Effect of short term exclosure on physical and chemical properties soil and woody species diversity in Piranshahr forests, northern Zagros

Excessive presence of forest dweller and their cattle are most important agents that accelerate destruction of Zagros forest ecosystems. The aim of this study is to investigate of 7 years enclosure on woody species diversity and changes of soil physical and chemical properties in a part of northern Zagros forests. Two grazed and ungrazed areas were selected. Based on the transect method of sampling, 18 circular sample plots with an area of 400m2 were taken. The type and number of woody species were recorded. To analyze soil physical and chemical properties, a combined surface soil (0-20cm depth) was sampled and transported to laboratory. Results the t-test showed that status of richness and evenness indices in ungrazed area was better than grazed area and Shannon index of richness and Hill index of evenness were significantly different in both areas. Also, results of mean comparisons of soil physical and chemical properties showed significant difference in bulk density, silt, sand, Phosphorus, pH and Potassium in two areas. There were no significant difference for variables such as particle density, porosity, percentage of moisture saturation, clay, organic Carbon, Nitrogen and electrical conductivity in both areas. According to this study, enclosure leads to improvement of species diversity and soil physical and chemical properties during 7 years. However, it seems to enhance soil status and reconstruction of it in the ecosystems managed for conversation, much more time is needed.