Introduction

The progressive impact of humans on the European continent for the past several centuries has caused the degradation of a large part of the natural systems, limiting the natural or slightly altered areas to small units, generally located in zones with difficult access or small economic value. This degradation of natural areas has caused an isolated evolution of those ecosystems that are better conserved and where wild species of fauna and flora develop. In many cases the geographical disconnection so produced has provoked the extinction of species or the diminishment of their populations to the point of endangerment. Another effect of this geographical isolation is seen in the limited dispersion of the animal species and the endogamy that is produced in some cases.

The Doñana area is an example of this isolation phenomenon, and if a large part of its territory from the past still exists, it is because of the small or null economic value that this land has had. On the other hand, its ecological characteristics have enhanced the conservation of its ecosystems. Once the Doñana territory has been considered protected, it is important to consider the problems of its isolation and disconnection from other natural territories that long ago were interconnected. The Guadiamar river constitutes an element of considerable value as a link between two great natural systems: the Doñana and the Sierra Morena mountains.

We can consider the Guadiamar basin as an area where culture and nature are integrated but which over time has been losing value in both senses, and which surely has been greatly devaluated since an important mining accident happened in April 1998.