Effect of rangeland rehabilitation and restoration on composition and diversity

Evaluation of changes in rangeland ecosystem after rehabilitation and restoration projects is important to determine the positive or negative effects of these projects. Parts of species composition in rangelands are in the soil seed bank as living seeds which are a potential for regeneration. Management and environmental factors may change the soil seed bank. This Study was carried out in mountain rangelands in Kabir watershed in Mazandaran province. A restoration project was done in this area 7 years ago and this study aimed to assess the effect of this project on soil seed bank. Soil was sampled random-systematically in control and restoration sites (210 samples) from 0-5 and 5-10 cm depths. Then seed bank composition was identified after seed germination in greenhouse. The results of this study showed that there were 38 species in soil seed bank whereas 71 species were existent in vegetation. Only 16 species were common between seed bank and vegetation. We found greater species diversity and richness in vegetation than that of soil seed bank. Only 18 species were common in the soil seed bank of control and restoration sites. Seventeen species were restricted to the seed bank of restored site. Among common species between soil seed bank of two sites, the project significantly influenced the seed bank of two species. Also, the restoration project significantly increased the richness and diversity of soil seed bank. Some species were unique to the specific soil depth. The results of this study showed that the soil seed bank would be altered by restoration and rehabilitation project and this depended on vegetation change due to restoration, type of treatment and time since project was performed.