The natural world is made up of living and non-living things. Interactions between these components especially in resource sharing, allocation and use, have an important function in the environment. To understand interrelationships existing in our environment we need to look into ecology. Ecology is the study of relationships between living organisms, including humans, and their physical environment; it seeks to understand the vital connections between plants and animals and the world around them. Ecology also provides information about the benefits of ecosystems and how we can use Earth’s resources in sustainable ways to supply the needs of future generations.

Ecology elucidates the ways wherein people and nature depend on one another. Specialized fields in ecology provide us with information to better understand our world and also help us improve our environment, manage our natural resources, and protect human health. Predictions on the human effects on the environment is borne out of understanding how ecological systems work. Studying how different species rely on one another can also aid in protecting critical populations of species. Lack of understanding of these relationships have led to reduction of species numbers and even to extinction in the past.

Human populations can also benefit from the natural services that ecosystems provide. Ecologists have discovered that marshes and wetlands filter toxins and other impurities from water. Leaving some of these filtering ecosystems intact can reduce the burden on water treatment plants that have been built to perform the same service. By using natural filtering systems, we have the option to build less treatment plants. Harnessing these natural services has been a key point in global initiatives to mitigate environmental degradation. This book provides opportunities for students to study, practice, and develop quantitative and analytical skills in learning about ecology.