| Soil carbon pool is the largest carbon pool sink in terrestrial ecosystems,and its storage exceeds the sum of carbon in the atmosphere and vegetation,the small changes in its storage will have a significant impact on atmospheric carbon content.The stability of soil carbon pool is related to ecological processes such as exogenous carbon input,carbon retention time and soil respiration and other organic carbon mineralization releases,which are easily affected by climate and environment.Climate warming affects the composition of ecosystem and soil carbon cycling.The tundra ecosystem has a simple structure,weak anti-interference ability,and its vegetation and soil microorganisms are extremely sensitive to climate change,which has important indicative significance for global changes.Based on this,this paper took the tundra of Changbai Mountain as the study area,delineates the quadrats in the invasion community of Deyeuxia.Angustifolia（Kom.）Y.L.Chang caused by climate change,set up Open Top Chamber for warming,and set up control（no warming）quadrat,field observations,sampling and indoor analysis were combined to explore the effects of warming on the total amount of soil organic carbon pools,changed in organic carbon pool budgets,and components of organic carbon pools,and discussed the effects of warming on the stability of soil organic carbon pools in the Changbai Mountain tundra ecosystem,in order to reveal the possible impact of global climate change on the carbon cycle process.The main results were as follows:（1）Warming slightly increased the total amount of soil organic carbon pool,but didn’t reach a significant level（P>0.05）,and there was a significant positive correlation between soil organic carbon（SOC）and total soil nutrients（TC、TN、TP、C/N）.（2）Warming increased the changes of the budget of soil organic carbon pools.Warming increased the input of exogenous carbon,which was mainly manifested in the changes of the quantity,but had little effect on the properties of exogenous carbon;warming promoted the release of CO2and the release of soil available nutrients,increased the soil carbon output.（3）Different soil organic carbon components had different responses to warming.Warming increased the content of dissolved organic carbon（DOC）,easily oxidizable organic carbon（EOC）,and light group organic carbon（LFOC）in soil active organic carbon,but decreased the content of soil microbial biomass carbon（MBC）,heavy group organic carbon（HFOC）.The increase of soil organic carbon content by warming was mainly dominated by active organic carbon.Among the soil active organic carbons,warming had the most significant effect on easily oxidizable organic carbon（EOC）,followed by light group fraction organic carbon（LFOC）,and had the lowest effect on dissolved organic carbon（DOC）.（4）Due to the slow decomposition and more organic carbon accumulation,the stability of soil carbon pool in Changbai Mountain tundra were good.Warming increased the activity and quality of the organic carbon pool in Changbai Mountain tundra soil,but the stability will be slightly worsened by warming.Soil carbon pool stability had the strongest positive correlation with soil easily oxidizable organic carbon（EOC）and its proportion（EOC/SOC）.Warming makes soils release more CO2into the atmosphere,which will further exacerbating the greenhouse effect. |
