Forest ecosystem includes a complex assemblage of different kinds of biotic communities. Optimum conditions such as temperature and ground moisture are responsible for the establishment of forest communities.
Forests may be evergreen or deciduous which are distinguished on the basis of leaf into broad-leafed or needle leafed coniferous forests in the case of temperate areas. classified into three major categories: coniferous forest, temperate forest and tropical forest.
All these forest biomes are generally arranged on a gradient from north to south latitude or from high to lower altitude
Coniferous forest (boreal forest):
Cold regions with high rainfall, strong seasonal climates with long winters and short summers
evergreen plant species such as Spruce, fir and pine trees, etc and by animals such as the lynx, wolf, bear, red fox, porcupine, squirrel, and amphibians like Hyla, Rana, etc.
Boreal forest soils are characterized by thin podozols and are rather poor. Both because, the weathering of rocks proceeds slowly in cold environments and because the litter derived from conifer needle (leaf is decomposed very slowly and is not rich in nutrients.
These soils are acidic and are mineral deficient.
This is due to movement of large amount of water through the soil, without a significant counter-upward movement of evaporation, essential soluble nutrients like calcium, nitrogen and potassium which are leached sometimes beyond the reach of roots. This process leaves no alkaline oriented cations to encounter the organic acids of the accumulating litter.
The productivity and community stability of a boreal forest are lower than those of any other forest ecosystem.
Temperate deciduous forest:
The temperate forests are characterised by a moderate climate and broad-leafed deciduous trees, which shed their leaves in fall, are bare over winter and grow new foliage in the spring.
The precipitation is fairly uniform throughout.
Soils of temperate forests are podozolic and fairly deep.
Temperate evergreen forest:
Parts of the world that have Mediterranean type of Climate are characterised by warm, dry summers and cool, moist winters. low broad leafed evergreen trees.
Fire is an important hazardous factor in this ecosystem and the adaptation of the plants enable them to regenerate quickly after being burnt.
Temperate rain forests:
seasonality with regard to temperature and rainfall
Rainfall is high, and fog may be very heavy. It is the important source of water than rainfall itself
The biotic diversity of temperate rain forests is high as compared to other temperate forest.
the diversity of plants and animals is much low as compared to the tropical rainforest.
Tropical rain forests:
Near the equator.
Among the most diverse and rich communities on the earth.
Both temperature and humidity remain high and more or less uniform.
The annual rainfall exceeds 200 cm and is generally distributed throughout the year.
The flora is highly diversified The extreme dense vegetation of the tropical rain forests remains vertically stratified with tall trees often covered with vines, creepers, lianas, epiphytic orchids and bromeliads.
The lowest layer is an understory of trees, shrubs, herbs, like ferns and palms.
Soil of tropical rainforests are red latosols, and they are very thick
Tropical seasonal forests:
also known as monsoon forest occur in regions where total annual rainfall is very high but segregated into pronounced wet and dry periods.
This kind of forest is found in South East Asia, central and south America, northern Australia, western Africa and tropical islands of the pacific as well as in India.
Subtropical rain forests:
Broad-leaved evergreen subtropical rain forests are found in regions of fairly high rainfall but less temperature differences between winter and summer
Epiphytes are common here.
Animal life of subtropical forest is very similar to that of tropical rainforests.