Ground spider diversity in the Kenting uplifted coral reef forest, Taiwan: a comparison between habitats receiving various disturbances

The effects of various disturbances on diversity and community structures of ground spiders in the Kenting National Park uplifted coral reef forest were investigated using pitfall traps. In each of the following five sampling sites, ten trap stations were established and were monitored once every month for a whole year: primary forest, primary forest with tourism activities, secondary forest, grassland with tourism activities and abandoned grassland. A total of 2237 adult spiders from 20 families and 110 species were collected, among which 86 (78.2%) were new or newly recorded species to Taiwan. Dominant species can be divided into two major groups according to temporal abundance variations: abundant in the dry season and abundant in the wet season. Habitat preference of 12 dominant species was assessed by comparing their relative abundance between sampling sites. Half of the species exhibited strong habitat preference and two species could only be found in habitats receiving no tourism disturbance. The Shannon–Weaver function, Simpson index and Evenness were not significantly different among the sites, suggesting that these sites had a similar community structure characterized by few dominant species and numerous rare species. However, the species composition differed considerably among the five sites. Results of a UPGMA analysis using pairwise Euclidean distance demonstrated that specimens from 50 trap stations can be divided into four major clusters: primary forest, secondary forest, grassland I and grassland II. Also, among 110 species obtained, 61 were distributed in one sampling site only, and each site had between 11 and 16 unique species. In addition to species composition, foraging guild composition also differed significantly among sampling sites. These results suggest that the diversity of ground spiders in the KTNP uplifted coral reef forest is quite heterogeneous, and any management activity should consider the uniqueness of each habitat type.