Soil surface communities known as biological soil crusts are assemblages of cyanobacteria, lichens, mosses and fungi that form a coherent layer on dryland soils. Research by Jayne Belnap U.S. Geological Survey documents their capacity to bind particles and mediate key biogeochemical cycles. In desertification reversal, these crusts are often an early and essential component of resilient landscapes.
Functions in soil stabilization and fertility
Biocrusts reduce wind and water erosion by physically cementing loose sands and silt into a protective skin, which directly lowers dust emissions and soil loss. They modify surface roughness and increase water infiltration in many contexts, helping to retain scarce rainfall for plant use. Biocrust organisms also perform nitrogen fixation and contribute to carbon accumulation, improving soil fertility where deeper-rooted vegetation can later establish. These functions make crust recovery a practical tool for re-establishing productive soil structure in degraded drylands.
Restoration approaches, limits, and social context
Restoration techniques include passive protection from trampling and vehicles and active approaches such as translocation of crust fragments or inoculation with cultured cyanobacteria. Successful programs typically couple crust-focused interventions with grazing management and native vegetation restoration. Recovery times can be long—years to decades—especially for lichens and mosses—so early protection is crucial. Degradation drivers include overgrazing, off-road driving, and amplified drought and temperature extremes under climate change; these drivers vary by territory and are often entangled with local livelihoods and cultural land uses. International frameworks like the United Nations Convention to Combat Desertification highlight soil restoration and nature-based solutions as priorities for sustaining rural communities and reducing land degradation.
When crusts are restored and protected, the consequences are tangible: reduced dust storms, increased seedling establishment for shrubs and grasses, and gradual improvements in soil nutrients that support pastoral and agricultural uses. However, relying on crust restoration alone is insufficient; integrated strategies that address grazing policies, land tenure, and community knowledge produce the most durable reversal of desertification. Combining biocrust stewardship with vegetation recovery and governance reforms aligns ecological repair with social resilience across affected territories.