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 area size results from the combined effects of climate change and species’ adaptive capacity. Under this context, climatic factors can be considered a pivotal link between genetic diversity and area size, exerting a regulatory influence on their relationship. 

Methods: To assess the above hypothesis, the current study examined the cytochrome c oxidase subunit I (COI) gene fragment in avian species, exploring the influence of 8 climatic 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 area size, as well as nucleotide diversity and area size. Haplotype diversity and nucleotide diversity were utilized as principal indicators of genetic diversity in this analysis. 

Results: Results show that the overall nucleotide diversity of birds was 0.008 ± 0.001(mean ± SE), and the haplotype diversity was 0.699 ± 0.011. Additionally, the results revealed that climatic factor differentially affect the relationship between genetic diversity and area size. Notably, climatic factor predominantly influence the relationship between haplotype diversity and area size indirectly by altering the area size (df = 6, χ² = 10.77, AIC = 2,231.8, BIC = 2,270.5). In contrast, for nucleotide diversity, the climatic factor exert a dual impact, affecting both the area size and nucleotide diversity, thereby mediating the relationship between nucleotide diversity and area size in a more complex manner (df = 0, χ² = 0, AIC = 2,155.0, BIC = 2,219.6). 

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–species area relationship, mediate