Instruct: Given a question, retrieve relevant passages that can help answer the question.
Query: How thick is the bark of a redwood tree?
Bark on mature redwood trees of coastal California can vary from 4 to 18 inches in thickness. Redwood bark is thick, stringy and tough; and can cause sawmill machinery to malfunction. Men called peelers removed bark from fallen trees in the woods through the early 20th century, but the process was dangerous and labor intensive. In the mid-20th century hydraulic barkers were built at several large sawmills including the Union Lumber Company at Fort Bragg, California, the Northern Redwood Company at Korbel, and the Pacific Lumber Company at Scotia, California. The last was featured in a popular sawmill tour.
Discovered in 1997 and located near one of the Big Brook tributaries, The Marlboro Tree, a massive black willow tree has been certified by the New Jersey Forest Service as a "State Champion" tree, signifying that it is the largest known tree of its species in the State of New Jersey, and the largest tree of any kind in Marlboro Township. It is about 152 years old and measures high and 19' 8" in circumference. Five grown people must hold hands to fully encircle the tree.
It is 22 metres high and 47 metres in circumference. The trunk diameter was 10.64 metres (only the Glencoe Baobab up to its 2009 split was larger), and the crown diameter is 30.2 metres. The trunk consists of two connected sections, each with its own enormous hollow, and these are connected by a narrow passage. One third of the Boabab tree collapsed in August 2016. This was ascribed to age and the natural hollowing of the trunk with time. The property owners intend to leave the fallen trunk section as it fell, allowing natural processes to reshape and assimilate the feature.
The fruits are up to 78mm (3″) wide and 85mm long, and can weigh as much as 260g.
The skin is a dark mahogany colour with russet freckles and small areas of rough skin. The flesh is a pale yellow or cream, tinged green under the skin.
In the U.S. Pacific Northwest, a major Christmas tree growing region, Douglas-fir has always been the primary species grown. A full one-half of all trees produced in the Pacific Northwest are Douglas-fir. Douglas-firs typically take five to seven years before they are mature enough to sell as Christmas trees. Also common in the region are noble fir, a tree which commands a higher price than Douglas-fir, and grand fir, which accounts for about 10 percent of the annual harvest in the Northwest. Other species collectively account for only 3–5 percent of the total Northwest harvest.
Angel Oak is a Southern live oak ("Quercus virginiana") located in Angel Oak Park on Johns Island near Charleston, South Carolina. The tree is estimated to be 400-500 years old. It stands 66.5 ft (20 m) tall, measures 28 ft (8.5 m) in circumference, and produces shade that covers 17,200 square feet (1,600 m). Its longest branch distance is 187 ft in length. Angel Oak was the 210th tree to be registered with the Live Oak Society.
The oak derives its name from the estate of Justus Angel and his wife, Martha Waight Tucker Angel. Local folklore tells stories of ghosts of former slaves appearing as angels around the tree.
The Angel Oak is a living Southern live oak tree located on Johns Island. Estimates of the tree's age range from 400 to 1500 years old. The oak is tall, with a trunk circumference of . In spite of the popular belief that the Angel Oak is the oldest tree east of the Mississippi River, there are many baldcypress trees throughout the south which are many hundreds of years older. The Angel Oak stands on part of the land given to Jacob Waight in 1717 as part of a land grant. The Angel Oak was acquired by the City of Charleston in 1991. Today, Angel Oak Park provides visitors a close look at the tree. The park area is complete with a gift shop and picnic tables.
Tropical evergreen forests (or "tropical rainforests") are usually found in areas receiving more than 234 cm of rainfall and having a monthly mean temperature of 20 °C or higher in the coldest months. They occupy about seven percent of the Earth's surface and harbour more than half of the planet's terrestrial plants and animals. Tropical evergreen forests are dense, multi-layered, and harbour many types of plants and animals. These forests are found in the areas receiving heavy rainfall (more than 200  cm annual rainfall). They are very dense. Even the sunlight does not reach the ground. Numerous species of trees are found in these forests. Different types of trees shed their leaves at different times of the year. Therefore, these forests always appear green and are known as evergreen forests. These forests are found in the Andaman and Nicobar Islands, along with the slopes of the Western Ghats and parts of Northeastern states of Assam, West Bengal and Odisha. These areas experience hot and humid climate with the short dry season. The important trees of these forests are rosewood, ebony and mahogany
As per the India State of Forest Report 2017, recorded forest area in the state is , while in 2013, forest area was , which was 18.93% of the state's geographical area, compared to the then national average of 21.23%. Reserves and protected and unclassed forests constitute 59.4%, 31.8%, and 8.9%, respectively, of forested areas, as of 2009. Part of the world's largest mangrove forest, the Sundarbans is located in southern West Bengal.
From a phytogeographic viewpoint, the southern part of West Bengal can be divided into two regions: the Gangetic plain and the littoral mangrove forests of the Sundarbans. The alluvial soil of the Gangetic plain, combined with favourable rainfall, makes this region especially fertile. Much of the vegetation of the western part of the state has similar species composition with the plants of the Chota Nagpur plateau in the adjoining state of Jharkhand. The predominant commercial tree species is "Shorea robusta", commonly known as the sal tree. The coastal region of Purba Medinipur exhibits coastal vegetation; the predominant tree is the "Casuarina". A notable tree from the Sundarbans is the ubiquitous "sundari" ("Heritiera fomes"), from which the forest gets its name.
The Marlboro Tree, located in Marlboro Township, New Jersey is certified by the State of New Jersey as the largest known example of this tree in the state. It is about 152 years old and measures in height and in circumference. Five grown people must hold hands to fully encircle the tree.
On 23 August 2010, the tree was blown down by high winds during a storm, breaking off approximately above ground. It fell across a garden wall and damaged garden sheds but did not damage anything else. The tree was estimated to be between 150 and 170 years old.
The life cycle of a Christmas tree from the seed to a tree takes, depending on species and treatment in cultivation, between 8 and 12 years. First, the seed is extracted from cones harvested from older trees. These seeds are then usually grown in nurseries and then sold to Christmas tree farms at an age of 3–4 years. The remaining development of the tree greatly depends on the climate, soil quality, as well as the cultivation and how the trees are tended by the Christmas tree farmer.
The "blade" of a cricket bat is a wooden block that is generally flat on the striking face and with a ridge on the reverse (back) which concentrates wood in the middle where the ball is generally hit. The bat is traditionally made from willow wood, specifically from a variety of white willow called cricket bat willow ("Salix alba" var. "caerulea"), treated with raw (unboiled) linseed oil, which has a protective function. This variety of willow is used as it is very tough and shock-resistant, not being significantly dented nor splintering on the impact of a cricket ball at high speed, while also being light in weight. The face of the bat is often covered with a protective film by the user.
The combination of form, needle retention, dark blue-green color, pleasant scent and excellent shipping characteristics has led to Fraser fir being a most popular Christmas tree species. Growing and harvesting this species for Christmas trees and boughs is a multimillion-dollar business in the southern Appalachians. North Carolina produces the majority of Fraser fir Christmas trees. It requires from 7 to 10 years in the field to produce a high tree. In 2005, the North Carolina General Assembly passed legislation making the Fraser fir the official Christmas tree of North Carolina.
Since the Ontario forests are so plentiful the wood resource would be sustainable for some time. Most companies are doing their own part to help ensure that there is enough lumber within Ontario to support numerous generations to come. Tembec Industries has invested a large amount of time and money into planting trees. Tembec recently celebrated their 250 millionth tree planted in Ontario. The Ontario Government’s land use strategy helps protect and sustain all of Ontario’s natural resources, including wood products. The Ontario Forest Accord provides security by forcing the forest industry and the environmental community to establish protected areas, while at the same time meeting the needs of the forestry industry.
Trees are either evergreen, having foliage that persists and remains green throughout the year, or deciduous, shedding their leaves at the end of the growing season and then having a dormant period without foliage. Most conifers are evergreens, but larches ("Larix" and "Pseudolarix") are deciduous, dropping their needles each autumn, and some species of cypress ("Glyptostrobus", "Metasequoia" and "Taxodium") shed small leafy shoots annually in a process known as cladoptosis. The crown is a name for the spreading top of a tree including the branches and leaves, while the uppermost layer in a forest, formed by the crowns of the trees, is known as the canopy. A sapling is a young tree.
The grey gum regenerates by regrowing from the base and branches after bushfire. Trees live for over a hundred years. The grey-headed flying fox ("Pteropus poliocephalus") eats the flowers, while the leaves form a staple of the diet of the koala ("Phascolarctos cinereus"). Leaves in winter contain less nitrogen than those in summer, which the koalas make up for by eating more in winter months. The brown-headed honeyeater ("Melithreptus brevirostris") and yellow-tufted honeyeater ("Lichenostomus melanops") have been observed eating gum exudate from the stems. 
Fieldwork at several sites around central New South Wales showed that the red wattlebird ("Anthochaera carunculata") and noisy friarbird ("Philemon corniculatus") preferred to forage on the foliage of the grey gum over other trees, with the former appearing to oust the latter if both species were present.
Blue-leaved stringybark is a koala food tree. A field study conducted in the Campbelltown district southwest of Sydney published in 2000 found that koalas preferred Blue-leaved Stringybark and Grey Gum but only when the two tree species were growing on shale-based rather than sandstone soils. Stringybarks are some of the most difficult of all eucalyptus plants to identify. However, the bluish colour of the leaves makes this species fairly easy to identify.
There are more than 20,000 North American Christmas tree growers, 95 percent of the trees they produce are sold or shipped directly from the farms. On each of the planted in Christmas trees annually there are usually about 2,000 trees, the number of trees that survive to harvest varies from 750–1,500 depending upon location. Christmas trees take an average of 6 to 10 years (from transplant) to mature for harvest and each year 73 million new Christmas trees are planted.
Named forests are found within eight distinct regions. These forests may also be part of ecosystems, a number of which extend south into the United States. For example, the Northern hardwood forest is an ecosystem located in large areas of southeastern and south central Canada as well as in Ontario and Quebec. This system extends south into the United States.
The Black Forest stretches from the High Rhine in the south to the in the north. In the west it is bounded by the Upper Rhine Plain (which, from a natural region perspective, also includes the low chain of foothills); in the east it transitions to the , and hill country west of the . The Black Forest is the highest part of the South German Scarplands and much of it is densely wooded, a fragment of the Hercynian Forest of Antiquity. It lies upon rocks of the crystalline basement and Bunter Sandstone, and its natural boundary with the surrounding landscapes is formed by the emergence of , which is absent from the Black Forest bedrock. Thanks to the fertility of the soil which is dependent on the underlying rock, this line is both a vegetation boundary as well as the border between the ("old settlement land") and the Black Forest, which was not permanently settled until the High Middle Ages. From north to south the Black Forest extends for over , attaining a width of up to 50 kilometres in the south, and up to 30 kilometres in the north (). Tectonically the range forms a lifted fault block, which rises prominently in the west from the Upper Rhine Plain, whilst seen from the east it has the appearance of a heavily forested plateau.
The desert bloodwood has a rough bark, which when penetrated oozes a thick red kino. Typical of desert flora, the tree has tough leathery leaves. Flowers appear during cooler months, producing pollen and nectar which is harvested by a variety of wildlife. The hard fruit produced by the tree is the gumnut. The tree generally grows 8 – 10 metres (30 feet) in height. 
Occasionally a bloodwood tree will shed a piece of bark, hence opening a "wound" through which a blood-like kino will flow. The sap flows until it crystallises, covering up the hole in the bark. Australian Aboriginals collect this substance as bush medicine. They apply the sticky gum directly to sores or cuts and it works as an antiseptic. If the sap is in a dried form, it can be crushed into powder and boiled in water to use as an antiseptic wash.
Bark: The bark of "Polylepis" consists of numerous layers of thin, dark red exfoliating sheets. In some cases, the layered bark can be more than an inch thick. A majority of the larger branches have similar shredding bark. It would seem that the bark serves as insulation from both the nightly frosts and the intense daytime irradiation. The thick bark of Polylepis also serves an important function as protection against fire. It is thought to originally have been a protection against epiphytic mosses, whose thick masses may damage trees by adding weight to the branches and providing a suitable environment for fungi which attack the trees.
Branching pattern and leaf arrangement: "Polylepis" trees tend to have twisted, crooked stems and branches with repeated sympodial branching. Contorted growth is often associated with windy, cold, or arid habitats. The leaves are generally congested along the branch tips often at the end of long, naked branch segments.
In 1931, Major Frederick Russell Burnham commissioned a survey near Bull Flat Creek in Humboldt County, a spot where League founder Madison Grant believed the world's tallest tree might be found. When the tree, a 364-foot redwood, was indeed found, the California State Park Commission dedicated the tree to the founders of the Save the Redwoods League on September 13, 1931: "As a living monument symbolizing eternal life and duration of our gratitude." Burnham lead the main address in which he declared: "It is an ancient and racial urge that has brought us together today in the shade of this far Western forest like the druids of old." The Founders Tree immediately became and remains the most visited spot in the redwoods region and the focus of many ceremonies. The height measurement has since been revised to 346.1 feet.
Heights of the tallest coast redwoods are measured yearly by experts. Even with recent discoveries of tall coast redwoods above , it is likely that no taller trees will be discovered.
Diameter stated is as measured at 1.4 m (about 4.5 ft) above average ground level (at breast height). Details of the precise locations for most tallest trees were not announced to the general public for fear of causing damage to the trees and the surrounding habitat. The tallest coast redwood easily accessible to the public is the Founders Tree in Humboldt Redwoods State Park, standing over 346 ft tall. A taller coast redwood is also accessible to the public in Tall Trees Grove of Redwood National Park.