Impactability of Structure, and Biomass of Masal Forests of Guilan Province from Conservation

With the registration of Hyrcanian forests in UNESCO and increasing environmental sensitivities, these forests are in a state of conservation. The aim of current study is to investigate the effects of conservation on the structure, biomass and diameter distribution of mixed beech forests of Asalem of Guilan province. For this purpose, two protected and unprotected parcels were selected in a series five of watershed-12. In each area, 50 sample plots were accomplished by randomized systematic method and the diameter and height of all trees in the plots were measured. After calculating the common quantitative indicators, aboveground biomass of trees in the two stands was estimated using allometric equations. Then, the diameter distribution of trees in the two regions was modeled using eight probability distribution functions. Based on the results, the average number per hectare, basal area and volume of trees in non-conserved stands were calculated significantly less than the conserved stand. The biomass of the non-conserved area was 75.25 tons per hectare less than the conserved area. Among the distribution functions used, Johnson and beta functions in the conserved stand and Johnson and gamma in the non-conserved stand showed the best fit with the diameter distribution of the trees. The results of the this study showed that conservation had a significant effect on the biomass structure and diameter distribution of trees and lack of conservation had the greatest negative effect on low-diameter trees.