The impact of land use on the relative abundance and composition of soil bacterial communities

Land-use change is one of the most important factors influencing soil microbial communities, which play a pivotal role in most biogeochemical and ecological processes. In order to determine the effect of land use on the relative abundance and composition of soil bacterial communities by using Real-time PCR, a study was carried out in three different land uses (orchard land, farmland and shrubland) in Jiroft plain, Iran. 12 surface soil samples were collected from each land use and some soil physicochemical properties were measured. The NucleoSpin® Soil kit was used for extraction and purification of DNA from soil samples. Quantitative comparison of the concentration and melting temperature of 16S rDNA amplicons, respectively, for assessment of the relative abundance and composition of soil bacterial communities in different land uses were performed by using Real-time PCR system and based on the relative standard curve method. The results related to the concentration and quality of soil DNA indicated that extraction of DNA from soil samples by using NucleoSpin® Soil kit was favorable. As the results of Kruskal-Wallis nonparametric ANOVA showed, land use had significant effect on the relative abundance and composition of soil bacterial communities at the level of 5%. Means comparison showed that the relative abundance of soil bacterial communities in orchard land use was higher than that of two other land uses. Furthermore, the composition of soil bacterial communities in orchard and farm land uses was significantly different from shrub one. It can be concluded that land-use changes in Jiroft plain from shrubland to orchard land, and from shrubland to orchard land and farmland have caused an increase in the relative abundance as well as a significant change in the composition of soil bacterial communities, respectively.