* Grasslands are characterized by their grassy vegetation and few trees. They are found in temperate and subtropical regions around the world.
* Forests are characterized by their dense tree cover. They are found in temperate, tropical, and boreal regions around the world.
* Deserts are characterized by their lack of vegetation and extreme temperatures. They are found in hot and dry regions around the world.
* Tundra is characterized by its low temperatures and permafrost. It is found in the Arctic and Antarctic regions.
* Ice caps and glaciers are characterized by their permanent ice cover. They are found in the polar regions and on high mountains around the world.
* Aquatic ecosystems characterized by the presence of water. They include oceans, lakes, rivers, and streams.