en عمومى General مقاله اصیل Original Article <div style="text-align: justify;"><span class="fontstyle0">Background: </span><span class="fontstyle2">Biological soil crusts (BSCs) that are able to produce sticky extracellular polymeric substances (EPS) play an important role in the formation of soil aggregates, thereby, reducing soil erosion. In this study, experiments were undertaken to identify biocrust species that produce EPS, in<br> order to combat desertification in the Sejzi desert of Iran.</span><br> <span class="fontstyle0" style="color:rgb(21,107,56);">Methods: </span><span class="fontstyle2">A biocrust distribution map of Sejzi plain was prepared using Landsat 8 OLI images, then, various sampling points were selected. Some physicochemical parameters of samples from lichendominated and non-biocrusted areas were measured. The relationship between soil parameters and biocrusts presence was confirmed based on the Pearson&rsquo;s correlation coefficient and principal component analysis (PCA) method. The type of chemical compounds in the soil content were determined via Fourier transform infrared spectroscopy (FTIR), including polysaccharides. To estimate the degradability of polysaccharides, each soil sample was placed under defined UV-B radiation for 24, 48, and 72 hours at three replications.</span><br> <span class="fontstyle0" style="color:rgb(21,107,56);">Results: </span><span class="fontstyle2">There was no significant correlation between moss and lichen species with the amount of EPS (%) values and various occurring cyanolichen species in three biocrusted soil samples, which included</span><span class="fontstyle3"> Collema coccophorum</span><span class="fontstyle2">, </span><span class="fontstyle3">Collema tenax</span><span class="fontstyle2">, </span><span class="fontstyle3">Peccania terricola</span><span class="fontstyle2">, and </span><span class="fontstyle3">Placidium squamulosum</span><span class="fontstyle2">. It was speculated that these polysaccharides were produced by the photobiotic partners (microalgae or cyanobacteria) and secreted to the soil.</span><br> <span class="fontstyle0" style="color:rgb(21,107,56);">Conclusion: </span><span class="fontstyle2">According to the results, the cyanobacteria species of biocrusted samples might have high potential to combat desertification and soil stabilization in Sejzi desert.</span></div> Cyanobacteria, Fourier transform infrared, Lichens, Polysaccharides, Sejzi plain, Iran 153 167 http://ehemj.com/browse.php?a_code=A-10-1-217&slc_lang=en&sid=1 Leila Kashi Zenouzi lzenouzi@yahoo.com 10031947532846008842 10031947532846008842 No Faculty Desert Studies, Semnan University, Semnan, Iran Seyed Hasan Kaboli hkaboli@semnan.ac.ir 10031947532846008843 10031947532846008843 Yes Corresponding author: Faculty Desert Studies, Semnan University, Semnan, Iran Kazem Khavazi 10031947532846008844 10031947532846008844 No Department of Soil Biology, Soil and Water Research Institute, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran Mohammad Sohrabi 10031947532846008845 10031947532846008845 No Iranian Research Organization for Science and Technology, Tehran, Iran Mohammad Khosroshahi 10031947532846008846 10031947532846008846 No Desert Research Division, Research Institute of Forests and Rangelands, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran Ulf Karsten 10031947532846008847 10031947532846008847 No Institute of Biological Sciences, Applied Ecology & Phycology, University of Rostock, Germany