Hydrochemistry of Rainfall and Stemflow of Juglans regia Linn and Cupressus sempervirens L. Var. Fastigiata in the North of Iran

The relocation of nutrients and water fluxes to the forest floor varies spatially due to artition of rainfall into throughfall and stemflow by tree canopies. In this study, nutrient concentrations of rainfall and stemflow were measured for seven rainfall events in Chaboksar area in the Hyrcanian ecozone of Iran composed of Juglans regia Linn and Cup. Sempervirens L.Var. Fastigiata where such information was absent. In the course of the study, a total of 24 samples were collected, and stemflow samples of these species were analysed in relation to rainfall. The results of this study suggest that the nutrient concentrations in stemflow are mainly influenced by vegetation species. The concentrations of CaCO3, nitrate, calcium, magnesium, sodium, zinc, and chloride, were all higher in the stemflow of cypress tree than that of the walnut tree. The concentration of iron in both stemflow samples was zero. The pH level in the stemflow of Juglans regia Linn and Cup. Sempervirens L. Var. Fastigiata was slightly lower than rainfall pH level. However, in terms of heavy metals, the concentration of lead in cypress stemflow was found to be higher than that in walnut stemflow. Furthermore, a very small amount of copper was detected in the stemflow of cypress tree. Electrical conductivity of cypress stemflow was also higher than that of walnut stemflow.