We should conserve both because
(i) Among flora, trees provide us wood to serve our various requirements, besides providing shelter from the hot sun in summer.
(it) Crops provide our food including cereals, vegetables and fruits.
(iii) Many plant extracts are used for making medicines to cure and prevent diseases.
(iv) Among fauna, milch animals provide milk products as food.
(v) Poultry animals provide eggs and other animals as well as fish are also providing us food articles.
(vi) Insects help in pollination of crops and biologically control other harmful insects. All these maintain a balanced ecosystem and so should be conserved.