Biodiversity refers to the variety and variability of organisms. Diverse biota provide ecosystem service and goods on which the survival of man is dependent. However, world today is under tremendous threat of unprecedented loss of biodiversity due to widespread habitat fragmentation, overexploitation and global climate change. Consequently, environmental issues like global warming, pollution, recurrent natural calamities and human population rise are of major concern to the conservationists. The book, in its third edition, covers a complete range of topics from the concept of biodiversity, its history, importance of species diversity, systematics, present status of bioresources, and pattern of distribution of global species to the genetic diversity and ecosystem diversity. It also elaborates on various drivers that lead to biodiversity loss and the impact on global climate change on biota. Moreover, the topics on biopiracy, environmental laws and policies, and the importance of indigenous knowledge of indigenous communities are also described in the text. The use of biotechnology-based methods and various measures to preserve natural resources are highlighted in the text. An all-inclusive, the book provides a detailed account of the conservation measures of biodiversity and proves to be the most comprehensive text encompassing both principles and applications of biodiversity. The book is primarily designed for the undergraduate and postgraduate students of Environmental Science, Zoology and Botany. Besides, it will also be of immense value to the students pursuing postgraduate diploma or other professional courses in Environmental Science and aspirants of various competitive examinations.