0000000000182672
AUTHOR
Yvonne Vadeboncoeur
Is there light after depth? Distribution of periphyton chlorophyll and productivity in lake littoral zones
Periphyton and phytoplankton contribute to the base of lake food webs, and both groups of microalgae are influenced by resources and physical forcing. Spatial variation in light availability interacts with the physical dynamics of the water column to create predictable depth gradients in resources and disturbance that may differentially affect periphyton vs phytoplankton. We characterized the depth distribution of chlorophyll and productivity of periphyton on sediments (epipelon) and phytoplankton in the euphotic zones of 13 oligomesotrophic lakes that span a large size gradient (0.017–32,600 km2 ). Epipelic chlorophyll usually increased with depth in the epilimnion. Light was the primary d…
Potential for large-bodied zooplankton and dreissenids to alter the productivity and autotrophic structure of lakes.
While limnological studies have emphasized the importance of grazers on algal biomass and primary production in pelagic habitats, few studies have examined their potential role in altering total ecosystem primary production and it's partitioning between pelagic and benthic habitats. We modified an existing ecosystem production model to include biotic feedbacks associated with two groups of large-bodied grazers of phytoplankton (large-bodied zooplankton and dreissenid mussels) and estimated their effects on total ecosystem production (TEP), and the partitioning of TEP between phytoplankton and periphyton (autotrophic structure) across large gradients in lake size and total phosphorus (TP) co…