Climate change and physical disturbance cause similar community shifts in biological soil crusts

In drylands worldwide, where plant cover is sparse, large amounts of the ground surface are covered by specialized organisms that form biological soil crusts (biocrusts). Biocrusts fix carbon and nitrogen, stabilize soils, and influence hydrology. Extensive physical disturbance from livestock/human trampling and off-road vehicles is known to destroy biocrusts and alter ecosystem function. More recent work also indicates that climate change can affect biocrust communities. Contrary to our expectations, experimental climate change and physical disturbance had strikingly similar impacts on biocrust communities, with both promoting a shift to degraded, early successional states. These results herald ecological state transitions in drylands as temperatures rise, calling for management strategies that consider risks from both physical disturbances and climate change.