森林土壤碳库空间变异研究进展

Forest soil carbon pools are critical components of the global carbon cycle,with their quantity and stability profoundly influencing atmospheric carbon dioxide levels and playing a significant role as ecological carbon sinks.Understanding the spatiotemporal heterogeneity and complexity of forest soil carbon pools under changing environmental conditions is a prerequisite for effective management of these carbon stores.However,current knowledge in this area remains insufficiently developed.This paper aims to review relevant domestic and international literature,elucidate the mechanisms underlying the formation of forest soil carbon pools,systematically analyze the spatial variability characteristics of these pools and their key influencing factors,and explore methodologies for studying spatial heterogeneity.It also identifies critical issues for future research on spatial variation in forest soil carbon pools,thereby providing a foundational basis for efforts to maintain and enhance these carbon reservoirs.Overall,research on the spatial variability of forest soil carbon pools still encounters considerable uncertainty.The disparities in forest soil carbon pools across different climatic zones are particularly pronounced:tropical regions exhibit high inputs and outputs of soil organic carbon(SOC),leading to relatively rich soil carbon reservoirs,whereas boreal regions demonstrate significant stability in their soil carbon pools due to lower temperatures.In contrast to humid regions,arid areas experience intensified spatial heterogeneity of forest soil carbon pools due to severe soil and water loss.Moreover,under varying elevation and topographical conditions,high-altitude regions accumulate soil carbon more significantly,favoring SOC retention,whereas low-altitude areas exhibit faster turnover of soil carbon pools.The SOC content varies significantly across different soil depths,with substantial quantities of SOC stored in deeper soils,which,influenced by global climate change,hold considerable potential for releasing CO2 into the atmosphere.Variations in forest management practices and land use across different countries and regions result in consistently higher soil carbon stocks in developed areas compared to less developed ones.Additionally,the spatial variability of forest soil carbon pools is influenced by multiple factors,including climate,vegetation,topography,human activities,and fire;the relationships among these factors are not merely linear but interactively contribute to the heterogeneous characteristics of forest soil carbon pools.In terms of research methodologies,traditional survey methods are suitable for small-scale studies,while novel modeling approaches can expand research areas and facilitate future predictions,albeit with slightly lower precision compared to conventional methods.Future research should aim to broaden the spatial scale of studies,further explore the balance points of land use changes,and strengthen investigations into forest soil carbon pools under the influence of various factors.Moreover,integrating the advantages of different research methodologies will enable a comprehensive understanding of the dynamic characteristics of soil carbon pools,while also focusing on deeper soil layers to obtain more comprehensive data on forest soil carbon reserves.