Human civilization has
developed very slowly. In the ancient times man was totally dependent on nature
for his needs but as he learnt abut agriculture he started interfering with the
laws of nature. He shaved off the forests for agriculture and tamed many wild
animals for his food and clothing. He left the caves and started living in
houses. With the development in man’s lifestyle, several civilizations of Summaries,
Egypt and Indus
valley spread over the vast areas of the world. It is a general belief that man
has conquered the nature but still he cannot control natural disasters.
Eating relations in a community
All the living beings on the earth utilize solar energy
and get essential elements from atmosphere, lithosphere and hydrosphere.
Animals and plants either depend on plants or on other animals for their food.
A balance exists between living and non living things in the nature. Whenever
any element of nature increases or decreases in large proportions, ecological
balance gets disturbed. The study which deals with the relationships of life
forms with each other and with their surroundings is called ecology. A group of
animals living in a particular physical environment is called ecosystem.
Today rapid industrialization and ever increasing human
requirements have disturbed these natural elements and created an ecological
imbalance. Increasing population, emission of carbon dioxide and other toxic
gases by factories and vehicles, occurrence of acid rain, nuclear tests and
poisonous chemicals have posed a serious threat to the ecological balance. The
entire earth and its inhabitants are affected by pollution. Life on earth is
endangered. Now, the man ahs realized the need of ecological conservation and
safety of environment. Public awareness is being created for the protection of
life on the earth. Many programmes for a better environment and conservation of
natural resources are being carried out all over the world. The scientific
conservation programmes are mainly based on the principles of ecology. We can
get a better environment only when every body, specially the children, becomes
aware about it.
To study the ecosystem, it is necessary for us to acquire
deep knowledge of the trees, plants, ponds, rivers, lakes; air, water and land;
crops and creatures; marine animals, etc. this way we will be able to make our
ecosystem even better. It is our duty as well as responsibility to ensure the
safety of our food chains.