Biodiversity hotspot assessment in the Altai Mountains transboundary region based on Mammals and Aves

We focused on mammals and aves in this study. Mammals and birds are not only key indi- cators of ecosystem health but also play significant roles in their respective habitats. Mammals, such as the snow leopard and Altai maral, are crucial for maintaining the ecological balance by regulating prey populations and facilitating nutrient cycling. Birds, on the other hand, contrib- ute to pollination, seed dispersal, and pest control. Furthermore, these taxa are relatively well- documented in the Global Biodiversity Information Facility (GBIF) database, allowing for robust data analysis using the MaxEnt model. By studying these two groups, we aim to provide a comprehensive understanding of biodiversity distribution patterns and their underlying mechanisms in the AMTR. The distribution of BHs from the perspective of AMTR has not yet been fully understood. Understanding the distribution of biodiversity hotspots in transbound- ary areas is critical to protecting the unique wildlife in these areas, and also contributes to global biodiversity conservation efforts. Moreover, how future environmental changes will affect the region’s ecosystem, such as the altitude range of species in alpine and subalpine habi- tats, is critical to predicting future ecological trends. In this study, we aimed to evaluate comprehensively the distribution and action mecha- nisms of biodiversity potential hotspots of AMTR and to connect their interrelationships. Based on multiple types of environmental data, the MaxEnt models was used to evaluate biodi-

versity distribution. This information can provide information for environmental change miti- gation and adaptation strategies in the region. While the study focused on AMTR, the findings have broader implications. This study provides useful methods and strategies for biodiversity conservation and management. Materials and methods Study area The Altai Mountains are located in the middle of the Asian continent, running diagonally from northwest to southeast across four countries: China, Kazakhstan, Russia, and Mongolia, with a national boundary of about 1,205 km (Fig 1). The study area AMTR includes 7 adminis- trative regions in four countries: China’s Xinjiang Uyghur Autonomous Region Altay region, Russia’s Altai Republic and Altai Krai, Kazakhstan’s East Kazakhstan Oblast, and Abai Oblast, and Mongolia’s Bayan-Ulegi Province and Hovd Provinces, covering a total area of approxi- mately 780,000 km2. This area is also the origin and biodiversity center of various rare flora in North and Central Asia. It is the most representative and best-preserved area of the Siberian ecosystem. It has a typical continental climate and unique ecosystem diversity [26]. The Altai Mountain region boasts a rich diversity of flora and fauna, with vegetation primarily compris- ing coniferous forests, deciduous broad-leaved forests, meadows, shrublands, and alpine plant communities. The coniferous forests are dominated by Siberian fir, Siberian larch, and Sibe- rian pine, forming extensive areas of pristine forest. The deciduous broad-leaved forests, con-

sisting of species such as birch, Mongolian oak, and linden, are distributed in low-altitude areas. In high-altitude regions, endemic plants such as Altai Daphne and Altai Lithospermum thrive. Regarding fauna, the Altai Mountains serve as a crucial habitat for the snow leopard and are home to other mammals such as the Altai maral and lynx, as well as birds like the Altai woodpecker and golden eagle. These species collectively contribute to the complex and diverse ecosystem of the Altai Mountains, highlighting its unique ecological value and the importance of its conservation [31]. Data sources This study used data at four levels: climate, topography, landscape, and human activities (Table 1). (1) We downloaded seven environmental climate variables and 19 bioclimatic PLOS ONE Biodiversity hotspot assessment in the Altai Mountains transboundary region PLOS ONE | https://doi.org/10.1371/journal.pone.0314075 December 4, 2024 3 / 20