Assessing the Function of Biological Soil Crusts on Soil Fertility (Case Study: Kiamaky Wildlife Refuge, East Azerbaijan, Iran)

Biological soil crusts (BSCs), are common on soil surface in arid and semiarid regions. They consist of cyanobacteria, algae, fungi, lichens and bryophytes associated with soil particles. BSCs have significant influence on primary ecosystem processes and are known as ecosystem engineers in drylands. In this study, the effect of BSCs on different soil properties in Kiamaky Wildlife Refuge in Jolfa county, East Azerbaijan province, Iran was investigated. Soil sampling was done in adjacent locations with BSCs, and bare substrate. The results showed that BSCs significantly increase the soil organic carbon, total nitrogen, microbial community population, soil respiration and microbial biomass carbon & nitrogen, as well as significantly decrease CaCO3 content. In addition, BSCs lightly increased electrical conductivity and availability of micronutrients in soil. The effect of BSCs significantly decreased along increasing depth. Generally, it was revealed that BSCs enhance the soil fertility, which can improve soil quality and ecosystem productivity in arid and semiarid regions.