An ecosystem refers to the living and non-living things that make up a specific location, such as a pond, forest, river grassland, desert or tundra. Ecosystems are often confused with biomes, which are regions of the world that share similar climate, plant and animal life.
In an ecosystem, all of the plants, animals, bacteria and other organisms in that system rely on one another for survival, and also on the other environmental elements, such as water, soil and nutrients. Each member of an ecosystem has its own specific role that it plays in contributing to the overall health and survival of that ecosystem.
Although ecosystems do not have any set size or official boundaries, they are generally much smaller than biomes. In fact, a biome is made up of thousands, even millions of different ecosystems put together. This means that while a particular forest is its own ecosystem, it also belongs to either the tropical rain forest or temperate forest biome (or one of the many sub-biomes).
There is much disagreement about the number of biomes on the planet, but most scientists suggest there are seven: marine, temperate forest, tropical rainforest, tundra, desert, taiga and grassland. Still, others split the marine biome into freshwater and ocean. In addition, many scientists further split each biome up into a number of subgroups.