Hemlock woolly adelgid (HWA) is a non-native invasive pest that impacts eastern hemlock (Tsuga canadensis) and Carolina hemlock (Tsuga caroliniana).  Hemlock trees serve an important ecological role in the southern Appalachians as a keystone species in near-stream areas.  In 2005, we established 8 intensive research plots in riparian areas with greater than 30% basal area hemlock to measure the effects of adelgid infestation and hemlock mortality on nutrient cycling; reference plots were established in non-hemlock areas. Individual hemlock trees were girdled in 4 hemlock plots to measure effects of hemlock mortality.  Measurements included throughfall nutrient fluxes, soil solution chemistry, soil N mineralization potential, and soil chemistry.  Data show that hemlock plots have greater PO₄ inputs via throughfall and hardwood reference plots loose greater amounts of NH₄ through leaching.  These are the only differences in nutrient cycling processes between treatments after almost 3 years of increasing hemlock decline and mortality.  We hypothesize that impacts of hemlock loss on nutrient cycling will be measured when significant changes occur in forest floor and soil chemistry.