Research of the Seca

Research of the Seca

The “Seca” - The dying of the trees, forest decline in the Dehesas caused by the fungus Phytophthora cinnamomi.

The Dehesa is the final barrier against the advance of the African desert terrain in the south of Europe. In the past 25 years more than 500,000 holm and cork oaks died of the “seca” in southeast Spain, according to “Report of the Study of the protection of Ecosystem Dehesa” (“Informe de la Ponencia de Estudio Sobre la Protección del Ecosistema de la Dehesa”) by the Spanish government.

If we lose these trees, pasture will disappear, biodiversity will disappear, the land will erode and the door will be opened to desertification. Since the problem began, the administration has taken no efficient means to address it.

Given the land affected (more than 2,000 km2 only in the province of Huelva) and the magnitude and gravity of this problem, the drying out of the oak trees is the largest environmental problem facing Europe. At this rate, the majority of the Dehesas will disappear in the next 25-50 years and be replaced by deserts.

Fundación Monte Mediterráneo is cooperating in the dissemination of the information about the situation and realizing various research and investigation programs on the Dehesa San Francisco.

Ranchers and managers of Dehesas promote the following manifesto:



1. The Holm Oak is the most abundant tree in Spain; the Dehesa is the principal ecosystem in the Iberian Peninsula, and the only in the world with unquestionable environmental, social and cultural values as recognized by the protection given by international organizations (UNESCO and the Council of Europe).

2. The Dehesa is an agro-eco-system with life stock breeding that has been conserved thanks to the work of its residents for hundreds of years.

3. The Dehesa is experiencing an unprecedented crisis, motivated fundamentally by the dying off of the woodland, but also the stifling bureaucratization affecting the extensive life-stock breeding.

4. The disappearance of the Dehesa is an international problem, affecting the Iberian Peninsula (Spain and Portugal) and northern Africa, and due to its magnitude is the largest environmental crisis in Europe.

5. As of yet there is no administrative strategy to confront this problem in any level of government, from the local government to the European Union. Therefore, it is urgent that means are taken now to confront this situation. Local governments must move forward by working with the owners, ranchers and technicians affected.

6. Society must understand the unique and finite values of Dehesas and the grave and severe problems of this way of extensive life-stock-breeding. It is a sustainable system that has existed for thousands of years. It is a producer of food and a model of environmental conservation that is in danger of extinction.

7. The European Union must be informed and be confronted with the situation of the Dehesas. The lack of response to this environmental catastrophe is a radical failure in the aspiration for a Green Europe.

8. We must stop the advancing desertification in southern Europe, and assure that the Dehesa is protected for the people and future generations.


The following photos show the dramatic development:

Dehesas in the Andévalo, Province of Huelva (Aerial photo between 1977-1980)


Dehesas in the Andévalo, Province of Huelva 30 years later (Aerial photo between 2010-2011)


Research Project “seca”:

Prof. Dr. Laura E. Rose, Dr. Melanie Sapp, Heinrich Heine University Düsseldorf, Institute of Population Genetics, Universitätsstraße 1, 40225 Düsseldorf, Germany

Prof. Dr. Georg Bareth, GIS & RS Group, Institute of Geography, University of Cologne, 50923 Cologne, Germany

Improving soil by applying ecological substrates – liquid and solid – to empower the soil to defend itself against the ink disease. Dr. Aída López Sánchez Prof. Dr. Ramón Perea García-Calvo Dpto. de Sistemas de Recursos Naturales, Universidad Politécnica de Madrid.

Access DOWNLOADS to see the project files


Work Group “seca”:

Dipl.-Biol. Peter Bretschneider, Bernd-Blindow-Schulen Friedrichshafen, FB Biologie und Biotechnologie

Korbinian Schelzig, Universität Heidelberg, Bsc. Biowissenschaften

Alicia Rissi, Hochschule für Forstwirtschaft, Bsc. Ressourcenmanagement Wasser