Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要:
Peatlands in Zoige Plateau contains more than half of peatland carbon stock in China. This part of carbon is losing with climate change through dissolved organic carbon (DOC) export and carbon dioxide (CO2) emissions, both of which are vulnerable to the environmental changes, especially on the Zoige Plateau with a pace of twice the observed rate of global climate warming. This research aimed to understand how climate change including soil warming, rainfall reduction and water table change affect CO2emissions and whether the trends of changes in CO2emission are consistent with those of pore water DOC concentration. A mesocosm experiment was designed to investigate the CO2emission and pore water DOC during the growing seasons of 2009–2010 under scenarios of passive soil warming, 20% rainfall reduction and changes to the water table levels. The results showed a positive relationship between CO2emission and DOC concentration. For single factor effect, we found no significant relationship between water table and CO2emission or DOC concentration. However, temperature at 5�cm depth was found to have positive linear relationship with CO2emission and DOC concentration. The combined effect of soil warming and rainfall reduction increased CO2emission by 96.8%. It suggested that the drying and warming could stimulate potential emission of CO2. Extending this result to the entire peatland area in Zoige Plateau translates into 0.45�Tg CO2emission per year over a growing season. These results suggested that the dryer and warmer Zoige Plateau will increase CO2emission. We also found the contribution rate of DOC concentration to CO2emission was increased by 12.1% in the surface layer and decreased by 13.8% in the subsurface layer with combined treatment of soil warming and rainfall reduction, which indicated that the warmer and dryer environmental conditions stimulate surface peat decomposition process. � 2016 Elsevier Ltd
School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China; CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utlization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China; Zoige Peatland and Global Change Research Station, Chengdu Institute of Biology, Chinese Academy of Sciences, Hongyuan, China; Laboratory for Ecological Forecasting and Global Change, College of Forestry, Northwest A & F University, Yangling, China; State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China; Center of CEF/ESCER, Department of Biological Science, University of Quebec at Montreal, Montreal, Canada
Recommended Citation:
Yang G,, Wang M,, Chen H,et al. Responses of CO2 emission and pore water DOC concentration to soil warming and water table drawdown in Zoige Peatlands[J]. Atmospheric Environment,2017-01-01,152