生态环境学报2026，Vol.35Issue(6)：831-842,12.DOI:10.16258/j.cnki.1674-5906.2026.06.001
高寒草地土壤总有机碳与活性碳组分对退化和地形的响应
Responses of Soil Total Organic Carbon and Labile Carbon Components to Degradation and Topography of Alpine Grassland
摘要
Abstract
Soil organic carbon and labile organic carbon components decreased inevitably as the grassland degradation degree intensified,but their response mechanisms to topography type remain unclear.In this study,plant and soil samples with soil depth of 0-40 cm were collected from alpine degraded grasslands across different topography types on the Qinghai-Xizang Plateau.The mass fraction of soil organic carbon and the ratio of labile organic carbon components to total organic carbon were analyzed to explore the influence of grassland degradation and topography on the stability of soil organic carbon pool.Results showed that 1)compared with non-degraded beachland,the mass fraction of soil organic carbon(SOC),the ratios of microbial biomass carbon(MBC),dissolved organic carbon(DOC),easily oxidized organic carbon(EOC)to SOC in the heavily degraded beachland decreased by 18.8％,62.1％,36.6％and 38.1％,respectively.While in the heavily degraded steep-slopeland,these decreased by 41.8％,51.3％,34.2％and 11.6％,respectively compared with non-degraded steep-slopeland.This indicates that grassland degradation increases the stability of soil organic carbon pool,relatively.2)The mass fraction of SOC in the steep-slopeland was 30.0％higher than that in the beachland,but the w(MBC)/w(SOC),w(DOC)/w(SOC),w(EOC)/w(SOC)in the steep-slopeland were 66.9％,43.0％,and 36.7％lower than those in the beachland,respectively.This indicates that the stability of the soil organic carbon pool in the steep-slopeland increased relatively.3)Labile organic carbon components were positively correlated with above-ground biomass,below-ground biomass,soil organic carbon,soil moisture mass fraction,total carbon,total nitrogen,and negatively correlated with pH value,and below-ground biomass was the key factor affecting mass fraction of soil organic carbon and labile organic carbon components.In conclusion,the grassland degradation and topography affected the mass fraction of soil organic carbon and the ratio of labile organic carbon components to total organic carbon.The ratio of labile organic carbon components to total organic carbon can be used as key indicators to reflect the degradation of alpine grassland.For the restoration of alpine degraded grasslands under different topography types,appropriate methods should be adopted to reduce soil carbon emissions according to local conditions to cope with global climate change.关键词
高寒草地/草地退化/地形/土壤有机碳/土壤活性有机碳组分Key words
alpine grassland/grassland degradation/topography/soil organic carbon/soil labile organic carbon component分类
资源环境引用本文复制引用
王宇星,王文颖,熊友才,杨方堃,马燕梅..高寒草地土壤总有机碳与活性碳组分对退化和地形的响应[J].生态环境学报,2026,35(6):831-842,12.基金项目
国家重点研发计划项目(2023YFF1304305) （2023YFF1304305）
青海省自然科学基金项目(2025-ZJ-969T) （2025-ZJ-969T）
111引智基地(D23029) （D23029）
