Subterranean ecosystems - Universidade de Évora

Preface
Ecosystem services are defined as the goods and benefits provided to people by ecosystems, including
provision of food, fuel, wood and water; regulating services; supporting services such as soil formation and
nutrient cycling and cultural services such as opportunities for recreation and spiritual experience.
A recent study of the Millennium Ecosystem Assessment has concluded that many of the Earth’s ecosystem
services are seriously affected by overuse and exploitation of resources. In fact, groundwater resources are
facing increasing pressure from consumption in various socioeconomic activities, the most dramatic of which
is the general rise in water demand. On the other hand, climate changes have contributed to the decrease in
groundwater availability, especially in some sensitive regions such as arid and semi-arid areas and coastal/
estuarine zones. All these anthropogenic changes pose a significant threat to the health of the groundwater
ecosystems and negative modifications on the services provided by them.
During the last two decades, groundwater ecology has very rapidly developed as a new research area, originating
important concepts such as Groundwater Dependent Ecosystem (GDE). These ecosystems totally or partially rely
on groundwater to maintain their species composition and natural ecological processes. Furthermore, their
characterization is regulated by the level of dependency on groundwater.
Subterranean ecosystems reveal specific fauna and show high biodiversity and habitat heterogeneity at spatial
and temporal scales. Besides, the biological component of subterranean ecosystems provides an important
ecosystem service of water purification through microbial degradation of contaminant compounds.
In conclusion, there is a growing need to develop interdisciplinary methodologies in order to properly analyse
and understand the complex interrelationships in all these specific ecosystems; and geology, hydrogeology,
geochemistry, biology, economy, geomathematics play an essential role in the process.
Implementation of the European Water Framework Directive (WFD) and the complementary ‘Directive on the
Protection of Groundwater against Pollution’ [European Union Groundwater Directive] demands an initial
characterization of all groundwater bodies.
The initial main criterion for the Directives was the definition of the groundwater status from the point of view of
quantity and quality (chemical). However, due to its relevance, the ecological perspective was also introduced
in the Groundwater Directive, recognizing the importance of the ecological functions of groundwater and
their interactions with GDEs.
The International Association of Hydrogeologists (IAH) has set up a Commission on Groundwater Dependent
Ecosystems, acknowledging the important ecological role of groundwater in rivers, wetlands and other coastal
and terrestrial environments. The main goals of this GDE Commission are:
• To promote wider understanding of the ecological role of aquifers and the impacts of groundwater
abstraction to decision makers.
• To provide a forum to promote, link and coordinate research in terrestrial, aquatic and marine Groundwater
Dependent Ecosystems (GDEs) between IAH members.
• To connect IAH with other organizations active in ecohydrology and related disciplines.
• To potentially attract a new group of groundwater scientists to IAH.
And, UNESCO has also included the concept of GDE in the Ecohydrology theme of the International
Hydrological Programme.
The objectives of this XXXV IAH Congress, the first one organized by IAH dedicated to Groundwater and
Ecosystems, are:
• To experience exchange of knowledge on integral groundwater management with dependent
ecosystems.
• To propose methods of defining, preventing, controlling and mitigating negative environmental impacts
related with groundwater on the ecosystems.
• To discuss specific issues such as climate changes, groundwater quantity and quality as well as threatening
processes in dependent ecosystems, biological aspects of groundwater dependent ecosystems and