In the Historic Territory of Alava the Atlantic and Mediterranean Biographical Regions converge, the limit being marked by a series of mountain ranges on the south of the Territory. Although Izki is located completely in the Atlantic Zone, the ecological processes of this enclave are clearly influenced by the Mediterranean environment, considered a transition area.

There are various enclaves of notable interest in this space, but those that especially stand out are the surfaces occupied by a type of oak, the Pyrenean oak (Quercus pyrenaica). Although this space is present in other areas of Alava, there is no other place where it occupies such a great expanse or in such great conditions.

Nevertheless, the Pyrenean oak presents certain conservation problems. In general there is a slow but constant substitution of the Pyrenean oak by the beech, a type of forest which is generally more abundant in Alava, but of less interest in Izki. This colonization process is fundamentally due to the scant vigour of the feet of the Pyrenean oak wood which have an aged root system, versus the elevated ability of the beech to grow under the shade of the Pyrenean oak.

The PRO-Izki project revolves around the protection of this forest habitat and the small moss peat enclaves immersed in the wooded mass and includes conservation actions directed at some of the species associated with these habitats, like the middle spotted woodpecker (Dendrocopos medius), the Bechstein bat (Myotis bechsteinii) and the agile frog (Rana dalmatina).