Subject: Forest: Our Lifeline
- Large area of land covered with huge trees, shrubs (rose) and herbs(grass) is called forest.
- Forests serve as green lungs and water purifying systems in Nature.
- Plant variety in a forest:- Bamboo, Neem, Palash, Teak, Fig, Ferns, Mosses, Maple, oak, pine, sal, semal, Sheesham, Khair, Amla, kachnar.
- Animal variety in a forest :- boar, bison, jackals, porcupine, elephant.
Who has planted so many trees in forest?
->In nature, trees produce enough seeds. The forest floor provides favourable conditions for them to germinate and develop into seedlings and saplings. Some grow up into trees.
Layers of forest:- Three layers
1.Crown:-
•The branchy part of a tree above the stem is called as crown.
2.Canopy:-
•It is the structure formed by collection of individual plant crowns of a plant community.
3.Understorey in forest:-
•Plant layers growing beneath the forest canopy.
•Forest understory receive less intense light than the forest canopy.
Autotrophs:-Prepare their own food. e.g., plants, some algae and bacteria.
Heterotrophs:-
Depend on others for their food.e.g., animals, humans, fungi.
It includes:-
✓Herbivores ,
✓Carnivores and
✓Omnivores.
Decomposer/Saprotrophs:- •Organisation which feed on dead bodies of plants and animals.
Or
Micro-organism which convert the dead plants and animals to humus.
•E.g. bacteria, fungi.
•Live in soil
Decomposition:- Process in which complex organic matter are broken down into simpler forms.
Detritus:- Raw material for decomposition including dead plant remains , dead animals remains and faecal matter.
Rate of decomposition:- Several factors determine rate of decomposition.
1.Soil quality:-
✓Abundance of micro-organism,
✓moisture content,
✓Temperature,
✓High aeration,
✓pH,
2.Compostion of organic matter:-
3.Climate.
Importance of decomposition:-
- Convert dead plant and Animals remains into humus.
- Improve soil fertility
- Nutrients are releasing back to soil.
Humus:-
- Decomposers when eat upon dead plant and animal tissues, they convert them into a dark colour substance called humus.
- Presence of humus ensures that the nutrients of the dead plants and animals are released into soil.
Forests are called green lungs. Why?
Because plants release oxygen through the process of photosynthesis. The plants help to provide oxygen for animal respiration. They also maintain the balance of oxygen and carbon dioxide in the atmosphere . That is why forests are called lungs.
Food chain:- series of living organisms feeding on one another.
3 step food chain:-
grass -> deer -> lion
4 step food chain:-
Plant -> goat -> fox -> lion
5 step food chain:-
Grass -> insects -> frog -> snake -> eagle
Trophic level:- Each level of a food chain is called trophic level.
Food web:- Network of food chains is called food web. In nature food web exist.
Threat to forests:-
Human activities pose a threat to forests.
Deforestation:- permanent destruction or conversion of forest areas for other purposes.
Cause of deforestation:-
•Overpopulation,
•Agriculture,
•Human settlement,
•Making furniture,
•Fuel
•Forest fires
Harmful effects of deforestation:-
•Loss of species,
•Soil erosion,
•Increased concentration of Carbon dioxide,
•Increase of earth's temperature,
•Lower ground water level,
•Destroy forest ecosystem.
•Possibility of flood increases
•Possibility of drought increase
Major Victims of deforestation:-
Plants and animals
IMPORTANCE OF FOREST:-
•Provide a home for many animals and plants.
•Provide useful products like gum, oils, spices, fodder for animals etc.
•Provide habitat to animals, birds and insects.
•provide food and shelter to many tribes
•support growth to plants
•maintain the balance of Oxygen and carbon dioxide in atmosphere so called green lungs
•furniture making
•Medicinal use of many plants
•control floods
•Natural absorber of rain water so help to Recharge ground water and thus maintain water table
•Prevent water logging in soil during heavy rainfall.
• Absorb noise
Forest is a dynamic living entity.
i.e., it is full of life
Keyword:-
1.canopy:-It is the structure formed by collection of individual plant crowns of a plant community
2.Crown:-The branchy part of a tree above the stem is called as crown
3.Decomposers:-Organisation which feed on dead bodies of plants and animals.
Or
Micro-organism which convert the dead plants and animals to humus.
•E.g. bacteria, fungi.
•Live in soil
4.Deforestation:-permanent destruction or conversion of forest areas for other purposes.
5.Humus:-Decomposers when eat upon dead plant and animal tissues, they convert them into a dark colouref substance called humus.
Presence of humus ensures that the nutrients of the dead plants and animals are released into soil
6.Regeneration:-Process of formation of new plant from old one.
7.Seed dispersal:-Seed dispersal is the movement, spread or transport of seeds away from the parent plant.
8.Soil erosion:-The removal of top fertile layer is called soil erosion.
9.Understorey:-Plant layers growing beneath the forest canopy.
•Forest understory receive less intense light than the forest canopy
Thankyou 😃😃....
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