关键词: 康定市, 生物多样性, 两栖动物, 丰富度, 相对多度, 分布格局

Abstract

Aims: Amphibians are very sensitive to environmental changes. Understanding their spatio-temporal distribution patterns is of great significance for amphibian conservation and habitat monitoring. Despite many previous investigations of amphibian has conducted in Kangding City, Sichuan Province, gaps still remain in the amphibian diversity and its spatial distribution. This study aims to conduct a large-scale field survey to fully grasp the current situation and spatio-temporal distribution pattern of amphibian diversity, and to provide scientific basis for the conservation of amphibian biodiversity, ecological environment management in Kangding City.
Methods: This investigation was carried out in September 2016, May and July 2017. A total of 61 survey grids were selected to survey from the 130 effective grids (10 km × 10 km). The transect method was used in this investigation, and no less than 3 survey lines were set in each grid. The survey lines were near the water, and the distance between survey lines was greater than 500 m. During the survey, the coordinates of the start and end points of the transect, altitude, habitat type of the survey area, type, quantity, location of amphibians, and the impact of human activities were recorded.
Results: There is one grid surveyed with the most amphibians with 10 species, followed by 2 grids with 7 species surveyed, and only 1 specie was found in 15 grids. Amphibians were not investigated in 11 grids. A total of 2,639 individuals of amphibians were recorded, belonging to 14 species, 7 genera, 5 families and 2 orders. Among them, Bufo gargarizans has the highest dominance, followed by the Nanorana pleskei, Rana kukunoris and Scutiger jiulongensis. Compared with the historical record, the number of species was the same as the original record. The Boulenophrys minor and the Amolops loloensis were newly discovered, however the Batrachuperus tibetanus and the Amolops lifanensis weren’t found which previous recorded in this survey. The abundance of individuals surveyed was the highest in May, with 966 individuals being found, and the number of species surveyed was the highest in September, with 13 species being found. The dominant species surveyed is Bufo gargarizans in May and July, and Nanorana pleskei in September. Most amphibians are distributed at altitude between 3,000 m and 4,000 m. The Amolops mantzorum and the Bufo gargarizans had a wider range of altitude distribution, distributed between the altitude of 1,300 m and 3,600 m, and the species Scutiger mammatus and S. jiulongensis had a smaller altitude distribution range. Mean precipitation and number of vegetation types were significantly correlated with species richness, followed by mean altitude. Mean temperature and normalized difference vegetation index (NDVI) were relatively weakly correlated.
Conclusions: Precipitation and vegetation type are the main factors affecting amphibian richness. The habitat of amphibians has an important impact on species richness, and the relative abundance of species is greatly affected by seasons, especially the breeding season. This study revealed the diversity and spatio-temporal distribution patterns of amphibians in Kangding City, which provide basic data for biodiversity conservation of Kangding City.

Key words: Kangding City, biodiversity, amphibian, richness, relative abundance, distribution pattern