OUR ENVIRONMENT

Our Environment includes physical

surrounding like air ,water bodies , soil, and the organisms such as

plants ,animals, human beings and micro organisms

like bacteria .

An ecosystem is a biological environment consisting of all the living organisms or biotic component, in a particular area, and the nonliving, or abiotic component, with which the organisms interact, such as air, soil, water and sunlight.

COMPONENTS OF ECOSYSTEM

Abiotic components includes :physical environment ,inorganic substances ,physical factors .

Biotic components includes: A community of organisms

which is made up of many different inter -dependent populations .

FOOD WEB

The inter-connected food chains operating in an ecosystem which establish a network of relationships between various species, is called food web.

F O O D C H A I NThe sequence of living organisms in a community in which one organism consumes another organism to transfer food energy, is called food chain

Consider with an example [IN FOREST] GRASS DEER TIGER

IN GRASSLAND

PLANTS WORMS BIRDS CAT

IN A PONDALGAE PROTOZOA SMALL BIG FISH FISH

TROPIC LEVELS

The various steps in a food chain at which the transfer of food takes place are called tropic levels.

TEN PERCENT LAW

RAYMOND LINDEMAN : The scientist who gave ten percent law for transfer in food chain . This law was given by him in 1942 .

According to his law ,only 10 percent of the energy entering a particular trophic level of orgnisms is available for transfer to the next higher trophic level

What will happen if we kill all the organisms in one trophic level ?

Organism in the next trophic level will decrease due to none availability of food

Organism in the lower trophic levels will increase because no one will be there to feed upon them

This will result in the imbalance in the ecosystem

Importance of decomposers

The decomposers help in decomposing the dead bodies of plants and animals and hence act as cleansing agents of environment ..

They help in recycling the material in theecosystem so that the process of life may

go on and on like an unending chain

BIOLOGICAL MAGNIFICATION

Certain harmful substances, usually ones not found in nature but introduced by man, may get into plants and animals. These poisonous substances may not be broken down in the body . Instead, they accumulate in the tissues, and as the living organism eats more, the concentration of these substances increases and they pass from one trophic level to the next.

In the 1960s, DDT in the food chain threatened bird populations.

Many birds of prey came close to extinction

HARM CAUSE TO OUR

ENVIRONMENT BY OUR ACTIVITIES

Two main reasons are :-

* Ozone layer

* Garbage disposal

The ozone layer..

OZONE (O3)

MADE BY THREE ATOM OF OXYGEN

OXYGEN IS THE MOST IMPORTANT

OZONE IS DEADLY HARFULL

IT COVERS OUR EARTH

PROTECTS FROM UV RAYS

THE FORMATION OF OZONE LAYER.

Ozone at the higher level of the atmosphere is a product of UV-rays acting on oxygen molecule.

UV-rays split the oxygen(O2)in to free oxygen atom.

02 uv-rays O+O

O+O2 O3(Ozone)

Depletion of ozone

Due to CFCs (refrigerants

)

In year 1987 CFCs are stopped in

use

Humans are using up the earth’s resources, including fossil fuels.

Sulphur dioxide will dissolve in rain producing Acid Rain

Acid rain damages trees and pollutes rivers and lakes.

Burning fossil fuels in cars and power stations produces carbon dioxide, sulphur dioxide and

other greenhouse gases

carbon dioxide traps heat in the atmosphere and causes the temperature of the earth to rise.

This leads to disruption of the weather patterns eg drought, floods

Some weeds may thrive on the extra carbon dioxide while other plants are killed

HAVE WE EVER THOUGHT WHAT HAPPENS AFTER WE ADD OUR WASTES TO OUR ENVIRONMENT ?

The material which can be broken down by the action of micro-organisms are called biodegradable substances . This action is caused the biological agents such as bacteria ..

The materials which cannot be broken down into harmless substances in natue by these agents are called non biodegradable substances ..

Plastic usually is non-biodegradable, because there are very few natural processes that could break the plastic down into smaller elements, whereas something like wood, will rot and decay and be recycled back into the soil.

What about plastics ???

What can we Do?

•The less use of natural resources by cutting down on those practices which lead to their wastage . .

•Using the same things again …

•We should collect the used and discarded items of paper ,plastics ,glass ,and send them to the respective indutries for making fresh paper ,plastic etc..

ways to reduce pollution ………

Avoid dumping garbage on the street. Dispose them in a garbage dump; you can also make a compost pit to convert garbage into manure .

•Request your family members to use automobiles only when necessary; walking or cycling can be a pleasure when the distance is short;

Avoid using plastic materials such as plates and carry bags which cannot be used again

OUR EARTH IS NOT A DUST BIN

We can protect our environment in many ways. Let us act now and persuade others to join us. This will ensure safety for our future generations.

Thank you .

Made by

DIVYA SHRI SNEHA URVASHI