Unlike deciduous trees that shed their foliage during winter, evergreen trees keep their leaves year-round. Thousands of species are considered evergreens, including conifers, palm trees and most trees found in the rain forest. Many evergreen tree species are considered valuable resources, providing humans with everything from lumber and firewood to medicinal ingredients and food.
Evergreen trees are widely distributed around the world, particularly in colder regions of the Northern Hemisphere. Coniferous forests cover roughly 15 percent of the land on Earth and are comprised of mostly evergreen trees like cedars, junipers, pines, Douglas-firs and hemlocks. Tropical rain forests, the largest of which are found in South America, sub-Saharan Africa and East Asia, also are largely made up of evergreen trees due to consistently warm, humid climates that vary little from season to season.