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FOREST:OUR LIFELINE

INTRODUCTION

 Forests are one of the most usefull reneuable resources. They provide habitat to many type of animals & plants.
 The forest is a biotic community spread over a large area of land & composed of tall trees, herbs, shrubs, climbers & wild animals.

INTERDEPENDENCE OF PLANT & ANIMALS 

A forest is home to many kinds of plants, animals & microorganism. These living organisms depend on each other for their survival.

 

DEPENDENCE OF ANIMALS ON PLANT 

1.  For food :
    All animals depend for their food directly or indirectly on green plants. Herbivores feed on plant material directly while carnivores feed on the herbivores. 
2.  For Oxygen :
    Plants produce oxygen during photosynthesis and animals use this oxygen for respiration. 
3.  For shelter :
    Some animals depend on plants for shelter and safety. Trees provide protection from rain and shade from the heat of the sun to the animals. Most of the birds make their nest on branches of trees. Monkeys, apes and bats also live on trees. 

DEPENDENCE OF PLANTS ON ANIMALS

1.   For Carbon Dioxide :
     Animals produce carbon dioxide during respiration which is released in the atmosphere. Plants use this carbon dioxide for preparing food by the process of photosynthesis. In this way plants play an important role in maintaining carbondioxide and oxygen balance in nature. 


2.   For Pollen and Seed Dispersal :
     A number of insects, birds and bats help in pollination. Some animals help in dispersal of fruits and seeds.


3.  For Supplying Nutrients :
     Animal excreta and their dead bodies add nutrients to the soil. They act as manure and provide mineral for plant growth.

RECYCLING OF NUTRIENTS IN A FOREST  

    Plants are called producers as they can produce their own food. They are also called autotrophs. Animals are called consumers they cannot produce their own food & depends on plants.
    Animals are also called heterotrophs. Decomposers are the micro organisms which break down dead remains of plant and animals into simpler substances & release these nutrient into soil, water & air.

FOOD CHAIN

    The process of food transfer from plants through a series of organisms with repeated eating and being eaten is called a food chain.
    For example, a grasshopper eats a green plants, a frog eats a grasshopper a frog is eaten by a snake and snake is eaten by an eagle
    Plant --> Grasshopper ---> Frog ---> Snake ---> Eagle 
    Food and energy get transferred several times between organisms but ends with dead animals and plants. Bodies of dead organism are then broken down into simpler nutrients in the soil by decomposers. 

FOOD WEB

    All food chains are interlinked. This interconnected network of food chains is called food web.
    For example, grass or plants may be eaten by grasshoppers as well as rabbits, cattle and deer. These herbivores, in turn, may be eaten by carnivores like frogs, birds, snakes, tigers or hawks depending on their food habits.

BIODIVERSITY IN A FOREST

    Our forest is a home for several kinds of plants and animals. These plants and animals live close relation with each other. some examples of plants and animals found in forest are as follows
1.   Forest Plants :
      Sal, teak, semal, sheesham, neem, palash, fig, khair, amla, bamboo, etc.      
2.   Forest Animals :
      Bear, jackal, porcupine, elephant, monkey, lion, tiger, leopard butterfly, spider etc.

USE OF FOREST

Forest are beneficial to a man in several ways which are given below.
1.  Provide Timber :
    Timber is used for making furniture, railway

...
carts, boats, ships, sports goods, ploughs, etc.
2.   Provide Food :
    Tribal people living in the forest take tubers roots, leaves and fruits of plants as their food.
3.    Provide Medicines :
    Leaves of eucalyptus, neem and tulsi are well known for their medicinal value. Cinchona, ephedra, ishabgul and aloe vera plants also have medicinal value.       
4.   Provide Other Forest Products :
    Forests provide a large number of important products such as gum, oil, spices, fodder, resins, bamboo, lac, silk, honey, etc.
5.    Prevent Soil Erosion and Floods :
    Roots of trees bind the soil particles together and prevent the soil from being washed or blown away
6.    Regulate  Climate of a Place :
    Forest increases the water vapour in the atmosphere by transpiratoion. Helps in keeping the air cool and also helps in inducing rain.
7.    Improve Quality of Soil :
    Dead fallen leaves of trees decay and form humus that increases the porosity and fertility of the soil.
8.    Reduce Atmosphere Pollution :
    forests reduce atmospheric pollution by using carbon dioxide for photosynthesis and by collecting suspended particulate matter on their leaves. Thus, trees help in checking global warming
9.    Control Water Flow :
    The thick layer of humus in the forest absorbs and holds rainwater like a sponge. The leaves of the trees also reduce the force of the rain drops to keep soil intact. The latter allows a gradual run off of water to· prevent flash floods. This ensures perennial supply of water to streams, springs and wells
10.    Provide Fuelwood :
    Wood is one of the most important fuels used for cooking in several rural areas even today. Charcoal is also used during winters to keep ourselves warm
11 Aesthetic Value :
    Forests give a beautiful and pleasing look. Many people go to forests for recreation because temperature in forests is lower than normal and the air is pure. Forests are a good place for picnic, hunting, hiking, camping, fishing, photography, etc. 

CONSERVATION OF FOREST

    The maintenance and upkeep of forests is cal1ed forest conservation. The following steps should be undertaken to conserve forests:

  •     Massive afforestation work should be undertaken to cover large areas of land with useful plants
  •     Large scale cutting of forest trees must be stopped. If it is essential to cut a few trees, then make sure to plant more trees in their place.      
  •     Forest fires should be prevented. Huge forest areas are destroyed by fire every year. People should avoid smoking or cooking in the forest areas.      
  •     Overgrazing by cattle, horses, sheep and goats should be prevented.
  •     Forests must be protected from insects and pests.
  •     All activities leading to soil erosion should be controlled.
  •     Air, water and soil pollution should be reduced so that trees and other vegetation can survive and develop in a forest.
  •     Plants should be given free of cost to the people for growing them near their house.
  •     People should be made aware of the impact of forest on their life through advertisements, television, radio and plays.
  •     Guidelines of international organizations like WWF and UNESCO for forest conservation should be followed.     
  •     Van Mahotsava which is celebrated every year should be made more popular, meaningful and effective.  
     

UNSOLVED PROBLEMS (EXERCISE I)

Q.1    Mention two ways in which plants are useful to animals.

Q.2    What do you mean by producers? 

Q.3    Name two animals and two trees found in forests. 

Q.4    Give one example of a food chain taking place in a forest. 

Q.5    What is a food chain? Explain with an example.

Q.6    In what way do forests prevent floods ?

Q.7    What is a food web ?

Q.8    How are animals classified according to their role in the food chain ? 

Q.9    How do forests help to control soil erosion ?

Q.10    What are decomposers and what role do they play in the forest?

Q.11    List five methods for the conservation of forests. 

Q.12    How do trees help in checking noise pollution ? 

Q.13    What measures should be taken to conserve forests ?

Q.14    Why are forests beneficial to man ? Explain it in points.

Q.15    What are the differences between food chain and food webs ? Explain it with suitable examples.

EXERCISE II

Q.1    The first link in all food chains is -
    (A) Herbivores                     (B) Carnivores 
    (C) Green plants                  (D) All of these 

Q.2    Which of the following is a producers ?
    (A) Herbivores                    (B) Green plants 
    (C) Carnivores                    (D) Decomposer 

Q.3    Which of the following is not a forest product?
    (A) Wood                           (B) Honey
    (C)  Nylon                         (D) Gum

Q.4    Which of the following is a decomposer ?
    (A) Tulsi                           (B) Snake
    (C) Fungi                          (D) Lion

Q.5    The lowest layer in the forest is occupied by -
    (A) Trees                          (B) Shurbs
    (C) Herbs                         (D) All of these 

Q.6    Soil erosion can be prevented by:
    (A) Overgrazing    
    (B) Removal of vegetation
    (C) Afforestation    
    (D) Deforestation

Q.7    Deforestation generally decreases.
    (A) Rain fall                     (B) Soil erosion
    (C) Drought                     (D) Global warming

Q.8    Deforestation has an alarming effect on:
    (A) Soil erosion    
    (B) Increase in grazing area
    (C) Weed control
    (D) Sunlight

Q.9    In a forests ecosystem green plants are:
    (A) Primary producers    
    (B) Primary consumers
    (C) Consumers
    (D) Decomposers

Q.10    In a food chain green plants form:
    (A) First trophic level
    (B) Second trophic level
    (C) Third trophic level
    (D) Complete food chain

ANSWER KEY

1.     C    2.    B    3.     C    4.      C
5.     C    6.     C    7.     B    8.     A
9.    A    10.    A    

EXERCISE III

1.    Trees that give us timber
    (A) Rosewood    
    (B) Mahogany
    (C) Teak    
    (D) All of these

2.    Trees that have a medicinal value
    (A) Bamboo    
    (B) Neem
    (C) Teak    
    (D) All of these

3.    Tress that give us essential oils
    (A) Camphor    
    (B) Eucalyptus
    (C) Pine    
    (D) All of these

4.    Essential oils are used in 
    (A) Confectioneries
    (B) Bakeries
    (C) Cosmetics    
    (D) All of these

5.    A fibre used to make ropes and mattresses
    (A) Cane    
    (B) Coir
    (C) Wool    
    (D) None of these

6.    Cane is used to make
    (A) Furniture    
    (B) Paper
    (C) Medicines    
    (D) Essential oils

7.    Bamboo is used for
    (A) Paper    
    (B) Baskets
    (C) Fodder     
    (D) All of these

8.    Common plant fibre(s) used to make cloth
    (A) Linen    
    (B) Flax
    (C) Cotton    
    (D) All of these

9.    The main reasons for deforestation are 
    (A) Cattle ranching    
    (B) Illegal logging
    (C) Excessive agriculture            (D) All of these

10.    Few measures of conservation of forests are
    (A) Planned cultivation
    (B) Afforestation
    (C) Prevention of overgrazing            (D) All of these

11.    Soil erosion can be prevented by -
    (A) Overgrazing
    (B) Removal of vegetation
    (C) Afforestation
    (D) Deforestation

12.    Deforestation generally decreases -
    (A) Rain fall    
    (B) Soil erosion
    (C) Drought    
    (D) Global warming

13.    Deforestation has an alarming effect on -
    (A) Soil erosion
    (B) Increase in grazing area
    (C) Weed control    
    (D) Sunlight

14.    In a forests ecosystem green plants are -
    (A) Primary producers
    (B) Primary consumers
    (C) Consumers    
    (D) Decomposers

15.    In an ecological pyramid green plants form
    (A) First trophic level
    (B) Second trophic level
    (C) Third trophic level
    (D) Complete food chain

16.    Ecosystem comprises both abiotic and biotic components. Biotic component of an ecosystem consists of -
    (A) Producers    
    (B) Consumers
    (C) Decomposers
    (D) All the above

17.    In a natural ecosystem, decomposers include -
    (A) Bacterial and fungi
    (B) Parasitic algae
    (C) Macroscopic animals            (D) All the above

18.    In a forest ecosystem, the fungi come under the category of -
    (A) decomposers
    (B) primary producers
    (C) secondary consumers            (D) tertiary consumers

19.    In a food chain, the largest population is that of -
    (A) Producers
    (B) Decomposers
    (C) Secondary consumers            (D) Primary consumers

20.    A group of interconnected food chain is -
    (A) complex of food chain
    (B) food cycle
    (C) food web
    (D) pyramid of energy

ANSWER KEY
1.    D    2.        B    3.    D    4.    D
5.    B    6.        A    7.    D    8.    D
9.    D    10.    D    11.    C    12.    A
13.    A    14.    A    15.    A    16.    D
17.    A    18.    A    19.    A    20.    C

EXERCISE-I

Section-A
•    Fill in the blanks

1.    Spines of seeds help them to stick to body of ___________ for dispersal. 
2.    Quinine is derived from bark of ___________ tree.
3.    Insect like honeybee helps in ___________of plants.
4.    Industrialization is one of factor responsible for ___________ or cutting down of forest. 
5.    ___________ serve as water purifying system in nature. 
6.    Boar are found in ___________ area of forest.
7.    Branchy part of tree above stem is known as ___________
8.    In forest, tall tree are present over small like roof. This arrangement is known as ___________
9.    ___________ matter found on forest floor is moist and warm 
10.    Herbs are present in ___________ layer in forest
11.    Penicillin is obtained from ___________.

Section-B
•    True or False

1.    Inside of forest is quite dark
2.    Jackals are found in outer part of forest, near boundary of villages
3.    Trees and animals found in forest are more or less of same type all over world
4.    Herbivore depends on plants but carnivores don’t depend on plants
5.    Sequence of animal eaten by one another is known as food chain
6.    Bacteria and fungi are decomposers 
7.    Kerosene is forest product
8.    Deforestation results in increase in earth’s temperature
9.    In India forest covers about 21% area
10.    Medicinal plants are grown in artificial nurseries and are not obtained from forest

EXERCISE-II

Section-A                              (Marks-1)
1.    Name two animals found deep inside the forest?
2.    Why forest are dark even during day time?
3.    What is importance of forest for wildlife?
4.    Give role of forest in environmental maintenance.
5.     How forest helps in purification of water?
6.    Give two reasons behind deforestation.
7.    Name two products obtained from forest.
8.    Give an example of food chain.
9.    What would happen if we remove one of the component of forest ?
10.    What is humus?
11.    Name some cereals of pulses?
    
Section-B                                 (Marks-2)
1.    Define decomposers. Give their role in environment cleaning.
2.    Give importance of forests for tribes.
3.    How forests help herbivores to get protection from carnivores?
4.    How plant depends on animals?
5.    How forest helps in maintaining water table?
6.    Define afforestation?
7.    Difference between food chain and food web.

Section-C                               (Marks-3)
1.    How deforestation results in global warming?
2.    Forest helps in preventing flood – justify this statement?
3.    How balance of oxygen and carbon-dioxide is maintained?
4.    How water cycle is maintained by forest?
5.    Why nothing goes waste in forest?
                        
Section-D                                  (Marks-4)
1.    Give importance of forest.
2.    Justify why forest are ‘dynamic living entity’?
3.    Give economic importance of forest in terms of daily iterms provided by forest.
4.    Plants and animals are interdependent. Justify this statement.
5.    Describe in detail why forests are being cut these days?
6.    Describe in detail about the major plants products?

EXERCISE-III

                        Section-A
•    Multiple Choice Questions

1.    More than ___________ percent of species are found in rain forests.
    (A) 50%        (B) 25%        (C) 35%        (D) 75%
2.    Which of following is/are forest products?
    (A) Plywood        (B) Gum        (C) Resin         (D) All of these
3.    Bacteria act as
    (A) Decomposer    (B) Herbivore        (C) Omnivore        (D) Carnivore
4.    Deforestation results in:
    (A) Increased rainfall    (B) Global warming    (C) Increase in water table (D) Flood prevention
5.    Cause of deforestation includes:
    (A) Agriculture        (B) Industrialization    (C) Both A and B    (D) None of these
6.    Plant depends on animals for:
    (A) Carbon-dioxide    (B) Pollination        (C) Seed dispersal    (D) All of these
7.    Forest comprises of:
    (A) Plants        (B) Animals        (C) Micro-organisms    (D) All of these
8.    Forest influence:
    (A) Rainfall        (B) Climate        (C) Water quality    (D) All of these
9.    Trees in forest are covered with:
    (A) Creepers        (B) Climbers        (C) Both (A) and (B)    (D) None of these
10.    ___________ is present in forest:
    (A) Shrubs        (B) Herbs        (C) Grasses        (D) All of these
11.    Part of tree above stem is:
    (A) Shade        (B) Crown        (C) Clown        (D) None of these
12.    Green plants are
    (A) Autotrophs        (B) Chemo-Autotrophs    (C) Heterotrophs    (D) Both (A) and (B)
13.    Dark coloured substance found at floor of forest:
    (A) Humus        (B) Decomposed    (C) Both (A) and (B)    (D) None of these
14.    ___________ helps water to seep down:
    (A) Root system    (B) Branches        (C) Leaves        (D) All of these
15.    Forest are ___________ living entity:
    (A) Dynamic        (B) Static        (C) Surplus        (D) None of these
16.    ___________ layer of forest canopy interrupted flow of rain drop.
    (A) Upper        (B) Center        (C) Lower        (D) None of these
17.    Water ___________ in forest:
    (A) Stagnate        (B) Do not stagnate    (C) Flow out        (D) None of these
18.    ___________ helps in maintaining supply of nutrients to growing plants:
    (A)  Decomposers    (B) Omnivores        (C) Producer        (D) All of these
19.    Plants release ________ by photosynthesis: 
    (A) Glucose        (B) Carbon-dioxide    (C) Oxygen        (D) All of these
20.    Trees add water to environment by:
    (A) Excretion        (B) Transpiration    (C) Volatization        (D) All of these

Section-B
•    One Word 

1.    Name lungs of planet
2.    Uppermost horizontal layer of forest
3.    ___________ serve as habitat for wildlife 
4.    Give source of catechu
5.    Animals & plants of different forest differ due to difference in which conditions.
6.    Name ultimate source of food
7.    Complete given food chain
    Grass  insect ________Snake
8.    Where can we find mushroom in forest?
9.    Why level of noise is low inside forests?
10.    Why decomposers are important?

                        Section-C
•    Match the following

I    Column I            Column II
    (A) Gum            (P) Natural water purifying system
    (B) Forest            (Q) Food chain
    (C) Sequence of eating        (R) Decomposer 
    (D) Mushroom            (S) Forest product

ANSWER KEY

Exercise-I
                        Section-B
    1.    True    2.    False    3.    False    4.    False    5.    True    
    6.    True    7.    False    8.    True    9.    True    10.    False
 

Exercise-III
                 Section-A

    1.    A    2.    D    3.    A    4.    B    5.    C    6.    D    7.    D    8.    D    9.    C    10.    D    11.    B    12.    A    13.    A    14.    A    15.    A    16.    A    17.    B    18.    A    19.    C    20.    B