The relationships between land use and amphibian assemblages in a traditional agricultural area, the Sun Moon Lake, of Taiwan

Context. Understanding the relationships between land use and anuran habitat selection would help make conservation-management and habitat-restoration decisions. However, only a few studies have investigated all the available amphibian habitats in terrestrial and aquatic environments. Aims. The objective of the present study is to assess the associations between different land-use types and individual anuran species in a traditional agricultural area. We also hypothesise that connectivity and land-use heterogeneity are important in determining species richness. Methods. We conducted monthly roadside calling surveys at 71 sites in the Sun Moon Lake (SML) region in central Taiwan during 2008-2010. Non-metric multidimensional scaling (NMDS) with envfit was used to investigate the relationships between land-use characteristics and anuran assemblage. We use a site-occupancy model to assess the associations between land use and occupancy rate of each species. Generalised linear regression with Poisson distribution was used to assess the relationships among connectivity, land-use heterogeneity and species richness. Key results. In total, 19 species in five families were detected by roadside calling surveys. The NMDS results showed anuran assemblages in the SMLregion being distributed through an environmental gradient from those most dominated by agricultural land to forest-dominant sites. According to site-occupancy models, the occupancy rates of anurans were mainly correlated with proportion of agricultural land, grassland and distance to river. The species richness was positively correlated with land-use heterogeneity. Conclusions. The results showed that the distributions of anurans largely depended on surrounding land-use types in the terrestrial environment. The major trend of anuran assemblages in the traditional agricultural area was dependent on the transition from forest to agricultural land. Implications. The data suggested that land-use heterogeneity should be a primary consideration for increasing amphibian species richness.