Distribution of biologically functional habitats within a lowland river, United Kingdom

Abstract

The assessment and appraisal of river habitat quality for purposes of legislative compliance requires a sound understanding of the interactions between the hydrogeomorphological and ecological components of the instream environment. Reconciliation of complementary habitat concepts developed from geomorphology (‘physical biotopes’) and from ecology (biologically ‘functional’ habitats) offers improved integrity of both concepts, but may be limited by factors such as the distributional characteristics of functional habitats. Field surveys conducted on a lowland river in Shropshire, UK, reveal differences in both the spatial organisation and seasonal variations in abundance among functional habitat categories. Furthermore, the level of human modification to the channel and banks appears to influence the spatial organisation of certain functional habitats within the river channel. These factors have implications for rapid field survey methods and for the potential for linking functional habitats with the complementary geomorphological concept of physical biotopes.

Keywords:

• aquatic macrophytes
• substrate
• aquatic habitat
• physical biotopes

Acknowledgements

This paper was produced as part of research projects NER/T/S/2001/01250, ‘Vegetation influences on fine sediment and propagule dynamics in groundwater-fed rivers: implications for river management, restoration and riparian biodiversity’, and NER/D/S/2000/01263, ‘Formation of a new river channel: flow, sediment and vegetation dynamics’ funded by the UK Natural Environment Research Council. Gemma Harvey was supported by a Research Studentship from the University of Nottingham and field assistance was provided by Alexander Henshaw and Kelly Watson.