Landscape attributes impacting terrestrial mammal assemblages in the Lacandona Rainforest, Mexico

Background/Question/Methods

Intensification of land use is considered the main driver of global biodiversity change in terrestrial ecosystems. Because a large proportion of global biodiversity is nowadays located in fragmented landscapes, understanding species responses to changes in landscape spatial pattern is necessary for designing appropriate conservation and management strategies. We assessed the effects of five landscape-scale metrics (forest cover, number of forest patches, total forest edge, connectivity, and matrix permeability) and three patch-scale metrics (patch size, shape, and isolation) on number of species and patch occupancy of mid- and large-sized Neotropical mammals in the fragmented Lacandona rainforest, southeastern Mexico. Using camera traps, track surveys and visual censuses, we sampled terrestrial mammal assemblages in 28 sites, 24 focal forest patches and four control areas within a continuous forest. The landscape-scale metrics were measured at two different spatial scales: within a 100-ha buffer, and within a 500-ha buffer from the center of each sampling site.

Results/Conclusions

A total of 21 species from 13 families were recorded. The number of species increased with patch size and shape complexity at the patch scale. However, the landscape attributes influencing mammal assemblages varied with the spatial scale: the number of species increased with matrix permeability when considering 100-ha buffers, but tended to decrease in landscapes with higher fragmentation degree when considering 500-ha buffers. The landscape- and patch-scale metrics that predicted the presence of each individual species within the focal patches were different, but in general, the landscape-scale metrics were better predictors. To conserve mammal assemblages in the region it is necessary to maintain larger patches and prevent forest patches from being increasingly isolated from each other by creating vegetation corridors, especially riparian corridors. More multi-scale and long-term studies are vital to comprehend how species respond to the new human-modified landscapes.