Soil Organic Matter Changes of Turnover Ecosystems Traced by Stable Carbon Isotopes
稳定碳同位素示踪农林生态转换系统中土壤有机质的含量变化

On the basis of different photosynthetic pathway, there's obvious difference in delta 13C values between C3 plants and C4 plants. Use this characteristic, the organic carbon content (forest lands: 1.81%-16.00%; farms: 0.43%-2.22%) and delta 13C values (forest lands: -23.86@1000(-)-27.12@1000; farms: -19.66@1000(-)-23.26@1000) of three profile soil samples either in farms and forest lands near Maolan Karst virgin forest was analyzed, there plant C3 plants previously and plant C4 plants now. Results show that clearing forest have accelerated the decompose rate of soil organic matter and decreased the proportion of active-component in soil organic matter, reducing of soil fertility.