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.