2 CLASSSIFICATION OF NATURAL RESOURCES 1 Renewable Resources those can renew or generate or replenish themselves Some examples are wind water plants forests etc Most renewable resources are exhaustible if we use them faster than they are renewed They are renewed by their own natural cycles For example Oxygen in the air which is consumed during respiration is replenished by photosynthesis This is natural cycle which maintains its equilibrium Nitrogen which forms a vital part of all living beings in the form or proteins Its gets transferred from one species to another and is finally released into the atmosphere This is also a natural cycle which constantly renews the supply of nitrogen All the living organisms maintain their population by constant cycles of growth reproduction and death All biological communities are renewable Example all the forests can renew themselves through growth and reproduction 2 Non renewable Resources those can t be replenished at the speed at which they are consumed or can t be generated at all For example Coal Petroleum fossil Fuels Minerals iron gold copper diamonds Soil it s a long term process not renewable in the life span of human Minerals are present in impure forms called ore in the earth Once we dig out out and use all the ores present there will be no new once to dig up