Decomposition and nutrient dynamics of hardwood leaf litter in the Fernow Whole-Watershed Acidification Experiment

Two watersheds are part of an on-going long-term artificial acidification experiment: the treatment watershed (WS3) has received 60.5 kg S ha(-1) year(-1) and 54 kg N ha(-1) year(-1) via aerial applications of ammonium sulfate fertilizer since 1989. After 3 years of treatment, freshly fallen leaves of four hardwood tree species (Liriodendron tulipifera, Prunus serotina, Acer saccharum, and Berula lenta) were collected and placed in litter bags, which were placed in stands in the treatment and control watersheds. Decay rates differed for L. tulipifera, Prunus serotina, and B. lenta between the two watersheds, with litter from WS3 decaying more slowly over the 2 year study period than litter from the control watershed. Initial concentrations of N, Ca, and K differed between treatment and control watersheds, but these differences disappeared after 2 years. Nutrient loss rates did not vary with treatment.