Roy, DebnarayanDr. Debnarayan Roy, Officer-in-Charge and Associate Professor of Jhargram Raj College, Jhargram, West Bengal, India.Mr. Samir Patra, M.Sc. in Zoology, Vidyasagar University, Joint CSIR-UGC NET, B. Ed., Internal examiner at Kharagpur College under NSOU.Mr. Dipak Das, Assistant Teacher in Biology at Dorokrishnanagar Bani Mandir (H.S), M. Sc., M.Ed.

All living organisms and the environment they live in are mutually reactive, affecting each other in various ways. Environment plays a major role in the critical stages of the life cycle of the species. The species reacts to the environmental changes and adjusts itself structurally and physiologically. The environment also changes according to certain species- specific activities like growth, dispersal, reproduction, death, decay, etc. All plants and animals are related to each other by their coaction and reaction on the environment. Under similar climatic conditions, there may simultaneously develop more than one community, some reaching the climax stage, and others under different stages of succession.In this book we simplified the basic concept about environment, ecological services and its regulation, biome and its features etc. We also demonstrated the relevant picture for better understanding and well references for further study. Its our pleasure when it better understood and clarified by all readers.