摘要
为了探讨土壤有机质在降解过程中的迁移、赋存规律 ,利用C3植物与C4 植物明显的δ13C值差异 ,选取贵州茂兰保护区内农林生态系统发生转换生长的地域 ,分析土壤的不同粒径组分和比重组分中土壤有机质的δ13C值 .结果表明 ,粗砂中的土壤有机质年代最新 ,细粉中的土壤有机质年代最老 ,有机质在降解过程中 ,在土壤各粒径组分中的迁移次序是 :粗砂 <细砂 <粗粉 <粘土 <细粉 ;土壤重组分中的有机质年代较老 ,以降解充分、稳定的有机无机复合体为主 ,相对而言 ,轻组分中的有机质含有更多的降解尚不充分。
On the basis of different photosynthetic pathway,there's obvious difference in δ 13 C values between C\-3 plants and C\-4 plants.Use this characteristic,the δ 13 C values in different size and density fractions of two profile soil samples either in farm land and forest lands near Maolan Karst virgin forest was analyzed,there plant C\-3 plants previously and plant C\-4 plants now.Results showed that the δ 13 C values of different size fractions in forest soil aere δ 13 C coarse sand < δ 13 C fine sand < δ 13 C coarse silt < δ 13 C clay < δ 13 C fine silt ,and the δ 13 C values of different size fractions in farmland soil were δ 13 C coarse sand > δ 13 C fine sand > δ 13 C coarse silt > δ 13 C clay > δ 13 C fine silt ,it indicated that the soil organic matter was fresh in coarse sand and oldest in fine silt.The δ 13 C values of different density fractions in forest soil ware δ 13 C light < δ 13 C heavy ,and the δ 13 C values of different density fractions in farmland soil were δ 13 C light > δ 13 C heavy ,it also indicated that the soil organic matter was fresh in light fractions and old in heavy fractions.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2002年第4期89-92,共4页
Environmental Science
基金
国家自然科学基金项目 (498330 0 2和 4 9772 175 )
中科院知识创新工程项目 (KZCX2 10 5 )
环境地球化学国家重点实验室创新领域项目
