Slide 1: Natural Vegetation (mass of plants growing in a particular place) There is a close relationship between height of land and the character of Vegetation.
With the change in height, the climate changes and that changes Natural Vegetation.
The growth of vegetation depends on the following factors, Temperature, moisture, slope and soil.
The type and thickness of natural vegetation varies from place to place because of the variation in these factors.
Natural vegetations are classified into 3 broad categories, FOREST, GRASSLANDS and SHRUBS Slide 2: a large area of land covered in trees and other plants growing close together, where temperature and rainfall are plentiful to support a tree cover.
Forest can be of dense type or of open type. As such the following types of forest are found in our planet.
Tropical evergreen forest.
Tropical deciduous forest.
Temperate evergreen forest.
Temperate deciduous forest.
Coniferous forest. Slide 3: Large forest area located in the Earth’s equatorial zone, dominated by broadleaved trees, which form dense layered stands, often exceeding 50 m (165 ft) in height. Although the trees themselves are not evergreen, they retain their leaves throughout the year because temperature and precipitation are sufficiently high for continuous growth. These trees develop their own rhythms for flowering, fruiting, and shedding leaves. Within and below the canopy there is a diversity of plant and animal species Tropical rainforests are found in the Amazon basin in Brazil, Central America, central Africa, South East Asia, the western coast of India, and northern Queensland in Australia. The forests are thought to cover about 1.76 billion hectares tropical rain forest Slide 4: mahogany tree rosewood tree anaconda caiman jaguar Slide 5: Tropical deciduous forest are also called Monsoon forest, found in large part of India, Northern Australia and in central America.
As the region experience seasonal changes, trees shed their leaves in the dry season to conserve water.
Hardwood trees found in these region are Sal, Teak, Neem and Shisham.
Hardwood trees are extremely useful for making furniture, transport and constructional material.
Tigers, Lions, elephants, langoors and monkeys are the common animals of these region. Slide 6: langur monkey tiger lion Slide 7: In the middle latitudes, the prevailing winds carry moisture-laden air masses over the west coasts of the continents, which receive substantial rainfall in consequence. In the temperate evergreen forests of the west coasts, rainfall is concentrated in the cool winter months. The mild summers are comparatively dry. The most extensive region of subtropical evergreen forests is in East Asia, south east USA and in south east Brazil, where rain falls throughout the year and summers are hot.
Both hard and soft wood trees like oak, pine and eucalyptus are found here. temperate evergreen forest Slide 8: oak trees eucalyptus pine trees Slide 9: Forests composed of deciduous species—ones that periodically shed their leaves—grow in well-watered parts of the temperate zone in which a long, warm growing season alternates with a cold winter.
Precipitation, as either rain or snow, tends to fall throughout the year.
Deciduous trees, shrubs, and woody vines, whether in the tropics or in the middle latitudes, drop their leaves during a time of drought.
These forest are found in USA, China, New Zealand, Chile and western Europe.
Oak, ash, beech etc are the common trees.
Deer, foxes, wolves are the common animals. temperate deciduous forest Slide 10: oak ash beech Slide 11: The vegetation of the Mediterranean zone is dominated by evergreen trees and by shrubs that have adaptations to reduce water loss during the hot, dry summers.
Many have small, dark green, leathery evergreen leaves that have low surface areas relative to their volume.
The leaves have thick-walled cells and their outer surfaces are covered with a thick, waxy layer.
Plants escape drought by becoming dormant during the summer, examples include various orchids and wild iris.
Although the plants of each of the five Mediterranean regions are diverse and often unrelated, they are very similar in form. The Mediterranean basin has a very long history of human occupation, so its vegetation has been exploited for many thousands of years.
European agriculture originated in the Mediterranean environment of the Middle East about 10,000 years ago.
Grazing by domesticated goats, sheep, and cattle over the subsequent millennia has had a strong influence on the structure and composition of the vegetation.
Trees have been exploited for fuel wood, for charcoal, and as a source of construction material.
The result of this human impact has been the degradation of the natural forest vegetation to the scrub vegetation of the region,
Out side the Mediterranean region this type
Of vegetation is found in California, south west Africa, s w South America and s w Australia. mediterranean vegetation Slide 12: mediterranean vegetation Slide 13: Conifer, common name for a group of plants that is characterized by seed-bearing cones and that includes about 600 of the 740 or so known species in the world today. Conifers usually have needle-shaped or scale-like leaves, and nearly all are evergreen trees.
It is found in the higher latitudes of Northern hemisphere, these trees are tall and soft,
They are very useful for making pulp, which is used for manufacturing paper and newsprint, packing boxes and match box are also made from the soft wood. Slide 15: Grassland, An ecosystem in which grasses and other forage plants (plants grown to feed animals) form the dominant type of vegetation.
Grassland can be of the following types :
-Tundra. Slide 16: Savanna, open tropical grassland sometimes with a scattering of shrubs and trees. The word savannah is derived from the 16th century-Spanish word zavanna, meaning “treeless plain”, but today it is applied to a more diverse set of landscapes from the truly treeless grasslands of parts of South America and the tree-dotted grasslands of Africa, to the lightly wooded savannahs of northern Australia. The biome occurs in areas where rainfall is sufficient to prevent the establishment of desert vegetation but too low to support rainforests. Slide 17: Emus dingoes hyenas ostrich kangaroo cheetah Hunting dog vulture Slide 18: In the middle latitudes, grasslands occupy areas that are wetter than deserts but drier than forests. Annual precipitation is not only too low to support the growth of forests but also too unpredictable. Periods of drought lasting for months are frequent, and total precipitation, both rain and snow, may vary significantly from year to year. Slide 19: Animals of the temperate grassland buffalo ante antelope bison Slide 20: permafrost Willow tree birch moss lichens tundra vegetation Slide 21: Silver fox Polar bear mink Artic owl Musk oxen Slide 22: ibex Slide 23: Desert plants have evolved ways of conserving and efficiently using the water available to them.
Some flowering desert plants are ephemeral; they live for a few days at most. Their seeds lie dormant in the soil, sometimes for years, until a soaking rain enables them to germinate and quickly bloom.
Woody desert plants either have long root systems that reach deep water sources or have spreading shallow roots that are able to take up surface moisture quickly from heavy dews and occasional rains.
Desert plants usually have small leaves. This conserves water by reducing surface area from which transpiration can take place.
Other plants drop their leaves during the dry period. A number of desert plants are succulents, storing water in leaves, stems, and roots.
Thorns, which are modified leaves, serve to guard the water from animal invaders.
These plants may take in and store carbon dioxide only at night; during the day their stomata, or pores, are closed to prevent evaporation. Slide 24: gerbil Kangaroo rat jerboas Oryx Slide 25: desert life Slide 26: savanna -- east africa Slide 27: campos -- brazil Slide 28: Llanos -- venezuela Slide 29: pampas -- argentina Slide 30: prairie -- north america Slide 31: veld -- south africa Slide 32: steppe -- central asia Slide 33: down -- australia