A 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." Using this definition, Global Forest Resources Assessment 2020 found that forests covered 4.06 billion hectares, or approximately 31 percent of the world's land area in 2020.
Taiga, generally referred to in North America as a boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces, and larches.
In graph theory, a tree is an undirected graph in which any two vertices are connected by exactly one path, or equivalently a connected acyclic undirected graph. A forest is an undirected graph in which any two vertices are connected by at most one path, or equivalently an acyclic undirected graph, or equivalently a disjoint union of trees.
In the fields of horticulture and botany, the term deciduous means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, after flowering; and to the shedding of ripe fruit. The antonym of deciduous in the botanical sense is evergreen.
Reforestation is the natural or intentional restocking of existing forests and woodlands (forestation) that have been depleted, usually through deforestation but also after clearcutting.
A woodland is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood, a low-density forest forming open habitats with plenty of sunlight and limited shade. Some savannas may also be woodlands, such as savanna woodland, where trees and shrubs form a light canopy.
A savanna or savannah is a mixed woodland-grassland ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. According to Britannica, there exists four savanna forms; savanna woodland where trees and shrubs form a light canopy, tree savanna with scattered trees and shrubs, shrub savanna with distributed shrubs, and grass savanna where trees and shrubs are mostly nonexistent.
An old-growth forest, sometimes synonymous with primary forest, virgin forest, late seral forest, primeval forest, or first-growth forest—is 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. More than one-third of the world's forests are primary forests. Old-growth features include diverse tree-related structures that provide diverse wildlife habitat that increases the biodiversity of the forested ecosystem. Virgin or first-growth forests are old-growth forests that have never been logged. The concept of diverse tree structure includes multi-layered canopies and canopy gaps, greatly varying tree heights and diameters, and diverse tree species and classes and sizes of woody debris.
Laurel forest, also called laurisilva or laurissilva, is a type of subtropical forest found in areas with high humidity and relatively stable, mild temperatures. The forest is characterized by broadleaf tree species with evergreen, glossy and elongated leaves, known as "laurophyll" or "lauroid". Plants from the laurel family (Lauraceae) may or may not be present, depending on the location.
The Aberdare Range is a 160 km (99 mi) long mountain range of upland, north of Kenya's capital Nairobi with an average elevation of 3,500 metres (11,480 ft). It straddles across the counties of Nyandarua, Nyeri, Muranga, Kiambu and Laikipia. The mountain range is located in west central Kenya, northeast of Naivasha and Gilgil and lies just south of the Equator. The mountain range is called Nyandarua among the Agikuyu people in whose territory this forest and mountain range is located. The name Nyandarua comes from the Kikuyu word rwandarua meaning a drying hide, due to the distinctive fold of its silhouette.
The Usambara Mountains of northeastern Tanzania in tropical East Africa, comprise the easternmost ranges of the Eastern Arc Mountains. The ranges of approximately 90 kilometres (56 mi) long and about half that wide, are situated in the Lushoto District of the Tanga Region. They were formed nearly two million years ago by faulting and uplifting, and are composed of Precambrian metamorphic rocks. They are split into two sub-ranges; the West Usambaras being higher than the East Usambaras, which are nearer the coast and receive more rainfall.
Calodendrum capense, the Cape chestnut, is an African tree which was first studied at The Cape in South Africa and cultivated widely for its prolific flower display. The tree obtained the common name of "Cape chestnut" because explorer William Burchell saw a resemblance to the horse chestnut in terms of flowers and fruit, though the two are not closely related.
Calodendrum is a genus of medium-sized evergreen trees comprising two species from Africa. Calodendrum capense, the Cape chestnut, is a well known tree that is widely cultivated, while Calodendrum eickii is a rare forest tree from Tanzania. The botanical name comes from Greek, kalos means beautiful and dendrum means tree. Both species are harvested for their timber in Africa.
The Orto Botanico "Pietro Castelli" dell'Università di Messina, also known as the Orto botanico di Messina, is a botanical garden operated by the University of Messina and located at Piazza 20 Settembre, Messina, Sicily, Italy.
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees.
Papilio cynorta, the mimetic swallowtail or common white banded papilio, is a butterfly of the family Papilionidae. It is found in Africa, including Sierra Leone, Liberia, Ivory Coast, Ghana, Togo, southern Nigeria, Cameroon, Equatorial Guinea, the Democratic Republic of the Congo, Angola, the Republic of the Congo, Uganda, Kenya and Tanzania.
Papilio phorcas, the apple-green swallowtail or green-banded swallowtail, is a butterfly of the family Papilionidae. It is found in Africa.
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial factor in shaping plant community, biodiversity, metabolic processes and ecosystem dynamics for montane ecosystems. Dense montane forests are common at moderate elevations, due to moderate temperatures and high rainfall. At higher elevations, the climate is harsher, with lower temperatures and higher winds, preventing the growth of trees and causing the plant community to transition to montane grasslands, shrublands or alpine tundra. Due to the unique climate conditions of montane ecosystems, they contain increased numbers of endemic species. Montane ecosystems also exhibit variation in ecosystem services, which include carbon storage and water supply.
Graphium adamastor, the Boisduval's white lady, is a butterfly in the family Papilionidae (swallowtails). It is found in Guinea, Sierra Leone, Mali, Burkina Faso, Ivory Coast, Ghana, Togo, Benin, Nigeria, Cameroon, the Republic of the Congo, the Central African Republic and the Democratic Republic of the Congo.
This is an alphabetical list of useful timber trees, indigenous and exotic, growing in the Gauteng area of South Africa. These trees range in size up to some 1.5m DBH, such as Cedrus deodara, the Himalayan Cedar. Hobbyists will seek out even small pieces of highly valued timber, such as Buxus macowanii, the South African counterpart of Buxus sempervirens, for turnery or the making of boxes and small items. Despite the wealth of useful woods available in Gauteng, most of the trees, felled or fallen, are dumped or cut into short lengths for fuel. Trees grown in urban or suburban environments are rarely pruned and are consequently often knotty. Timber frequently holds nails, wire and spikes, attesting to a variety of abuse during the lifetime of a tree, and requiring the use of a metal detector by the sawmiller. Garden cuttings and dead leaves are occasionally piled next to trees and burnt, leaving charred scars and inclusions.
