Identifying forest structure types using National Forest Inventory Data: the case of sessile oak forest in the Cantabrian range

The objective of this work was the creation of a structural stand classification for sessile oak dominated forests in the Cantabrian Range (northern Spain) as a basic tool for typological inventories. A dichotomous classification system and discriminant classification equations of nine forest types were defined with an accuracy of more than 95% by evaluating the data of the second Spanish National Forest Inventory (SNFI). The presence of large old trees appears as one of the main characteristics of the Cantabrian sessile oak forests. The structure assessment method presented in this study, based on a dataset (SNFI) and free-access software, can be considered an important low-cost alternative to traditional quantitative inventory methods.