Soils of moist equatorial forests: characteristic types for this zone and features

Equatorial forests occupy a vast area of Central Africa, South America and Southeast Asia. Consider the features of soils of moist equatorial forests, common types - red-yellow and red soils, their origin, structure, morphological features and characteristics. What kind of vegetation usually grows in equatorial forests.

Features of soils of equatorial forests

Rain forests are common in the equatorial belt, which is located north of the equator to 25 ° north latitude and south to 30 ° south latitude. In this area, stable climatic conditions - year-round temperatures are on average above 25 ° C and high humidity - it rains almost constantly, more than 2500 ml of precipitation falls annually.

2 types of soils are formed under them - red-yellow and red. Their characteristic feature is red-orange and dark red color due to the presence of iron and aluminum oxide. Due to the leaching water regime, mineral elements do not linger in the upper soil layer, they are washed down.

Equatorial soils are not very fertile, because, despite the accumulation of foliage and other organic matter, nutrients do not accumulate in the soil, but are constantly consumed by the plants themselves. The humus content is low. The rapid decay of plant and animal remains caused by bacteria prevents the accumulation of a layer of humus. In areas where the soil is quite young, especially when of volcanic origin, fertility is higher.

Common types

On the territory of equatorial forests there are 2 types of soils - red-yellow and red. They have much in common, but there are also differences.

Red-yellow

Soils of this type are typical for the warmest and wettest areas of the equatorial belt. The percentage of humus in the upper horizon is 4-5. In the lower ones, its concentration cannot be more than 1%. Humus is formed from fulvic compounds, which give it its yellowish color.

The profile of such a soil consists of a forest floor, a humus horizon 12-17 cm thick, then there is a reddish-brown horizon, under it is a red or brick-colored soil-forming rock. All layers are acidic. The intensity of absorption is negligible. The predominant compounds among those absorbed are hydrogen and aluminum, the concentration of silica is relatively low. Red-yellow type soils are well suited for trees of equatorial species, which have high productivity here.

Reds

Formed in the equatorial zone, with a large amount of precipitation with alternating 3-4-month dry season, during which the soil dries up.The soil acquires a red color due to the thermal effect on iron, which is contained in the soil layer in abundance. The upper layer is 30-40 cm thick, the humus content is 4%, and fulvic substances predominate in its composition.

Red soils are formed under the influence of laterization processes. This is a process in which iron compounds are diluted with soil solutions. Under hydromorphic conditions, the lower horizons are dense and have a thick layer. When dried, they harden if they come to the surface. In this form, red soils are not suitable for agricultural use, although they are used as a building material.

Vegetation

Humidity and warmth of the equatorial climate ensure the constant rapid growth of all kinds of vegetation, due to the density of plants, wet forests are still difficult to pass and little explored.

Equatorial forests are considered complex ecosystems that comprise hundreds of different species of plants, insects, and animals. 2-3 hundreds of plant species can grow on one hectare.

There are many endemic varieties found here that are not found anywhere else. Trees grow densely, in several tiers, there are few shrubs and herbaceous vegetation.

The red-yellow and red soil cover of the equatorial forest is not very productive due to the generally low fertile capacity. The result of plowing the land showed that it is difficult to get large yields from them. In most cases, a decent yield is observed only in the first years after development, then it is necessary either to clear a fresh territory, or to use complex agrotechnical measures.

The soils of the equatorial forests are formed under the influence of a year-round humid and warm climate, contain a lot of iron, and are not sufficiently saturated with nutrients in the fertile layer. Their economic value is small.