Красный дуб северный: описание и распространение.

Species of flowering plant in the beech and oak family Fagaceae

Quercus rubra, the northern red oak, is an oak tree in the red oak group (Quercus section Lobatae). 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.

In many forests, Quercus rubra grows straight and tall, to , exceptionally to tall, with a trunk of up to in diameter. Open grown trees do not get as tall, but can develop a stouter trunk, up to in diameter. It has stout branches growing at right angles to the stem, forming a narrow round topped head. Under optimal conditions and full sun, northern red oak is fast growing and a 10 year old tree can be tall. Trees may live up to 400 years; a living example of 326 years was noted in 2001. Northern red oak is easy to recognize by its bark, which features ridges that appear to have shiny stripes down the center. A few other oaks have bark with this kind of appearance in the upper tree, but the northern red oak is the only tree with the striping all the way down the trunk.

The species grows from the north end of the Great Lakes, east to Nova Scotia, south as far as Georgia, Mississippi, Alabama, and Louisiana, and west to Oklahoma, Kansas, Nebraska, and Minnesota. It grows rapidly and is tolerant of many soils and varied situations, although it prefers the glacial drift and well drained borders of streams. Pollination occurs in the first growing season, but fertilization and acorn maturation occur during the second growing season.

Over the last few decades, the northern red oak has dealt with several environmental factors, mainly disease, predation by insects, and limited opportunities for dispersal. These stresses have impacted the species' ability to proliferate in both the Northeast and Europe. The various environmental responses observed in Quercus rubra across several temperate environmental conditions have allowed for it to serve as a model organism for studying symbiotic relationships, dispersal, and habituation between tree species.

Canker pathogen, Diplodia corticola, has become a major pathogen to the species over the last decade, causing leaf browning, bark cracking and bleeding, and high rates of tree mortality across the northeastern United States. The northern red oak is also characterized as one of the most susceptible species to plant fungi Phytophthora cinnamomi and Phytophthora ramorum, which have caused severe, red black cankers in the trunk region of the species. Both P. cinnamomi and P. ramorum grow under warmer temperature conditions; as a result, northern red oak trees found in California, France, and northern Spain all have a higher incidence of fungal infection. Oak Wilt caused by the fungus Bretziella fagacearum is a major pathogen found in eastern North America that can kill trees quickly. There has been a recent northern red oak decline in Arkansas which is “unique in that it is associated with increases in red oak borer” (Enaphalodes rufulus) which “is native to the eastern United States and usually occurs in mixed oak forests”. “It damages the phloem, sapwood, and heartwood which means the ability for growth and repair is attacked as well as the stability of the tree”.

Northern red oak seedlings have been known to have a high mortality rate in northeast regions prone to spring freeze, particularly in Massachusetts. Acorns produced by oaks in this region are typically smaller in size as an adaptation to frost produced in high latitudes; however, the resulting smaller seedlings have produced limited opportunities for animal consumption and dispersal. Flooding along the continental United States has been shown to be a major issue for the northern red oak, in which decreased phloem transport and photosynthetic activity has been observed, but only after multiple days of flooding, indicating that the northern red oak has adapted moderate resistance to excess water exposure. The northern red oak has also developed tolerance mechanisms for heat stress, particularly observed in deciduous forests in the Southeastern United States, where, during summer heat waves, temperatures can exceed The leaves of the northern red oak have been observed to have an acclimation to Rubisco activase activity that is directly correlated to acclimations with repeated exposure to heat waves. Consistent photosynthetic activity in the red oak has also been observed in the presence of high carbon dioxide levels that often occur as a result of elevated temperatures.

Northern red oak kernels have highly concentrated amounts of bitter tasting tannin, a biochemical classified as a predator deterrent, which has limited appeal for consumption among animals. Despite this, the acorns are eaten by deer, squirrels and birds. Due to this, germination rates among the northern red oak acorns have decreased significantly and resulted in less seed dispersal by animals within Poland. In addition, limited opportunities for dispersal have become costly for the northern red oak in Europe. European animals known for dispersing tendencies, such as the European jay and wood mouse, have been found to be more attracted to local oak species.

Quercus rubra has effective ectomycorrhizal relationships that have been correlated with increased growth rates. Northern red oak trees have been shown to increase growth in the presence of various ascomycetes that coil at the base of the oak trunk. The fungi, which eventually proliferate at the stumps of deciduous trees, have been found to be host specific to both Quercus rubra and Quercus montana and primarily promote growth upon infection. the Urals and Western Siberia). The northern red oak is primarily found on the edges of woodland reserves in Europe, where light availability, tannin concentration, and animal dispersal are the most necessary component for the species' longevity and survival. The high influx of the species in Europe is primarily based on its economic productivity as a fast growing source of timber; however, it has been linked to lower percentages of trace elements and minerals found in the surrounding soil and reduced richness among native oak species such as Quercus robur.

The northern red oak is one of the most important oaks for timber production in North America. Quality red oak is of high value as lumber and veneer, while defective logs are used as firewood. Other related oaks are also cut and marketed as red oak, although their wood is not always of as high a quality. These include eastern black oak, scarlet oak, pin oak, Shumard oak, southern red oak and other species in the red oak group. Construction uses include flooring, veneer, interior trim, and furniture. It is also used for lumber, railroad ties, and fence posts. Red oak wood grain is so open that smoke can be blown through it from end grain to end grain on a flat sawn board. For this reason, it is subject to moisture infiltration and is unsuitable for outdoor uses such as boatbuilding or exterior trim. The acorns can be collected in autumn, shelled, tied up in a cloth, and leached to remove bitterness. They can then be eaten whole or ground into meal.

Quercus rubra is grown in parks and large gardens as a specimen tree. It is not planted as often as the closely related pin oak as it develops a taproot and quickly becomes difficult to transplant, however modern growing pots have made starting seedlings with taproots easier than in the past.

It is the state tree of New Jersey and the provincial tree of Prince Edward Island.

Ashford Oak – A very large Northern Red Oak in Ashford, Connecticut. The tree has suffered falling limbs because of its great age. However, this tree is still a sight to behold; the trunk is in circumference and the root knees are also particularly impressive. The oak is located on Giant Oak Lane off U. S. Highway 44. There are several other large oaks in the area.