Relationship between area size and elevational distribution pattern of cryptic pheasant species in Mts. Gaoligong, China

Abstract

The size of a geographic area is believed to be one of the most important factors that drive patterns of species richness. Studies have shown that mountains have a diverse range of patterns (area, species distribution, etc.) along an elevation gradient. Therefore, an understanding of the relationship between the distribution patterns of mountainous species and the area of altitudinal bands is of great importance to accurately determine and monitor global patterns of species diversity. However, the effects of area size on the distribution of species depends on taxon-specific idiosyncrasies. Few studies have assessed such effects on the secretive terrestrial pheasant species. In this study, we conducted three-dimensional map-based interview survey (3DIS) with local human communities that inhabit the same environments as the pheasants in Mts. Gaoligong, Western China. We obtained distributional information for 15 pheasant species, which enabled further analyses to be conducted. The area sizes of the different elevation bands were determined using a Digital Elevation Model database, and the altitudinal range of each species was calculated via interpolation. The area sizes at different altitudes showed a unimodal hump-shaped pattern that matched the diversity distribution of the pheasants. This study confirmed that the pattern of biodiversity of cryptic pheasants in the mountainous areas of Southwest China was hump-shaped, which is a very typical biodiversity pattern for most biotaxa. Regression analysis also revealed that area size was a key factor that affects the diversity and distribution of pheasant species, and may act concurrently with other factors, such as climate, energy, geometric constraints, and human disturbance. Keywords: Vigilant species, Species-area relationship, Vertical distribution, Hump-shaped pattern, 3D map-based interview survey