Comparison of Some Soil Characteristics in Pure and Mixed Oak Plantations

Sustainable afforestation requires maintenance of nutrient elements in soil and stability of soil properties. This study was conducted at the Chamestan Forest and Rangeland Research Station of Iran, starting in 1994. In this completely randomized plan, the oak was planted purely and mixed with four species of Siberian elm, maple, hackberry and hornbeam at 50:50 ratio. 12 characteristics of the soils were tested in two depths to study the probable effects of these plantations on the soil physical and chemical characteristics. Two statistical tests, namely, ANOVA and Duncan were used to compare the different combinations of plantations. The results showed that some planting treatments had caused increase in C:N ratio and decrease in soil CaCO3, absorbable Ca and Mg, and pH compared with the control treatment. Among the pure oak treatment and the mixed treatments, some statistically significant differences were observed such that the pure oak treatment had the minimum amount of total N and the maximum ratio of C:N ratio in the upper layer of soil, while in the lower layer of soil, the pure plantation had the maximum amount of EC compared with the mixed plantations. This study indicates that planted tree species in different types of plantation can affect soil characteristics and, hence, this issue should be considered in forest management.