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Abstract. The relationship between species richness of plants and animals and altitude can be either hump-shaped, a monotonic decrease or increase. In this study the altitudinal distribution of moths on one of the highest mountains in South Korea was investigated. Moths were captured using a UV-light trap from May to October in 2007 and 2008. This revealed that the relationship between the total numbers of moth species and individuals and altitude is hump-shaped. A significant relationship was also recorded between the size of the area at each altitude and moth abundance and richness. However, the evenness index yielded a consistent decrease with increase in altitude because of the dominance of few species at high altitudes. Non-metric multidimensional scaling identified two major axes for the moth assemblage on Mount Jirisan. The correlations between the axes and variables demonstrated that the first axis was strongly correlated with altitude and aspect and the second axis with forest and site location.
Key words. Lepidoptera, species diversity, moths, altitude, distribution, mid-domain effect, Korea
INTRODUCTION
Mountains are found on all continents. High altitude ecosystems on mountains differ from all other ecosystems as the environment at high altitudes is uniquely harsh (Mani, 1990). Mountain habitats are spatially and structurally complex when trees or larger shrubs form part of the landscape, producing a mosaic of different habitat types with their own particular vegetation and/or microclimate (Haslett, 1997; Hodkinson, 2005). Utilization of these mosaic patches by different plants and animals may reflect more their specific life history strategies and ability to exploit a particular type of habitat than the total taxonomic diversity present at a particular altitude (Haslett, 1997; Hodkinson, 2005).
Patterns in the altitudinal distribution of species richness have frequently been cited as compelling evidence for hypotheses that propose associations with productivity and ambient energy, as well as past and current climates, since these factors vary with altitude (Rahbek, 2005). Two patterns in the altitudinal distribution of species richness are frequently observed (Rahbek, 2005). The first is a monotonic decrease with altitude. This is expected if resource limitation and thermal constraints govern species diversity (Fiedler & Beck, 2008). The second is that the pattern of species richness is hump-shaped, the middomain effect (Colwell & Lees, 2000). This pattern is expected if the...