Influence of Canopy Architecture on Stemflow in Agroforestry Trees in Western Himalayas

Rainfall event on a tree can be partitioned into throughfall, interception loss and stemflow. In this study, stemflow was measured for 39 rainfall events in 5-year-old plantations of 3 trees each, belonging to Morus alba and Grewia optiva in Dehradun, India. Diameter of selected Morus and Grewia trees varies from 7 to 9.3 and 8.12 to 10 cm respectively, whereas height varies from 4 to 4.5 and 5.5 to 6.5 m respectively. The minimum and maximum rainfall events recorded during the study period were 1.01 and 121.70 mm per day respectively. When the rainfall magnitude was less than or equal to 50 mm and more than 50 mm, stemflow volume from Morus was approximately 2.72 and 1.85 fold higher respectively, compared to Grewia. Maximum stemflow volume recorded for Morus and Grewia was 48,065 and 30,633 ml with respect to rainfall magnitude of 109.58 and 121.70 mm respectively. The generation of higher stemflow volume in case of Morus is due to concave orientation of branches and leaves. Results showed that a significant amount of nutrients leached from Grewia and Morus through stemflow process.