Biogeography of global drylands

Despite their extent and socio-ecological importance, a comprehensive biogeographical synthesis of drylands is lacking. Here we synthesize the biogeography key organisms (vascular nonvascular vegetation soil microorganisms), attributes (functional traits, spatial patterns, plant–plant plant–soil interactions) processes (productivity land cover) across global drylands. These areas have long evolutionary history, are centers diversification for many plant lineages include important diversity hotspots. This captures strikingly high portion variation in leaf functional observed globally. Part this associated with large response effect traits shrubs encroaching dryland grasslands. Aridity its interplay interacting species largely shape patterns interactions, patterns. also drives composition biocrust communities productivity, which shows geographical variation. We finish our review by discussing major research gaps, include: studying regular patterns; establishing large-scale field surveys assessing individual-level trait measurements; knowing whether impacts interactions on biodiversity predictable; how elevated CO2 modulates future aridity conditions productivity.