Towards holistic assessment of the functioning of ecosystems under the Water Framework Directive

The assessment of chemical and ecological status in the context of the Water Framework Directive requires concrete, holistic knowledge about the abiotic and biotic structural properties and processes that determine the functioning of ecosystems. Ecological indicators typically exhibit non-linear responses to anthropogenic pressures together with great spatial and temporal variability, which underpin emerging key characteristics of natural systems. Recent research on the relationships between ecological indicators and anthropogenic pressures reveals several features of these relationships that can be used to predict meaningful changes of community structure and ecosystem functioning. The effective integration of strategies for assessing chemical status, including complementary biological tools, with strategies for assessing ecological status using functional end-points of ecosystems may reduce the inherent costs of monitoring and increase the level of protection of the environment. (C) 2008 Elsevier Ltd. All rights reserved.