The effect of different sequences of biological crusts on soil organic carbon in Inche Brun of Golestan province

Introduction: Biological soil crusts are formed on the soil surface in many low-productivity ecosystems Biological soil crusts are formed on the soil surface in many low-productivity ecosystems around the world, including dry and cold environments Vegetation is limited in these areas due to unsuitable environmental conditions, inadequate rainfall, and acute shortage of soil moisture (Jha & Srivastava, ۲۰۱۸; Azhdari & Bazrafshan, ۲۰۲۲). They may be composed of any type of cyanobacteria, eukaryotic algae, lichen, moss, and the collection of decomposing organisms including bacteria, fungi, and animal food webs on the soil surface (Belnap, ۲۰۰۳). These organisms on the soil surface have great importance, as it was recently estimated that they cover about ۱۲% of the Earth's surface (Naylor et al., ۲۰۲۰). Biocrusts improve the soil’s physical properties. Because their microorganisms adhere to the soil or contact directly with the soil surface. This activity of microorganisms that are accumulated in the surface layer of the soil and promote its preservation and stability, is known as the biological crust (Belnap, ۲۰۰۳). The group of autotrophs and heterotrophs of biological crusts stabilize the soil, increase soil nutrients and are effective in the carbon cycle. They also help determine the amount of atmospheric precipitation. The ability of biological crusts in soil stabilization has been studied and identified in the past years, and it is suggested that crusts may be used an effective management measure for arid regions. Feldeh et al. (۲۰۱۸) investigated the capacity of biological crusts to stabilize the soil of the Naqf desert, through the measurement of penetration resistance and cementing factors and their mutual relationships with soil characteristics. In addition to soil stabilization, biocrusts affect carbon and nutrient cycling, as well as microbial communities. The role of biocrusts on soil nutrient status was reviewed more than ۲۵ years ago (Bellnap and Harper ۱۹۹۵). With the continuation of studies in the following decades, this was hypothesized that biological crusts result in exchange of carbon through a symbiotic fungal network (Green et al. ۲۰۰۸). Loess plateau is one of the most severely eroded areas in the world and biological soil crusts are important components of this fragile environment. The role of biological soil crusts in this ecological system has been studied previously. The objective of this study was to investigate the different sequences of biological crusts on soil organic carbon to identify the effect of biocrusts on the development and evolution of soil in the Incheh Borun region, Golestan province, Iran.

کلیدواژه ها:

biocrusts ، physical crust ، soil organic carbon ، Iran