关键词: 经验统计分析法, 植被恢复, 临界值, 彭冲涧小流域, 降水变化

Abstract: Stoichiometry plays an important role in elucidating the supply status and relationship of nutrient elements in ecosystems and in revealing the limiting factors that affect forest structure and function. The present study selected natural broadleaved mixed forest, Quercus mongolica forest, Pinus tabuliformis forest, Larix gemelinii plantation, and Pinus koraiensis plantation and investigated ecological stoichiometry characteristics and their difference among different forest types, through measuring the contents of carbon (C), nitrogen (N) and phosphorus (P) in leaves, litter, and soil. Our results showed that (1) the contents of C, N and P differed significantly among the five forest types, and those in leaves and litter were consistently higher than in the soil. In particular, N content was the highest in the natural broadleaved mixed forest and lowest in the Q. mongolica forest. (2) The rank of the C∶N and C∶P in the five forest types was litter>leaf>soil, while N∶P was leaf>litter>soil. The mean of leaf N∶P was 12.16, indicating that the growth of plants in this area might be limited by N. (3) The correlations in N, P, C∶N and N∶P were positively associated between leaves and litter, while N and C∶N in both leaves and litter were negatively correlated with those in the soil. These results suggest that the understanding of stoichiometry characteristics of nutrients in “plantlittersoil” is essential to reveal the nutrient status and the biochemical cycle of forest ecosystems.

Key words: Pengchongjian small watershed, vegetation restoration, critical value, precipitation variation, empirical statistics analysis method