关键词: SOC含量, 植被类型, 坡向, 官司河流域

Abstract: [Objective] The aim of the study was to determine soil organic carbon (SOC) and storage at the depth of 40 cm in different vegetation types and slope positions. [Method] Soils (0-20 cm and 20-40 cm)on different slope positions of five vegetation types in the basin were sampled to determined SOC content.Additionally,according to forest resources investigation data,SOC density and storage was calculated. [Results] SOC content showed significant differences among vegetation types,slope positions and soil layers.SOC content decreased with increase in soil depth.SOC content in coniferous forests and economic forests were significantly negatively correlated with slope positions (r=-0.731 and r=-0.859).However,no significant correlation was found in theropencedrymion and mixed coniferous forest.SOC content at the depth of 40 cm followed the order:economic plantation (10.21 g/kg) > coniferous forest (9.21 g/kg) > theropencedrymion (9.15 g/kg) > farmland (8.97 g/kg) > mixed coniferous forest (7.21 g/kg).The soil organic carbon storage in the basin was 8.88×10⁴ t. [Conclusion] SOC content in mixed forests were lower compared to pure forests (coniferous forests and economic forests).Rationally cutting,improving plant diversity and soil organic matter may be effective measures to increaseSOC storage.Human disturbance is the main reason to reduce SOC storage of natural secondary forest in the basin.Therefore,in order to improve SOC storage in the Guansi basin,protecting natural secondary forest from human disturbance and strengthening plantation management would be efficient measures.

Key words: soil organic carbon storage, vegetation types, slope positions, Guansi basin