Poaceae are dominant are estimated to constitute 40.5% of the land area of the Earth, excluding Greenland and Antarctica. Grasses are also an important part of the vegetation in many other habitats, including wetlands, forests and tundra. The Poaceae are the most economically important plant family, providing staple foods from domesticated cereal crops such as maize, wheat, rice, barley, and millet as well as forage, building materials (bamboo, thatch, straw) and fuel (ethanol). Though they are commonly called "grasses", seagrasses, rushes, and sedges fall outside this family. The rushes and sedges are related to the Poaceae, being members of the order
Lists of organisms by population 400 billion trees on our globe. However, more recently, in 2015, using better methods, the global tree count has been estimated at about 3 trillion. Other studies show that the Amazonian forest alone yields approximately 430 billion trees. Extrapolations from data compiled over a period of 10 years suggest that greater Amazonia, which includes the Amazon Basin and the Guiana Shield, harbors around 390 billion individual trees. Lists of organisms by population This is a collection of lists of organisms by their population. While most of the numbers are estimates, they have been made by the experts in their fields.