Groundwater-dependent ecosystems (GDEs) are a vital yet poorly understood component of the natural environment. Typical examples of these systems are spring (hydrosphere) and wetland ecosystems where groundwater seep to soil surface occur. In these systems groundwater contribute to water and nutrients which maintain a rich and unique biodiversity adjusted to these special conditions. Also rivers receive groundwater particularly in low flows and dry conditions. Some terrestrial ecosystems such as forests may also depend on groundwater.
Groundwater-dependent ecosystems are vulnerable to environmental change. Groundwater contribution can change due to i) regional changes, ii) reduced groundwater level and input and (iii) by increased seepage from ecosystems. The degree and nature of dependency of groundwater will influence the extent to which ecosystems are affected by changes in the groundwater system, both in quality and quantity.
Groundwater-dependent ecosystems are of special concern in EC groundwater directive. On-going research activities on these systems are financed by the European Community in the Seventh Framework Programme-project GENESIS - Groundwater and Dependent Ecosystems.