关键词: 岷山北部, 食草动物, 相机陷阱, 垂直分布, 植被类型

Abstract: A variety of biodiversity distribution patterns are formed due to variation in the distribution of resources and gradation in environmental variables. Montane ecosystems often have highly heterogeneous habitats, distributing resources in discrete patterns that offer ideal natural experiments to study the spatial distributions of biodiversity. Our aim was to investigate the diversity of ungulates and their spatial distribution patterns and drivers in the northern Minshan mountains based on the analysis of field monitoring data in and near Baihe National Nature Reserve, Sichuan Province, China. In total, 160 infrared cameras were deployed from May 2017 to July 2020 within Baihe National Nature Reserve and its marginal forests. We calculated the relative abundance index (RAI) and species richness of the detected forest ungulates, classifying the cameras by vegetation (eight vegetation types) and elevation (five distinct elevation bands), which ranged between 1 700 m and 3 700 m asl throughout the study area. We adopted GLM and related statistical methods to identify the role of vegetation type and elevation in shaping ungulates diversity and distribution patterns. A total of six ungulate species were recorded in the study area. Tufted deer (Elaphodus cephalophus) was the most abundant species with an RAI of 41. 12, followed by Chinese goral (Naemorhedus griseus; RAI=14. 10), wild boar (Sus scrofa; RAI=6. 76), takin (Budorcas taxicolor; RAI=0. 59), and forest musk deer (Moschus berezovskii; RAI=0. 34). Species richness was highest in the Spruce forest and Fir forest (with all 6 species recorded), while the highest RAI (96. 86) was found in the evergreen rhododendron shrub habitat and both species richness and RAI (19. 66) were the lowest in the cypress forest. The six ungulate species were classified into three elevation ranges:forest musk and takin were restricted to high elevation (> 2 900 m asl); tufted deer and Chinese serow were present in middle and low elevations (< 2 900 m asl) and Chinese goral and wild boar were found across the entire elevation range. Species diversity and richness were the highest in the middle elevation range, generally presenting a bell-shaped distribution pattern. Based on the model, vegetation and the interactive effects between vegetation and elevation were the main factors shaping the spatial distribution of ungulates in the study area. Based on our study, there are two suggestions for future management and monitoring:(1) reduce anthropogenic disturbances and activities at the low-medium elevation range and control livestock populations in meadows, and (2) monitoring or surveys should increase sampling effort at extremely high altitudes (> 3 300 m asl).

Key words: Northern Minshan, Herbivores, Camera traps, Vertical distribution, Vegetation types