Effects Of Simulated Climate Warming On Carbon Stability From Alpine Peat Wetland And Its Mechanism

The energy balance of the entire ecosystem is affected by the terrestrial carbon cycle.Carbon cycle have attracted widespread attentions,since the stability of terrestrial soil carbon pools dependend upon environmental change characterized by warming caused by the increase of CO2 concentration,nitrogen deposition and nutrient input.The research was carried by open top chamber(OTC)in alpine peat wetland,in the eastern region of the Qinghai-Tibet,China,and Carex muliensis and lasiocarpa is the research object,using OTC to simulate the field warming.The response of the litter decomposition rate,soil mineralization rate,labile carbon pools and molecular structure to warming was investigated.High-throughput sequencing was used to detect microbial communities to reveal the influence mechanism,and the results of our finding are as follows:The OTC realized multi field gradient increasing greenhouse warming,and increasing temperature also lead to soil water content to decrease,and low,medium and high temperature decreased the water content by 1%,4%and 7%,respectively.Temperature enhancement has significantly increased litter degradation rate,and promoted carbon input.Litter decomposition rate increased by 5%,8%and 6%by the low,medium and high temperature.The residual rate of nutrients in litter varied with the number of days of decomposition.The residual rate of organic carbon decreased with the number of decomposition days,while nitrogen residual rate had been increased before decreased.Increasing the temperature increases soil mineralization rate and soil carbon output.Soil CO2 flux in response to temperature were 15?>25?>5?,suggesting that storage carbon capacity in soil was decreased by temperature.The concentration of water-soluble carbon and oxidizable carbon components was increased by 7%and 5%by warming in the soil,respectively.Increasing the temperature not only improved water-soluble and oxidizable labile organic carbon concentration,but also shifted the relative content of carbon functional groups in the soil.The relative contents of alkoxy C and carboxyl C were increased by 8%and 15%by temperature,whereas the relative contents of alkyl C and aromatic C were reduced by 6%and 11%.Increasing temperature significantly decreased the degradability,humification and hydrophobicity,leading to lower stability of soil organic carbon.The bacteria of proteobacteria is mainly bacteria in the soil,and the low,medium and high temperature increased the number of soil bacterial OTU by 11%,11%and 2%,respectively.The diversity and the abundance of the bacteria were significantly increased by the low temperature and high temperature relative to the control,whereas high temperature exerted a neutral effect on it.Temperature increase not only increased bacterial diversity,but also increased soil urease,(3-glucosidase and phosphatase activity.?-glucosidase activity was increased by 4%,10%and 6%by low,medium and high temperature,respectively.Warming increased microbial activities,promoted C cycle and reduced C stability.