Microbial diversity as an index in monitoring of desert soil quality

Background and Aim : Microorganisms have vital roles in soil processes such as geochemical cycles of elements and maintenance of the soil structure. However, information on the soil diversity especially in arid and semiarid areas, which cover %۴۰ of the Earth and more than %۷۰ of Iran areas, is very limited. The aim of this study was to determine the effect of disturbance (grazed or not grazed) on soil chemical properties and bacterial diversity in a semiarid area.Methods : Two plots were selected in the cold and warm sites of Khabr National Park and Ruchun Wildlife Refuge, Kerman province. The soil samples were taken from the disturbed (grazed and undisturbed (not grazed) areas. The soil chemical properties and microbial diversity was determined via standard methods and the next generation sequencing (Illumina platform), respectively.Results : According to the results, the sensitivity of the soil chemical properties was less than the microbial diversity to grazing. Although there was no significant difference in chemical properties between grazed and not grazed area, the bacterial diversity differed qualitative and quantitative between the grazed and not grazed areas. The frequency of the diverse groups of bacteria differed as a result of disturbance. In addition, there were special taxonomic groups of bacteria under disturbance effect. The differences among microbial community compositions were more in the lower ranks of classification (family and genus) with more unknown phylotpes, showing challenges in microbial ecology in the soil complex environment.Conclusion : In conclusion, changes in the microbial community compositions at semiarid sites estimated by next generation sequencing, precede detectable changes in the soil chemical properties, thereby it can be used in the soil quality assessment or the soil destruction.

کلیدواژه ها:

Dessert ، Diversity ، Illumina ، Next Generation Sequencing ، Quality ، Soil