Comparison of Distribution of Precipitation in Quercus castanifolia, Ulmus glabra and Parotica percica Forest Types

In forest ecosystems, vegetation characteristics along with climatic parameters have a great influence on the distribution of precipitation components and water cycle. The present study was therefore conducted to measure the amounts of interception loss, throughfall and stemflow in Quercus castanifolia, Ulmus glabra and Parotica Percica at the campus of Faculty of Natural Resources of Tarbiat Modarres University, Noor, as representative of Hyrcanian forests of the country. Precipitation measurements were carried out by 23 collector containers over the course of a year from 06/10/2018 to 06/10/2019 with 34 storm events. The results showed that the rates of steamflow in Quercus, Parotica and Ulmus species were 0.97, 0.56 and 0.34%, respectively. There was a strong and positive and linear relationship between steamflow and precipitation in the Parotica type (R2 = 0.70). The interception losses were also 19, 17 and 8% in the Quercus, Ulmus and Parotica species, respectively. Regressions were also satisfactorily established between total precipitation and mean interception loss with coefficient of determination of 0.61, 0.62 and 0.46 for Quercus, Ulmus and Parotica stands, respectively. The results of ANOVA verified no significant difference between interception loss (P = 0.790) and throghfall values (P = 0.894) among the three study species. However, there was significant difference (p=0.015) between the moisture contents of litters in Quercus sp. compared to other two types of Ulmus sp. and Parotica sp. There was also significant difference between the values of Quercus sp and Ulmus sp (P = 0.009).