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Full-Text Articles in Life Sciences
Disentangling Climatic And Anthropogenic Controls On Global Terrestrial Evapotranspiration Trends, Jiafu Mao, Wenting Fu, Xiaoying Shi, Daniel M. Ricciuto, Joshua B. Fisher, Robert E. Dickinson, Yaxing Wei, Willis Shem, Shilong Piao, Kaicun Wang, Christopher R. Schwalm, Hanqin Tian, Mingquan Mu, Altaf Arain, Philippe Ciais, Robert Cook, Yongdiu Dai, Daniel Hayes, Forrest M. Hoffman, Maoyi Huang, Suo Huang, Deborah N. Huntzinger, Akihiko Ito, Atul Jain, Anthony W. King, Huimin Lei, Chaoqun (Crystal) Lu, Huimin Lei, Anna M. Michalak, Changhui Peng, Shushi Peng, Benjamin Poulter, Kevin Schaefer, Elshin Jafarov, Peter E. Thornton, Weile Wang, Ning Zeng, Zhenzhong Zeng, Fang Zhao, Qiuan Zhu, Zaichun Zhu
Disentangling Climatic And Anthropogenic Controls On Global Terrestrial Evapotranspiration Trends, Jiafu Mao, Wenting Fu, Xiaoying Shi, Daniel M. Ricciuto, Joshua B. Fisher, Robert E. Dickinson, Yaxing Wei, Willis Shem, Shilong Piao, Kaicun Wang, Christopher R. Schwalm, Hanqin Tian, Mingquan Mu, Altaf Arain, Philippe Ciais, Robert Cook, Yongdiu Dai, Daniel Hayes, Forrest M. Hoffman, Maoyi Huang, Suo Huang, Deborah N. Huntzinger, Akihiko Ito, Atul Jain, Anthony W. King, Huimin Lei, Chaoqun (Crystal) Lu, Huimin Lei, Anna M. Michalak, Changhui Peng, Shushi Peng, Benjamin Poulter, Kevin Schaefer, Elshin Jafarov, Peter E. Thornton, Weile Wang, Ning Zeng, Zhenzhong Zeng, Fang Zhao, Qiuan Zhu, Zaichun Zhu
Chaoqun (Crystal) Lu
We examined natural and anthropogenic controls on terrestrial evapotranspiration (ET) changes from 1982 to 2010 using multiple estimates from remote sensing-based datasets and process-oriented land surface models.A significant increasing trend of ET in each hemisphere was consistently revealed by observationally-constrained data and multi-model ensembles that considered historic natural and anthropogenic drivers. The climate impacts were simulated to determine the spatiotemporal variations in ET. Globally, risingCO2 ranked second in these models after the predominant climatic influences, and yielded decreasing trends in canopy transpiration and ET, especially for tropical forests and high-latitude shrub land. Increasing nitrogen deposition slightly amplified global ET via …
Environmental Forcing Does Not Induce Diel Or Synoptic Variation In The Carbon Isotope Content Of Forest Soil Respiration, Steven J. Hall, D. R. Bowling, J. E. Egan
Environmental Forcing Does Not Induce Diel Or Synoptic Variation In The Carbon Isotope Content Of Forest Soil Respiration, Steven J. Hall, D. R. Bowling, J. E. Egan
Steven J. Hall
Recent studies have examined temporal fluctuations in the amount and carbon isotope content (δ13C) of CO2 produced by the respiration of roots and soil organisms. These changes have been correlated with diel cycles of environmental forcing (e.g., sunlight and soil temperature) and with synoptic-scale atmospheric motion (e.g., rain events and pressure-induced ventilation). We used an extensive suite of measurements to examine soil respiration over 2 months in a subalpine forest in Colorado, USA (the Niwot Ridge AmeriFlux forest). Observations included automated measurements of CO2 and δ13C of CO2 in the soil efflux, the soil gas profile, and forest air. There …
Toward “Optimal” Integration Of Terrestrial Biosphere Models, Christopher R. Schwalm, Deborah N. Huntzinger, Joshua B. Fisher, Anna M. Michalak, Kevin Bowman, Philippe Ciais, Robert Cook, Bassil El-Masri, Daniel Hayes, Maoyi Huang, Akihiko Ito, Atul Jain, Anthony W. King, Hiumin Lei, Junjie Liu, Chaoqun (Crystal) Lu, Jaifu Mao, Shushi Peng, Benjamin Poulter, Daniel Ricciuto, Kevin Schaefer, Xiaoying Shi, Bo Tao, Hanqin Tian, Weile Wang, Yaxing Wei, Jia Yang, Ning Zeng
Toward “Optimal” Integration Of Terrestrial Biosphere Models, Christopher R. Schwalm, Deborah N. Huntzinger, Joshua B. Fisher, Anna M. Michalak, Kevin Bowman, Philippe Ciais, Robert Cook, Bassil El-Masri, Daniel Hayes, Maoyi Huang, Akihiko Ito, Atul Jain, Anthony W. King, Hiumin Lei, Junjie Liu, Chaoqun (Crystal) Lu, Jaifu Mao, Shushi Peng, Benjamin Poulter, Daniel Ricciuto, Kevin Schaefer, Xiaoying Shi, Bo Tao, Hanqin Tian, Weile Wang, Yaxing Wei, Jia Yang, Ning Zeng
Chaoqun (Crystal) Lu
Multimodel ensembles (MME) are commonplace in Earth system modeling. Here we perform MME integration using a 10-member ensemble of terrestrial biosphere models (TBMs) from the Multiscale synthesis and Terrestrial Model Intercomparison Project (MsTMIP). We contrast optimal (skill based for present-day carbon cycling) versus naïve (“one model-one vote”) integration. MsTMIP optimal and naïve mean land sink strength estimates (−1.16 versus −1.15 Pg C per annum respectively) are statistically indistinguishable. This holds also for grid cell values and extends to gross uptake, biomass, and net ecosystem productivity. TBM skill is similarly indistinguishable. The added complexity of skill-based integration does not materially change …
Large Fluxes And Rapid Turnover Of Mineral-Associated Carbon Across Topographic Gradients In A Humid Tropical Forest: Insights From Paired 14c Analysis, Steven J. Hall, G. Mcnicol, T. Natake, W. L. Silver
Large Fluxes And Rapid Turnover Of Mineral-Associated Carbon Across Topographic Gradients In A Humid Tropical Forest: Insights From Paired 14c Analysis, Steven J. Hall, G. Mcnicol, T. Natake, W. L. Silver
Steven J. Hall
It has been proposed that the large soil carbon (C) stocks of humid tropical forests result predominantly from C stabilization by reactive minerals, whereas oxygen (O2) limitation of decomposition has received much less attention. We examined the importance of these factors in explaining patterns of C stocks and turnover in the Luquillo Experimental Forest, Puerto Rico, using radiocarbon (14C) measurements of contemporary and archived samples. Samples from ridge, slope, and valley positions spanned three soil orders (Ultisol, Oxisol, Inceptisol) representative of humid tropical forests, and differed in texture, reactive metal content, O2 availability, and root biomass. Mineral-associated C comprised the …
Global Methane And Nitrous Oxide Emissions From Terrestrial Ecosystems Due To Multiple Environmental Changes, Hanqin Tian, Guangsheng Chen, Chaoqun (Crystal) Lu, Xiaofeng Xu, Wei Ren, Bowen Zhang, Kamaljit Banger, Bo Tao, Shufen Pan, Mingliang Liu, Chi Zhang, Lori Bruhwiler, Steven Wofsy
Global Methane And Nitrous Oxide Emissions From Terrestrial Ecosystems Due To Multiple Environmental Changes, Hanqin Tian, Guangsheng Chen, Chaoqun (Crystal) Lu, Xiaofeng Xu, Wei Ren, Bowen Zhang, Kamaljit Banger, Bo Tao, Shufen Pan, Mingliang Liu, Chi Zhang, Lori Bruhwiler, Steven Wofsy
Chaoqun (Crystal) Lu
Greenhouse gas (GHG)-induced climate change is among the most pressing sustainability challenges facing humanity today, posing serious risks for ecosystem health. Methane (CH4) and nitrous oxide (N2O) are the two most important GHGs after carbon dioxide (CO2), but their regional and global budgets are not well known. In this study, we applied a process-based coupled biogeochemical model to concurrently estimate the magnitude and spatial and temporal patterns of CH4 and N2O fluxes as driven by multiple environmental changes, including climate variability, rising atmospheric CO2, increasing nitrogen deposition, tropospheric ozone pollution, land use change, and nitrogen fertilizer use. The estimated CH4 …
Differential Effects Of Canopy Trimming And Litter Deposition On Litterfall And Nutrient Dynamics In A Wet Subtropical Forest, Steven J. Hall, Whendee L. Silver, Grizelle González
Differential Effects Of Canopy Trimming And Litter Deposition On Litterfall And Nutrient Dynamics In A Wet Subtropical Forest, Steven J. Hall, Whendee L. Silver, Grizelle González
Steven J. Hall
Humid tropical forests have the highest rates of litterfall production globally, which fuels rapid nutrient recycling and high net ecosystem production. Severe storm events significantly alter patterns in litterfall mass and nutrient dynamics through a combination of canopy disturbance and litter deposition. In this study, we used a large-scale long-term manipulation experiment to explore the separate and combined effects of canopy trimming and litter deposition on litterfall rates and litter nutrient concentrations and content. The deposition of fine litter associated with the treatments was equivalent to more than two times the annual fine litterfall mass and nutrient content in control …