Savannahs and light forests are found, as a rule, in subequatorial belts. These zones are found in both hemispheres. But sections of the savannah can be found in the subtropics and tropics. This zone is characterized by a number of features. The climate in the savannah is always seasonally humid. There is a clear change of periods of drought and rain. It is this seasonal rhythm that determines all natural processes. Woodlands and savannahs are characterized by ferrallitic soils. The vegetation of these zones is sparse, with isolated groups of trees.
Savanna climate
Savannas and woodlands have climatic features. First, it is a clear, rhythmic change of two periods: drought and heavy rains. Each of the seasons, as a rule, lasts about six months. Secondly, the savanna is characterized by a change in air masses. Wet equatorial comes after dry tropical. The climate is also affected by frequent monsoon winds. They bring seasonal heavy rains with them. Savannahalmost always located between the dry zones of deserts and humid equatorial forests. Therefore, these landscapes are constantly influenced by both zones. At the same time, it is important to note that moisture does not last long enough in these areas. Therefore, multi-tiered forests do not grow here. But even the relatively short winter periods do not allow the savannah to turn into a desert.
Savanna soils
Savannah and light forests are characterized by the predominance of red-brown, as well as merged black soils. They differ primarily in the low content of humus masses. Soils are saturated with bases, so their pH is close to neutral. They are not fertile. In the lower part, in some profiles, ferruginous concretions can be found. On average, the thickness of the upper earthen layer is approximately 2 meters. In the area of predominance of red-brown soils, dark-colored montmorillonite soil appears in places where the relief is lowered. Especially often such combinations can be found in the Deccan plateau in its southern part.
Australian savannas
The savannas and woodlands of Australia occupy a significant area of the mainland. They are concentrated in the northern part of the continent. They also occupy large areas on the island of New Guinea, capturing almost the entire southern part. The Australian savannah is different. It is neither African nor South American. During the rainy season, its entire territory is covered with bright flowering plants. It is dominated by the ranunculus, orchid and lily families. Also in this area oftenthere are cereals.
The Australian savanna is also characterized by woody plants. Primarily eucalyptus, casuarina and acacia. They are concentrated in separate groups. Casuarinas have very interesting leaves. They consist of individual segments and resemble needles. In this area there are also interesting trees with thickened trunks. In them, they accumulate the necessary moisture. Because of this feature, they are called "bottle trees". The presence of such peculiar plants makes the Australian savanna unique.
Savannas of Africa
The savannas and woodlands of Africa from the north and from the south border on tropical forests. The nature here is unique. In the border zone, forests gradually thin out, their composition becomes noticeably poorer. And a patch of savannah appears in the midst of a continuous forest massif. Such changes in vegetation occur due to the shortening of the rainy season and the increase in the dry season. As you move away from the equatorial zone, the drought becomes longer.
There is a factual opinion that such a wide distribution of tall grass savannahs, which are replaced by mixed deciduous and evergreen forests, is directly related to human economic activity. For quite a long time, vegetation was constantly burned in these territories. Therefore, the inevitable disappearance of the closed tree layer occurred. This contributed to the arrival of numerous herds of hoofed mammals to these lands. As a result, the restoration of woodvegetation became almost impossible.
Savannas and woodlands of Eurasia
Savannahs are not common in Eurasia. They are found only in most of the Hindustan peninsula. Also, woodlands can be found on the territory of Indochina. Monsoon climate prevails in these places. In European savannahs, lone acacias and palm trees grow mainly. Grasses are usually tall. In some places you can find patches of forest. The savannahs and woodlands of Eurasia differ from those of Africa and South America. The main animals in these territories are elephants, tigers, antelopes. There is also an abundance of different types of reptiles. Rare areas of forests are represented by deciduous trees. During the dry season, they shed their leaves.
Savannas and woodlands of North America
The savannah zone in North America is not as widespread as in Australia and Africa. The open spaces of woodlands are mainly occupied by grassy herbaceous species. Tall grass alternates with small scattered groves.
The most common tree species that characterize the savannas and woodlands of North America are mimosa and acacia. During the dry season, these trees shed their foliage. The grasses dry up. But during the rainy season, the savannas bloom. From year to year, the area of woodlands only increases. The main reason for this is the active economic activity of man. Savannahs are formed on the site of a cut down forest. Animal worldthese zones are much poorer than on other continents. Some species of ungulates, cougars, rodents and a large number of snakes and lizards are found here.
Savannas of South America
The savannas and woodlands of South America border on tropical forests. Due to climate change, which is associated with the appearance of a long dry season, these zones are moving into one another. On the highlands of Brazil, savannas are located in a significant part of it. They are concentrated mainly in the hinterland. Here you can also find a strip of almost pure palm forest.
Savannahs and woodlands also occupy large areas in the Orinok Lowland. They are also found in the Guiana Highlands. In Brazil, typical savannahs are better known as campos. The vegetation here is represented mainly by cereal species. There are also many representatives of the family Asteraceae and legumes. Tree forms are completely absent in places. In some places, you can still find remote areas of small thickets of mimosa. Tree-like cacti, spurges and other succulents and xerophytes also grow here.
Brazilian Caatinga
Savannahs and woodlands in the northeast of Brazil are represented by sparse forests, which grow mainly drought-resistant shrubs and trees. This area is called "Caatinga". The soils here are red-brown. But more interesting are the trees. During the dry season, many of them shed their leaves, but there are also species that have a swollen trunk. ATit the plant accumulates a sufficient amount of moisture. These species include, for example, a vatochnik. Caatinga trees cover lianas and other epiphytic plants. There are also several types of palm trees in these areas. The most famous of them is the carnauba wax palm. Vegetable wax is obtained from it.
