Deforestation            :    The loss or continual degradation of forest habitat due to natural or human activities.
Afforestation            :     Planting of trees on a large scale to regenerate forest.
Desertification          :     The process of conversion of fertile land into deserts due to the removal of top layer of soil.
Ecosystem                 :     The basic unit of ecology which consists of the biotic and abiotic components.
Reforestation            :     It is the restocking of the destroyed forests by planting new trees.
Fauna                        :     The community of animals in a specific region or habitat.
Flora                          :     The plant life of particular area.
Endemic species       :     The species that are exclusively found in any geographical unit like a state, zone or a country or a habitat type are referred as endemic species.
Sanctuaries               :     The protected area which is reserved for the conservation of animals only and human activities upto a certain extent are allowed in these areas. 
National Park           :     The large and diverse reserves to protect whole sets of ecosystem  including flora, fauna, landscape and historical objects of an area are termed as national park.
Biosphere Reserve   :     A biosphere reserve is a unique concept which includes one or more protected areas and surrounding lands that are managed to combine both conservation and sustainable use of                                                 natural resources.

We have read in earliar classes that humans use a number of natural resources for their survival. However, as human population has been increasing at a high rate, the natural resources are also being used in greater quantity than ever before. With recent advances in science and technology, people now have a higher standard of living. As a result, there is a far great demand for the natural resources. 
It is for this reason that the natural resources must be 'conserved' so that there will be enough resources available for the future generations. 
It must be clearly understood that conservation does not mean that we have to stop the use of these resources completely. It only means that we have to use the resources wisely and judiciously. conservation is the wise and judicious use of resources. The overuse or wastage of resources would lead to imbalanaces among the various components of nature.

Aims of conservation
* To preserve the quality of environment, i.e., maintain a pollution-free environment.
*     To ensure a continuous yield of useful plants, animals and materials for generations to come.
   Importance of Forests