Spain’s Biogeographic Regions: Vegetation, Soil & Landscapes
Biogeographic Regions of Spain
Vegetation
Floral vegetation is the set of plant species in an area. On Earth, there are great floristic sets, called floral kingdoms, which are subdivided into regions. The Iberian Peninsula is part of the Holarctic kingdom, comprising the mainland north of the Tropic of Cancer, and has three major regions: the boreal region, the alpine floral Euro-Siberian region, and the Mediterranean region. The Macaronesian region is also represented in the Canary Islands.
Factors Influencing Vegetation
Vegetation is composed of plant groups distinguished by their size and appearance. The three basic types are forest, scrub, and grassland. Spanish vegetation has a great diversity of species, some 6,000, a result of the variety of factors that affect it. The most important physical factors are the diversity of climate, because each plant requires specific conditions of temperature and precipitation. Human factors include introduced species, which are interesting for their economic value, or the degradation of existing vegetative cover. When the vegetation of an area is the result of human intervention, it is called secondary growth.
The Plant Landscape in Spain
Plant formations are arranged in communities, which together constitute the vegetation of an area. Climate exerts a decisive influence on the vegetation.
The Plant Landscape of Oceanic Climate
The deciduous forest is made up of tall trees with straight trunks and smooth, large leaves that fall in autumn, as well as moors and meadows. The heath is a dense thicket, which can be low or reach four meters. The meadows are herbaceous vegetation occupying large tracts of land in the ocean views.
The Mediterranean Climate Plant Landscape
Its vegetation characteristics are the evergreen forest and scrubland. These formations are adapted to summer drought through various systems: root development, widespread evergreen leaves, protective coatings (resin, wax, or rubber), and the formation of spines, etc.
Landscape of Riparian Vegetation
On the banks of rivers, the soil is impregnated with moisture, so the vegetation has features different from that of its surroundings, especially in dry climates. The constant presence of water means that only certain species can live there.
The Mountain Plant Landscape
In the mountains, the vegetation is available on floors with different vegetation types, depending on the height and orientation. The Alpine or Pyrenean mountain consists of the alpine and the floor level, and the rest of the peninsular mountains are formed by a basement floor above the forest floor on top.
The Vegetation Landscape of the Canary Islands
The vegetation of the Canaries has an extraordinary wealth. Its origin is mainly Mediterranean, but has African influence and the South Atlantic.
Soil
Soil disturbance results from the rocky ground due to climate and living things. First, atmospheric phenomena disintegrate the rock, then colonizing plants, organisms, and microorganisms contribute organic matter and allow the implementation of more complex biological communities. Over time, the ground evolves to equilibrium with the environment. Therefore, the factors affecting the formation and evolution of the soil are as follows: the bedrock, climate, topography, living organisms, and time.
The Horizons and Soil Profile
Soils are made of individual layers or horizons with their physical, chemical, and biological characteristics. The whole horizon is the soil profile.
The Soil Types
There are several classifications of the soil. One is based on its origin and evolution, and the other on their characteristics.
Zonal Soils
a) The soils of oceanic climate are evolved, rich in organic matter, and acidic. The acidity is enhanced when the rock is siliceous and natural vegetation is replaced by spaces such as pine and eucalyptus. On rocky silicon, the acidity increases. On rocky limestone, soil acidity is lower. b) The soils of the Mediterranean climate are very disturbed by erosion and human activity. On siliceous rock, the soil is poor due to its acidity. In the limestone soils, the earth has a reddish clayey horizon due to iron oxide. In clay and loam, vertisols or black soil arise, formed by expansive clay that shrinks when dry and swells when wet. In the Mediterranean areas of steppe climate, predominantly gray sub-desert soil is found.
Intra-zonal and Azonal Soils
Intrazonal and azonal soils can be found in any climatic area. Azonal soils do not have a defined profile. Intrazonal soils have a well-defined profile.