Ecology reveals the richness of the biosphere – the entire portion of Earth inhabited by life.
The scientific study of the interactions between organisms and the environment is called ecology.
Because of its great scope, ecology is an enormously complex and exciting area of biology, as well as one of the critical importance. Ecology reveals the richness of the biosphere – the entire portion of Earth inhabited by life – and can provide the basic understanding that will help us to conserve and sustain that richness, now threatened more than ever by human activity.
The richness of biosphere is particularly apparent in tropical forests. Earth's tropical forests are home to millions of species, including an estimated 5-30 million still undescribed species of insects, spiders, and other arthropods. In fact, every part of the biosphere is inhabited by diverse life forms, most of which, especially the microbial species, are unknown to science. This chapter introduces the science of ecology and describes some of the factors, both living and non–living, that affect the distribution of organisms. It also surveys the major types of aquatic and terrestrial habitats where organisms live and where ecologists go to study them. The scientific discipline of ecology addresses the full scale of life, from tiny bacteria to processes that span the entire planet.