Old-growth forestAn old-growth forest, sometimes synonymous with primary forest, virgin forest, late seral forest, primeval forest, first-growth forest, or mature forestis a forest that has attained great age without significant disturbance, and thereby exhibits unique ecological features, and might be classified as a climax community. The Food and Agriculture Organization of the United Nations defines primary forests as naturally regenerated forests of native tree species where there are no clearly visible indications of human activity and the ecological processes are not significantly disturbed.
Boreal forest of CanadaCanada's boreal forest is a vast region comprising about one third of the circumpolar boreal forest that rings the Northern Hemisphere, mostly north of the 50th parallel. Other countries with boreal forest include Russia, which contains the majority; the United States in its northernmost state of Alaska; and the Scandinavian or Northern European countries (e.g. Sweden, Finland, Norway and small regions of Scotland). In Europe, the entire boreal forest is referred to as taiga, not just the northern fringe where it thins out near the tree line.
WoodlandA woodland (ˈwʊdlənd) is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the plurale tantum woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see differences between British, American, and Australian English explained below). Some savannas may also be woodlands, such as savanna woodland, where trees and shrubs form a light canopy. Woodlands may support an understory of shrubs and herbaceous plants including grasses.
WildernessWilderness or wildlands (usually in the plural) are natural environments on Earth that have not been significantly modified by human activity, or any nonurbanized land not under extensive agricultural cultivation. The term has traditionally referred to terrestrial environments, though growing attention is being placed on marine wilderness. Recent maps of wilderness suggest it covers roughly one-quarter of Earth's terrestrial surface, but is being rapidly degraded by human activity.
ForestA forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' Food and Agriculture Organization (FAO) defines a forest as, "Land spanning more than 0.5 hectares with trees higher than 5 meters and a canopy cover of more than 10 percent, or trees able to reach these thresholds in situ. It does not include land that is predominantly under agricultural or urban use.