Light and Nutrients in the Control of Aquatic Plant Community Structure. II. In Situ Observations

This is the authors' abstract. We don't add key points for this paper.

(1) The biomass and growth-form composition of submerged plant communities growing along natural gradients of irradiance and sediment fertility were investigated to test the hypothesis that environmental factors determine community composition. (2) Increasing sediment fertility was associated with an increase in the proportion of the total plant biomass attributable to canopy-producing or erect growth forms and a decrease in the importance of rosette and bottom-dwelling forms. (3) Comparison of the sediment and irradiance responses under controlled conditions and in nature showed that each growth form achieved a biomass greater than or comparable with the other forms under similar conditions both in monoculture and in situ. (4) These results suggest that the growth-form composition of aquatic plant communities is primarily determined by the physical environment.