Instruct: Given a question, retrieve passages that answer the question.
Query: How thick is the bark of a redwood tree?
The coast redwood can reach 115m (377ft) tall with a trunk diameter of 9m (30ft).[10] It has a conical crown, with horizontal to slightly drooping branches. The bark can be very thick, up to 1-foot (30cm), and quite soft and fibrous, with a bright red-brown color when freshly exposed (hence the name redwood), weathering darker. The root system is composed of shallow, wide-spreading lateral roots.
Before September 2006, the tallest living specimen known was the Stratosphere Giant, outside the park in Humboldt Redwoods State Park, which was 370 feet (110m) in 2004. For many years, one specimen simply named Tall Tree in Prairie Creek Redwoods State Park and within the RNSP was measured at 367.8 feet (112.1m), but the top 10 feet (3.0m) of the tree was reported to have died in the 1990s.[27] One tree that fell in 1991 was reported to be 372.04 feet (113.40m). Only the giant sequoia has more mass. The largest redwood by volume is the 42,500cubic foot (1,205m³) Lost Monarch, located in Jedediah Smith Redwoods State Park. Mature Coast redwoods live an average of 500–700years and a few are documented to be 2,000years old, making them some of the longest-living organisms on earth.[23][28] They are highly resistant to disease, due to a thick protective bark and high tannin content. Redwoods prefer sheltered slopes, slightly inland and near water sources such as rivers and streams.
The oldest known coast redwood is about 2,200 years old;[17] many others in the wild exceed 600 years. The numerous claims of older redwoods are incorrect.[17] Because of their seemingly timeless lifespans, coast redwoods were deemed the "everlasting redwood" at the turn of the century; in Latin, sempervirens means "ever green" or "everlasting". Redwoods must endure various environmental disturbances to attain such great ages. In response to forest fires, the trees have developed various adaptations. The thick, fibrous bark of coast redwoods is extremely fire-resistant; it grows to at least a foot thick and protects mature trees from fire damage.[18][19] In addition, the redwoods contain little flammable pitch or resin.[19] If damaged by fire, a redwood readily sprouts new branches or even an entirely new crown,[18][16] and if the parent tree is killed, new buds sprout from its base.[16] Fires, moreover, appear to actually benefit redwoods by causing substantial mortality in competing species while having only minor effects on redwood. Burned areas are favorable to the successful germination of redwood seeds.[18] A study published in 2010, the first to compare post-wildfire survival and regeneration of redwood and associated species, concluded fires of all severity increase the relative abundance of redwood and higher-severity fires provide the greatest benefit.[20]
In general, along the bayshore and valleys, the Ohlone constructed dome-shaped houses of woven or bundled mats of tules, 6 to 20 feet (1.8 to 6 m) in diameter. In hills where redwood trees were accessible, they built conical houses from redwood bark attached to a frame of wood. Residents of Monterey recall Redwood houses. One of the main village buildings, the sweat lodge was low into the ground, its walls made of earth and roof of earth and brush. They built boats of tule to navigate on the bays propelled by double-bladed paddles.
The tree forms a thick, rugged bark containing high levels of suberin. Over time the cork cambium layer of bark can develop considerable thickness and can be harvested every 7 to 10 years to produce cork. The harvesting of cork does not harm the tree (though such activity tends to reduce its life expectancy), in fact, no trees are cut down during the harvesting process. Only the bark is extracted, and a new layer of cork regrows, making it a renewable resource. The tree is cultivated in Spain, Portugal, Algeria, Morocco, France, Italy and Tunisia. Cork oaks are considered to be soil builders and their fruits have been shown to have useful insecticidal properties. Cork oak forests cover approximately 25,000 square kilometres in those countries (equivalent to ). Portugal accounts for around 50% of the world cork harvest. Cork oaks cannot legally be cut down in Portugal, except for forest management felling of old, unproductive trees, and, even in those cases, farmers need special permission from the Ministry of Agriculture.
Tree branches and more often roots of the same species will sometimes naturally graft; this is called inosculation. The bark of the tree may be stripped away when the roots make physical contact with each other, exposing the vascular cambium and allowing the roots to graft together. A group of trees can share water and mineral nutrients via root grafts, which may be advantageous to weaker trees, and may also form a larger rootmass as an adaptation to promote fire resistance and regeneration as exemplified by the California black oak ("Quercus kelloggii"). Additionally, grafting may protect the group from wind damages as a result of the increased mechanical stability provided by the grafting. Albino redwoods use root grafting as a form of plant parasitism of normal redwoods.
Fire impacts plants most directly via heat damage. However, new studies indicate that hydraulic failure kills trees during a fire in addition to fire scorching. High temperature cuts the water supply to the canopy and causes death of the tree. Fortunately, thick bark can protect plants because they keep stems away from high temperature. Under the protection of bark, living tissue won't have direct contact with fire and the survival rate of plants will be increased. Heat resistance is a function of bark thermal diffusivity (a property of the species) and bark thickness (increasing exponentially with bark thickness). Thick bark is common in species adapted to surface or low-severity fire regimes. On the other hand, plants in crown or high-severity fire regimes usually have thinner barks because it is meaningless to invest on thick bark without it conferring an advantage in survivorship.
The rhytidome is the most familiar part of bark, being the outer layer that covers the trunks of trees. It is composed mostly of dead cells and is produced by the formation of multiple layers of suberized periderm, cortical and phloem tissue. The rhytidome is especially well developed in older stems and roots of trees. In shrubs, older bark is quickly exfoliated and thick rhytidome accumulates. It is generally thickest and most distinctive at the trunk or bole (the area from the ground to where the main branching starts) of the tree.
The height of S.sempervirens is closely tied to fog availability; taller trees become less frequent as fog becomes less frequent.[22] As S.sempervirens' height increases, transporting water via water potential to the leaves becomes increasingly difficult due to gravity.[23][24][25] Despite the high rainfall that the region receives (up to 100cm), the leaves in the upper canopy are perpetually stressed for water.[26][27] This water stress is exacerbated by long droughts in the summer.[28] Water stress is believed to cause the morphological changes in the leaves, stimulating reduced leaf length and increased leaf succulence.[24][29] To supplement their water needs, redwoods utilize frequent summer fog events. Fog water is absorbed through multiple pathways. Leaves directly take in fog from the surrounding air through the epidermal tissue, bypassing the xylem.[30][31] Coast redwoods also absorb water directly through their bark.[32] The uptake of water through leaves and bark repairs and reduces the severity of xylem embolisms,[33][32] which occur when cavitations form in the xylem preventing the transport of water and nutrients.[32] Fog may also collect on redwood leaves, drip to the forest floor, and be absorbed by the tree's roots. This fog drip may form 30% of the total water used by a tree in a year.[28]
Many species of tree show varying degrees of resistance, such as the heartnut, Butternut, and the Japanese, Black, and Persian Walnuts. It is sometimes claimed that higher levels of resistance result from thicker bark; however, since the disease enters through "breaks" in the bark, it is unlikely that bark thickness influences resistance. Additionally, both trees produce phenolics immediately upon attack, later producing gums and tyloses to surround the pathogen.
"Tsuga chinensis" is a large tree with bark that is a blackish brown in colour. The scaly bark has irregular longitudinal breaks, and lenticels that are very inconspicuous. The outer bark is about 6 mm thick with alternating tiered layers of pale yellowish brown corky bark, and brown lignified fibrous bark. The newly formed periderm is a purplish red. The inner bark is about 4 to 5 mm thick and pale reddish brown in colour. It is fibrous in texture with minute, almost inconspicuous sclereid, or stone cell groups. The cambium as well as the newly formed phloem are nearly inconspicuous. Freshly cut wood is a pale yellowish white with inconspicuous wood rays.
In the case of angiosperms and gymnosperms, the outermost layer of the trunk is the bark, mostly composed of dead cells of phellem (cork). It provides a thick, waterproof covering to the living inner tissue. It protects the trunk against the elements, disease, animal attack and fire. It is perforated by a large number of fine breathing pores called lenticels, through which oxygen diffuses. Bark is continually replaced by a living layer of cells called the cork cambium or phellogen. The London plane ("Platanus × acerifolia") periodically sheds its bark in large flakes. Similarly, the bark of the silver birch ("Betula pendula") peels off in strips. As the tree's girth expands, newer layers of bark are larger in circumference, and the older layers develop fissures in many species. In some trees such as the pine ("Pinus" species) the bark exudes sticky resin which deters attackers whereas in rubber trees ("Hevea brasiliensis") it is a milky latex that oozes out. The quinine bark tree ("Cinchona officinalis") contains bitter substances to make the bark unpalatable. Large tree-like plants with lignified trunks in the Pteridophyta, Arecales, Cycadophyta and Poales such as the tree ferns, palms, cycads and bamboos have different structures and outer coverings.
In the lower elevations and canyons, the California Redwood is often found. Its thick bark, along with foliage that starts high above the ground, protect the species from both fire and insect damage, contributing to the coast redwood's longevity. Fire appears to benefit redwoods by removing competitive species. A 2010 study compared post-wildfire survival and regeneration of redwood and associated species. It concluded that fires of all severity increase the relative abundance of redwood and higher-severity fires provide the greatest benefit.The July 2016 Soberanes Fire was caused by unknown individuals who started and lost control of an illegal campfire in the Garrapata Creek watershed. After it burned 57 homes in the Garrapata and Palo Colorado Canyon areas, fire fighters were able to build lines around parts of the Big Sur community. A bulldozer operator was killed when his equipment overturned during night operations in Palo Colorado Canyon.
The prehistoric fossil range of the genus is considerably greater, with a subcosmopolitan distribution including Europe and Asia until about 5 million years ago. During the last ice age, perhaps as recently as 10,000 years ago, redwood trees grew as far south as the Los Angeles area (coast redwood bark found in subway excavations and at La Brea tar pits).
"Quercus pubescens" is a medium-sized deciduous tree growing up to 20 m. Forest-grown trees grow tall, while open-growing trees develop a very broad and irregular crown. They are long-lived, to several hundred years, and eventually grow into very stout trees with trunks up to 2 m in diameter. Open-grown trees frequently develop several trunks. The bark is very rough, light grey and divided into small flakes. Large trees develop very thick whitish bark cracked into deep furrows, similar to the pedunculate oak but lighter in colour.
While the bark and foliage are similar to another closely related genus of redwoods, "Sequoia", "M. glyptostroboides" differs from the coast redwood in that it is deciduous, like "Taxodium distichum" (bald cypress). Similar to "T. distichum", older trees may form wide buttresses on the lower trunk. "M. glyptostroboides" is a fast-growing tree, exceeding in height and in trunk diameter by the age of 50, in cultivation (with the potential to grow to even greater dimensions). The trunk forms a distinctive "armpit" under each branch. The bark is vertically fissured and tends to exfoliate in ribbon-like strips.
"Betula lenta" is a medium-sized deciduous tree reaching tall, exceptionally to with a trunk up to diameter. In younger trees the bark is characteristic of most birches, with smooth bark and distinct horizontal lenticels. It is sometimes mistakenly identified as a cherry tree. In older tree specimens the bark (unlike the more commonly known birches) develops vertical cracks into irregular scaly plates revealing rough dark brown bark patterns. This, however, only occurs in mature, or ancient, trees and these specimens are not often identified by the public as "B. lenta" due to the difference between the tree's smooth young bark (which the public is most familiar with) and the tree's rough, cracked and plated mature bark. The twigs, when scraped, have a strong scent of wintergreen due to methyl salicylate, which is produced in the bark. The leaves are alternate, ovate, long and broad, with a finely serrated margin. The flowers are wind-pollinated catkins long, the male catkins pendulous, the female catkins erect. The fruit, maturing in fall, is composed of numerous tiny winged seeds packed between the catkin bracts. Seed production mainly occurs in trees that are between 40 and 200 years old, although light crops may occur as early as 15 years and as long as the tree lives. Contrary to common knowledge, the lifespan of "B. lenta" is typically around 200 years, and many individuals will reach 250 and even 300 years. The oldest known "B. lenta" has been confirmed to be 368 years old, and the species may live even longer than that in an undisturbed ancient forest. Due to the cracking and developing of bark plates, a rough age estimate of "B. lenta" can be determined by how many bark layers a tree has. Generally the tree's smooth young bark begins to split around 40-50 years of age, that then begins to peel off the trunk around the age of 70-80 and is then replaced by another layer of bark, the second set will begin to peel around 130-150, and the third will peel when the tree has reached 200-210 years and achieved old growth status. This will continue to occur as long as the tree lives, but the individual bark layers become indiscernible after roughly 250 years of age.
Coast redwoods are resistant to insect attack, fungal infection, and rot. These properties are conferred by concentrations of terpenoids and tannic acid in redwood leaves, roots, bark, and wood.[16] Despite these chemical defenses, redwoods are still subject to insect infestations; none, however, are capable of killing a healthy tree.[16] Redwoods also face predation from mammals: black bears are reported to consume the inner bark of small redwoods, and black-tailed deer are known to eat redwood sprouts.[16]
In some plants, the bark is substantially thicker, providing further protection and giving the bark a characteristically distinctive structure with deep ridges. In the cork oak ("Quercus suber") the bark is thick enough to be harvested as a cork product without killing the tree; in this species the bark may get very thick (e.g. more than 20 cm has been reported). Some barks can be removed in long sheets; the smooth surfaced bark of birch trees has been used as a covering in the making of canoes, as the drainage layer in roofs, for shoes, backpacks etc. The most famous example of using birch bark for canoes is the birch canoes of North America.
Extensive logging of redwoods began in the early nineteenth century. The trees were felled by ax and saw onto beds of tree limbs and shrubs to cushion their fall.[16] Stripped of their bark, the logs were transported to mills or waterways by oxen or horse.[16] Loggers then burned the accumulated tree limbs, shrubs, and bark. The repeated fires favored secondary forests of primarily redwoods as redwood seedlings sprout readily in burned areas.[16][36] The introduction of steam engines let crews drag logs through long skid trails to nearby railroads,[16] furthering the reach of loggers beyond the land nearby rivers previously used to transport trees.[36] This method of harvesting, however, disturbed large amounts of soil, producing secondary-growth forests of species other than redwood such as Douglas-fir, grand fir, and western hemlock.[16] After World War II, trucks and tractors gradually replaced steam engines, giving rise to two harvesting approaches: clearcutting and selection harvesting. Clearcutting involved felling all the trees in a particular area. It was encouraged by tax laws that exempted all standing timber from taxation if 70% of trees in the area were harvested.[16] Selection logging, by contrast, called for the removal 25% to 50% of mature trees in the hopes that the remaining trees would allow for future growth and reseeding.[36] This method, however, encouraged growth of other tree species, converting redwood forests into mixed forests of redwood, grand fir, Sitka spruce, and western hemlock.[36][16] Moreover, the trees left standing were often felled by windthrow; that is, they were often blown over by the wind.
Mature trees range from tall with short trunks and round-topped canopies. The roots are thick, fleshy, and covered with bright orange bark. The tree's mature bark is dark, deeply furrowed and scaly. The plant has significant potential to invade unmanaged habitats.
Sooty bark disease causes wilting of the crown and dieback of branches. Rectangular patches of bark, and later long strips of bark, become detached from the trunk exposing thick layers of black fungal spores. It has been found that the fungus spreads more rapidly through the tree's tissues at than at , and in the former instance, more rapidly when the tree is under greater water stress. This would seem to suggest that the disease is associated with raised summer temperatures.
Volume tables created with Girard form class use the assumption that trees of the same diameter and merchantable height have similar rates of taper above the first log. This implies that volume differences in trees with the same diameter and merchantable height can be mostly attributed to taper variations in the first log. Volume tables using Girard form class are composite tables and are created independently of tree species.
To calculate GFC, you need several things: DIB (Diameter inside bark) @ 17.3', DOB (diameter outside bark) @ 17.3', DBH (diameter @ 4.5'), and [single] bark thickness (which will be used to calculate double bark thickness).
In mountainous regions where redwood trees grew, they may have built conical houses from redwood bark attached to a frame of wood. One of the main village buildings, the sweat lodge, was built low into the ground, its walls made of earth and roof of earth and brush. They built boats of tule to navigate on the bays propelled by double-bladed paddles.
The bark remains smooth for a long time in this species, and only old trees have rough bark at the base of the trunk. The bark is thick, with deep, longitudinal fissures and rough, elongated plates. On the upper part of the trunk and branches smooth to finally scaly. Greyish brown.