Biologist Harry W. Godwin measures stemflow and throughfall from a white oak tree (Quercus alba). Initial data suggests that levels of carbon , tannins, and phenolics, are often 10X that of control rain water. Values of 4.8 pH in control rain water (rainfall from an open area) can increase to 7.2 in stemflow solutions which vary in color from pale yellow to deep orange. The manifold on the tree is designed to separate stemflow into timed samples. This work is being conducted to study the implications of stemflow and throughfall on silvopastures in Appalachia.

Photo by Barry Harter