Landscape Features Shape Maternal Genetic Structure of Asian Elephants in Thailand: Insights from mtDNA

Abstract

Landscape features often shape maternal genetic structure by influencing connectivity. In this study, habitat fragmentation, a major threat to the Asian elephant (Elephas maximus), was assessed through an integrated approach involving mitochondrial DNA (mtDNA), habitat-suitability modeling, and circuit-based landscape-resistance analyses. Two regions from Thailand, Phu Khieo (PK) and Khao Ang Rue Nai (ARN) Wildlife Sanctuaries, were investigated. Fourteen mtDNA haplotypes were identified among 66 samples, with relatively high diversity and population expansion in PK. Maternal genetic differentiation was identified between the PK and ARN groups. Environmental variables, such as urbanization and road proximity in ARN and topographic wetness and stream distance in PK, were associated with genetic distances, suggesting these features restricted female-mediated connectivity. Fine-scale spatial analysis revealed significant local genetic structure only in PK, whereas no autocorrelation was detected in ARN, suggesting potential impacts of fragmentation. Genetic landscape surfaces illustrated spatial heterogeneity, pinpointing isolation zones near high anthropogenic disturbance. These findings demonstrate that broad-scale models may overlook fine-scale patterns of maternal genetic isolation. Therefore, conservation strategies should incorporate spatially explicit analyses to identify and restore crucial movement corridors, particularly in fragmented regions like ARN, for promoting connectivity and population viability.