Study on the effect of forest degradation and planting on some soil quality factors in the Shastkalate watershed, Golestan province

Deforestation has detrimental effects on the watershed environment which resulted in increasing flooding and sediment yield. The aim of this study was to evaluate the effects of land use change on some selected factors of soil quality in the three land uses i.e. natural forest, planting and disturbed forest in Shastkalate watershed. 30 Samples were taken of 0-30 cm depth in a completely randomized design from three Land uses in hill physiographic unit. Chemical, physical and biological parameters of soil quality factors were analyzed. Analysis of data showed that with conversion of natural forest to disturbed forest, the amount of clay increased 13.5%, sand 46%, bulk density 18%, plasticity index 26%, Soil pH 6.64%, calcium carbonate 48.4% and available phosphorus 19.8%. The amount of silt decreased 22.7%, mean weighted diameter 24%, specific surface 29.6%, electrical conductivity 25.9%, organic carbon 64%, nitrogen 59%, cation exchange capacity 19.7% and microbial respiration 35% and planting could not compensate this statistically significant changes. The results showed conservation of forest lands can be the most important operation in soil conservation plan in the area. Although planting plan is used but this operation because of short time of settlement had no significant effect on soil properties and major effects need more time and long time studies.