This document provides information about ecosystems. It begins by defining an ecosystem as a community of living organisms interacting with their environment. It then describes the main components of ecosystems, including producers, consumers, and decomposers.
It classifies ecosystems into two main types - terrestrial and aquatic. Terrestrial ecosystems discussed include forests, deserts, grasslands, and mountains. Forest ecosystems are described in more detail. Aquatic ecosystems include marine, freshwater, and wetlands.
The document also covers food chains and webs, and ecological pyramids including pyramids of numbers, biomass and energy. Finally, it introduces the topic of environmental pollution, which will be covered in more depth in the next unit.