Papel de la geología en el desarrollo globalla importancia de los humedales

Abstract

Wetlands are rich and productive environments, as well as fragile. Thus, due to climate change, water diversion and land use policy, these environments are disappearing even faster than forests. Essential services for health and human well-being are derived from the natural processes that take place in wetlands, such as food and raw material production, water purifi- cation, flood and erosion control, and groundwater replacement. Although it is not usually taken into account, wetlands play a significant role in mitigating climate change, since they can act as CO2 sinks. Besides peatlands, carbonate precipitates can accumulate carbon, as occurs in the alkaline lakes of Coca-Olmedo (Duero Basin). Geology plays a fundamental role in understanding the dynamics of these systems; however, it is rarely mentioned in the studies and management of wetlands, that commonly only consider biological and economical aspects. This is seen in Spain, in spite of the fact that the aforementioned environments show a great diversity of waters (fresh, brackish, hypersaline –Lillo wetland in Toledo–, alkaline) and varied hydrogeological contexts (phreatic, surface or rainfall feeding, endorheic or exorheic basins –Ebro delta–). From a geologi- cal point of view, wetlands represent different sedimentary environments where specific sedimentary facies form. In addition, wetlands are natural laboratories that allow us to model precipitation of carbonates, sulfates and biominerals, whose origins have not yet been determined exactly, and that are common on planet Earth and other celestial bodies of the Solar System. In this way, geologists have the opportunity and responsibility to make known to society the geological characteristics of wetlands that would help to implement appropriate management and conservation policies.