Vegetation Nutrient Dynamics Associated with Sedimentation in Headwater Riparian Forests

• Published in: Soil Science Society of America journal Vol. 74; no. 4; pp. 1389 - 1397
• Main Authors: Jolley, Rachel L, Lockaby, B. Graeme, Governo, Robin M
• Format: Journal Article
• Language: English
• Published: Madison Soil Science Society 01.07.2010; Soil Science Society of America; American Society of Agronomy
• Subjects: Agronomy. Soil science and plant productions; biogeochemical cycles; Biological and medical sciences; carbon; Coastal plains; Dynamic tests; Dynamics; Earth sciences; Earth, ocean, space; Efficiency; Exact sciences and technology; Floodplains; forest litter; forested watersheds; Forests; Freshwater; Fundamental and applied biological sciences. Psychology; headwaters; nitrogen; nutrient content; Nutrient dynamics; nutrient retention; nutrient use efficiency; Nutrients; phosphorus; plant nutrition; Ratios; Recycling; Riparian forests; Riparian vegetation; sandy soils; sediment transport; Sedimentation; Sedimentation rates; sediments; soil erosion; Soil fertility; Soil science; Soils; Surficial geology; Trends; Vegetation; Water quality; Georgia; Vegetation type; Riparian vegetation; Riparian forests; Soil science; Vegetation dynamics; Earth science; sedimentation; nutrients
• ISSN: 0361-5995; 1435-0661
• DOI: 10.2136/sssaj2009.0142

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.