Drylands encompass a large part of Earth’s land surface, supporting vital human and natural environments. A major challenge facing land-use planning in such regions is the application of several disparate classifications (e.g., dry, desert, arid, etc.) – comprising broad and non-overlapping regions. We examined several dryland designations to evaluate their degree of global congruence, protected area coverage, and current and future land-use pressures. We focus on four of the foremost landcover designations among major international organizations – (1) Deserts and Xeric Shrublands (WWF), (2) Drylands (UNEP-WCMC), (3) World Terrestrial Ecosystems (USGS-Nature Conservancy-ESRI), and (4) Global Agro-Ecological Zones (FAO) – each utilizing dissimilar methodologies categorizing “drylands”. We identify core regions of drylands identified as such across all designations, in addition to regions falling under only one or few designations – thereby highlighting their potential complementarity, while also identifying unique desert regions omitted by other designations. Our findings reveal significant variation among designations, and unique desert regions encompassing approximately 12.1 million km^2. We also find that relative to other biomes, deserts are among the least protected by assigned conservation areas aimed at protecting biodiversity (i.e., IUCN categories I-IV), particularly the most arid subtypes, and the extent of this coverage varies among designations. These attributes were further highlighted in major dryland regions separately, revealing regions of very low protection and high human agricultural and urban pressures (e.g., Asia), representing high conservation priority. Identifying desert classifications and their spatial distributions will be integral to determining potential threats, requisite conservation interventions and land-use planning in desert regions globally.
