| 稳定碳同位素示踪农林生态转换系统中土壤有机质的迁移和赋存规律 |
| 摘要点击 1366 全文点击 2223 投稿时间：2001-03-16 修订日期：2001-06-11 |
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| 中文关键词 生态系统 δ13C值 土壤有机质 粒径组分 比重组分 |
| 英文关键词 ecosystem δ13C values soil organic matter size fractions density fractions |
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| 中文摘要 |
| 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 |
| 英文摘要 |
| On the basis of different photosynthetic pathway,there's obvious difference in δ13C values between C3 plants and C4plants.Use this characteristic,the δ13C 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 C3 plants previously and plant C4 plants now.Results showed that the δ13C values of different size fractions in forest soil aere δ13C coarse sand < δ13C fine sand < δ13C coarse silt < δ13C clay < δ13C fine silt ,and the δ13C values of different size fractions in farmland soil were δ13C coarse sand > δ13C fine sand > δ13C coarse silt > δ13C clay > δ13C fine silt ,it indicated that the soil organic matter was fresh in coarse sand and oldest in fine silt.The δ13C values of different density fractions in forest soil ware δ13C light < δ13C heavy ,and the δ13C values of different density fractions in farmland soil were δ13C light > δ13C heavy ,it also indicated that the soil organic matter was fresh in light fractions and old in heavy fractions. |
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