A Nutritional Evaluation of the Pure and Mixed Plantations of Oak Using Retranslocation Rate

This research was performed based on a completely randomized sample design in Chamestan Forest and Rangeland Research Station. In this research oak was planted pure and mixed with other broadleaf species including maple, hornbeam, hackberry and Siberian elm with 50%-50% ratio. Goal of this project was evaluation of forest site on the basis of leaf retranslocation process. The sampling was performed in August for fresh leaves and in December for senescent leaves. The nutrition elements amount of leaves was measured in laboratory and retranslocation rate of elements was calculated. The results show that oak had the most retranslocation of phosphorous in the mixed plantation with hackberry and it had the least amount in the mixed plantation with Siberian elm. The most and the least retranslocation rate was belong to pure oak plantation and mixed with maple respectively. There were no significant differences between treatments in nitrogen retranslocation. The results showed effective role of mixed plantations compare with pure plantations based on sustainable ecosystem cycles. The hornbeam trees showed less amount of N retranslocation among five species and it can improve soil C/N ration. Hackberry and Siberian elm showed least retranslocation of P and K respectively. The results of this research can help forest managers for selection of suitable tree species for plantation in order to achieve site fertility and maintenance of nutritional elements.