摘要
以贵州为中心的西南喀斯特地区的石漠化是我国实施西部大开发战略中所面临的根本性地域环境问题之一,喀斯特地区石漠化是一种与脆弱生态背景和人类活动相关联的土地退化过程,而土壤退化是土地退化的核心部分。本研究采集了贵州喀斯特地区的砂岩黄壤剖面和石灰土剖面的土壤样品,测定了剖面样品的土壤有机碳含量、土壤碳酸盐含量和土壤碳酸盐δ^(13)C。结果表明,砂岩黄壤和石灰土碳酸盐含量在剖面上的分布存在差异,黑色石灰土碳酸盐含量在剖面上的总体变化均表现出从上到下逐渐减小的趋势,土壤碳酸盐含量主要集中在表层土壤,而黄色石灰土和砂岩黄壤碳酸盐含量在剖面上的变化不大。而且在砂岩黄壤和石灰土中,土壤碳酸盐δ^(13)C值在剖面深度上的变化情况不同,表明了土壤有机碳向无机碳转化的程度,不同的成土过程及程度和成土环境的差异可能是砂岩黄壤和石灰土中土壤碳酸盐δ^(13)C值组成差异的主要原因。本研究提高了对区域碳库特征的认识,为喀斯特生态系统土壤有机质的生物地球化学循环研究提供了理论支撑。
Rocky desertification in the karst region of Southwest China with Guizhou Province as the center is one of the fundamental regional environmental problems faced by China in the implementation of the western development strategy.Rocky desertification in karst area is a land degradation process associated with fragile ecological background and human activities,and soil degradation is the core part of land degradation.In this study,soil samples from sandstone yellow soil profile and calcareous soil profile in Guizhou karst area were collected.The soil organic carbon content,soil carbonate content and its δ^(13)C of the profile samples were measured.The results showed that the distribution of carbonate in sandstone yellow soil and calcareous soil was different.The overall change of carbonate content in black limestone soil decreased gradually from top to bottom.While,for yellow limestone soil,carbonate mainly concentrated in surface soil,and little change was found for sandstone yellow soil.In addition,the variation of δ^(13)C in sandstone yellow soil and calcareous soil is different,which indicates the degree of transformation from organic carbon to inorganic carbon.The difference of soil forming process and degree,soil forming environment may be the main reason for the difference of δ^(13)C composition between sandstone yellow soil and calcareous soil.This study improves the understanding of regional carbon pool characteristics and provides theoretical support for the study of biogeochemical cycle of soil organic matter in karst ecosystem.
作者
李龙波
张兴勇
蔡大为
LI Longbo;ZANG Xingyong;CAI Dawei(Guizhou Institute of Geo-Environment Monitoring,Guiyang 550081,China;State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;Key Laboratory of Karst Environment and Geohazard Prevention,Ministry of Land and Resources,Guizhou University,Guiyang 550025,China)
出处
《地球与环境》
CAS
CSCD
北大核心
2021年第4期409-415,共7页
Earth and Environment
基金
国土资源部喀斯特环境与地质灾害重点实验室开放基金资助(2018K02)。
