Multi-scale impacts of land use change and fragmentation on reptile diversity patterns in subtropical landscapes from Mexico

Land use change drives biodiversity loss, but fragmented landscapes can still support substantial biodiversity. To explore the dynamics between landscape characteristics and diversity, multi-scale analyses are needed. We examined the effect of land use change and fragmentation on reptile abundance and taxonomic and functional diversity patterns in two subtropical landscapes within the Sierra Madre del Sur, a biodiverse region in southern Mexico with urgent conservation needs. For this, we sampled reptile communities within different land use types (large and small forest patches, croplands and non-natural pastures), identifying environmental and landscape factors explaining such patterns at the local (i.e., within each land use type) and landscape (i.e., at surrounding areas of each land use type) scales. We also evaluated variations in species functional traits between land use types and identified functionally unique, specialized, and endangered species in conserved versus disturbed habitats. We observed greater trait diversity in forest patches, as well as functionally specialized, unique, and endangered species. Reptile abundance and diversity were positively related to local vegetation and forest cover within 100–500 m spatial extents from focal sites. At larger spatial extents, the presence of other land use types was an important driver of overall diversity. These findings underscore the conservation value of both large and small forest patches for reptile conservation, serving as source habitats for disturbed land uses. However, at broader scales, a more heterogeneous landscape may enhance overall diversity, so efforts should consider the conservation value of other land use types within the landscapes. A holistic conservation approach, integrating landscape-scale factors and local variables, is essential for understanding and preserving reptile diversity in these fragmented landscapes.

This dataset can be used to reproduce the analyses performed in this research. Particularly, we provide data to:

1) Calculate reptile taxonomic and functional diversity, functional diversity standardized effect sizes, using Hill’s numbers, and functional uniqueness, functional specialization and the FUSE (functionally unique, specialized, and endangered) indexes, in the four land use types evaluated.
2) Perform a RLQ and Fourth-corner analysis to evaluate variations in species functional traits between land use types.
3) Model the relationships between both diversity dimensions, and local and landscape-scale variables using generalized additive models (GAMs), and identify the scale of effect (i.e., the scale where environmental variables have the most influence on diversity) for each dependent variable.