This book is intended as a reference book for students in Science field.As humans, we are engaged in a wide range of activities that are causing serious damage to the ecosystems that sustain both our species and Earth's life support systems. This is witnessed by pollution, climate warming, collapsing fisheries, deforestation, the degradation of agricultural soil, extinctions and endangerment of species, and other damages.Nevertheless, we don't approach these issues as pessimists. If we take constructive actions now, or at least soon, we can prevent or repair many of these environmental problems. Within limits, humans are prescient creatures, and our society is capable of implementing a sustainable economy that can support our livelihoods as well as healthy ecosystems.The present book, EVS and ECOLOGY gives a vibrant scientific field where scientists from many fields including all sciences, use their skills to explore and explains ecosystems as well as environmental side. This also serves as an excellent pathway for students intending to pursue postgraduate study. We are thankful to god & our parents.