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Articles 1 - 11 of 11

Full-Text Articles in Life Sciences

Responses Of Global Terrestrial Evapotranspiration To Climate Change And Increasing Atmospheric Co2 In The 21st Century, Shufen Pan, Hanqin Tian, Shree R. S. Dangal, Qichun Yang, Jia Yang, Chaoqun (Crystal) Lu, Bo Tao, Wei Ren, Zhiyun Ouyang Jan 2015

Responses Of Global Terrestrial Evapotranspiration To Climate Change And Increasing Atmospheric Co2 In The 21st Century, Shufen Pan, Hanqin Tian, Shree R. S. Dangal, Qichun Yang, Jia Yang, Chaoqun (Crystal) Lu, Bo Tao, Wei Ren, Zhiyun Ouyang

Chaoqun (Crystal) Lu

Quantifying the spatial and temporal patterns of the water lost to the atmosphere through land surface evapotranspiration (ET) is essential for understanding the global hydrological cycle, but remains much uncertain. In this study, we use the Dynamic Land Ecosystem Model to estimate the global terrestrial ET during 2000–2009 and project its changes in response to climate change and increasing atmospheric CO2 under two IPCC SRES scenarios (A2 and B1) during 2010–2099. Modeled results show a mean annual global terrestrial ET of about 549 (545–552) mm yr−1 during 2000–2009. Relative to the 2000s, global terrestrial ET for the 2090s would increase …


Complex Spatiotemporal Responses Of Global Terrestrial Primary Production To Climate Change And Increasing Atmospheric Co2 In The 21st Century, Shufen Pan, Hanqin Tian, Shree R. S. Dangal, Chi Zhang, Jia Yang, Bo Tao, Zhiyun Ouyang, Xiaoke Wang, Chaoqun (Crystal) Lu, Wei Ren, Kamaljit Banger, Qichun Yang, Bowen Zhang, Xia Li Nov 2014

Complex Spatiotemporal Responses Of Global Terrestrial Primary Production To Climate Change And Increasing Atmospheric Co2 In The 21st Century, Shufen Pan, Hanqin Tian, Shree R. S. Dangal, Chi Zhang, Jia Yang, Bo Tao, Zhiyun Ouyang, Xiaoke Wang, Chaoqun (Crystal) Lu, Wei Ren, Kamaljit Banger, Qichun Yang, Bowen Zhang, Xia Li

Chaoqun (Crystal) Lu

Quantitative information on the response of global terrestrial net primary production (NPP) to climate change and increasing atmospheric CO2 is essential for climate change adaptation and mitigation in the 21st century. Using a process-based ecosystem model (the Dynamic Land Ecosystem Model, DLEM), we quantified the magnitude and spatiotemporal variations of contemporary (2000s) global NPP, and projected its potential responses to climate and CO2 changes in the 21st century under the Special Report on Emission Scenarios (SRES) A2 and B1 of Intergovernmental Panel on Climate Change (IPCC). We estimated a global terrestrial NPP of 54.6 (52.8–56.4) PgC yr−1 as a result …


Impact Of Large-Scale Climate Extremes On Biospheric Carbon Fluxes: An Intercomparison Based On Mstmip Data, Jakov Zscheischler, Anna M. Michalak, Christopher Schwalm, Miguel D. Mahecha, Deborah N. Huntzinger, Markus Reichstein, Gwenaëlle Berthier, Philippe Ciais, Robert B. Cook, Bassil El-Masri, Maoyi Huang, Akihiko Ito, Atul Jain, Anthony King, Huimin Lei, Chaoqun (Crystal) Lu, Jiafu Mao, Shushi Peng, Benjamin Poulter, Daniel Ricciuto, Xiaoying Shi, Bo Tao, Hanqin Tian, Nicolas Viovy, Weile Wang, Yaxing Wei, Jia Yang, Ning Zeng Jun 2014

Impact Of Large-Scale Climate Extremes On Biospheric Carbon Fluxes: An Intercomparison Based On Mstmip Data, Jakov Zscheischler, Anna M. Michalak, Christopher Schwalm, Miguel D. Mahecha, Deborah N. Huntzinger, Markus Reichstein, Gwenaëlle Berthier, Philippe Ciais, Robert B. Cook, Bassil El-Masri, Maoyi Huang, Akihiko Ito, Atul Jain, Anthony King, Huimin Lei, Chaoqun (Crystal) Lu, Jiafu Mao, Shushi Peng, Benjamin Poulter, Daniel Ricciuto, Xiaoying Shi, Bo Tao, Hanqin Tian, Nicolas Viovy, Weile Wang, Yaxing Wei, Jia Yang, Ning Zeng

Chaoqun (Crystal) Lu

Understanding the role of climate extremes and their impact on the carbon (C) cycle is increasingly a focus of Earth system science. Climate extremes such as droughts, heat waves, or heavy precipitation events can cause substantial changes in terrestrial C fluxes. On the other hand, extreme changes in C fluxes are often, but not always, driven by extreme climate conditions. Here we present an analysis of how extremes in temperature and precipitation, and extreme changes in terrestrial C fluxes are related to each other in 10 state-of-the-art terrestrial carbon models, all driven by the same climate forcing. We use model …


Climate And Land Use Controls On Soil Organic Carbon In The Loess Plateau Region Of China, Yaai Dang, Wei Ren, Bo Tao, Guangsheng Chen, Chaoqun (Crystal) Lu, Jia Yang, Shufen Pan, Guodong Wang, Shiqing Li, Hanqin Tian May 2014

Climate And Land Use Controls On Soil Organic Carbon In The Loess Plateau Region Of China, Yaai Dang, Wei Ren, Bo Tao, Guangsheng Chen, Chaoqun (Crystal) Lu, Jia Yang, Shufen Pan, Guodong Wang, Shiqing Li, Hanqin Tian

Chaoqun (Crystal) Lu

The Loess Plateau of China has the highest soil erosion rate in the world where billion tons of soil is annually washed into Yellow River. In recent decades this region has experienced significant climate change and policy-driven land conversion. However, it has not yet been well investigated how these changes in climate and land use have affected soil organic carbon (SOC) storage on the Loess Plateau. By using the Dynamic Land Ecosystem Model (DLEM), we quantified the effects of climate and land use on SOC storage on the Loess Plateau in the context of multiple environmental factors during the period …


Effect Of Continued Nitrogen Enrichment On Greenhouse Gas Emissions From A Wetland Ecosystem In The Sanjiang Plain, Northeast China: A 5 Year Nitrogen Addition Experiment, Changchun Song, Lili Wang, Hanqin Tian, Deyan Liu, Chaoqun (Crystal) Lu, Xiaofeng Xu, Lihua Zhang, Guisheng Yang, Zhongmei Wan Jun 2013

Effect Of Continued Nitrogen Enrichment On Greenhouse Gas Emissions From A Wetland Ecosystem In The Sanjiang Plain, Northeast China: A 5 Year Nitrogen Addition Experiment, Changchun Song, Lili Wang, Hanqin Tian, Deyan Liu, Chaoqun (Crystal) Lu, Xiaofeng Xu, Lihua Zhang, Guisheng Yang, Zhongmei Wan

Chaoqun (Crystal) Lu

Mounting evidence supports that wetland ecosystems, one of the largest carbon pools on the earth, are exposed to ample nitrogen (N) additions due to atmospheric deposition or N loading from upstream agricultural fertilizer application. However, our understanding of how N enrichment affects the fluxes of greenhouse gases (GHGs) in wetlands is weak. A 5 year N addition experiment was conducted to examine the responses of CH4 and N2O fluxes as well as ecosystem respiration from wetlands in the Sanjiang Plain, Northeast China, through 2005 to 2009. Four levels of N addition (control, 0 kg N ha−1 yr−1; low-level, 60 kg …


Effects Of Elevated Carbon Dioxide And Increased Temperature On Methane And Nitrous Oxide Fluxes: Evidence From Field Experiments, Feike A. Dijlstra, Stephen A. Prior, G. Brett Renion, H. Allen Torbert, Hanqin Tian, Chaoqun (Crystal) Lu, Rodney T. Venterea Dec 2012

Effects Of Elevated Carbon Dioxide And Increased Temperature On Methane And Nitrous Oxide Fluxes: Evidence From Field Experiments, Feike A. Dijlstra, Stephen A. Prior, G. Brett Renion, H. Allen Torbert, Hanqin Tian, Chaoqun (Crystal) Lu, Rodney T. Venterea

Chaoqun (Crystal) Lu

Climate change could alter terrestrial ecosystems, which are important sources and sinks of the potent green-house gases (GHGs) nitrous oxide (N2O) and methane (CH4), in ways that either stimulate or decrease the magnitude and duration of global warming. Using manipulative field experiments, we assessed how N2O and CH4 soil fluxes responded to a rise in atmospheric carbon dioxide (CO2) concentration and to increased air temperature. Nitrous oxide and CH4 responses varied greatly among studied ecosystems. Elevated CO2 often stimulated N2O emissions in fertilized systems and CH4 emissions in wetlands, peatlands, and rice paddy fields; both effects were stronger in clayey …


Century-Scale Responses Of Ecosystem Carbon Storage And Flux To Multiple Environmental Changes In The Southern United States, Hanqin Tian, Guangsheng Chen, Chi Zang, Mingliang Liu, Ge Sun, Arthur Chappelka, Wei Ren, Xiaofeng Xu, Chaoqun Lu, Shufen Pan, Hua Chen, Dafeng Hui, Steven Mcnulty, Graeme Lockaby, Eric Vance Jun 2012

Century-Scale Responses Of Ecosystem Carbon Storage And Flux To Multiple Environmental Changes In The Southern United States, Hanqin Tian, Guangsheng Chen, Chi Zang, Mingliang Liu, Ge Sun, Arthur Chappelka, Wei Ren, Xiaofeng Xu, Chaoqun Lu, Shufen Pan, Hua Chen, Dafeng Hui, Steven Mcnulty, Graeme Lockaby, Eric Vance

Chaoqun (Crystal) Lu

Terrestrial ecosystems in the southern United States (SUS) have experienced a complex set of changes in climate, atmospheric CO2 concentration, tropospheric ozone (O3), nitrogen (N) deposition, and land-use and land-cover change (LULCC) during the past century. Although each of these factors has received attention for its alterations on ecosystem carbon (C) dynamics, their combined effects and relative contributions are still not well understood. By using the Dynamic Land Ecosystem Model (DLEM) in combination with spatially explicit, long-term historical data series on multiple environmental factors, we examined the century-scale responses of ecosystem C storage and flux to multiple environmental changes in …


Net Exchanges Of Co2, Ch4, And N2o Between China's Terrestrial Ecosystems And The Atmosphere And Their Contributions To Global Climate Warming, Hanqin Tian, Xiaofeng Xu, Chaoqun (Crystal) Lu, Mingliang Liu, Wei Ren, Guangsheng Chen, Jerry Melillo, Jiyuan Liu Jun 2011

Net Exchanges Of Co2, Ch4, And N2o Between China's Terrestrial Ecosystems And The Atmosphere And Their Contributions To Global Climate Warming, Hanqin Tian, Xiaofeng Xu, Chaoqun (Crystal) Lu, Mingliang Liu, Wei Ren, Guangsheng Chen, Jerry Melillo, Jiyuan Liu

Chaoqun (Crystal) Lu

China's terrestrial ecosystems have been recognized as an atmospheric CO2 sink; however, it is uncertain whether this sink can alleviate global warming given the fluxes of CH4 and N2O. In this study, we used a process-based ecosystem model driven by multiple environmental factors to examine the net warming potential resulting from net exchanges of CO2, CH4, and N2O between China's terrestrial ecosystems and the atmosphere during 1961–2005. In the past 45 years, China's terrestrial ecosystems were found to sequestrate CO2 at a rate of 179.3 Tg C yr−1 with a 95% confidence range of (62.0 Tg C yr−1, 264.9 Tg …


Impacts Of Tropospheric Ozone And Climate Change On Net Primary Productivity And Net Carbon Exchange Of China's Forest Ecosystems, Wei Ren, Hanqin Tian, Bo Tao, Arthur Chappelka, Ge Sun, Chaoqun (Crystal) Lu, Mingliang Liu, Guangsheng Chen, Xiaofeng Xu May 2011

Impacts Of Tropospheric Ozone And Climate Change On Net Primary Productivity And Net Carbon Exchange Of China's Forest Ecosystems, Wei Ren, Hanqin Tian, Bo Tao, Arthur Chappelka, Ge Sun, Chaoqun (Crystal) Lu, Mingliang Liu, Guangsheng Chen, Xiaofeng Xu

Chaoqun (Crystal) Lu

We investigated how ozone pollution and climate change/variability have interactively affected net primary productivity (NPP) and net carbon exchange (NCE) across China's forest ecosystem in the past half century. Using the dynamic land ecosystem model (DLEM) in conjunction with 10-km-resolution gridded historical data sets (tropospheric O3 concentrations, climate variability/change, and other environmental factors such as land-cover/land-use change (LCLUC), increasing CO2 and nitrogen deposition), we conducted nine simulation experiments to: (1) investigate the temporo-spatial patterns of NPP and NCE in China's forest ecosystems from 1961–2005; and (2) quantify the effects of tropospheric O3 pollution alone or in combination with climate variability …


Attribution Of Spatial And Temporal Variations In Terrestrial Methane Flux Over North America, X. F. Xu, Hanqin Tian, C. Zhang, M. L. Liu, Wei Ren, G. S. Chen, Chaoqun (Crystal) Lu, L. Bruhwiler Nov 2010

Attribution Of Spatial And Temporal Variations In Terrestrial Methane Flux Over North America, X. F. Xu, Hanqin Tian, C. Zhang, M. L. Liu, Wei Ren, G. S. Chen, Chaoqun (Crystal) Lu, L. Bruhwiler

Chaoqun (Crystal) Lu

The attribution of spatial and temporal variations in terrestrial methane (CH4) flux is essential for assessing and mitigating CH4 emission from terrestrial ecosystems. In this study, we used a process-based model, the Dynamic Land Ecosystem Model (DLEM), in conjunction with spatial data of six major environmental factors to attribute the spatial and temporal variations in the terrestrial methane (CH4) flux over North America from 1979 to 2008 to six individual driving factors and their interaction. Over the past three decades, our simulations indicate that global change factors accumulatively contributed 23.51 ± 9.61 T g CH4-C (1 Tg = 1012 g) …


Spatial And Temporal Patterns Of Ch4 And N2o Fluxes In Terrestrial Ecosystems Of North America During 1979–2008: Application Of A Global Biogeochemistry Model, Hanqin Tian, X. Xu, M. Liu, Wei Ren, C. Zhang, G. Chen, Chaoqun (Crystal) Lu Sep 2010

Spatial And Temporal Patterns Of Ch4 And N2o Fluxes In Terrestrial Ecosystems Of North America During 1979–2008: Application Of A Global Biogeochemistry Model, Hanqin Tian, X. Xu, M. Liu, Wei Ren, C. Zhang, G. Chen, Chaoqun (Crystal) Lu

Chaoqun (Crystal) Lu

Continental-scale estimations of terrestrial methane (CH4) and nitrous oxide (N2O) fluxes over a long time period are crucial to accurately assess the global balance of greenhouse gases and enhance our understanding and prediction of global climate change and terrestrial ecosystem feedbacks. Using a process-based global biogeochemical model, the Dynamic Land Ecosystem Model (DLEM), we quantified simultaneously CH4 and N2O fluxes in North America's terrestrial ecosystems from 1979 to 2008. During the past 30 years, approximately 14.69 ± 1.64 T g C a−1 (1 T g = 1012 g) of CH4, and 1.94 ± 0.1 T g N a−1 of N2O …