Relation between climatic variables and chemical elements concentration in healthy and declined wood Iranian oak trees in Khorramabad (Case Study: Dadabad)

Among climatic factors, temperature and precipitation are of two particular importance, which directly and indirectly affects the uptake and transport of minerals. In order to study the relationship between climatic variables and chemical element concentrations in two groups of healthy and declined Iranian oak trees, three healthy trees and three declined trees were cut in Dadabad habitat of Khorramabad. A disk was selected from each tree. Then, growth rings over the last 35 years were determined including three five-years and two 10-years pieces. The samples were cut and extracted by using the wet digestion method, and the concentration of different elements (Ca, K, Mg, Fe, Na, Zn, Cu, Pb, Ni, Si, Cr) was measured by using atomic absorption apparatus. The result showed that there was no significant difference between concentration elements of healthy and declined wood trees. The Pearson correlation between concentration elements and the average of seasonal temperature and rainfall was significant; in healthy trees, potassium with autumn rainfall (-0.931), magnesium with winter rainfall (0.959) as well as spring temperature (-0.969) and summer (-0.967) had significant correlations, and in declined trees, potassium with spring temperature (-0.961) and summer (-0.949), calcium with autumn (-0.953), silicon with autumn (-0.686) and lead with spring (0.966) temperatures had significant correlations. The difference between element concentrations of two groups of trees regrading climatic factors can be caused by the difference between genetics and physiological characteristics of trees, environmental physiography (especially light regulation and moisture regime), and physiology of uptake.