Assessing Mammal Conservation Effectiveness in the World's Highest-Elevation Protected Area Network

Aim

Protected areas (PAs) are central to global biodiversity conservation, but their effectiveness in understudied regions, such as high-altitude ecosystems, remains poorly understood. Tibet contains the world's highest-elevation PA network and a remarkably diverse mammalian fauna, especially medium- and large-bodied mammals (MLM) that are of major conservation concern given their important role in ecosystem functioning and high sensitivity to human activities. The Tibetan PAs offer an opportunity to evaluate the effectiveness of PAs in protecting MLMs in extreme environments. Here, we explored spatial patterns and influencing factors of MLM diversity across Tibetan PAs and related them to PA attributes, environmental and anthropogenic factors.

Location

Eighty-nine PAs of Tibet, China.

Methods

Based on a comprehensive occurrence dataset of 77 MLM species, we quantified mammal diversity within PAs using five indices (species richness, functional diversity, phylogenetic diversity, completeness index and defaunation index) and evaluated their key influencing factors (environmental, anthropogenic and PA attribute factors) through generalised additive models. The effects of species' body size, trophic level and protection status on the defaunation index were evaluated. We further estimated the PA size threshold for effective mammal conservation.

Results

PA protection status and vegetation heterogeneity are significantly associated with five diversity indices; specifically, PAs with stricter management and greater habitat heterogeneity supported higher MLM diversity. Medium-bodied, herbivore species with Class I protection exhibited higher levels of defaunation, highlighting the need for urgent conservation attention. PA size threshold varies among diversity indices and trophic levels, indicating that effective protection of MLMs of different trophic levels requires different PA sizes.

Main Conclusions

Our findings highlight the value of integrating a multidimensional biodiversity framework and PA attributes into conservation planning. Future conservation in Tibet should focus on strengthening PA management and reducing human disturbance, with PA sizes planned according to the ecological needs of different mammal groups.