Geomorphic controls of biological soil crust distribution, Mojave Desert (USA)

Biological soil crusts (BSCs) are vital features of arid regions. These crusts form living skin that mitigates erosion, influences soil fertility, manages soil moisture/temperature, and prevents desertification. BSCs are fragile resources, easily destroyed by physical disturbances and potentially impacted by climate change. Our investigation employs a novel, interdisciplinary approach to investigate BSC biotic potential (bridging gaps among biology, ecology, soils, hydrology, statistics, chemistry, geomorphology, remote sensing, and GIS). Our study documents important links among BSCs, soils, geomorphology, and land stability. Results indicate geomorphic stability and dust influx impact BSC composition and development. Soil stability ultimately controls biotic potential of cyanobacterial versus moss-lichen crust; however, dust influences both crust types through texturally enhanced water-holding capacity and increased soil fertility. Soil chemistry of moss-lichen substrates exhibit a potential dust signature, with elevated Ca, K, Mg, B, Fe, Ni, Co, Mn, Cl, and EC. While results indicate inherent geomorphic stability controls BSC development, we suggest BSCs enhance their propagation through dust capture and erosion mitigation. These soil-geomorphic relationships present insight into arid landscape evolution, providing tools to improve BSC mapping and land management.