Comparison of soil seed bank characteristics between grazed and ungrazed areas in two different depths

This study aimed to compare soil seed bank characteristics (density, diversity, richness and its similarity with above ground vegetation) between grazed and ungrazed areas, and between two different depths, 0-5 and 5-10 cm in rangelands of Kahnuj, Kerman province. Thirty plots in 2×2 m dimentions in ungrazed area and 135 plots in grazed area were established. Soil samplings were collected in each plot in two different depths after seed dispersion. The cover percentage of all vascular plants was estimated during the next growth season. Soil samplings were then treated in a cold condition for three months and were transported to greenhouse to allow viable seeds to germinate. All seedlings germinated in the greenhouse were identified and removed after identification step.Soil seed bank density per square meter, seed composition richness, seed diversity and similarity between soil seed bank and above ground vegetation were calculated for each plot and for each depth. Non parametric test (Mann-whitney U) was used to compare soil seed bank characteristics between the two depths and between grazed and ungrazed areas. Results showed that soil seed bank density and similarity between seed bank and above ground vegetation were higher in ungrazed area than grazed area. All studied seed bank characteristics were higher in upper soil layer than deeper soil layer. Generally, it can be concluded that the exclosure can be improved vegetation by soil seed bank in this area.