Spatial patterns and influencing factors of ground ant species diversity on the land-bridge islands in the Thousand Island Lake, China

Abstract

To explore spatial patterns and environmental factors affecting ground ant species diversity in the Thousand Island Lake, China, we surveyed ground ants using pitfall traps, leaf litter extraction and hand collecting on 33 islands from May to August in 2017 and 2018. We divided all ground ants into predator or omnivore ants and then used the regression models to analyze relationships between ant species diversity and island attributes. Island area had positive effects on species richness of total ants, predator ants and omnivore ants; but isolation had no significant effects. The β diversity of ants was dominated by spatial turnover component. Difference in island area had positive effects on the nestedness-resultant component of total ants, predator ants and omnivore ants communities. Difference in isolation had significant positive effects on the total β diversity of omnivore ants. Island area was the main factor affecting spatial patterns of ant species richness. In addition, island area affected the β diversity of ants via changing nestedness-resultant component, which indicates a selective extinction process in ant community assembly. Different responses of predator ants and omnivore ants to island attributes may be due to variation of dispersal ability.