Drylands, supporting significant global biodiversity, exhibit abrupt, non-linear responses to increasing aridity with drastic declines after threshold crossing. While plant and soil responses are documented, impacts on other organisms remain unclear. Animals possess movement capacities and adaptations that may enhance aridity resistance but increase sensitivity to anthropogenic disturbances. We investigated how aridity affects taxonomic and trophic richness across multiple organisms (bacteria to mammals) in dryland ecoregions. All groups showed threshold responses to aridity, occurring sequentially with varying biodiversity losses (19-54.3% depending on trophic group) after crossing thresholds. Responses were most widespread in hyper-arid and arid regions, primarily affecting herbivores and detritivores in semi-arid areas, and were exacerbated by human disturbance and land-use change. However, primary productivity and richness of primary producers and prior trophic levels partially buffered these declines. Biodiversity loss with increasing aridity scales across multiple dryland organisms and trophic levels but can be mitigated through plant biodiversity conservation and anthropogenic pressures.