Man is just one among the numerous organisms on earth. No other organism on earth depends on other organisms so much for its sustenance. The plants and animals in the environment provide us food, clothing, shelter, medicine, fuel, etc. Like air and water, soil is also important for survival. You have already learnt about ecosystem and food chain. Man is the last kink in the continuous process of evolution in nature.
The interventions of man in nature with selfish motives will have adverse effects. Interaction in nature without disturbing its diversity is an important aspect in the conservation of the environment. Conservation of the environment and its diversity is a must for the healthy sustenance of not only man but all life forms as well.