Combined effect of environmental factors on distribution of Geometridae (Lepidoptera) in South Korea

Sei-Woong CHOI,Jung-Hwa CHUN

doi:10.14411/eje.2009.011

Abstract

We analyzed patterns of geometrid species richness in South Korea to assess the observed and estimated species richness gradient, to determine predictors for the distribution of moths and to investigate the effect of latitude on the species richness of moths in the Korean peninsula. The species richness was analyzed for 541 geometrid moths across 17 quadrates, with each quadrate defined by one degree of latitude and longitude. Two subgroups of geometrid moths were adopted according to their distributional ranges: Palearctic (435 species, 80.4%) and Oriental (106 species, 19.6%). To investigate the relationship between the distribution of geometrid moths and environment, eight variables were used. The estimated species richness of geometrids was calculated using the Chao 2 estimator because there was uneven sampling effort across the quadrates. Due to multicollinearity we used covariance values produced by principal component analysis and the first four axes adopted have eigenvalues >= 1.0. Two models of regression analyses were applied based on multiple linear regression using eight variables (model I) and principal components axes (model II). Of the two subgroups of geometrid moths the Palearctic species richness increased with latitude, but not that of Oriental species richness. A combined effect of abiotic (maximum altitude, temperature, rainfall, and latitude) and biotic (plant species richness and vegetation) variables was indicated by both models of regression analyses. The different effect of each spatial and environmental predictor on the distribution of geometrid moths on the Korean peninsula is discussed. The significant relationship between estimated species richness and latitude indicate a peninsular effect on geometrid moths in South Korea.

Highlights

The Korean peninsula is elongated, surrounded by ocean to the west, south and east, and connected to the Asian continent in the north
The geometrid moths used in the present study were divided into two groups based on their distributional ranges, since Palearctic and Oriental elements make up the biota of the Korean peninsula
It is widely accepted that the pattern of diversity on peninsulas may be a result of several factors, such as geographic orientation, ecological constraints, historical events and habitat diversity (Wiggins, 1999; Rahbek & Graves, 2001; Tubelis et al, 2007)

Summary

Introduction

The Korean peninsula is elongated, surrounded by ocean to the west, south and east, and connected to the Asian continent in the north. It is classified as in the Palearctic region, and its biotic component is largely of Palearctic or Oriental origin. Being primary consumers and having high habitat fidelity, geometrid moths represent a suitable taxon for ecological and biogeographical studies (Intachat et al, 2001; Beck et al, 2002; Brehm & Fiedler, 2003; Axmacher et al, 2004). On the Korean peninsula, the total moth species richness is estimated to be about 3,000 species, and geometrid moths, with about 650 species, one of the dominant moth groups, along with Noctuidae and Pyralidae (Choi, 2006)

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