Concepts in river ecology: pattern and process in the catchment hierarchy
Townsend, C. R.
A sound conceptual framework is vital for river ecology, both to take the science forward and to guide effective management of our rivers. Our knowledge of whole river systems is fragmentary and more is known about small tributaries than large mainstems. One of our tasks is to evaluate the extent to which current concepts are appropriate to large river systems. I review and evaluate the diversity of concepts that have been proposed and argue that most are viable and can be meshed together into the broad spatiotemporal context of the catchment hierarchy of an entire river; this should be the unit of study for river ecologists. However, there are many gaps in our understanding of the workings of the catchment hierarchy. Thus, another task is to devise approaches and technologies to uncover new patterns and processes that are relevant at the larger scale.