[Effects of environmental factors on the distribution of amphibians in agricultural landscape].

We analyzed the relationship between the distribution of amphibians and the environmental variables at the habitat level and landscape level in Fengqiu County of Henan Province, a typical region of the lower reaches of the Yellow River, with the support of geographic information system (GIS) and R software. At the habitat level, dissolved oxygen (DO), conductivity (COND), turbidity (TURB), NH-N, pond-interior vegetation cover (VEG), emergent vegetation cover (EMER), pond-edge vegetation cover (VEG), benthic fauna predators (PRE), and pond area (AREA) were selected as habitat variables. At the landscape level, total area of ponds (AP), distance to the nearest road (DR), total area of farmlands (AF), total area of woodlands (AW), Shannon’s diversity index (SHDI), and contagion index (CONTAG) were selected as explanatory variables, calculated within a buffer of 250, 500, 1000 and 2000 m around the centroid of each pond. The results showed that the distribution of Bufo gargarizans was mainly related to the PRE and landscape variables within the larger radius buffer zone (AW2000, DR2000, SHDI1000, CONTAG1000). The distribution of Pelophylax nigromaculata was closely related to the EMER and landscape variables within the smaller radius buffer zone (SHDI500). VEG and PRE were the key factors determining the distribution of Pelophylax plancyi. Landscape variables (AF2000, SHDI2000) within the larger buffer radius were the most significant influencing factors on Fejervarya multistriata. For all amphibian species, the EMER and SHDI500 were variables that should be considered. For the protection of amphibian species in plain agricultural landscape, we suggested that conservation efforts should focus on improving the pond-interior vegetation cover, protecting the semi-permanent ponds, and enhancing the functional connectivity among ponds.