Meta_SGDC

Species diversity (SD) and genetic diversity (GD) are the two basic levels of biodiversity. In general, according to the consensus view, the parallel effects of environmental heterogeneity, area, and connectivity on two levels, can drive a positive correlation between GD and SD. Conversely, a negative correlation or no correlation will be expected, if these effects are not parallel. Our understanding of the relationships between SD and GD among different ecosystems, sampling methods, species, and under climate change remains incomplete. In the present study, we conducted a meta-analysis based on 184 observations from 40 studies and found a positive correlation between genetic structure and community assembly (95% confidence interval, 11.86 – 23.32%). However, significant relationships were not found in some ecosystems when we conducted species–genetic diversity correlation analysis based on a single ecosystem. Moreover, the magnitudes of the correlations generally decreased with the number of sampling units and the annual average the temperature of sampling units. In general, our results highlight the positive correlation between GD and SD, thereby indicating that protecting SD involves protecting GD in the conservation practice. Furthermore, our results also suggest that global increases in temperature during the 21st century will have great impacts on global biodiversity.