Nutrient Dynamics in Forest Ecosystems: Are Inputs from Litter-Trap Studies Underestimated?.

Many studies have found leaf-litter to be the greatest contributor of nutrients to soil in forest ecosystems. However, there is a possibility that the contribution of energy and nutrients from litter-fall is underestimated. The collection of leaf litter for subsequent analysis usually requires a litter-trap, set-up under the forest canopy, to catch freshly fallen litter. The litter from the trap is then periodically collected on a weekly or biweekly schedule. Between sampling periods the litter is subject to early stages of decomposition, thus nutrients leached from litter may become a part of the soil nutrient pool or soil water flux. The objective of this study is to evaluate the change in weight and nutrient content of freshly abscised American Beech (Carpinus caroliniana), American Basswood (Tilia americana), and Sugar Maple (Acer saccharum) leaves while being exposed to different levels of precipitation and freeze-thaw conditions in a laboratory setting, in addition to evaluating the affects and changes to microbial activity of the phyllosphere. Preliminary results show that the nutrient content and dry weight of leaf-litter is significantly (p<0.05) lower when exposed to simulated litter-trap leaching conditions. However, treatments receiving lower than (30mm), and higher than (100mm) average rainfall levels leached less nutrients than average treatments (60mm), as well as had lower microbial activity.