An ecosystem is a very distinct area that contains not only the many plants and animals that may be living on, over or under the area but the actual physical environment, the rocks, the soil and the air above. Ecosystems are distributed all over the Earth and are mainly grouped by climate, ranging from tropical rain forests and deserts to polar ice caps and tundra. From the cold and dry regions around the poles to the hot and wet regions around the equator, each ecosystem has living within it plants and animals that have adapted to the particular conditions of the area. Within these habitats, plants and animals have formed interdependent communities, each having a particular role as they compete for food and resources in order to survive. Together these plants and animals form food chains and webs. These habitats provide most of the food that its inhabitants require and can vary greatly in size.
| Ecosystem | Main Characteristics | Locations |
| Polar Regions | Very low temperatures | Arctic (North Pole), Antarctic (South Pole) |
| Seashores | Half land, half sea Constantly changing | Around the edges of all continents and land masses |
| Towns and Cities | Varied temperatures depending on location, More sheltered that countryside, Built up, habitats for humans | All around the world |
| Mountains | Varied climatic conditions according to height. | All continents |
| Rivers and Lakes | Freshwater ecosystems supporting a wide range of plant an animal life. | All around the world |
| Grasslands | Largely grass with only some other plants and animals. | Mainly Asia, North & South America and Africa |
| Oceans | The largest ecosystem of all taking up two thirds of the Earth’s surface. | All around the world |
| Rainforests | Very hot and wet with large numbers of species of plants and animals living there. | Central & South America, central Africa, Southeast Asia, and northern Australia. |
| Wetlands | Both freshwater and saltwater marshes and bogs | All continents except Antarctica. |