The purpose of the project is to find out how global change affects the oak groves of Quercus pyrenaica in the Sierra de Guadarrama National Park.

The Spanish Society of Plant Conservation Biology (SEBICOP) has carried out the project “Climate change and the floristic composition of habitats: have there already been changes in the Sierra de Guadarrama National Park?”, whose objective was to find out the impact of global change on the oak groves of Quercus pyrenaica, a type of forest whose main world stands are in Spain and which is listed as of Community Interest. The initiative has had the support of the Biodiversity Foundation through its call for grants. The initiative has been developed in the Sierra de Guadarrama National Park and its Peripheral Protection Zone (Community of Madrid and Castilla y León).

The study has involved carrying out a floristic inventory in the oak groves of Quercus pyrenaica in the Sierra de Guadarrama , which has allowed them to be compared with inventories carried out in the 80s, as well as an analysis of meteorological data to know the climatic evolution.

The adaptation of any activity to climate change requires prior knowledge of the extent or disturbance that this change introduces. Thanks to the study carried out within the framework of this project, it has been possible to better understand how the oak forests of the Sierra de Guadarrama National Park and its Peripheral Protection Zone are changing. A basic knowledge to improve the silvo-pastoral management of these forests as well as their conservation.

The study concludes that there is a clear trend towards an increase in temperatures in the area of 1.66 degrees Celsius and an apparent, although less significant, decrease in rainfall of 186 mm (average annual values). The forests in the area are richer than previously thought, as up to 247 plant species have been detected.

A certain reduction in the abundance of typical nemoral species, typical of fresh forests, and an increase in meadow species have been detected, both trends that would be in accordance with a certain aridification of the area and, perhaps, an increase in grazing in this habitat.

Outside the objectives of the project, although as a collateral finding of the study carried out, very rare plant species have been found in the Community of Madrid, including some that were not known in it (Linaria repens, Verbascum lychnitis), reflecting that floristic studies are necessary to know the distribution of rare species, many of them threatened. No invasive alien species have been detected in the habitats of the Sierra de Guadarrama National Park and its Peripheral Protection Zone.