Navigating the possibilities and pitfalls of biocrust recovery under a changing climate

Authors: PHILLIPS, MICHALA - Us Geological Survey; Young, Kristina; LAURIA, CARA - Us Geological Survey; JECH, SIERRA - Northern Arizona University; GIRALDO-SILVA, ANA - Public University Of Navarra (UPNA); REED, SASHA - Us Geological Survey

Submitted to: American Journal of Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/2025
Publication Date: 6/19/2025
Citation: Phillips, M., Young, K.E., Lauria, C., Jech, S., Giraldo-Silva, A., Reed, S. 2025. Navigating the possibilities and pitfalls of biocrust recovery under a changing climate. American Journal of Botany. 112(6). Article e70055. https://doi.org/10.1002/ajb2.70055.
DOI: https://doi.org/10.1002/ajb2.70055

Interpretive Summary: Biological soil crusts, or biocrusts, are communities of organisms like lichens, mosses, bacteria, and cyanobacteria that form a living layer on dryland soils around the world. Despite their small size, biocrusts play a large role in keeping drylands intact and resilient by stabilizing soil, retaining water, and providing nutrients to the soil. However, biocrusts are fragile and easily damaged by activities like off-road vehicles, livestock grazing, and development. A key question for scientists studying drylands is whether biocrusts can recover naturally after being disturbed and, if so, how long it takes. Early research suggested recovery might take thousands of years, but more recent studies show that under the right conditions and with help from restoration techniques, biocrusts can recover much faster. Recovery depends on factors like the local climate, soil type, and the kind of disturbance the biocrusts experienced. This review explores how biocrusts recover, how climate change might affect their recovery, and the growing use of restoration strategies to help recover biocrust cover.

Technical Abstract: Biological soil crusts are complex communities composed of lichens, mosses, bacteria, and cyanobacteria that create a living skin on the soil surface across drylands worldwide. While small in size, the vast area biocrusts cover and the critical functions they provide make them a cornerstone of dryland health and resiliency. In addition to being important, biocrusts are exceptionally vulnerable to certain types of disturbance. In particular, while they can withstand a wide range of temperatures and long periods without precipitation, biocrusts are highly sensitive to land-use change – and are vulnerable to physical and compressional disturbance (i.e. trampling, vehicles, cattle, heavy machinery). In the face of these disturbances, a critical, long-standing question of interest to dryland ecologists is: Can biocrusts recover following disturbance without active intervention and if so, how long does it take? Early estimates of biocrust recovery suggested recovery can be incredibly slow (on the order of thousands of years), with more modern studies finding potential for faster recovery, especially with intervention. Multiple lines of evidence agree that recovery is context dependent – differing across climates, soils, and with both disturbance and biocrust type. Additionally, active restoration of biocrusts is becoming more common as we develop tractable strategies for facilitating the establishment of biocrusts after disturbance. Here, we add to the body of knowledge about biocrust recovery following disturbances by reviewing recovery patterns, their connection to climate change, considerations for recovery in changing climates, and the role of restoration.