Determining the Ecological Carrying Capacity of Forests

To determine the Annual Allowable Cut (AAC) in agreement with sustainable development, presenting a comprehensive approach which considers the ecological indices, seems quite essential and inevitable. One of the principal and useful concepts for determining the allowable limits for environmental changes is Carrying Capacity (CC) concept, by which maintaining the key elements of the ecosystems. Therefore, present study addresses the determination of the AAC in Gorazbon district of Kheyrud Forest located in the Northern Forests of Iran applying the CC concept. For this purpose first, the site was classified into ecological homogenous units then the amount of increment was estimated for each unit. The analysis showed that there is no difference between the ecological units. Therefore, to find the real homogenous units with different ecological capability, units with the most similarity were integrated and finally the real homogenous units were distinguished. The results showed that Gorazbon district consists of two separated ecological units and in each unit the AAC estimated from the traditional method(4.90) is significantly different from the CC method(5.65 and 4.74) (p<0.01). For the parcels with different capability, we considered both upper and lower limit of CC to cover the heterogeneity. Regarding the comprehensiveness and fuzzy nature of the CC concept in making up the existing deficiencies and uncertainties in estimating the AAC, this method can be a highly practical alternative for determining the AAC in the forest ecosystems with the capability for wood harvesting.