Attributes for assessing the environmental quality of riparian zones

Abstract

Seven attributes of riparian systems are proposed to be considered for assessing the ecological status of riparian zones. They can be easily evaluated by taking into consideration some features of the structure and functioning of riverine systems, largely determined by their hydromorphological dynamics. The structure of riparian zones could be characterized by the longitudinal continuity of vegetation, the lateral dimensions (width) of the channel containing natural riparian vegetation and the composition and structure of riparian vegetation communities. These attributes basically define the morphology of riparian areas, reflecting a static view of the river. They also define the spatial dimensions where riparian functions take place, indicating the possibilities of carrying on riparian restoration activities at short time scales. The functioning of riparian systems may be assessed considering the ratio of natural woody species regeneration, bank conditions, lateral connectivity and permeability of riparian soils. These attributes indicate the temporal behaviour of riparian zones, that is showed in a more dynamic or video view of the river. They are more related to the potential of achieving riparian restoration at longer time scales, representing key elements to guarantee the self-maintenance of fluvial processes and riparian biodiversity. The aforementioned attributes provide a framework to assess the ecological status of riparian zones, and offer a minimum checklist of criteria to evaluate strategies for restoring and preserving river ecosystems.