Once covering more than 14% of the earth's land surface, these rain forests now cover no more than 6%. Although India has only $2.4$% of the world's land area, its share of the global species diversity is an impressive 8.1%. More than 25% of the drugs currently sold in the market worldwide are derived from plants. Amazon forest is estimated to produce, through photosynthesis, 20% of the total oxygen in the earth's atmosphere.