Chapter 5 Natural Vegetation and Wild Life Class

Transcription

1 Chapter 5 Natural Vegetation and Wild Life 1. Five Types of Forests, Vegetation and wild life in India 5. Mangrove Forests: mostly along the eastern coast, at the estuaries of major rivers. Swampy soil made of silt and mud. Trees with roots submerge in water. Sundari, palm, coconut, keora, agar, Jute plants. Royal Bengal Tiger, crocodiles, gharial, turtles,snakes. 4. Montane Forests: in the Himalayas, Shiwaliks. Decreasing temperatures, increasing altitudes. a) Above 3,600 cm, Alpine vegetation, shrubs, mosses, lichens near the snowline. b) 3000 cm to 1500 cm. Temperate forests and grasslands, mostly in Southern slopes of Himalayas. c) 2000 cm to 1000 cm. Wet Temperate Forests. Yak, wild sheep, Kashmir stag, spotted deer, jack rabbit, mountain goats, snow leopard, squirrels, bear, rare red panda, wild ibex or ox that weighs one tonne. 3. Tropical Thorn Forests and Shrubs.: Less than 70 cm rains. North western parts if India, Thar Desert, Kutch area in Gujarat, parts of Malwa plateau. Acactas, palms, euphorbias, cacti. Camel, horse, tigers, lions, fox, wolf, wild ass, rabbits, rats, mice. 1. Tropical Evergreen Forests : Need heavy rainfall, warm and wet climate with more than 200 cm rains. Trees grow to above 60 metres. and shed leaves. Ebony, Mahogany, Rosewood, Rubber, Cinchona are examples. 1 Elephants, monkey, lemur, deer, and variety of birds. Horned Rhino found in Assam and Bengal only. 1.1 Western Ghats 1.2 Islands of Lakshadweep; Andaman Nicobar. 1.3 Tamil Nadu coast. 1.4 Upper parts of Assam. 2. Tropical Decidious Monsoon Forests: Need warm and wet climate with 200 cm to 70 cm rains. Jharkhand, Orissa, Chhattisgarh, and across India from Shiwaliks to Eastern Ghats. Trees shed leaves in summer for two months. 2.1 Dry Decidious Forests: 100 cm to 70 cm rains. Peninsular plateau, Bihar, Uttar Pradesh. 2 Teak, Bamboo, Sal, Shisham, Sandalwood, Khair, Kusum, Arjun, Mulberry. Lions, tigers, deers, elephants, tortoise. Variety of birds, snakes, lizards. 1. Choose the right answer from the four alternatives given below: 1.1 To which one of the following types of vegetation does rubber belong to? a) Tidal b) Tundra 10 x 10 Learning TM Page 1

2 c) Himalayan d) Tropical Evergreen 1.2 Cinchona trees are found in the areas of rainfall more than a) 100 cm b) 50 cm c) 70 cm d) less than 50 cm 1.2 In which of the following state is the Simlipal bio reserve located? a) Punjab b) Delhi c) Odisha d) West Bengal 1.3 Which one of the following bio reserves of India is not included in the world network of bio reserve? a) Manas b) Nilgiri c) Gulf of Mannar d) Nanda devi A glimpse of Tropical Evergreen Forests in Western Ghats 10 x 10 Learning TM Page 2

3 2. Answer the following questions briefly. 2.1 Define an ecosystem. Answer. An ecosystem is a distinct area in which groups of vegetation types, micro organism, insect colonies, birds, water life, co exists as they provide life support to each other. The animal life is a part of the ecosystem. All are interdependent and interrelated in their physical environment. Humans are also a part of the ecosystem. But humans tend to extract excessively from the ecosystem. This results in destroying the balance of the ecosystem. All natural forests are self sustaining ecosystems. 10 x 10 Learning TM Page 3

4 Deforestation for purpose of development has been destroying these ecosystems and creating natural calamities such as recurring floods. (b) Air for respiration of plants and animals and CO2 for photosynthesis. It serves as medium of flight for birds and insects, and as an agency for dispersal of seeds and pollen grains for plants in the form of winds. (c ) Water: received as rainfall, absorbed by plants and soil, and accumulated by ponds, lakes and rivers. Used by life forms for drinking. (d) Warmth in the forest influences the activities of living organisms. (e) Soil: is the primary component for all action of life as provider of mineral and nutrients to plant life, micro organisms, burrows and living spaces for animals. Tropic level 1 (producers, plants) Tropic level 2 Primary herbivore consumer Tropic level 3 Secondary consumer -carnivore Tropic level 4 Tertiary consumer Ecosystem The ABIOTIC or nonliving component of Forest consists of (a) Sunlight that is for production of plant food by photosynthesis. BIOTIC or living component of the forest ecosystem consists of four Tropic levels from the green plants at level 1 to Tertiary or top level consumers. -Pond ecosystem - River ecosystem - Forest ecosystem coastal area ecosystem - lagoon ecosystem Flora are plants naturally occurring in the ecosystem. Fauna : are animals in the ecosystem An ecosystem is a self contained area composed of different organisms, living and interacting with sunlight. Air, water, soil, climatic factors, prevailing in the area An ecosystem has (a) food producers, (b) primary and secondary consumers, (c) Decomposers such as bacteria and fungi. 2.2 What factors are responsible for the distribution of plants and animals in India? Answer. Distribution of plants and animals in India is as per the five major climatic zones. Climatic zones are grouped on basis of variation in physical terrain, distance from Sea, temperature range, altitude, winds, rains, Soil types, the intensity of sunlight and sun s position on the horizon i, precipitation and local weather conditions. Depending on the climatic conditions, plants and animals form an ecosystem, in which each species is interdependent. From micro organisms to larger animals the ecosystem system sustains the food chain. Plants, insects, small animals assist one another 10 x 10 Learning TM Page 4

5 2.3 What is a bio reserve? Give two examples. Answer. Bio reserves are ecosystems declared as protected by the Government. In these places, hunting or cutting of wood, clearance of forests or taking away of forest produces is not allowed. If anyone is caught in these acts it becomes a criminal offence, punishable under the law. In India there are bio reserves called Wildlife Sanctuaries, Bird Parks, Marine life Parks, Special Sanctuaries for Lions (Gir Forest) Tigers ( Sundarbans) Elephants, Silent Valley. 2.4 Name two animals having habitat in tropical and montane type of vegetation. Answer. Deer, Stags, wild goats, leopard and snow leopard are a few animals that are found in tropical and montane types of habitats. 3. Distinguish between 3.1 Flora and Fauna 3.2 Tropical Evergreen and Deciduous forests 3.1 Flora Fauna 1 Flora is a generic name to refer to all the different kinds of vegetations from the micro level of mushrooms, mosses, lichens, grasses to the tallest trees. In sum, all forms of natural vegetation found in a climatic zone, is referred to as flora. 2. The term is used only for plants found in nature. It does not include the various genetically modified Fauna is a generic name for all form of micro organisms insects small animals, birds, water life, and larger animals that inhabit an ecosystem in a climatic zone. The term is used only for animals, birds, insects, and micro organisms found in nature. 3 It does not include the plants or trees that are cultivated as crops or plantations, through agriculture. 4 Flora does not include any of the various genetically It does not include any of the genetically modified species or living organisms, that come under biotic, anti biotic or pharmaceuticals. Fauna also does not include any of the animal species reared or 10 x 10 Learning TM Page 5

6 modified flower plants that are grown as part of horticulture. In fact, such flowers do not have any essence or aroma that is distinct to each natural flower. Such flowers are cultivated only to look bright and colourful, last longer, and have a wider variety of hue. domesticated or genetically modified by humans for consumption as food. 3.2 Tropical Evergreen Forests Deciduous Forests 1. a) Tropical Evergreen Forests grow in conditions of warm and wet climate of more than 200 cm rains. b) The forests are dense and thick. They are evergreen because different species of trees shed leaves in different months. Therefore, greater part of the forest is always covered with a thick green canopy. c) Trees grow to heights of above 60 metres, and grow very close to one another. Therefore, the canopy of Tropical Evergreen Forests is very thick. d) Ebony, Mahogany, Rosewood, Rubber, Cinchona are a few examples of species of trees that grow in these forests. a) Deciduous Forests are identified in two groups of Wet and Dry. The wet forests grow in warm tropical conditions in areas where the range of monsoon rainfall is 200 cm to 70 cm. b) Trees have broad leaves and grow to heights of 40 metres. All species of trees in deciduous forests shed leaves together during two months of summer. c) These forests are found in Jharkhand, Orissa, Chhattisgarh, and across India from Shiwaliks to Eastern Ghats. d) Teak Bamboo, Sal, Shisham, Sandalwood, Khair, Kusum, Arjun, Mulberry are a few trees that are found in these forests. e) The Dry Deciduous Forests grow in warmer zones that have 100 cm to 70 cm rains. f) Parts of Peninsular, Malwa plateau, Chota Nagpur plateau, Bihar, Uttar Pradesh have such forests. 1. Thick evergreen forests 2. Thinner Deciduous forests 10 x 10 Learning TM Page 6

7 Where darkness exists below And between the trees where sky and sunlight is seen from between the trees 3. Name different types of Vegetation found in India and describe the vegetation of high altitudes. Answer. The different types of vegetation found in India include Tropical Evergreen Forests, Tropical Deciduous Forests, Dry Deciduous Forests, Tropical Thor n Forests and Shrubs, Montane Forests and Tundra vegetation, Mangrove Forests. The vegetation in high altitudes includes pine, fir, and other coniferous trees and shrubs. In the highest altitudes of the Himalayas, Tundra type of vegetation is found. This comprises of mosses and lichens variety of single cell vegetation. 10 x 10 Learning TM Page 7

8 a) Estimated million hectare = % of total geographical area: b) Dense forests = % c) Open forests = 8.75 % d) Mangrove = 0.14 % 1. Quite a few species of plants and animals are endangered in India. Why? Answer. Cataloguing of plants and animal species of India was started towards the last decades of the 19 th century. Little is known about the species that were already endangered or became extinct due to the wasteful practice of hunting by the royalty. Extinction of animal species became a major trend due to the use of gun for hunting purposes initially by the East India Company and then under the British rule. Vast tracks of forests were also destroyed for construction of railways and roads by the British. The over killing of lions and tigers in particular, along with many species of birds, brought about their extinction. Animal / Plant / forest Black buck Category of existence Endangered means their survival is difficult without protection. Eg. Crocodile, Indian wild ass, Indian Rhino, lion, tailed macaque, sangai or Manipuri brown anter deer. Asiatic elephant Vulnerable means population has declined to levels from where it could become endangered in near future. Eg. Gangetic dolphins 10 x 10 Learning TM Page 8

9 Andaman wild pig Himalayan brown bear Pink head duck Endemic means found only in specific local areas isolated by natural barriers. Eg Andaman teal, Nicobar pigeon, Andaman wild pig mithun in Arunachal Pradesh Rare means species with a very small population and may become endangered. Eg. Wild Asiatic buffalo, desert fox, hornbill. Extinct means species no longer in existence either in India or elsewhere in the world. Indian Animals and Category of existence a) Black buck : Endangered means their survival is difficult without protection. Eg. Crocodile, Indian wild ass, Indian Rhino, lion, tailed macaque, sangai or Manipuri brown ante deer. b) Asiatic elephant: Vulnerable means population has declined to levels from where it could become endangered in near future. Eg. Gangetic dolphins c) Andaman wild pig : Endemic means found only in specific local areas isolated by natural barriers. Eg Andaman teal, Nicobar pigeon, Andaman wild pig ; mithun cow in Arunachal Pradesh, Mizoram, Nagaland d) Himalayan brown bear: Rare means species with a very small population and may become endangered. Eg. Wild Asiatic buffalo, desert fox, hornbill. e) Pink head duck: Extinct means species no longer in existence either in India or elsewhere in the world. 10x10learning.com Why has India a rich heritage of flora and fauna? Answer. India is a subcontinent as it has five major climatic and vegetation types, ranging from the hottest deserts in the Thar region, to the coldest climate in higher ranges of the Himalayas. The Montane Forests and vegetation, the Tropical Evergreen Forests, the Tropical Deciduous Forests, Dry Deciduous Forests, and the Mangrove forests of major river estuaries. This climatic, vegetation and physical terrain variety has enabled many 10 x 10 Learning TM Page 9

10 ecosystems to develop and sustain a very rich heritage of flora and fauna. In addition, India is a tropical as well as a temperate climate country. It has several perennial river systems and very large natural lakes. These attract a huge variety of migratory birds for the six winter months. Biodiversity in India Diversity is immensely rich in the form of wildlife and over 81,000 species of flora and fauna: 47,000 plant species and 15,000 flowering plants are indigenous to India. About 10 per cent of recorded wild flora and 20 per cent of mammals are on threatened list. The biodiversity varies as per kind of Forests: Equatorial forests, (5 degrees North and South of Equator) ; Tropical Rain Forests ( 10 degrees N and S ), Tropical forests ( 23 ½ degrees N and S), Temperate forests ( beyond the Tropics). 10x10learning.com 2 i Sun s position on the horizon refers to the position of the Sun from the place, during the daily rotation revolution of the Earth. In the Tundra region the Sun is never overhead. For six months in a year, it is continuously seen just above the horizon, as if It is just rising or setting. Overhead position means Sun s position at the zenith, as at 12 noon, during the Summer months. Such a position of the Sun is visible only in tropical countries and temperate zone countries that are located between the two tropics, namely the Tropic of Cancer at 23 ½ 0 N, and Tropic of Capricorn at 23 ½ 0 S. The Sun is directly overhead of the Equator twice in an year on the two Equinox days on 21 st March and 23 rd September. The reason these are called Equinox days is because the days and nights during the week are equal at all placed on Earth. 10 x 10 Learning TM Page 10