Climate change may alter conditions for growth of oak trees in Euskadi

Neiker-Tecnalia has carried out a study on trends in the future distribution of habitats of Basque woodlands, pointing out that climate change may alter the conditions necessary for the growth of a tree as representative of the Basque lands as the oak.

The research was undertaken on the basis of the most pessimistic and severe scenarios for conditions of climate change in the future and claims that for 2080, the oak woods of the Basque Country would undergo a significant or almost total reduction of their habitat, given that, in our territory, wooded areas will not meet the variables of temperature and humidity necessary for their development. Neiker-Tecnalia experts consider that this study illustrates the tendency towards the 'Mediterraneanisation" of woods in Euskadi.

The technological centre is analysing this possible impact of climate change on the distribution of the habitat of forestry species, within the K-Egokitzen and Adaptaclima projects, financed by the Basque Government and the European Union (Interreg IVB SUDOE) respectively. One of the end goals of both projects involved drawing up methodologies in order to help understand how the forestry habitats will be in a short and a long term. In the conclusions from the Neiker-Tecnalia specialists, it is seen that the oak will find favourable conditions for its development in increasingly higher latitudes as time passes.

Based on the results, and assuming the capacity for dispersion of the oak allows it, it is conceivable that it may be a tendency for migration of oak woods towards the north of Europe. Nevertheless, they would keep its own natural habitat in the Basque Country until 2080, a time when it has been predicted they would undergo a significant or almost total reduction of the species´ habitat. This phenomenon could result in the oak by that year, while still having a great adaptative capacity to the predicted climate change, meeting with a threshold of conditions in which it cannot maintain its population.

The study shows that the oak would lose out potential habitat to make way for other Mediterranean species, such as the cork. Other trees, such as the pyrenean oak, present in the Basque territory, would maintain their populations as they are adapted to the climatic conditions of the Mediterranean region.

The predictions for the cork provide one of the clearest examples of the 'Mediterraneanisation' of the Atlantic part of the Iberian Península. Despite being a typically Mediterranean species, in Euskadi could be adecuate conditions for their development throughout the eighties of this century.

Those conclusions do not mean that Mediterranean species will substitute the species that nowadays exist in the Basque Country, since, this study has been carried out using statistical models whose results do not show where the species will be found, but where similar relation of current climate conditions for the species will be given in the future. Besides, the real distribution of one species is determined by an infinite number of factors that statistical models do not take into consideration, such as species competition, dispersion ability or the adaptation ability to climate changes.

To undertake the research on trends in the evolution of the habitat, scientists took into account a total of 19 bioclimatic variables, amongst which were the annual mean temperature, the maximum temperature of the hottest quarter, minimum temperature of the coldest, annual precipitation and the rainfall in the wettest and driest quarters. The conclusions, thus, of this research, should be complemented in the future with new variables which, as with the bioclimatic ones, affect the distribution of tree species.

Provided by Elhuyar Fundazioa