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Environment Book Summary Presented Bu Aartee Mishra
CHAPTER 3 TERRESTRIAL ECOLOGY (Part-1)
Since mountains are found at all latitudes therefore alpine tundra shows day and night temperature variations. FOREST ECOSYSTEM .The 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. Coniferous forest (boreal forest): Cold regions with high rainfall, strong seasonal climates with long winters and short summers are characterised by boreal coniferous forest This is characterised by evergreen plant species such as Spruce, fir and pine trees, etc and byanimals such as the lynx, wolf, bear, red fox, porcupine, squirrel, and amphibians like Hyla,Rana, etc
Tropical & subtropical moist broadieaf forests Tropical & subtropical dry broadleaf forests Tropical & subtropical coniferous forests Deserts & xeric shrublands Temperate grasslands, savannas, & shrublands Montane grasslands & shrublands Temperate conifer forests Flooded grasslands & savannas Boreal forests/taiga Mangroves Tundra Mediterranean forests, woodlands, & scrub
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. 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. These are commonly inhabitated by 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. Tropical rain forests: Tropical rain forests occur near the equator. Tropical rain forests are 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 fems and palms. Soil of tropical rainforests are red latosols, and they are very thick. . . The high rate of leaching makes these soils virtually useless for agricultural purposes,
Tropical seasonal forests: 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 rainforests 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.