The Influence of Climate and Sections on Soil Stoichiometric Characteristics on Unstable Mountain Slopes in Jiangjiagou Watershed, Kunming

According to the vertical climate zone spectrum of Jiangjiagou watershed, the temperate humid mountainous region(TH), subtropical and warm temperate semi-humid region(SW), and subtropical dry hot valley(SD) in the watershed were selected as the research area to study the spatial distribution characteristics of soil nutrient content and stoichiometric ratio of typical unstable slopes and their relationships with climate and section. The results showed that the soil C∶N, C∶P and N∶P in the study area ranged from 10.98 to 29.43, from 22.39 to 38.19, and from 1.74 to 2.20. The C∶N and C∶P in the TH were significantly higher than SW and SD. TH with good hydrothermal conditions was conducive to soil nutrient accumulation. In terms of sections, the soil C∶N, C∶P, and N∶P showed stable area > unstable area > deposition area, indicating the section significantly affected the soil C∶N, C∶P and N∶P. Correlation analysis and variance analysis results showed that climate factors(temperature and precipitation) significantly affected the stoichiometric characteristics of soil carbon, nitrogen, and phosphorus on unstable mountain slopes in Jiangjiagou watershed. In our study, TH with good hydrothermal conditions had significantly higher soil C∶N and C∶P than the other 2 climates, while SW and SD affected by unstable slopes showed significant differences of stable area > unstable area > deposition area in soil stoichiometric ratios.