氮添加对森林土壤有机碳库固存及CO2排放的影响研究进展OA北大核心CHSSCDCSTPCD

Nitrogen addition causes changes in soil physicochemical properties and nutrient effectiveness.As a result,the carbon assimilation capacity of forest plants and the belowground carbon allocation patterns also change accordingly,generally promoting the growth of woody plants and increasing the input of carbon from litter and plant roots into the soil.This alteration in plant-derived organic matter quantity and chemical composition occurs in response to nitrogen addition.At the same time,the community structure and ecological functions of soil microorganisms are also influenced by nitrogen addition.Since the processes such as organic carbon decomposition,transformation,and stabilization in soil are driven by microorganisms,the differences in substrate supply and microbial response caused by nitrogen addition will affect the mineralization of organic carbon in forest soils,and ultimately affect the canbon sequestration and stabilization,and CO2 emission from forest soil organic carbon pools.However,the influencing mechanism of nitrogen addition impact on the sequestration capacity and CO2 emission characteristics of forest soil organic carbon pools is still unclear.Therefore,this paper takes the carbon cycle process of forest soils as a clue and reviews the effects of nitrogen addition on the processes of substrate supply,soil organic carbon excitation effect,and microbial carbon metabolism.We try to sort out the microbial-driven mechanism of organic carbon decomposition,transformation,and stabilization in forest soils under the influence of nitrogen addition.The results will help predict the actual effects of nitrogen addition on the carbon sequestration capacity caused by nitrogen addition in forest soils,in order to better predict the characteristics of forest soil carbon cycle in the context of increasing nitrogen deposition in the future.It provides a reference for improving the sequestration capacity of forest soil organic carbon pools and reducing CO2 emissions.At the same time,problems and shortcomings existing in the current research are analyzed and prospects for future research hotspots in this field are provided.