A 6-Yr Record of Nutrient Element Sedimentation and Recycling in Three North Temperate Lakes
Sedimentation of C, N, and P from the water column was assessed during the ice-free seasons of 1986–91 in three northern Wisconsin lakes. Seasonal trends in mass sedimentation were different among lakes but consistent from year to year within each lake. High rates of nutrient sedimentation were associated with spring and fall blooms of large siliceous algae. Nutrient recycling, calculated as the difference between uptake during photosynthesis and loss to sedimentation, showed seasonal trends that were related to sedimentation. Recycling within the water column was the most important source of nutrients to primary producers, accounting for 85–90\% of P demand during the summer stratified period.