Desertification Reversal and Dust Emission by Fortifying Biological Soil Crust

Desertification leading to harmful environmental risks such as dust emission and destructive floods has greatly increasingly attracted researchers' attention to present methods to combat this phenomenon. Although one of the most common methods to prevent soil erosion and reduce dust emission is petroleum mulching. long-term studies have found that this method imposes petroleum mulching on the desert ecosystem including an increase in temperature of the soil depth, growth prevention of desert plants, and quality reduction of rainwater that is absorbed into soil. In this term, the aim of this study is to introduce a sustainable biological solution to reverse desertification and to study the benefits and challenges of this method. Biological soil crusts are generally classified into mosses, lichens, cyanobacteria, and fungi that have a significant impact on soil fertility and the reduction of soil erosion by wind and water. Early studies showed that parameters affecting the development of biological soil crust can be fallen into two categories consisting of abiotic (moisture, light intensity, temperature, nutrient availability) and biotic factors (physiological characteristics of the different species and their interaction). It was also determined that terrestrial cyanobacteria that can survive in the harsh conditions of desert play a vital role in the formation of the biological layer. One of the main features of cyanobacteria is that they excrete exopolysaccharides which have adherent properties and help to aggregate the soil particles. It was found that inoculation of terrestrial cyanobacteria has highly significant benefits such as soil erosion prevention, dust emission control, nitrogen and carbon fixation, and regulation of the water cycle. In this sense, identification, screening, and fortifying of native cyanobacteria along with the study of the interactions with the desert environment are of great importance. The way the challenges are managed can assure the efficient performance of this method in harsh environments of high temperature, low nutrient availability, and high salinity.

کلیدواژه ها:

Desertification ، Soil Immobilisation ، Soil Crust Strengthening ، Cyanobacteria ، Soil Erosion ، Exopolysaccharides