Biogeographical Regions of the Iberian Peninsula

I. Biogeographical Regions and Main Plant Life

I.1. Introduction

The diverse climates of the Iberian Peninsula, particularly variations in precipitation, influence the presence of three distinct biogeographical regions.

I.2. The Euro-Siberian Region

This region is associated with wet Iberia, primarily located in the northern peninsula, the central system, and some areas of the Iberian system. Within this region, two plant provinces are distinguished:

I.2.1. Atlantica

This province occurs in the higher elevations of the mountains. Deciduous tree species predominate. Up to 1000m, oaks (Carballo, Pyrenean oak, etc.) are common; above 1000m, beech trees prevail. Chestnut, pine, and eucalyptus (introduced for reforestation) are also present. In degraded areas, trees are replaced by shrubs such as heath and moorland, and also by grasslands. These species are adapted to both siliceous and calcareous soils.

I.2.2. Submediterranean

This province is found on the southern slopes of the Pyrenees and in the lower areas of the Iberian system, specifically in leeward areas. It features an alternation of Atlantic vegetation (oak, gall oak, pine) and Mediterranean vegetation (Aleppo pine, juniper, etc.).

I.3. The Mediterranean Region

This region covers most of the Peninsula and the Balearic Islands, characterized by a Mediterranean climate. Evergreen vegetation predominates, including holm oak, cork oak, and Aleppo pine. Riparian areas tend to have deciduous trees like poplars, cottonwoods, and ash. Some areas feature native pines (plateau) or reforestation efforts (west coast). The region is significantly influenced by summer drought and coincides with major agricultural areas, leading to the progressive destruction of native forests over the centuries.

I.4. The Canary or Macaronesian Region (Atlantic Islands)

This region is notable for its high level of endemism. It features a mix of Mediterranean and African vegetation. Due to the mountainous terrain, vegetation is distributed in stages:

• Below 500m: Predominance of dry scrubland.
• 500-1000m: Alternation of shrubs and trees (with higher moisture) such as laurel.
• 1000-2000m: With increasing humidity and decreasing temperature, conifers (Canary Island pine) begin to appear.
• 2000-3000m: Return of scrubland.
• Above 3000m: Rocks and permanent snow.