An oak is a tree or shrub in the genus Quercus of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably Lithocarpus, as well as in those of unrelated species such as Grevillea robusta and the Casuarinaceae (she-oaks). The genus Quercus is native to the Northern Hemisphere, and includes deciduous and evergreen species extending from cool temperate to tropical latitudes in the Americas, Asia, Europe, and North Africa. North America has the largest number of oak species, with approximately 160 species in Mexico of which 109 are endemic and about 90 in the United States. The second greatest area of oak diversity is China, with approximately 100 species.
Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic, species, and ecosystem level.
Quercus rubra, the northern red oak, is an oak tree in the red oak group. It is a native of North America, in the eastern and central United States and southeast and south-central Canada. It has been introduced to small areas in Western Europe, where it can frequently be seen cultivated in gardens and parks. It prefers good soil that is slightly acidic. Often simply called red oak, northern red oak is so named to distinguish it from southern red oak (Q. falcata), also known as the Spanish oak. Northern Red Oak is sometimes called champion oak.
Reforestation is the natural or intentional restocking of existing forests and woodlands (forestation) that have been depleted, usually through deforestation but also after clearcutting.
An invasive or alien species is an introduced species to an environment that becomes overpopulated and harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native species that become harmful to their native environment after human alterations to its food web – for example the purple sea urchin which has decimated kelp forests along the northern California coast due to overharvesting of its natural predator, the California sea otter. Since the 20th century, invasive species have become a serious economic, social, and environmental threat.
The Fagaceae are a family of flowering plants that includes beeches, chestnuts and oaks, and comprises eight genera with about 927 species. Fagaceae in temperate regions are mostly deciduous, whereas in the tropics, many species occur as evergreen trees and shrubs. They are characterized by alternate simple leaves with pinnate venation, unisexual flowers in the form of catkins, and fruit in the form of cup-like (cupule) nuts. Their leaves are often lobed and both petioles and stipules are generally present. Their fruits lack endosperm and lie in a scaly or spiny husk that may or may not enclose the entire nut, which may consist of one to seven seeds. In the oaks, genus Quercus, the fruit is a non-valved nut called an acorn. The husk of the acorn in most oaks only forms a cup in which the nut sits. Other members of the family have fully enclosed nuts. Fagaceae is one of the most ecologically important woody plant families in the Northern Hemisphere, as oaks form the backbone of temperate forest in North America, Europe, and Asia, and are one of the most significant sources of wildlife food.
A lignotuber is a woody swelling of the root crown possessed by some plants as a protection against destruction of the plant stem, such as by fire. Other woody plants may develop basal burls as a similar survival strategy, often as a response to coppicing or other environmental stressors. However, lignotubers are specifically part of the normal course of development of the plants that possess them, and often develop early on in growth. The crown contains buds from which new stems may sprout, as well as stores of starch that can support a period of growth in the absence of photosynthesis. The term "lignotuber" was coined in 1924 by Australian botanist Leslie R. Kerr.
A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur naturally on all continents except Antarctica and are found in most ecoregions of the Earth. Furthermore, grasslands are one of the largest biomes on earth and dominate the landscape worldwide. There are different types of grasslands: natural grasslands, semi-natural grasslands, and agricultural grasslands. They cover 31–69% of the Earth's land area.
Quercus robur, the pedunculate oak, is a species of flowering plant in the beech and oak family, Fagaceae. It is a large tree, native to most of Europe and western Asia, and is widely cultivated in other temperate regions. It grows on circumneutral soils in the lowlands and is notable for its value to natural ecosystems, supporting a very wide diversity of herbivorous insects and other pests, predators and pathogens.
Quercus petraea, commonly known as the sessile oak, Cornish oak, Irish Oak or durmast oak, is a species of oak tree native to most of Europe and into Anatolia and Iran. The sessile oak is the national tree of Ireland, and an unofficial emblem in Wales and Cornwall.
Quercus falcata, also called southern red oak, spanish oak, bottomland red oak or three-lobed red oak is an oak. Native to the southeastern United States, it gets its name the "Spanish Oak" as these are the areas of early Spanish colonies, whilst "southern red oak" comes from both its range and leaf color during late summer and fall. The southern red oak is a deciduous angiosperm, so has leaves that die after each growing period and come back in the next period of growth.
Afforestation is the establishment of a forest or stand of trees (forestation) in an area where there was no previous tree cover. Many government and non-governmental organizations directly engage in afforestation programs to create forests and increase carbon capture. Afforestation is an increasingly sought-after method to fight climate concerns, as it is known to increase the soil quality and organic carbon levels into the soil, avoiding desertification. Afforestation is mainly done for conservational and commercial purposes.
Ilex chinensis, the Kashi holly, oriental holly, or purple holly, is a species of flowering plant in the family Aquifoliaceae, native to Vietnam, southern China, Taiwan, and central and southern Japan.
Quercus arbutifolia is the accepted name of an endemic bush / small-tree species in the Asian sub-genus of 'ring-cupped oaks' and the family Fagaceae; there are no known subspecies.
Quercus × crenata, commonly known as Spanish oak, is a tree in the family Fagaceae. It is a hybrid between the European trees Turkey oak and cork oak. This hybrid has in the past often been called Quercus × hispanica, a name that properly refers to presumed hybrids between Portuguese oak and Quercus suber.
Gleditsia japonica, the Japanese locust, is a species of flowering plant in the family Fabaceae, native to the eastern Himalayas, central and southern China, Manchuria, Korea, and central and southern Japan. It is used as a street tree in a number of cities in China and Europe.
Castanopsis eyrei is a species of flowering plant in the family Fagaceae, native to southern China, and Taiwan. An evergreen tree typically 8 to 20 m tall, it is usually found in late successional forests from 300 to 1,700 m above sea level, where it is often the dominant species. It is used as a street tree in a number of southern Chinese cities.
Fraxinus longicuspis, the taper-tip ash or Japanese ash, is a species of flowering plant in the family Oleaceae, native to the mountains of central and southern Japan. A deciduous tree, it is hardy to USDA zone 5. It is used as a street tree in a few cities around the world.
Fraxinus platypoda, the Chinese red ash, is a species of flowering plant in the family Oleaceae, native to central China, and Japan. In the latter stages of succession it often dominates the mountain riparian forest habitat in which it is found.
Syzygium buxifolium, the boxleaf eugenia or fish-scale bush, is a species of flowering plant in the family Myrtaceae, native to northern Vietnam, southern China, Hainan, Taiwan, the Ryukyu Islands, and southern Kyushu, Japan. A shrub or small tree, it is suitable for hedges, containers, and bonsai. It is used as a street tree in a number of southern Chinese cities.
