Landscape heterogeneity and the confluence of regional faunas promote richness and structure community assemblage in a tropical biodiversity hotspot

Abstract

Crane flies (Limoniidae; Limoniinae) were sampled at national parks and protected areas across central to northern Thailand to observe patterns of species richness and faunal turnover in the Indo-Burma biodiversity hotspot. Prior to sampling, the crane fly fauna of this region was poorly known and no taxonomic keys existed for specimen identification. Utilizing a multi-access taxonomic key to the Limoniinae genera of the Oriental Region designed for this project, identification of collected specimens revealed a crane fly fauna displaying higher richness than inventories from temperate regions. Sixty-six morphospecies from 29 genera/subgenera were collected using a combination of light trapping and Malaise trapping. Richness estimators projected that a total of 70–81 species are to be collected with future sampling, with mountainous northern Thailand projected to have the highest richness. The faunas of Central and Northern Thailand were different, with the north generally composed of more temperate genera and the south composed of more tropical genera. The increased diversity in northern Thailand was significantly influenced by landscape topology. Sampling that spread across two mountain ranges displayed faunas that were divided into both high elevation (>1,000 m) and lower elevation (<1,000 m) faunas. This change in community assemblage across elevation illustrates faunas that were more alike at similar elevations between mountain ranges than they were within national parks.