Submerged macrophytes in Big Spring Creek, WI: Distribution and influence on phosphorus dynamics

Abstract

Submerged macrophytes affect many aspects of lotic ecosystems, including nutrient dynamics. We performed longitudinal vegetation surveys to describe the distribution of macrophytes in Big Spring Creek, Wisconsin. We also measured environmental factors and used in situ mesocosms to estimate Soluble Reactive Phosphorus (SRP) uptake by submerged macrophytes. Biomass ranged from 1.5 g/m2 to 60.3 g/m2 throughout the year. Below-canopy Photosynthetically Available Radiation (PAR) and water velocity were the most significant indicators of plant biomass in the stream. Macrophytes had an uptake rate in the range of 364.3-573.5 µg/m2/day, resulting in a maximum uptake potential of 0.0029 - 0.0045% of daily SRP load. Although macrophytes in Big Spring have normal SRP uptake capabilities, this results in very little impact on the nutrient dynamics in the system.