Original paper

The influence of different sediment nutrient contents on growth and competition of Elodea nuttallii and Myriophyllum spicatum in nutrient-poor waters

Angelstein, Susanne; Wolfram, Christa; Rahn, Karsten; Kiwel, Uwe; Frimel, Siegfried; Merbach, Ines; Schubert, Hendrik

Abstract

Elodea nuttallii and Myriophyllum spicatum are highly competitive invaders replacing established vegetation in Europe and North America, respectively. In this study, the effect of different sediment nutrient contents on growth and competition potential of these two macrophyte species in nutrient-poor environments was investigated. When the sediment nutrient content was decreased, both species showed a gradual decrease in vitality, in terms of decreasing nutrient contents in the plant tissue, decreasing length relative growth rate (RGR) and increasing root:shoot ratios. E. nuttallii also revealed a decrease in weight RGR. At lower sediment nutrient contents both species were severely phosphorus-limited. As an evidence for inter-specific competition, we found a decreasing strength of the plant tissue: sediment relationships for nitrogen and phosphorus in M. spicatum if exposed to E. nuttallii.

Keywords

oligotrophic lake conditionsroot competitionmacrophytesediment fertilityphosphorus limitation