An ionome study in Persian oak (Quercus brantii Lindl) to evaluate factors affected oak decline

Zagros forests with an area over six million hectares are important for economic, social and environmental aspects. More than one million hectare of Zagros forests has been declined. This research was carried out by selecting six sites at different altitudes and slopes. At each site, 30 oak (Quercus brantii) trees were selected. Sampling was done at any point on a certain level with an area of 20 hectares.  It was achieved in June and October and 20 elemental parameters were measured. In order to investigate the relationship between ionomics and oak decline, oak stands were classified into healthy, endangered, and damaged bases. The results of univariate analysis of variance based on three factors of season, region, and crown health index showed a significant difference in the number of elements such as N, P, C, K, C / P, C / K, Fe, Ca, Mg, Na, Cu, Mn, Zn, Si in spring and autumn (P <0.05). Also, there was a significant difference among six sites examined for the amount of C, C / P, Ca, Mg, Cu, Mn, and Ni. In terms of health index, a significant difference was observed amongst N, P, C / P, K / P, N / K, C / N. The results of the principle component analysis indicate that the traits with the greatest effect on the explanation of the first component can be used as decline factors. The present study provided a precise estimate of the ionome characteristics of Iranian oak, in order to provide a suitable step for enhancing the ability of oak species to cope with environmental problems.