Aims: The relationship between the elevation and biodiversity has long been one of the central issues in ecology, biogeography and conservation biology. This study investigate the diversity of birds and mammals and their elevational distribution, based on infrared camera monitoring in Guangdong Nanling National Nature Reserve, China.
Methods: We utilized infrared cameras to monitor the mammals and birds across the entire elevation of the Guangdong Nanling National Nature Reserve for 10 consecutive years. In addition, we also analyzed the current diversity and conservation status of birds and mammals. By combining both horizontal and vertical distribution patterns, we conducted hotspot and vacancy analysis to assess the diversity patterns of birds and mammals.
Results: Between 2012 and 2021, a total of 116 camera sites were deployed, capturing 85,164 days of work, and obtaining 21,194 identifiable independent and valid photos. Over this period, 24 mammal species and 50 bird species were recorded, with a relatively high proportion of threatened mammals at 45.83%. The top five mammals with the highest relative abundance index (RAI) were Muntiacus vaginalis, M. reevesi, Dremomys pyrrhomerus, Melogale moschata, and Macaca thibetana. However, Herpestes javanicus and Rusa unicolor were only recorded once and have the lowest RAI. The top four birds with the highest RAI were Lophura nycthemera, Myophonus caeruleus, Tragopan caboti and Arborophila gingica. Forty-two bird species had RAI less than 1, mainly belonging to Passeriformes, Piciformes and Strigiformes. The generalized additive model showed that the richness of mammals and birds were significantly related to elevation, displaying a typical “single-peak pattern” with a significantly high species richness at mid-elevation (around 1,000-1,400 m). Beta diversity analysis showed that the classification differences between the low and high elevational range and other sites were the highest, while the differences between the middle elevational sites were relatively small. Hotspot and vacancy analysis, integrating horizontal and vertical distributions, revealed that the mammals and birds in the reserve were mainly concentrated in three hotspots, distributed in the middle and high elevation. In addition, it was observed that certain areas outside of the reserve also exhibited a high diversity of birds and mammals. In conclusion, wildlife within the reserve continues to face severe protection pressure.
Conclusion: Regarding the construction of Nanling National Park, we suggest that the local management organization should: (1) Formulating conservation and management policies for key protected species in the future, especially for large and medium-sized mammals. (2) Focusing on the habitat management in the middle and high elevational areas, and maintain the complete climate and biological vertical zone in the reserve. (3) Establishing a multitrophic biodiversity monitoring system, which emphasis the effect of comprehensive factors on wildlife, such as human disturbance, environmental factors, functional traits, species interaction networks, and evolution history.