The occurrence of a species along an environmental gradient can be considered as the product of its physiological requirements and competitive interactions with other species. One may, therefore, expect that this realized habitat differs between areas when a species has to co-exist with different species. To test this hypothesis, we compared the responses of wetland plants to hydrological conditions in two European lowland river valleys: the Drentse A valley (The Netherlands) and the Peene valley (eastern Germany). We used mean water level and water level amplitude as hydrological parameters to analyse differentiation in realized habitats within species. Most species occurred in slightly wetter conditions, with higher fluctuations in the German site but with narrower tolerances for these parameters. We suggest that this may result from a higher competition intensity for light, possibly caused by a larger local species pool and/or presence of more dominant species with a high competitive ability. The consequences for practical applications—such as parameter estimation for predictive models—are discussed.

, , ,
Acta botanica neerlandica

CC BY 3.0 NL ("Naamsvermelding")

Koninklijke Nederlandse Botanische Vereniging

W. Kotowski, R. van Diggelen, & J. Kleinke. (1998). Behaviour of wetland plant species along a moisture gradient in two geographically distant areas. Acta botanica neerlandica, 47(3), 337–349.