مجله جنگل ایران (Apr 2009)
Economic valuation of soil nutrients retention function of Sabzkouh forests
Abstract
As a strong supporting tool, valuation of forest ecosystems’ goods and services and estimating the costs of forest degradation and soil erosion are an effective remedy for planners and policy maker of environment. This could lead to restoration, preservation and choice of the best land uses. This research was carried out in forest lands of Sabzkouh protected area (Chaharmahal-e-Bakhtiari province) located in Zagros forest. This study was conducted to assess the soil conservation and prevention of nutritional losses as the principle economic functions of the forest land; First, sub-catchments of the studied region were separated and the outflowing volume of each sub-catchment was measured with Erosion Potential Method (EPM), then N,P,K losses based on measured nutrients in non-eroded regions were determined as control. Finally, the economic cost of nutritional conservation based on forest coverage was calculated. Results showed that 452.19kg of N, P, K elements were annually lost due to soil erosion in degraded forests with a net present value of 103.75US$/ha/year. Also, nearly 88 tons of N,P,K elements were lost annually in 5447.648 hectares at the studied area due to soil erosion leading to decrease of fertility and undertaking the environmental costs about 56597 US$.
