Phosphorus Availability and Growth of Benthic Primary Producers in Littoral Lake Sediments: Are Differences Linked to Induced Bank Filtration?

Abstract

Submerged macrophytes and periphyton are benthic primary producers that play an important role for several ecosystem functions of lakes. Their growth often depends on the availability of phosphorus (P) in sediments and overlying water. This P availability is assumed to potentially be affected by induced bank filtration (IBF), a cost-effective method for drinking water production. In this study, we tested whether littoral sediments sampled at sites with high and low influence of IBF in a temperate eutrophic lake used for bank filtration since more than 100 years affects periphyton and macrophyte growth. Sediments differed in aerobic desorbed water-soluble phosphorus (P H2O ) and iron (Fe) content and the growth of macrophytes in sediments with a high impact of IBF was lower compared to sediments with low impact of IBF. We also found that P addition to the nutrient solution increased periphyton growth and that periphyton limited macrophyte growth. While these results point to a potential impact of IBF on P availability in sediments that can cascade to benthic primary producers, we could not prove mechanistic links between high rates of IBF and the lower macrophyte growth. Additional research to assure a sustainable application of this valuable drinking water production method is therefore needed.

Niche Models Differentiate Potential Impacts of Two Aquatic Invasive Plant Species on Native Macrophytes

“…Water depth is one of the strongest gradients in aquatic systems, with plant species spanning from tolerating seasonally saturated soils to completing their entire life cycles underwater [35]. Additionally, depth gradients capture other important gradients such as nutrient availability [38], sediment resuspension, and hydraulic forces [39]. Light is a critical determinant of all plant growth that is particularly constraining in aquatic environments, where photosynthetically active radiation rapidly decays with water depth and transparency [35,40].…”