Investigating Some Chemical Soil Properties in the Pollarded and Less-disturbed Forest Stands in the Northern Zagros (Case study: Baneh forest, Kurdistan)

A Northern Zagros oak forests have been pollarded since a long time ago and finally they have been destroyed by forest dwellers. This study was aimed to investigate the effect of pollarding on some soil chemical properties.

 Two adjacent oak forest stands with similar physiography were selected including a less-disturbed area (as control stand) and pollarded stands that it periodically pollarded once every three years. 10 composite soil samples under the tree crown have been taken from 0-15 cm soil depth of each area. Finally, soil organic carbon, total nitrogen, C/N ratio, phosphorus, potassium, calcium, magnesium, pH and EC were analyzed.

 The results showed that all soil factors had significant differences in theses area except magnesium and C/N ratio. The amount of calcium and pH increased in pollarded area compare with control while soil organic carbon, total nitrogen, phosphorus, potassium and EC decreased.

 The results of this study showed that preservation of trees and stop pollarding trees in control area can produce a better soil condition compare with pollard stands. People use trees foliage to feeding livestock by oak pollarding in this forest so that these pollarding activities of local dwellers can reduce the amount of soil organic matter content and soil nutrient reserves. The decreasing of soil nutrient reserves will be very harmful to conserve the soil fertility and productivity.