喀斯特石漠化过程中地表凋落物δ¹⁵N特征

This study investigated isotopie composition and spatial distribution of nitrogen of surficial litters in karst rocky desertification areas with different type, grade and disturbed model within a small catchment of the Wangji-azhai peak-cluster depression basin, Qingzhen, Guizhou. Results showed that the most δ¹⁵ N values of surficial litters in yellow soil areas are between -4. 00‰ to -1. 83‰ with an average of -3. 13‰, and that between-4. 49‰∼ -2. 44%o with an average of -3. 39‰ in black calcareous areas. The hydrothermal condition of the environment is the key factor controls litters' δ¹⁵ N values. The δ¹⁵ N values of surficial litters show no significant difference for all sampling sites except those from slight or no rocky desertification sites in black calcareous areas. We suggest not significant (P ≤ 0.05) overall difference of surficial litters' δ¹⁵ N values in yellow soil and black calcareous areas as a result of the high habitat heterogeneity of the karst area.