Net precipitation in a northern hardwood forest

The two components of net precipitation, throughfall and stemflow, were measured during two summer leaf periods in the White Mountains of New Hampshire. Throughfall was caught in roving gages located at predetermined, randomly selected points. Stemflow was measured on two randomly located groups of trees. Regression equations were developed for a comparison of throughfall with gross rainfall. Throughfall accounted for 82 per cent of the gross rainfall. Strong differences in amounts of stemflow were found between various hardwood species. Stemflow values ranged from 1 per cent of gross rainfall for a storm of 0.07 inch to 6 per cent for a storm of 1.00 inch; the mean value was 5 per cent.