Influence of Oak (Quercus brantii Lindl.) on Selected Soil Properties of Oak Forests in Yasouj Region

Trees in many forests affect the soils below their canopies. Analysis of the relationships between trees and soil is one of the basic factors in management and planning of forests. Zagros forest ecosystem is one of the main degrading forest ecosystems in Iran and plays an important role in soil protection. Quercus brantii is the most important woody species in these forests. This study was conducted to determine the influence of oak on selected physico-chemical properties of soils of three oak forests in Yasouj region. The experimental design was a factorial 332 (3 depths, 3 regions and 2 distances) in a randomized complete block design with four replications. Soil samples (0-20, 20-40 and 40-60 cm depth) were taken from beneath canopies and adjacent open areas. The results showed that oak canopy increased mostly organic carbon, total N, available K, P, EC, EDTA extractable Fe, Zn and Mn, while CCE, pH, and DTPA extractable Cu were decreased. Oak canopy had no significant effect on soil texture. Our results suggested that the presence of Quercus brantii individuals may be an important source of spatial heterogeneity in these forests.