Air-monitoring: atmospheric deposition

A full evaluation of air pollution effects on ecosystems requires an estimate of total deposition fluxes. Collection of throughfall, the hydrologic flux of nutrients from the canopy to the forest floor, is widely acknowledged as a practical method of monitoring atmospheric deposition to forests. We have developed a "passive" throughfall collector in which the deposition is captured in ion exchange resin columns. This method of throughfall collection is much less expensive than conventional methods and provides an opportunity to quantify nitrogen and sulfur deposition at a greater number of sites than previously possible. Using this method we are increasing our understanding of what nitrogen deposition inputs cause various effects on forests throughout California and in other western ecosystems.