Evaluation of the effects of biological operations on functional diversity and soil of carbon stock (Case study: Arange watershed, Alborz province)

 Communities or ecosystems with higher biodiversity also have higher levels of ecosystem function and services, so the relationship between functional diversity and sustainability of plant communities is essential to predict ecosystem functioning. The aim of the present study was to investigate the relationship between carbon stocks and different species diversity and functional indices as well as the effects of biological and mechanical actions on vegetation and soil components. For this aim, Arengeh watershed with an area of 10098.53 ha in Alborz province was selected. The biological and mechanical measures studied in this study were clumping, seedling and grazing, grazing managementrespectively. The functional diversity indices studied in the sampling area included Rao, CHull, FEve, FDive, and FRich indixes. Vegetation sampling was carried out in systematic-random method in 800 plots of 1 m 2 along 80 transects of 100 m in the growing season of May and June. During each transect, three soil samples were taken from different depths of 0-15 and 15-30 cm in different treatments of regeneration and control. To examine more closely the relationship between variables at both sites, Pearson correlation between soil properties as well as between functional diversity indices and carbon stock was calculated. Species richness and diversity indices and functional diversity indices were calculated using Fdiversity software. Multivariate linear regression was also used to investigate the relationship between carbon stocks of richness indices and species and functional diversity. The results of multivariate regression analysis indicated that the highest R2 was related to carbon biomass of 0.72 and the variables affecting it were species richness. Also, Raochr('39')s, evenness, Shannon and functional diversity indices were influenced by total ecosystem carbon. The results showed that the highest amount of vegetable carbon storage in mechanical treatments related to gabion treatment, surface soil carbon storage lower soil carbon storage related to mortar rock treatment and was observed total soil carbon sequestration in treatment Gabion. Also, for biological treatments, grazing, piling, natural rangeland, and exclosure had the highest carbon storage, litter, surface soil, lower soil and total carbon sequestration, respectively.