Abstract: Exploring species composition of amphibians at different altitudes and in different habitats and the main driving factors is of great significance for the effective management of regional amphibians and the scientific protection of endangered species. Sangzhi County in Hunan Province, dominated by mountain forest ecosystem, located in Wuling Mountain biodiversity conservation priority area, is suitable for research on species composition and environmental factors. Grid method and line-transect method were used to divide Sangzhi County into 51 grids of 10 km × 10 km. Considering accessibility, habitat integrity and randomness, we selected 23 grids in which 2-4 lines per grid of amphibian survey were laid. The transect lines were arranged in the river, mountain streams or forests, while covering the elevations where amphibians are mainly distributed. We conducted three field surveys from July to September 2019 and from June to September 2020. We used principal coordinate analysis (PCoA) and analysis of similarity (ANOSIM) to compare the composition of amphibian species at different altitudes and habitats. Meanwhile, canonical correspondence analysis (CCA) was used to explore the main environmental factors affecting the distribution of amphibian species. We recorded 30 amphibian species, accounting for 34.88% of the total number of amphibian species in Hunan Province. Among which, five species are listed in the second class of National Key Protected Wild Animal List and four species are the type locality in Sangzhi County. The species composition of amphibians showed spatial variations (P<0.01), which may be related to habitat heterogeneity. The species composition of amphibians was mainly affected by factors related to temperature. The explanation rate of 10 environmental factors for amphibian species composition was 30.7%. The total and net effects of annual temperature variation, isotherm, and mean temperature of coldest quarter reached a significant level, and their explanation rates were 10.5%, 3.4% and 3.0%, respectively, which were the main factors affecting the amphibian species composition. According to the results obtained, the following suggestions are proposed: carrying out supplementary surveys and long-term monitoring of amphibian resources, perfecting amphibian protection measures at high altitudes, and strengthening wildlife publicity and law enforcement.

Key words: amphibian, species composition, species catalogue, Wuling Mountain biodiversity conservation priority area, county-level biodiversity survey