Abstract:

Aims: Understanding the link between genetic diversity and species distribution is crucial for biodiversity conservation. Genetic diversity facilitates species' adaptation to climate change, whereas species distribution area results from the combined effects of climate change and species' adaptive capacity. Under this context, climate factors can be considered a pivotal link between genetic diversity and species distribution area, exerting a regulatory influence on their relationship. 

Methods: To assess the above hypothesis, the current study examines the cytochrome c oxidase subunit I (COI) gene fragment in avian species, exploring the influence of 8 climate factors (Annual temperature, Annual temperature range, Annual precipitation, Annual precipitation range, Precipitation seasonality, Precipitation seasonality range, Temperature seasonality, Temperature seasonality range) on the relationships between haplotype diversity and species distribution area, as well as nucleotide diversity and species distribution area. Haplotype diversity and nucleotide diversity are utilized as principal indicators of genetic diversity in this analysis. 

Results: Results show that indicate that the overall nucleotide diversity of birds is 0.008 ± 0.001(MeanSE), and the haplotype diversity is 0.699 ± 0.011. Additionally, the results reveal that climate factor differentially affect the relationship between genetic diversity and species distribution area. Notably, climate factor predominantly influence the relationship between haplotype diversity and species distribution area indirectly by altering the species' distribution area (df = 6, X² = 10.77, AIC = 2231.8, BIC = 2270.5). In contrast, for nucleotide diversity, the climate factor exert a dual impact, affecting both the species distribution area and nucleotide diversity, thereby mediating the relationship between nucleotide diversity and species distribution area in a more complex manner (df = 0,X² = 0, AIC = 2155.0, BIC = 2219.6). 

Conclusion: Our results recommend that multiple genetic diversity indices should be considered when examining the effects of climate change on genetic diversity. Additionally, more targeted biodiversity conservation strategies should be developed to effectively address the challenges posed by future climate change.

Key words: Climatic factors, Birds, Genetic diversity-area relationship, Mediate