The comparison of soil seed bank characteristics in enclosure and grazing area in the Gomishan ranglands

The aim of the present study is to investigate the role of protection of pastures on the soil seed bank properties in pastures of Gomishan, located in Golestan province, Iran. Sampling was done after identifying the key areas inside and outside of the protected area in early winter. In each region, one-hundred-meter transects and along each transect 10 four-square-meter plots were deployed. Takeing samples of soil seed bank, in the center of each four-square-meter plot, frames of 20×20 cm were inserted into the ground, and the soil samples were taken from the depth of 0-5 cm and 5-10cm. Soil samples were kept at 3-5 °C for 3 months in a refrigerator. After the cold treatment, the samples were transferred into the greenhouse for cultivation, and they were evaluated by germination method. To investigate the effect of grazing, soil depth and its reciprocal effect on the density, richness, diversity and similarity of the soil seed bank on the covered ground, the GLM test was adopted and LSD was used for the comparison of the mean data. The results showed that the density, richness, diversity and similarity of the soil seed bank with vegetation in enclosure was significantly greater than the grazing region. Furthermore, the results of the statistical analysis demonstrated that the density, richness, diversity and similarity of soil seed bank with covered ground at the depth of 0-5 cm was significantly higher than the depth of 5-10 cm.