Habitat heterogeneity and anthropogenic disturbance jointly affect species spatial associations and persistence

Abstract

Interspecific interactions are of central importance to community assembly and are closely associated with ecosystem productivity, functioning, and stability. However, seasonal fluctuations in interspecific interactions and their resilience to anthropogenic disturbances and three-dimensional (3D) habitat heterogeneity remain largely unexplored. Traditional methods encounter difficulties in quantitatively describing 3D habitats. To address this, we integrated high-resolution unmanned aerial vehicle (UAV)-based light detection and ranging (LiDAR), systematic camera trapping, and dynamic multispecies, multistate occurrence models to investigate the persistence mechanisms of interspecific spatial associations. Focusing on large- and medium-sized mammal communities in human-dominated landscapes with 3D heterogeneity within the Tiebu Sika Deer Nature Reserve, our study provides new insights into the mechanisms underlying biotic interactions. Results indicated that mammals exhibited stronger antagonistic spatial associations in winter, characterized by stronger negative or weaker positive correlations. Free-ranging livestock influenced the distributions (pairwise interactions) and interspecific spatial associations (higher order interactions) of wildlife. The extent of this influence relied on the trophic interactions (predation or competition) between the free-ranging livestock and wildlife. Human disturbances, beyond domestic livestock, have further reversed species' spatial associations, compounding the effects of domestic animals. Conversely, 3D habitat heterogeneity can facilitate the persistence of species' spatial associations, encompassing both pairwise and intricate higher order interactions, thereby mitigating the impacts of human activities on these associations. In general, our results highlighted that various human disturbances can exert cumulative effects on the spatial associations between species, while three-dimensional habitat heterogeneity mediated the human impacts.