness (0.41) and Shannon index (-0.12). In contrast, BNPP was influenced directly by GST (-0.43) and indirectly by GSP via species richness (0.05) and Shannon index (-0.02). Therefore, we recommend using a joint approach of GAMs and SEMs for better understanding mechanisms behind the relationship between biodiversity and ecosystem function under climate change and human disturbance.
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Affiliation(s)
- Jianshuang Wu
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, 100101 Beijing, China; Freie Universität Berlin, Institute of Biology, Biodiversity/Theoretical Ecology, 14195 Berlin, Germany.
| | - Meng Li
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, 100101 Beijing, China
| | - Sebastian Fiedler
- Freie Universität Berlin, Institute of Biology, Biodiversity/Theoretical Ecology, 14195 Berlin, Germany
| | - Weiling Ma
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, 100101 Beijing, China
| | - Xiangtao Wang
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, 100101 Beijing, China; Xizang Agriculture and Animal Husbandry College, Department of Animal Sciences, 860000 Linzhi, China
| | - Xianzhou Zhang
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, 100101 Beijing, China
| | - Britta Tietjen
- Freie Universität Berlin, Institute of Biology, Biodiversity/Theoretical Ecology, 14195 Berlin, Germany; Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), 14195 Berlin, Germany
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25
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Liu W, Lü X, Xu W, Shi H, Hou L, Li L, Yuan W. Effects of water and nitrogen addition on ecosystem respiration across three types of steppe: The role of plant and microbial biomass. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 619-620:103-111. [PMID: 29145047 DOI: 10.1016/j.scitotenv.2017.11.119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 11/09/2017] [Accepted: 11/10/2017] [Indexed: 06/07/2023]
Abstract
Evaluating the regional variation of ecosystem respiration (Reco) in its response to the changes of soil water and nitrogen (N) availability is crucial for fully understanding ecosystem carbon (C) exchange and its feedbacks to global changes. Here, we examined the responses of Reco, plant community aboveground biomass (AB), microbial biomass carbon (MBC) and soil moisture (SM) to water and N addition, using intact soil monoliths from three different temperate steppes along a precipitation gradient, including meadow steppe, typical steppe, and desert steppe in northern China. We found that the meadow steppe held the highest value of Reco. Water addition significantly enhanced Reco while N addition had no effect on Reco in all three ecosystems. The response of Reco in the typical steppe was more sensitive than the other two ecosystems. The changes of plant community AB exhibited a much stronger explanatory power than that of MBC for Reco in the typical steppe. In contrast, MBC was the dominant factor explaining the variation of Reco in the desert steppe and the meadow steppe. These findings contribute to our understanding of regional patterns of ecosystem C exchange under scenarios of global changes and highlight the importance of water availability in regulating ecosystem processes in temperate steppe grasslands.
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Affiliation(s)
- Wei Liu
- School of Atmospheric Sciences, Center for Monsoon and Environment Research, Sun Yat-Sen University, Guangzhou 510275, China; State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Xiaotao Lü
- Erguna Forest-Steppe Ecotone Research Station, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Wenfang Xu
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huiqiu Shi
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Longyu Hou
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Linghao Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
| | - Wenping Yuan
- School of Atmospheric Sciences, Center for Monsoon and Environment Research, Sun Yat-Sen University, Guangzhou 510275, China.
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26
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Zhang X, Zhai P, Huang J, Zhao X, Dong K. Responses of ecosystem water use efficiency to spring snow and summer water addition with or without nitrogen addition in a temperate steppe. PLoS One 2018. [PMID: 29529082 PMCID: PMC5846795 DOI: 10.1371/journal.pone.0194198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Water use efficiency (WUE) is an important indicator of ecosystem functioning but how ecosystem WUE responds to climate change including precipitation and nitrogen (N) deposition increases is still unknown. To investigate such responses, an experiment with a randomized block design with water (spring snowfall or summer water addition) and nitrogen addition was conducted in a temperate steppe of northern China. We investigated net ecosystem CO2 production (NEP), gross ecosystem production (GEP) and evapotranspiration (ET) to calculate ecosystem WUE (WUEnep = NEP/ET or WUEgep = GEP/ET) under spring snow and summer water addition with or without N addition from 2011 to 2013. The results showed that spring snow addition only had significant effect on ecosystem WUE in 2013 and summer water addition showed positive effect on ecosystem WUE in 2011 and 2013, as their effects on NEP and GEP is stronger than ET. N addition increased ecosystem WUE in 2012 and 2013 both in spring snow addition and summer water addition for its increasing effects on NEP and GEP but no effect on ET. Summer water addition had less but N addition had greater increasing effects on ecosystem WUE as natural precipitation increase indicating that natural precipitation regulates ecosystem WUE responses to water and N addition. Moreover, WUE was tightly related with atmospheric vapor-pressure deficit (VPD), photosynthetic active radiation (PAR), precipitation and soil moisture indicating the regulation of climate drivers on ecosystem WUE. In addition, it also was affected by aboveground net primary production (ANPP). The study suggests that ecosystem WUE responses to water and N addition is determined by the change in carbon process rather than that in water process, which are regulated by climate change in the temperate steppe of northern China.
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Affiliation(s)
- Xiaolin Zhang
- College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, China
- State Key Laboratory of Grassland Agro-ecosystems, Lanzhou University, Lanzhou, China
- * E-mail:
| | - Penghui Zhai
- College of Agriculture, Shanxi Agricultural University, Taigu, China
| | - Jianhui Huang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing, China
| | - Xiang Zhao
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing, China
| | - Kuanhu Dong
- College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, China
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27
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Shi B, Wang Y, Meng B, Zhong S, Sun W. Effects of Nitrogen Addition on the Drought Susceptibility of the Leymus chinensis Meadow Ecosystem Vary with Drought Duration. FRONTIERS IN PLANT SCIENCE 2018. [PMID: 29535757 PMCID: PMC5835344 DOI: 10.3389/fpls.2018.00254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
It is not clear yet how extreme drought and nitrogen (N) deposition influence grassland ecosystem functions when they are considered together, especially in complex field conditions. To explore the response of the Leymus chinensis meadow ecosystem to manipulated extreme drought (45 days), N addition and their interaction, we measured leaf photosynthetic characteristics, aboveground phytomass on the community level and ecosystem C exchange in different treatments at the middle and the end of the drought period. The extreme drought treatment decreased the leaf net CO2 assimilation rate and ecosystem C exchange [gross ecosystem productivity (GEP), ecosystem respiration and net ecosystem CO2 exchange]. In contrast, the N addition treatment increased aboveground phytomass, GEP and net ecosystem CO2 exchange. The effects of N addition on the drought susceptibility of the L. chinensis meadow ecosystem varied with drought severity. The N addition treatment alleviated drought-induced suppression of CO2 exchange at the leaf and ecosystem levels in the middle of the drought period, whereas it exacerbated drought-induced suppression of the CO2 exchange and aboveground phytomass on the community level at the end of the drought period. Given that dominance by L. chinensis is a characteristic of the studied ecosystem, knowledge of the traits of L. chinensis and its response to multiple global change drivers will be crucial for predicting future ecosystem functions. Furthermore, increasing N deposition may affect the response of the L. chinensis meadow ecosystem to further droughts by increasing carbon allocation to roots and therefore root-shoot ratios.
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Affiliation(s)
- Baoku Shi
- Key Laboratory for Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
| | - Yunbo Wang
- Key Laboratory for Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
- Key Laboratory of Grassland Resources, Ministry of Education, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China
| | - Bo Meng
- Key Laboratory for Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
| | - Shangzhi Zhong
- Key Laboratory for Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
| | - Wei Sun
- Key Laboratory for Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
- *Correspondence: Wei Sun,
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28
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Peng Y, Li F, Zhou G, Fang K, Zhang D, Li C, Yang G, Wang G, Wang J, Yang Y. Linkages of plant stoichiometry to ecosystem production and carbon fluxes with increasing nitrogen inputs in an alpine steppe. GLOBAL CHANGE BIOLOGY 2017; 23:5249-5259. [PMID: 28614594 DOI: 10.1111/gcb.13789] [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: 10/26/2016] [Accepted: 06/02/2017] [Indexed: 06/07/2023]
Abstract
Unprecedented levels of nitrogen (N) have entered terrestrial ecosystems over the past century, which substantially influences the carbon (C) exchange between the atmosphere and biosphere. Temperature and moisture are generally regarded as the major controllers over the N effects on ecosystem C uptake and release. N-phosphorous (P) stoichiometry regulates the growth and metabolisms of plants and soil organisms, thereby affecting many ecosystem C processes. However, it remains unclear how the N-induced shift in the plant N:P ratio affects ecosystem production and C fluxes and its relative importance. We conducted a field manipulative experiment with eight N addition levels in a Tibetan alpine steppe and assessed the influences of N on aboveground net primary production (ANPP), gross ecosystem productivity (GEP), ecosystem respiration (ER), and net ecosystem exchange (NEE); we used linear mixed-effects models to further determine the relative contributions of various factors to the N-induced changes in these parameters. Our results showed that the ANPP, GEP, ER, and NEE all exhibited nonlinear responses to increasing N additions. Further analysis demonstrated that the plant N:P ratio played a dominate role in shaping these C exchange processes. There was a positive relationship between the N-induced changes in ANPP (ΔANPP) and the plant N:P ratio (ΔN:P), whereas the ΔGEP, ΔER, and ΔNEE exhibited quadratic correlations with the ΔN:P. In contrast, soil temperature and moisture were only secondary predictors for the changes in ecosystem production and C fluxes along the N addition gradient. These findings highlight the importance of plant N:P ratio in regulating ecosystem C exchange, which is crucial for improving our understanding of C cycles under the scenarios of global N enrichment.
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Affiliation(s)
- Yunfeng Peng
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Fei Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guoying Zhou
- Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- Key Laboratory of Tibetan Medicine Research, Chinese Academy of Sciences, Xining, China
| | - Kai Fang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Dianye Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Changbin Li
- University of Chinese Academy of Sciences, Beijing, China
- Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- Key Laboratory of Tibetan Medicine Research, Chinese Academy of Sciences, Xining, China
| | - Guibiao Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guanqin Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jun Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yuanhe Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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29
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Han H, Du Y, Hui D, Jiang L, Zhong M, Wan S. Long-term antagonistic effect of increased precipitation and nitrogen addition on soil respiration in a semiarid steppe. Ecol Evol 2017; 7:10804-10814. [PMID: 29299259 PMCID: PMC5743642 DOI: 10.1002/ece3.3536] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/02/2017] [Accepted: 09/16/2017] [Indexed: 11/10/2022] Open
Abstract
Changes in water and nitrogen (N) availability due to climate change and atmospheric N deposition could have significant effects on soil respiration, a major pathway of carbon (C) loss from terrestrial ecosystems. A manipulative experiment simulating increased precipitation and atmospheric N deposition has been conducted for 9 years (2005-2013) in a semiarid grassland in Mongolian Plateau, China. Increased precipitation and N addition interactively affect soil respiration through the 9 years. The interactions demonstrated that N addition weakened the precipitation-induced stimulation of soil respiration, whereas increased precipitation exacerbated the negative impacts of N addition. The main effects of increased precipitation and N addition treatment on soil respiration were 15.8% stimulated and 14.2% suppressed, respectively. Moreover, a declining pattern and 2-year oscillation were observed for soil respiration response to N addition under increased precipitation. The dependence of soil respiration upon gross primary productivity and soil moisture, but not soil temperature, suggests that resources C substrate supply and water availability are more important than temperature in regulating interannual variations of soil C release in semiarid grassland ecosystems. The findings indicate that atmospheric N deposition may have the potential to mitigate soil C loss induced by increased precipitation, and highlight that long-term and multi-factor global change studies are critical for predicting the general patterns of terrestrial C cycling in response to global change in the future.
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Affiliation(s)
- Hongyan Han
- International Joint Research Laboratory for Global Change Ecology School of Life Sciences Henan University Kaifeng Henan China
| | - Yue Du
- College of Life Sciences University of Chinese Academy of Sciences Beijing China
| | - Dafeng Hui
- International Joint Research Laboratory for Global Change Ecology School of Life Sciences Henan University Kaifeng Henan China.,Department of Biological Sciences Tennessee State University Nashville TN USA
| | - Lin Jiang
- School of Biology Georgia Institute of Technology Atlanta GA USA
| | - Mingxing Zhong
- International Joint Research Laboratory for Global Change Ecology School of Life Sciences Henan University Kaifeng Henan China
| | - Shiqiang Wan
- International Joint Research Laboratory for Global Change Ecology School of Life Sciences Henan University Kaifeng Henan China
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30
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Soil Nitrogen Storage, Distribution, and Associated Controlling Factors in the Northeast Tibetan Plateau Shrublands. FORESTS 2017. [DOI: 10.3390/f8110416] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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31
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Zhang B, Tan X, Wang S, Chen M, Chen S, Ren T, Xia J, Bai Y, Huang J, Han X. Asymmetric sensitivity of ecosystem carbon and water processes in response to precipitation change in a semi‐arid steppe. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12836] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Bingwei Zhang
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing100093 China
- University of Chinese Academy of Sciences Beijing100049 China
| | - Xingru Tan
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing100093 China
- University of Chinese Academy of Sciences Beijing100049 China
| | - Shanshan Wang
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing100093 China
- University of Chinese Academy of Sciences Beijing100049 China
| | - Minling Chen
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing100093 China
- College of Chinese Language and Culture Jinan University Guangzhou510610 China
| | - Shiping Chen
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing100093 China
| | - Tingting Ren
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing100093 China
| | - Jianyang Xia
- Tiantong National Forest Ecosystem Observation and Research Station School of Ecological and Environmental Sciences East China Normal University Shanghai200062 China
| | - Yongfei Bai
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing100093 China
| | - Jianhui Huang
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing100093 China
| | - Xingguo Han
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing100093 China
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32
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Identifying the Relative Contributions of Climate and Grazing to Both Direction and Magnitude of Alpine Grassland Productivity Dynamics from 1993 to 2011 on the Northern Tibetan Plateau. REMOTE SENSING 2017. [DOI: 10.3390/rs9020136] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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33
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Plant functional trait diversity regulates the nonlinear response of productivity to regional climate change in Tibetan alpine grasslands. Sci Rep 2016; 6:35649. [PMID: 27759112 PMCID: PMC5069490 DOI: 10.1038/srep35649] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 09/30/2016] [Indexed: 12/05/2022] Open
Abstract
The biodiversity-productivity relationship is still under debate for alpine grasslands on the Tibetan Plateau. We know little about direct and indirect effects of biotic and abiotic drivers on this relationship, especially in regard to plant functional trait diversity. Here, we examine how aboveground net primary productivity (ANPP) and precipitation use efficiency (PUE) respond to climate, soil and community structure across alpine grasslands on the Northern Tibetan Plateau. We found that both ANPP and PUE showed nonlinear patterns along water availability and site altitude variation, which together accounted for 80.3% and 68.8% of variation in ANPP and PUE, respectively, by optimal generalized additive models. Functional trait divergence (FTD) and community weighted mean (CWM) of plant functional traits were as important as plant species diversity (PSD) for explaining the nonlinear productivity-climate relationship. These findings were confirmed by results from principal component analyses and structural equation models. We also found that FTD was negatively correlated with PSD across different alpine grasslands. Our results implicate: first, the combinatorial influences of temperature and precipitation gradients are important for predicting alpine grassland dynamics; second, the convergence and divergence of plant functional traits may have the potential to elucidate the effect of plant diversity on ecosystem functionality.
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