关键词: 中国阿勒泰, 阿尔泰山, 鸟类, 生境类型, 区系特征, 物种丰富度

Abstract

The Altay Region in China is located in North Xinjiang, in the border region of China, Kazakhstan, Russia and Mongolia. The region contains the Altai Mountains and the desert and riparian landscapes south of them, which constitutes the Altai-Sayan biodiversity hotspot and one of the Global 200 Biodiversity Ecoregions. Being composed of diverse habitat types, the Atlay region harbors a rich avian fauna. Though there are several field studies on a few avian species in the Altay Region, few studies have focused on broad-scale species diversity and distribution patterns across different habitats and landscapes. Thus, we completed a comprehensive census across various landscapes and habitats in the region. In this study, we recorded bird species in different types of habitats on the southern slope of the Altai Mountains and the plains area south of the Altay Region from 2013 to 2016. We also collected information from the literature and local citizen science records. The resulting bird species inventory allowed us to use MaxEnt models to predict distributions and diversity patterns of 77 bird species in the Altay Region. Four classes of environmental predictor variables, i.e. climatic factors, land cover type, human footprint index and terrain were incorporated into the models. We predicted all species’ distribution patterns and added all species’ distribution layers together to determine broad-scale diversity patterns. In total, 19 orders, 55 families, 149 genera and 344 bird species were represented in the Altay Region of China. Along the vertical vegetation belts, there were 24 species in high mountain-bare rock belt; 35 in alpine meadows; 172 in mountain forest belt; 130 in brush land in low mountains; 84 in desert belt; 173 in riparian belt; and an additional 92 species in wetland and water areas. In the Altay Region, Palearctic type birds dominated the avian fauna with 170 species (49.4%) and followed by widespread northern species (93 species; 27.0%). The Altai Mountains belonged to Palearctic Realm, Europe-Siberia Sub-realm, Altai-Sayan Region and Altai Sub-zoogeographical Region, while the plain areas belonged to Palearctic Realm, Central Asia Sub-realm, Inner Mongolia-Xinjiang Region and West Desert Subregion. The MaxEnt models predicted high species diversity in the riparian, plains, and middle and lower montane areas, congruent with previous field data. Protecting tall trees and young saplings and shrubs through eco-friendly economic development strategies and preventing habitat fragmentation will help maintain high species richness in the Altay Region and the Altai-Sayan Ecoregion.

Key words: Altay Region, Altai Mountains, birds, habitat types, fauna, species richness