1. Tropical Rainforest
The tropical rainforest occur where there is always plenty of moisture and heat, no drought, no winter. They have a rich floristic and faunistic composition. The plants and animals of all kinds, which have no resistance to drought or cold, occur here. These forests are best developed in tropical America, particularly the Amazon basin, in the East Indies and surrounding areas, and to a lesser extent in Africa.
The typical rain forest has many layers. Dominant trees are generally 30 - 50 metres tall, emergent trees extend to 60 metres. Below the crowns of dominant trees are several other strata of plants that can tolerate deep shade. Concentration of life is in the canopy, where there is plenty of light. Since there is enough heat and moisture, the principal limiting factor in the rain forest is usually light. The crowns of large trees are covered with epiphytes, non-parasitic plants that use trees only for support. These epiphytic plants manufacture their own food, and with aerial roots or water catchments, get their water from the torrential rains that occur almost daily. In the American rain forest, orchids and bromeliads (relatives of the pineapple) are the most abundant epiphytes. In the East Indies, there are no bromeliads but orchids and ferns are abundant as epiphytes. Lianas, which are vines rooted in the ground but having their leaves and flowers in the canopy 30 metres above, are also characteristic of all tropical rainforests.
2. Tropical Monsoon Forest
The Tropical Monsoon forest has a smaller number of species than in the equatorial forest. Most of the trees are deciduous, losing their leaves in the hot dry season. Heavy rain and high temperatures in the wet season result in rapid growth and the trees soon become covered with leaves. The trees are tall rising up to about 30 metres, however they lack canopy. Thus the undergrowth is denser since more light reaches the ground.
They have a variety of tall species including camphor, ebony, teak and bamboo, valuable hardwoods such as teak. The tropical monsoon forest is found in Burma, Thailand, Cambodia, Laos, Vietnam, parts of India, east Java and the islands of the east, N. Australia.
3. Temperate Forests
i. Temperate Evergreen Forest
They occur in regions, which have rainfall throughout the year with winter temperatures over 10o C, which means that plant growth can go on all year. Most of the trees are broad-leaved evergreens, although there are deciduous trees as well. The forests contain evergreen oak, camphor, and walnut, which are all of economic value. Most of these forests look similar to tropical forests in that the vegetation is dense. Tropical evergreen forests are found in China, USA, southeast Australia South Africa - mainly on the eastern sides of the land masses in the warm temperate latitudes. Sometimes referred to as warm temperate forests.
ii. Deciduous Forest
Trees shade their broad leaves in autumn and remain bare in winter to minimize water by transpiration. As water availability improves on the onset of spring, the trees regain their leaves and remain green in summer. Many trees grow in stands of the same species including pine trees and firs.
iii. Coniferous Forest
Coniferous forests are specially adapted to the long cold and often snowy winters. They are conical is shape to combat the snowfall during winter. They also have needle shaped leaves, a characteristic that enables the trees to reduce water loss by transpiration during the winter when all the moisture is frozen in the soil. The leaves have a tough thick skin, which protects them from winter cold. The tree is conical and has flexible branches, which allow the snow to slide off. It has widely spread shallow roots to collect water
from the topsoil above the permafrost. Coniferous forests can only withstand the winter cold to a point beyond which they cannot survive towards the poles. The tree species are found in uniform stands. The major species are spruce, fir and pine. In low altitudes these forests are also found on high altitudes such as high mountainsides of tropical areas. In most coniferous forests, a thick carpet of mosses occurs. The forest species are generally few and large tracts of forests can consist of only one or two species.
Coniferous trees produce soft wood, which is in great demand for making paper, especially for making paper, newsprint, matches, furniture and synthetic fibres. These forests have practically not undergrowth because the soil is frozen for many months each year. Coniferous forests are most extensive in high latitudes and on high mountains although it does not develop on sandy soils in warmer regions. There are two main belts
of this forest: across Eurasia extending from the Atlantic to the Pacific, and across N. America extending from coast to coast.
iv. Mixed Forest
Coniferous forests give way to broad-leaved summer green deciduous forests in warmer well-watered localities. This zone of transition is referred to as mixed forests.
v. Mediterranean vegetation
In the Mediterranean countries of northern and southern Africa, the natural vegetation is adapted to withstand the long summer drought. Thus the evergreen trees and shrubs have thick hairy or oily leaves, which help to prevent loss of water through evaporation. Plants also have deep, widely spread roots reaching far beneath the ground in search of water. Bushes and short grasses are found near the borders with hot deserts. There are a wide variety of trees found in the Mediterranean areas. These include cork oak, olives,
pines, firs and cedar. The cork oak is very useful, because its bark is used in the manufacture of bottle corks. The Mediterranean vegetation occurs chiefly on the western sides of landmasses and in the warm temperate latitudes. Lowlands around the Mediterranean Sea, SW Australia, South Africa, central Chile and central California.
francis1897 answered the question on October 11, 2022 at 06:57