Vegetation Nutrient Dynamics Associated with Sedimentation in Headwater Riparian Forests
2010
Jolley, Rachel L. | Lockaby, B Graeme | Governo, Robin M.
Sedimentation associated with flooding has long been considered a nutrient subsidy, making floodplain forests some of the most productive forests on earth. Little is known, however, regarding how sediment deposits from upland erosion may affect nutrient processes within riparian forests. Consequently, we studied the impacts of sedimentation on vegetation nutrient dynamics in riparian forests at Ft. Benning, GA. We measured the concentration and content of N, C, and P in foliar litterfall and fine roots, internal recycling rates, and nutrient use efficiencies in 17 riparian forests along a gradient of sedimentation rates. Plots with the highest sedimentation rates (highly disturbed and moderately disturbed) had higher nutrient use efficiencies (N and P use efficiencies), suggesting that these nutrients may be limited in these forest systems. Litterfall and root nutrient contents also decreased in highly impacted plots, indicating a decline in nutrient turnover. Internal N recycling also appears to be more efficient in highly disturbed plots, which also suggests a deficiency. The results of this study indicate that increased rates of sandy, primarily inorganic sediment may impact vegetation nutrient dynamics in headwater riparian forests.
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