The Assessment of Some of the Forest Soils Characteristics in Several Gap Sizes in Sarcheshmeh Forests, Chalous

Due to the high importance of forest gaps, this research investigated soil conditions in forest gaps. Oak – Hornbeam stands with an area of 87 ha were selected for this purpose in Sarcheshmeh forests, Chalous. To study the gaps, we selected five gap sizes that consist of very small (200 m2), small (400 m2), medium (600 m2), large (800 m2), and very large (1000 m2) ones and every one with four replicate and control point in 25-30 meters distances. To investigate soil characteristics, three soil profiles of 50*50*45 sizes (with the pickup of organic layer and mineral soil in three depths 0-15 cm, 15-30 cm, and 30-45 cm) were selected random methods and were separated in edge and central positions of every gap. In this research we studied soil characteristics that consist of water content, carbon, nitrogen, C/N ratio, phosphorous and pH soil. The results showed that with the increase of gap size in the central position the amount of water content, carbon, C/N ratio and phosphorous decrease. Also pH soil has statistical linkage with gap size and the highest level of pH was observed in very large gaps. The highest amount of soil characteristics were on surface layer and except to pH, the other characteristics decreased while soil depth increased.