贵州省喀斯特地区石漠化土壤有机碳和全氮变异特征  

Soil organic carbon and nitrogen variability in the process of rocky desertification in karst region,Guizhou Province

作　　者：李孝良[1,2] 陈效民[1] 周炼川[1] 周方方[2] 

机构地区：[1]南京农业大学资源与环境科学学院,江苏南京210095 [2]安徽科技学院城建与环境学院,安徽凤阳233100

出　　处：《南京农业大学学报》2010年第4期75-80,共6页Journal of Nanjing Agricultural University

基　　金：国家973计划项目(2006CB403205)

摘　　要：通过对贵州省喀斯特地区不同石漠化阶段的土壤分析,研究了喀斯特地区土壤全氮和有机碳的变异特征。研究结果表明:随石漠化程度增加,土壤全氮、总有机碳、轻组有机碳和重组有机碳含量均呈降低的趋势,且轻组有机碳占总有机碳的比例有减少趋势。在土体分布上,研究区土壤全氮和总有机碳含量从大到小均依次表现为表土层、心土层、底土层,且随石漠化程度加深,表现出表土侵蚀现象。研究区土壤有机碳和全氮含量季节性变化特征明显,以高温高湿的夏秋季较低,冬季较高;在变异幅度上,以未石漠化和潜在石漠化土壤全氮和总有机碳的变异幅度较大,土壤总有机碳库的更新比例分别为19%和20%,而轻度和中度石漠化阶段土壤总有机碳库更新比例较低,仅为11%和14%。喀斯特地区土壤全氮、总有机碳、轻组有机碳和重组有机碳含量与土壤基本性质间表现出显著的相关关系,与土壤容重、碳酸钙含量、颗粒组成间呈显著或极显著线性相关关系。Through the soil analysis in different karst rocky desertification phases in Guizhou Province,the variability character of soil total nitrogen （N） and soil organic carbon （SOC） were studied.The results were as follows：with the aggravation of rocky desertification,the contents of soil total N,SOC,light fraction organic carbon （LFOC） and heavy fraction organic carbon （HFOC） trended downwards,and the ratio of LFOC in SOC was decreasing.The contents of soil total N and SOC in different soil profiles were surface layer,subsurface layer,and bottom layer.The soil surface erosion was found with the aggravation of rocky desertification.The temporal variability of soil total N and SOC in karst region was obvious during the studied period.Because of high temperature and humidity,the contents of soil N and SOC in summer and fall was lower than those in winter.The variability range of soil total N and SOC in the phase of non-degraded and potential rocky desertification was higher than that in light rocky desertification and moderate rocky desertification.The SOC refresh rates in the phase of non-degraded and potential,light and moderate rocky desertification were 19%,20%,11% and 14% respectively.There were significant correlative relationships between soil N,SOC,LFOC,HFOC and soil CaCO3 content, 0.02 mm sand,bulk density.

关 键 词：喀斯特石漠化 有机碳 全氮 变异特征 贵州省 

分 类 号：S153.6[农业科学—土壤学]