Geographical patterns of species richness and beta diversity of Larentiinae moths (Lepidoptera: Geometridae) in two temperate biodiversity hotspots

Abstract

Biodiversity hotspots have been in the mainstream of studies and debates regarding conservation and biodiversity. Results, however, are skewed towards vertebrates and the tropics, and cannot simply be generalized to invertebrates and temperate biodiversity hotspot regions. In this first study of its kind, we explored the spatial patterns of Larentiinae moth (except genus Eupithecia Curtis, 1825) species richness and beta diversity in two neighbouring temperate biodiversity hotspots, the Caucasus and the Irano-Anatolian biodiversity hotspots, Middle Palearctic. We explored how spatial gradients contribute to the formation of moth species richness in these two biodiversity hotspots by disentangling beta diversity patterns to spatial turnover and nestedness components. Larentiinae moths showed a positive association with latitude and a unimodal relationship with elevation. The latitudinal gradient contributed more than the elevational gradient in formation of biodiversity. Both hotspots showed similar patterns of beta diversity partitioning, demonstrating a large contribution of spatial turnover to biodiversity formation. Constant high values of spatial turnover across 17° of latitudinal gradient may indicate that diversity has been formed by a consistent mechanism of horizontal species level diversification of larentine moths throughout mountains.