The importance of native shrubs on the distribution and diversity of reptiles and amphibians in the central deserts of California

Abstract

Conservation and management of drylands is a global challenge. Key attributes of these ecosystems, such as dominant vegetation including shrubs, can provide a crucial mechanism to inform conservation strategies. The shrub species Ephedra californica and Larrea tridentata are common native shrub species within the deserts of California and frequently benefit other plant and animal species. Here, we tested the hypothesis that shrubs support reptile and amphibian communities through relative increases in available habitat, estimated through increasing shrub densities at the site level. Reported occurrence data from the Global Biodiversity Information Facility (GBIF) and high-resolution satellite images were used to test for local-to-regional patterns in reptile and amphibian distribution and diversity by shrub densities at sites. A total of 71 reptile and amphibian species were present regionally. Increases in shrub density across sites positively influenced the relative abundance and richness of reptiles and amphibians observed. Moreover, increasing shrub density also had a positive influence on species evenness. Aridity did not significantly influence the relationship between shrub density and herptiles suggesting the relationship is robust. This study highlights the importance of foundational shrub species in supporting reptile and amphibian communities in arid and semi-arid regions supporting better understanding of large-scale patterns of biodiversity supported by positive ecological interactions in the context of global change.