Deciduous Forests, Mediterranean Vegetation, and Soil Types

1 - The Deciduous Forest

It consists of tall trees with straight trunks, smooth bark, and large leaves that fall in autumn. This forest type has relatively few species, often forming large masses. The most common features are Carballo oak and beech. In the understory, ferns and mosses thrive in a somber mood created by the treetops.

2 - The Heath and Grasslands

The Landa is a dense shrubland, whose height can be low or reach 4 feet. Its most abundant species are heather, gorse, and broom. The heath is considered a form of deciduous forest degradation or supraforestal vegetation. It is often used for animal bedding and then as fertilizer.

The meadows are herbaceous vegetation occupying large tracts of land with ocean views.

The Vegetation of the Mediterranean Climate

This corresponds to the Mediterranean floral region. Its characteristic vegetation includes evergreen forest and scrub (maquis, garrigue, and steppe). These xeric formations are adapted to summer drought through various systems: the development of roots that spread widely on the surface or deep to collect water, and evergreen, sclerophyllous (hard, leathery) leaves with different systems to reduce perspiration, such as small size.

The Evergreen Forest

This is composed of trees of medium height, with non-straight, thick, rugged trunks and evergreen leaves. Its branches create large, globular canopies, which cast a shadow on the ground to mitigate sunshine and evaporation. The most characteristic species are the oak and cork oak. It has a rich understory, with species such as broom and gorse, as the trees are located some distance from each other and light penetrates easily.

The Bush

The Mediterranean maquis is not a climax formation but the result of forest degradation by human beings.

Flooring Ups, No Distinct Horizon

These soils have not had the time or conditions conducive to formation. Horizons are indistinguishable. Continuing contributions come from alluvial deposits (fluvisoles) or the decomposition of rocks (lithosols).

Flooring with a Poorly Differentiated Profile

Horizons begin to differentiate, but their composition or location means that their profile is still poorly differentiated. The main ones are:

• Those formed on slopes, which have only an upper horizon above the bedrock. If they are acidic, they are called rankers, and if they are located on limestone, rendzinas.
• The semi-arid climates, soils called xerosols or gray (in color).
• Materials consisting of difficult-to-differentiate clay.

Fully Formed Soils

These present distinct horizons and generally appear associated with forest areas. The main ones are:

• Brown soils: These appear in various forms throughout the peninsula.
• Mediterranean Red Lands (Terra Rossa): These owe their color to the presence of iron-rich clays.
• Fens and wet soils of mountains with a great accumulation of organic matter.

Soil Deterioration Process

The main example is podzols. In them, excess water and continuous soil washing cause the progressive destruction of the soil. Podzols show a gray ash on the horizon of organic matter.

Distribution of Soil

Schematically, it would be as follows:

• Oceanic climate: Moist brown soils, rankers, and if the area has been devoid of vegetation, podzols.
• Mediterranean climate: Brown soils and red soils, rendzinas.
• Arid Mediterranean climate: Gray soils (xerosols).
• Riverbed: Fluvisols.