Climate warming alters subsoil but not topsoil carbon dynamics in alpine grassland

2019 ◽  
Vol 25 (12) ◽  
pp. 4383-4393 ◽  
Author(s):  
Juan Jia ◽  
Zhenjiao Cao ◽  
Chengzhu Liu ◽  
Zhenhua Zhang ◽  
Li Lin ◽  
...  
Keyword(s):  
Climate Warming ◽  
Carbon Dynamics ◽  
Alpine Grassland

scholarly journals Projected changes of alpine grassland carbon dynamics in response to climate change and elevated CO2concentrations under Representative Concentration Pathways (RCP) scenarios

2019 ◽  
Author(s):  
Pengfei Han ◽  
Xiaohui Lin ◽  
Wen Zhang ◽  
Guocheng Wang
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Carbon Cycle ◽  
Carbon Budget ◽  
Carbon Fluxes ◽  
Carbon Dynamics ◽  
Alpine Grassland ◽  
The Tibetan Plateau ◽  
Rcp Scenarios ◽  
Representative Concentration Pathways

AbstractThe Tibetan Plateau is an important component of the global carbon cycle due to the large permafrost carbon pool and its vulnerability to climate warming. The Tibetan Plateau has experienced a noticeable warming over the past few decades and is projected to continue warming in the future. However, the direction and magnitude of carbon fluxes responses to climate change and elevated CO2concentration under Representative Concentration Pathways (RCP) scenarios in the Tibetan Plateau grassland are poorly known. Here, we used a calibrated and validated biogeochemistry model, CENTURY, to quantify the contributions of climate change and elevated CO2on the future carbon budget in the alpine grassland under three RCP scenarios. Though the Tibetan Plateau grassland was projected a net carbon sink of 16 ~ 25 Tg C yr-1in the 21st century, the capacity of carbon sequestration was predicted to decrease gradually because climate-driven increases in heterotrophic respiration (Rh) (with linear slopes 0.49 ~ 1.62 g C m-2yr-1) was greater than the net primary production (NPP) (0.35 ~ 1.52 g C m-2yr-1). However, the elevated CO2contributed more to plant growth (1.9% ~ 7.3%) than decomposition (1.7% ~ 6.1%), which could offset the warming-induced carbon loss. The interannual and decadal-scale dynamics of the carbon fluxes in the alpine grassland were primarily controlled by temperature, while the role of precipitation became increasingly important in modulating carbon cycle. The strengthened correlation between precipitation and carbon budget suggested that further research should consider the performance of precipitation in evaluating carbon dynamics in a warmer climate scenario.

scholarly journals Modeling the carbon dynamics of alpine grassland in the Qinghai-Tibetan Plateau under scenarios of 1.5 and 2 °C global warming

2019 ◽  
Vol 10 (2) ◽  
pp. 80-91 ◽  
Author(s):  
Shu-Hua Yi ◽  
Bo Xiang ◽  
Bao-Ping Meng ◽  
Xiao-Dong Wu ◽  
Yong-Jian Ding
Keyword(s):  
Global Warming ◽  
Tibetan Plateau ◽  
Carbon Dynamics ◽  
Alpine Grassland

scholarly journals The role of snow cover affecting boreal-arctic soil freeze–thaw and carbon dynamics

2015 ◽  
Vol 12 (19) ◽  
pp. 5811-5829 ◽  
Author(s):  
Y. Yi ◽  
J. S. Kimball ◽  
M. A. Rawlins ◽  
M. Moghaddam ◽  
E. S. Euskirchen
Keyword(s):  
Soil Carbon ◽  
Snow Cover ◽  
Climate Warming ◽  
Carbon Dynamics ◽  
Carbon Pool ◽  
Large Impact ◽  
Soil Layers ◽  
Freeze Thaw ◽  
The Past ◽  
Snow Cover Extent

Abstract. Northern Hemisphere permafrost affected land areas contain about twice as much carbon as the global atmosphere. This vast carbon pool is vulnerable to accelerated losses through mobilization and decomposition under projected global warming. Satellite data records spanning the past 3 decades indicate widespread reductions (~ 0.8–1.3 days decade−1) in the mean annual snow cover extent and frozen-season duration across the pan-Arctic domain, coincident with regional climate warming trends. How the soil carbon pool responds to these changes will have a large impact on regional and global climate. Here, we developed a coupled terrestrial carbon and hydrology model framework with a detailed 1-D soil heat transfer representation to investigate the sensitivity of soil organic carbon stocks and soil decomposition to climate warming and changes in snow cover conditions in the pan-Arctic region over the past 3 decades (1982–2010). Our results indicate widespread soil active layer deepening across the pan-Arctic, with a mean decadal trend of 6.6 ± 12.0 (SD) cm, corresponding to widespread warming. Warming promotes vegetation growth and soil heterotrophic respiration particularly within surface soil layers (≤ 0.2 m). The model simulations also show that seasonal snow cover has a large impact on soil temperatures, whereby increases in snow cover promote deeper (≥ 0.5 m) soil layer warming and soil respiration, while inhibiting soil decomposition from surface (≤ 0.2 m) soil layers, especially in colder climate zones (mean annual T ≤ −10 °C). Our results demonstrate the important control of snow cover on northern soil freeze–thaw and soil carbon decomposition processes and the necessity of considering both warming and a change in precipitation and snow cover regimes in characterizing permafrost soil carbon dynamics.

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