The use of ecology and engineering to predict, design, construct or restore, and manage ecosystems is known as ecological engineering. It is aimed at integrating human society with its natural environment. The applications in ecological engineering can be categorized into 3 spatial scales: mesocosms, ecosystems and regional systems. Mesocosms range from a single centimeter to hundreds of meters, ecosystems range from a single kilometer to ten kilometers, and regional systems are those systems which span over ten kilometers. There is an increase in the complexity of the design usually observed with an increase in the spatial scale. Applications of ecological engineering are focused on the creation or restoration of ecosystems such as wetlands and greenhouses. From theories to research to practical applications, case studies related to all contemporary topics of relevance to the field of ecological engineering have been included in this book. The detailed analyses and data will prove immensely beneficial to professionals and students involved in this area at various levels.