Characterization and Valuation of the Ecosystem Services of the Coastal Cantabrian Holm Oak Forest in Spain: The Example of the Urdaibai Biosphere Reserve (Bizkaia, Basque Country)

Holm oak groves of Quercus ilex subsp. ilex are one of the most characteristic environmental elements of the Cantabrian strip of the Iberian Peninsula. The Cantabrian holm oak forest does not have a clear origin. There is a possibility that it has a relict character, and it could also respond more to human activity over the last 10,000 years. Nowadays, it is a rare, scarce, and finicultural forest in this demarcation, but it provides many ecosystem services. To carry out a comparative analysis and assessment of its potential as Green Infrastructure and of its coastal facies (Urdaibai, Bizkaia), 10 random and stratified inventories were carried out. These plots were monitored regularly for more than 2 years and in seasonal visits to avoid phenological bias. The resulting synthetic syninventories were then assessed according to the LANBIOEVA (Landscape Biogeographical Evaluation) Methodology, which has been applied for more than 35 years in different ecosystems and landscapes at a global scale. Scores for various parameters related to ecosystem services are of high conservation interest, and the cultural services are medium to high. Concerning conservation priority, the low records of the three threat parameters result in mean values that are in the first quartile for this parameter, which attests to a good level of conservation. The conclusion is clear: the Biosphere Reserve status has had a positive influence on the proper management and conservation of the Cantabrian holm oak forest and its associated ecosystem services. However, certain threats that still weigh on this ecosystem need to be addressed.