PARTITIONING OF RAINWATER AND CHEMICALS INTO THROUGHFALL AND STEMFLOW IN DIFFERENT FOREST STANDS

The flow of nutrients throughout different components of forests was characterized using 13 years of data from a nutrient-cycling study involving three hardwood (broadleaved) and six softwood (conifer) forest stands. Included in this report is information on the distribution and chemistry of rainwater as it affects the quantity of nutrients cycled as throughfall and stemflow in different stands. A general formula empirically derived for partitioning rainwater into throughfall and stemflow is also described. The empirically derived equations were found to be suitable for calculating without rain data on an event basis, the weekly or monthly quantity of throughfall and stemflow reaching the ground under different stands. These equations were evaluated to increase their portability and applicability to forest stands of different regions. The results obtained with these calculations validated the among-species differences in the measured values of throughfall and stemflow. The differences among tree species with respect to their abilities to alter rain chemistry were also found to be significant. The differences in the concentrations of hydrogen and sulfate ions and total dissolved solids in the throughfall and stemflow samples as compared to those in the rainwater are also reported. © 1990.