Submerged Rootless Macrophytes Sustain a Stable State Against Free-Floating Plants

Abstract Both non-rooted submerged vegetation dominated by coontail ( Ceratophyllum demersum) and floating duckweed Lemna gibba ) can maintain their stable dominance in small ponds channels. We examined the competitive interactions between them how sustain its state against plants a range of nutrient concentrations. Coontail were co-cultured static semi-static microcosm experiments, impact on nutrients (N, P, Fe, Mn) water column was analysed. strongly reduced growth under low nitrogen level (0.2–2 mg N L ?1 ). This reduction seems to be due availability as derived from lower concentrations tissue or high pH water. High levels media (5–10 resulted an increasingly higher chance overgrow C. demersum L. gibba. Field observations revealed that over bodies with total below 3 , while occurred above 5 N. occurrence correlated negatively water, showed positive correlation. Furthermore, frequency . All findings together support theory certain range, rootless macrophytes have strong potential inhibit ponds, ditches channels, thus, they stabilize state.