Abstract:

Aims: Species diversity and functional diversity are the two main research contents of biodiversity. Studying species diversity and functional diversity in different regions can provide important theoretical support for biodiversity conservation.
Methods: In this study, the passerine birds in eleven eco-geographical regions of the Tibetan Plateau collected by the Northwest Institute of Plateau Biology, Chinese Academy of Sciences were taken as the research object, and the data of bird species and traits were combined to calculate three species α-diversity indices (species richness, Shannon entropy and Pielou evenness), three functional α-diversity indices (functional richness, functional evenness and functional divergence), species and function β-diversity and their respective turnover and nestedness components. The relationship between species diversity and functional diversity was analyzed.
Results: The species α-diversity of birds was higher in the southeast and lower in the northwest for the Tibetan Plateau. Functional richness and functional evenness showed clear spatial differences, and the average of species richness and functional richness were low in the whole region. Functional divergence was higher in the whole region. Species β-diversity was higher than functional β-diversity, but both of them had high values. Species β-diversity was mainly composed of turnover components, and the proportion of nestedness and turnover components were similar in functional β-diversity. Functional richness was positively correlated with species richness and Shannon entropy. There was a significant correlation between species and functional β-diversity, and a significant correlation between the contribution ratio of species and functional turnover components.
Conclusion: The above results indicate that birds in the regions with higher functional richness occupy a larger functional trait space, while the higher functional evenness and functional divergence indicate that birds could utilize food resources more evenly and effectively in these regions. The relationship between bird diversity and the ecosystem could be well characterized by combining species and functional α-diversity and β-diversity.

Key words: Tibetan Plateau, birds, eco-geographical regions, species diversity, functional diversity, α-diversity, β-diversity