Variable rainforests: soil, vegetation and fertility, application

Variable-moist forests are characteristic of areas where seasonal rains and dry weather alternate. They are distinguished by unique climatic characteristics, beautiful landscapes, diverse flora and fauna. During the humid period, these zones are similar to equatorial forests. The soils of variable wet forests also have unique characteristics.

Description and features

Such forests are predominantly located in the subequatorial climate, which is characterized by drought and precipitation patterns. This type of forest is located in small areas, but affects many regions - Africa, South and North America, Asia.

The main distinguishing feature of the soil of this type of forest is considered to be a bright red color. It is associated with the weathering of useful elements. For the formation of humus, vegetation is required that saturates the soil with organic matter. But heavy rainfall leads to the penetration of nutrients into the depths and reduces the content of humus in the upper horizon.

With the advent of dry weather, the final stage of the formation of red soils begins. The fact is that the useful substances that remain on the surface are weathered. As a result, iron oxides remain, which affect the color of the soil.

Such soils are typical for zones with sharply variable climate. Tropics and subtropics are a prime example. There, the duration of precipitation and dry days is 6 months each. The color of the soil depends on the climate and plants of the region. It can be red-brown or red-yellow. The first group of lands is called red soils, and the second - yellow soils.

Both types of soil are found in subtropical and tropical forests and steppes. They are characterized by a lumpy-granular structure. The main difference is the organic content. Red soils are considered the most weathered. However, they have more powerful humus than zheltozems, and therefore are considered more fertile.

Climate and geography

Summer temperature in the areas of such forests is +27 degrees. In winter, it rarely drops below +21 degrees. The rainy season comes after the hottest month.

Moist forests of variable type are mainly localized in the subequatorial climate. It is distinguished by the regime of drought and precipitation. This type of forest covers many regions:

Africa - Cameroon, southern Sudan, Congo, northern Angola;
North America;
South America - in particular, large areas of Brazil;
Indochina;
Sri Lanka;
India.

Such forests are typical for temperate and subtropical climatic zones. This primarily concerns the monsoon climate on the eastern side of Eurasia. Variably humid forests are found in China, Korea, and Russia. In the Russian Federation, they are localized in the Khabarovsk Territory, Primorye, Sakhalin.

What soils prevail in variable-moist forests

Soils in all areas of variable-moist forests differ significantly from other types.They are characterized by a red tint and strong weathering of minerals. In such areas, a lot of precipitation falls in a short period of time. Constant heat creates conditions for the active growth of greenery.

Vegetation is considered a source of organic acids. Water moves them into deep structures and starts the process of dissolution of mineral rocks. With active weathering and moisture, many minerals and biochemical elements are cleaned from the soil with water. As a result, only the most resistant remain - iron, quartz, kaolinite, aluminum.

Due to these features, soils are called ferallitic. Iron oxides present in the structure give the soil a red, dark brown and yellowish tint.

Vegetation and fertility

In order for the soil to be fertile, it must contain a large supply of humus. If its content is up to 4%, the soil is considered infertile. Lands of red color almost do not include humus. Its content is approximately 3%. Only the most resistant substances remain in the composition - quartz and kaolinite.

Due to the composition of the soil, the flora in variable-moist forests is considered to be very monotonous, since only specific plants have adapted to weather conditions. So, in the savannahs, in which red soils are found, trees can rarely be seen. Herbaceous vegetation prevails here. At the same time, sometimes there are trees - most often baobabs.

The vegetation of such forests is mainly represented by coniferous, deciduous and evergreen tree species. There are also creepers and ferns. It should be borne in mind that during the wet period, the trees are distinguished by rich green foliage. During dry climates, it crumbles.

The only exceptions are evergreens. These include palm trees, ficuses, bamboo. This category also includes cypresses, different types of magnolias, camphor tree. Quite often in these zones there are fir and spruce. Of the deciduous trees, it is worth highlighting linden, oak, maple, walnut, ash.

Application

Despite the low fertility of red soils, the humus in their composition is distinguished by excellent power. It is approximately 20 centimeters. Thanks to this, it is possible to use the land in agriculture. They allow you to grow citrus fruits and certain vegetables - in particular, beets.

Yellow soil types are considered less fertile. This is due to the high content of clay and weakly expressed humus. However, such land is also permissible to grow in agriculture. They are used for tea and vineyards.

Variably humid forests have a number of features. Such zones are distinguished by unique soil, which is allowed to be used in agriculture. At the same time, the soil is considered not very fertile and requires careful attention to the implementation of agrotechnical measures.