Integrating Genomic and Ecological Data to Assess the Impact of Habitat Fragmentation on Genetic Diversity in African Elephants in Central Africa

Abstract

The fragmentation of the habitat is a significant risk to the long-term sustainability of wide-ranging megafauna through the limitation of movement and lack of gene flow between populations. In Central Africa, there is a growing exposure of African elephants to landscape fragmentation as a result of land-use change, development of infrastructures and forest degradation, but quantitative synthesis between genetic pattern and ecological fragmentation has not been well documented. This paper utilizes an integrative landscape genetics model that is able to utilize published evidence of genomic and ecological hypothesis to determine the impacts of habitat fragmentation on genetic diversity, population structure and connectivity of the African elephant populations in Central Africa. Genetic indicators, such as heterozygosity, allelic richness, inbreeding coefficients and genetic differentiation, were combined with the landscape-level genetic fragmentation, resistance, and connectivity indicators using ecological and remote sensing data. The synthesis suggests that the observed heterozygosity (H0 0.69 - 0.71) and genetic differentiation (FST 0.02 -0.5) were higher in the elephant populations of low-fragmentation landscapes and lower in the populations of highly fragmented ones (H0 0.54 - 0.56). The landscape analyses also indicate that there exists a positive strong relationship between landscape resistance and genetic differentiation (r ≈ 0.68) where the functional corridors and low-resistance habitats possess more connectivity. This paper gives an ecological transferable framework to prioritizing areas of conservation and functional corridors by directly relating genomic indicators with ecological parameters of fragmentation. The results highlight the importance of conservation efforts in form of landscape conservation, which would ensure the connectivity of habitats to ensure the genetic and long-term evolutionary resilience of the African elephant population in Central Africa.