Changing Paradigms in Groundwater Ecology - from the 'Living Fossils' Tradition to the 'New Groundwater Ecology'

Groundwater ecology merged during the second part of the 20(th) century with modern ecological practice after having adopted the 'ecosystem concept'. The latter was first applied to karstic systems and separately for alluvial non-consolidated aquifers along surface running waters. Today groundwater ecosystems are studied within a multi- and transdisciplinary framework at various spatial and temporal scales by experts dealing with microbiology, the ecology and systematics of meio- and macro-fauna, geochemistry, hydrogeology and mathematical modelling. A further paradigmatic change occured with the recognition that subterranean assemblages of organisms are formed by both hypogean and epigean taxa. The biological diversity in subterranean ecosystems can be much higher than earlier thought and may even exceed surface diversity in some taxa. This largely unrecognized biodiversity in many cases deserves environmental protection. A third phase in the development of groundwater ecology has occured over the last 15 years with the incorporation of socio-economic research topics within groundwater ecology (GIBERT et al., 1994a) and in this sense today we have the New Groundwater Ecology.