Keystone species deserve protection because they play an important role in supporting other species. Are capable of surviving in harsh environmental conditions. Indicate presence of certain minerals in the soil. Have become rare due to overexploitation.

Keystone species are species which have a significant and disproportionately large influence on the community. Removal or decrease in their number causes disruption in the structure and function of the community. For example in intertidal regions starfish feeds on mussels. Removal of starfish leads to the dominance of mussels that excludes algae and browsing species. In tropical rain forests, fig trees function as keystone species as they provide fruits to a number of animals during the period of food scarcity.