Forests of The Iberian Peninsula - Stages of Degradation

Stages of Degradation

It is possible to identify successive stages in the process of degradation of these various forest formations, from an optimum state to the final phase of desertification.

These regressive states, in the case of leafy forests, are the following:

1. Dense forest representative of an optimal natural state, characterized by endemic species, compatible with local biological conditions.
2. Bosque aclarado, still with a predominance of the native species, but with abundant representation of a variety of species such as holly, maple, and ash. Frequently, leguminous plants predominate in the scrub of the underbrush.
3. Stage of pine forests. The native species have practically disappeared, as has the associated vegetation. Together with the pines, heliophilic (preferring dry and sunny habitats) and invasive brush start to appear, almost always based on the families Cistaceae and Ericaceae.
4. The stratum of trees as such disappears, along with its associated species, replaced progressively by brush representative of a very advanced degradation; there is a high frequency of thorny plants (Scorpion's thorn, blackthorn (Prunus spinosa), etc.) and a predominance of Lamiaceae y compuestas (Tomillo vulgar, heather, pennyroyal (Mentha pulegium), etc.).
5. The ground cover is reduced, not only in the size of plants, but also in the area it occupies; now it forms a hebaceous and discontinuous tapestry, with a general predominance of Dog's Tooth Grass. Woody plants are reduced to some thickets, the bedrock being exposed as a consequence of erosion. This is the typical landscape of the steppe.
6. The final stage of regression is represented by desertified ground.