2 results
Round Table 2: Biodiversity in groundwater/surface water ecotones: central questions
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- By P. MARMONIER, Université de Savoie, GRETI, 73376 he Bourget du Lac, France, J.V. WARD, Department of Biology, Colorado State University, Fort Collins, Colorado 80523, USA, D.L. DANIELOPOL, Limnological Institute, Austrian Academy of Sciences, A-5310 Mondsee, Austria
- Edited by Janine Gibert, Université Lyon I, Jacques Mathieu, Université Lyon I, Fred Fournier
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- Book:
- Groundwater/Surface Water Ecotones
- Published online:
- 07 September 2010
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- 28 February 1997, pp 231-235
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Summary
Biodiversity is the object of a large international programme of the IUBS-SCOPE-UNESCO and is important for many scientific, economic and ethic reasons (Solbrig, 1992). In groundwater, the study of biodiversity can be considered as a promising research field (Marmonier et al, 1993). Five major topics were discussed:
the importance of groundwater/surface water ecotone fauna in the estimation of global diversity;
the local and regional biodiversity;
factors promoting biodiversity;
biodiversity in gradients and impact of disturbances;
how to preserve biodiversity.
IMPORTANCE OF GROUNDWATER/SURFACE WATER ECOTONE FAUNA IN THE ESTIMATION OF GLOBAL DIVERSITY
Groundwater fauna is largely ignored in the calculation of global biodiversity. The number of species of tropical rain forests is estimated to be 10 or 20 times higher than those known to science (Cairns, 1988). Groundwater diversity is less well known than the diversity of surficial species in tropical forests globally: the total biodiversity of groundwater fauna is certainly higher than current estimations (in the Stygofauna Mundi, for example – Botosaneanu, 1986) and these organisms may represent an important part of the global biodiversity.
This is greatly important if groundwater fauna play an active role in groundwater system functioning (Fig. 1). It is especially true for microbes (microfauna, bacteria, fungi) which are still more or less unknown and may play an important role in the bank filtration of large rivers (the River Rhine for example is rather well studied from this point of view).
2 - Ecotonal animal assemblages; their interest for groundwater studies
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- By D.L. Danielopol, Limnological Institute, Austrian Academy of Sciences, A-5310 Mondsee, Austria, R. Rouch, Centre de Recherches Souterraines et Edaphiques, Laboratoire Souterrain, CNRS, F-09200 Moulis, France, P. Pospisil, Institute of Zoology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria, P. Torreiter, Institute of Zoology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria, F. Möszlacher, Institute of Zoology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
- Edited by Janine Gibert, Université Lyon I, Jacques Mathieu, Université Lyon I, Fred Fournier
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- Book:
- Groundwater/Surface Water Ecotones
- Published online:
- 07 September 2010
- Print publication:
- 28 February 1997, pp 11-20
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Summary
ABSTRACT In order to better understand the structure of the surface-groundwater organismal assemblages (SGOA), the concept of global aquifer/river system (GARS) of Castany is recalled. The pattern of SGOAs emerges within different space and time scales. Examples of SGOAs and of the processes which form them are presented using case studies from the alluvial sediment fauna of the rivers Rhone, the Danube at Vienna, and the Lachein brook, in southern France. The structure of these assemblages depends on the boundary conditions of the groundwater system, mainly the hydrologic dynamics, and on the initiating conditions offered by the ecological tolerances of each species which contributes in the assemblages. The possible role of the macroorganisms in the functioning of the groundwater ecosystem is discussed. Their role appears less important than was thought earlier. Finally we emphasize the necessity of protecting the diversity of ecotonal assemblages. Scientific, cultural and practical arguments are presented.
INTRODUCTION
The review deals with studies on surface-groundwater organismic assemblages (SGOA) in unconsolidated, porous media, mainly alluvial sediments. These animal assemblages are formed by hypogean dwelling organisms (Hy) and epigean ones (Epi) which live permanently or temporarily in such subsurface habitats. At a first approximation, the SGOA definition agrees with the concept of ecotone, sensu Odum (1971, p. 157): ‘a transition between two or more diverse communities’. The study of such ecotonal animal assemblages represents one of the core aspects of groundwater ecology (GW).