A positive relationship between groundwater velocity and submersed macrophyte biomass in Sparkling Lake Wisconsin

We measured groundwater velocity and submersed macrophyte biomass at 52 shallow (0.4–6.6 m) sites in mesotrophic Sparkling Lake, Vilas County, Wisconsin, during May–August 1985. Seventeen percent of variation in macrophyte biomass was explained by a significant ( P < 0.005) relation with depth [log(biomass + 1) = 0.49 depth − 0.08 (depth) 2 + 0.12]. Some of the remaining variation in macrophyte biomass was explained by a significant rank correlation of biomass#x2010;on#x2010;depth residuals with groundwater ( r s = 0.46, P < 0.01). These results suggest that water movement through the sediment#x2010;water interface may be a determinant of macrophyte abundance and distribution.