ecological land capability assessment for forestry in 2000 and 3000 watersheds in the north of iran using gis

forest ecosystems that have spent a long time to mature, offer important goods and services to humanity. hence, utilization and exploitation of these resources should be based on careful assessment of their ecological value and potential. ecological land evaluation is an approach based on land quality, vulnerability and potential assessment for different acceptable uses drawing upon related models. we used a geographical information system to prepare a data base including physiography and topography, elevation, slope, pedology, lithology, rainfall and temperature, forest density, tree growth and values for forest evaluation. the data base was clipped for the dohezar and sehezar watersheds in the north of iran. using seven descriptive models of forest capability in iran through a systematic land evaluation, we determined forest potential based on the boolean logic and boolean raster layers of the prepared data base. multiplication of the boolean raster layers or constraints resulted in the recognition of classes 1 to 5 of the models whereas no class 6 and 7 were distinguished. of the first 5 classes of the forest capability, class 3 had the highest share in terms of the areal coverage.