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108-475: Most of the area is characterized by the forest -covered mountains of the Shan Hills which reach a height of 2,129 m (6,985 ft) at Loi Lan , a mountain rising at the southern end of the administrative area. The capital town is Langkho (Langhkö), located in the northern part. The township borders with Mae Hong Son Province of Thailand in the south. This Shan State location article

216-570: A Latinate word denoting a woodland, may be admitted; in a specific technical sense it is restricted to denoting the species of trees that comprise the woodlands of a region, as in its sense in the subject of silviculture . The resorting to sylva in English indicates more precisely the denotation that the use of forest intends. The first known forests on Earth arose in the Middle Devonian (approximately 390 million years ago ), with

324-652: A rip saw is the most common method, because sawing allows logs of lower quality, with irregular grain and large knots, to be used and is more economical. There are various types of sawing: Dimensional lumber is lumber that is cut to standardized width and depth, often specified in millimetres or inches (but see below for information on nominal dimensions vs. actual dimensions). Carpenters extensively use dimensional lumber in framing wooden buildings. Common sizes include 2×4 (pictured) (also two-by-four and other variants, such as four-by-two in Australia, New Zealand, and

432-462: A "class 1 flame spread rating of 25 or less, when tested in accordance with ASTM standard E 84," which means it burns more slowly than almost all treated wood lumber. A timber mark is a code beaten on to cut wood by a specially made hammer to show the logging licence. The basic understanding of lumber, or "sawn planks", came about in North America in the seventeenth century. Lumber is

540-400: A 1-inch-thick (25 mm) board, 8/4 (eight quarter) is a 2-inch-thick (51 mm) board, etc. This "quarter" system is rarely used for softwood lumber; although softwood decking is sometimes sold as 5/4, even though it is actually one inch thick (from milling 1 ⁄ 8  in or 3.2 mm off each side in a motorized planing step of production). The "quarter" system of reference is

648-534: A 10-foot-long (3.0 m) 2×4 ( 1 + 1 ⁄ 2 by 3 + 1 ⁄ 2  in or 38 by 89 mm) into two 1×4s ( 3 ⁄ 4 by 3 + 1 ⁄ 2  in or 19 by 89 mm) of the same length is considered re-sawing. Structural lumber may also be produced from recycled plastic and new plastic stock. Its introduction has been strongly opposed by the forestry industry. Blending fiberglass in plastic lumber enhances its strength, durability, and fire resistance. Plastic fiberglass structural lumber can have

756-464: A combination of measures aimed at increasing forest carbon stocks, andsustainable timber offtake will generate the largest carbon sequestration benefit. The term forest-dependent people is used to describe any of a wide variety of livelihoods that are dependent on access to forests, products harvested from forests, or ecosystem services provided by forests, including those of Indigenous peoples dependent on forests. In India , approximately 22 percent of

864-405: A different classification of forest vegetation is often used: tree, shrub, herb, and moss layers (see stratification (vegetation) ). Forests are classified differently and to different degrees of specificity. One such classification is in terms of the biomes in which they exist, combined with leaf longevity of the dominant species (whether they are evergreen or deciduous ). Another distinction

972-437: A few main pathways, including increase in commercial tree plantations, adoption of agroforestry techniques by small farmers, or spontaneous regeneration when former agricultural land is abandoned. It can be motivated by the economic benefits of forests, the ecosystem services forests provide, or cultural changes where people increasingly appreciate forests for their spiritual, aesthetic, or otherwise intrinsic value. According to

1080-511: 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 (10.0 billion acres; 40.6 million square kilometres; 15.7 million square miles), or approximately 31 percent of

1188-409: A forest may be of a great variety of species (as in tropical rainforests and temperate deciduous forests ), or relatively few species over large areas (e.g., taiga and arid montane coniferous forests). The biodiversity of forests also encompasses shrubs , herbaceous plants, mosses , ferns , lichens , fungi , and a variety of animals . Trees rising up to 35 meters (115 ft) in height add

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1296-550: A forested area by cutting or burning, either to harvest timber or to make way for farming. Most deforestation today occurs in tropical forests. The vast majority of this deforestation is because of the production of four commodities: wood , beef , soy , and palm oil . Over the past 2,000 years, the area of land covered by forest in Europe has been reduced from 80% to 34%. Large areas of forest have also been cleared in China and in

1404-472: A framer much time, because they are pre-cut by the manufacturer for use in 8-, 9-, and 10-foot ceiling applications, which means the manufacturer has removed a few inches or centimetres of the piece to allow for the sill plate and the double top plate with no additional sizing necessary. In the Americas, two-bys (2×4s, 2×6s, 2×8s, 2×10s, and 2×12s), named for traditional board thickness in inches, along with

1512-452: A legal term, as seen in Latin texts such as Magna Carta , to denote uncultivated land that was legally designated for hunting by feudal nobility (see royal forest ). These hunting forests did not necessarily contain any trees. Because that often included significant areas of woodland, "forest" eventually came to connote woodland in general, regardless of tree density. By the beginning of

1620-403: A locale with more open space between trees, and distinguish kinds of woodlands as open forests and closed forests , premised on their crown covers . Finally, sylva (plural sylvae or, less classically, sylvas ) is a peculiar English spelling of the Latin silva , denoting a "woodland", and has precedent in English, including its plural forms. While its use as a synonym of forest , and as

1728-583: A region, releasing water from their leaves in anticipation of seasonal rains to trigger the wet season early. Because of this, seasonal rainfall in the Amazon begins two to three months earlier than the climate would otherwise allow. Deforestation in the Amazon and anthropogenic climate change hold the potential to interfere with this process, causing the forest to pass a threshold where it transitions into savanna. Deforestation threatens many forest ecosystems. Deforestation occurs when humans remove trees from

1836-399: A relatively small set of specified lengths; in all cases hardwoods are sold to the consumer by the board-foot (144 cubic inches or 2,360 cubic centimetres), whereas that measure is not used for softwoods at the retailer (to the cognizance of the buyer). Also in North America, hardwood lumber is commonly sold in a "quarter" system, when referring to thickness; 4/4 (four quarter) refers to

1944-452: A timber is referred to as one "timber" (材), and the dimensions of other structural components were quoted in multiples of "timber"; thus, as the width of the actual timber varied, the dimensions of other components were easily calculated, without resorting to specific figures for each scale. The dimensions of timbers in similar applications show a gradual diminution from the Sui dynasty (580–618) to

2052-443: A traditional North American lumber industry nomenclature used specifically to indicate the thickness of rough sawn hardwood lumber. In rough-sawn lumber it immediately clarifies that the lumber is not yet milled, avoiding confusion with milled dimension lumber which is measured as actual thickness after machining. Examples – 3 ⁄ 4 -inch, 19 mm, or 1x. In recent years architects, designers, and builders have begun to use

2160-426: A unit of dimensional lumber is limited by the height and girth of the tree it is milled from. In general the maximum length is 24 ft (7.32 m). Engineered wood products, manufactured by binding the strands, particles, fibers, or veneers of wood, together with adhesives, to form composite materials, offer more flexibility and greater structural strength than typical wood building materials. Pre-cut studs save

2268-722: A vertical dimension to the area of land that can support plant and animal species, opening up numerous ecological niches for arboreal animal species, epiphytes , and various species that thrive under the regulated microclimate created under the canopy. Forests have intricate three-dimensional structures that increase in complexity with lower levels of disturbance and greater variety of tree species. The biodiversity of forests varies considerably according to factors such as forest type, geography, climate, and soils – in addition to human use. Most forest habitats in temperate regions support relatively few animal and plant species, and species that tend to have large geographical distributions, while

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2376-412: A wide range of characteristics. Generally, richer households derive more cash value from forest resources, whereas among poorer households, forest resources are more important for home consumption and increase community resilience. Forests are fundamental to the culture and livelihood of indigenous people groups that live in and depend on forests, many of which have been removed from and denied access to

2484-404: Is a stub . You can help Misplaced Pages by expanding it . Forest A forest is an ecosystem characterized by a dense community of 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

2592-401: Is based on tree densities measured on over 400,000 plots. It remains subject to a wide margin of error, not least because the samples are mainly from Europe and North America. Forests can also be classified according to the amount of human alteration. Old-growth forest contains mainly natural patterns of biodiversity in established seral patterns, and they contain mainly species native to

2700-543: Is critical, such as trusses , rafters , laminating stock, I-beams and web joints. Machine grading measures a characteristic such as stiffness or density that correlates with the structural properties of interest, such as bending strength . The result is a more precise understanding of the strength of each piece of lumber than is possible with visually graded lumber, which allows designers to use full-design strength and avoid overbuilding. In Europe, strength grading of rectangular sawn lumber/timber (both softwood and hardwood)

2808-633: Is done according to EN-14081 and commonly sorted into classes defined by EN-338. For softwoods, the common classes are (in increasing strength) C16, C18, C24, and C30. There are also classes specifically for hardwoods and those in most common use (in increasing strength) are D24, D30, D40, D50, D60, and D70. For these classes, the number refers to the required 5th percentile bending strength in newtons per square millimetre. There are other strength classes, including T-classes based on tension intended for use in glulam . Grading rules for African and South American sawn lumber have been developed by ATIBT according to

2916-630: Is high compared to other vegetation communities. Much of this biomass occurs below ground in the root systems and as partially decomposed plant detritus . The woody component of a forest contains lignin , which is relatively slow to decompose compared with other organic materials such as cellulose or carbohydrate. The world's forests contain about 606 gigatonnes of living biomass (above- and below-ground) and 59 gigatonnes of dead wood. The total biomass has decreased slightly since 1990, but biomass per unit area has increased. Forest ecosystems broadly differ based on climate ; latitudes 10° north and south of

3024-443: Is legally protected from resource development. Much more forest land—about 40 percent of the total forest land base—is subject to varying degrees of protection through processes such as integrated land use planning or defined management areas, such as certified forests. Timber Lumber is wood that has been processed into uniform and useful sizes (dimensional lumber), including beams and planks or boards . Lumber

3132-670: Is mainly used for construction framing , as well as finishing (floors, wall panels , window frames ). Lumber has many uses beyond home building. Lumber is referred to as timber in the United Kingdom, Europe, Australia, and New Zealand, while in other parts of the world (mainly the United States and Canada) the term timber refers specifically to unprocessed wood fiber , such as cut logs or standing trees that have yet to be cut. Lumber may be supplied either rough- sawn , or surfaced on one or more of its faces. Rough lumber

3240-406: Is minimally 1 + 1 ⁄ 2 by 3 + 1 ⁄ 2 inches (38 mm × 89 mm). As previously noted, less wood is needed to produce a given finished size than when standards called for the green lumber to be the full nominal dimension. However, even the dimensions for finished lumber of a given nominal size have changed over time. In 1910, a typical finished 1-inch (25 mm) board

3348-559: Is more commonly made from softwood than hardwoods, and 80% of lumber comes from softwood. In the United States and Canada, milled boards are called lumber , while timber describes standing or felled trees. In contrast, in Britain, and some other Commonwealth nations and Ireland, the term timber is used in both senses. (In the UK, the word lumber is rarely used in relation to wood and has several other meanings.) Re-manufactured lumber

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3456-543: Is not on track to meet the target of the United Nations Strategic Plan for Forests to increase forest area by 3 percent by 2030. While deforestation is taking place in some areas, new forests are being established through natural expansion or deliberate efforts in other areas. As a result, the net loss of forest area is less than the rate of deforestation; and it, too, is decreasing: from 7.8 million hectares (19 million acres) per year in

3564-603: Is required. Under the prescription of the Method of Construction (營造法式) issued by the Song dynasty government in the early twelfth century, timbers were standardized to eight cross-sectional dimensions. Regardless of the actual dimensions of the timber, the ratio between width and height was maintained at 1:1.5. Units are in Song dynasty inches (31.2 mm). Timber smaller than the 8th class were called "unclassed" (等外). The width of

3672-459: Is smaller than the nominal dimensions because modern technology makes it possible to use the logs more efficiently. For example, a "2×4" board historically started out as a green, rough board actually 2 by 4 inches (51 mm × 102 mm). After drying and planing, it would be smaller by a nonstandard amount. Today, a "2×4" board starts out as something smaller than 2 inches by 4 inches and not specified by standards, and after drying and planing

3780-422: Is still continued in some places. Otherwise, logs were sawn using a two-person whipsaw, or pit-saw, using saddleblocks to hold the log, and a pit for the pitman who worked below. In 1420 the island of Madeira  – an archipelago comprising four islands off the northwest coast of Africa and an autonomous region of Portugal – was discovered. King Henry VI sent settlers to Madeira and

3888-428: Is that forests can turn from a carbon sink to a carbon source if plant diversity, density or forest area decreases, as has been observed in different tropical forests The typical tropical forest may become a carbon source by the 2060s. An assessment of European forests found early signs of carbon sink saturation, after decades of increasing strength. The Intergovernmental Panel on Climate Change (IPCC) concluded that

3996-526: Is the raw material for furniture-making, and manufacture of other items requiring cutting and shaping. It is available in many species, including hardwoods and softwoods , such as white pine and red pine , because of their low cost. Finished lumber is supplied in standard sizes, mostly for the construction industry – primarily softwood , from coniferous species, including pine , fir and spruce (collectively spruce-pine-fir ), cedar , and hemlock , but also some hardwood, for high-grade flooring. It

4104-437: Is the result of secondary or tertiary processing of previously milled lumber. Specifically, it refers to lumber cut for industrial or wood-packaging use. Lumber is cut by ripsaw or resaw to create dimensions that are not usually processed by a primary sawmill . Re-sawing is the splitting of 1-to-12-inch (25–305 mm) hardwood or softwood lumber into two or more thinner pieces of full-length boards. For example, splitting

4212-605: Is well utilised in the construction industry. Attempts to maintain lumber quality over time have been challenged by historical changes in the timber resources of the United States – from the slow-growing virgin forests common over a century ago to the fast-growing plantations now common in today's commercial forests. Resulting declines in lumber quality have been of concern to both the lumber industry and consumers and have caused increased use of alternative construction products. Machine stress-rated and machine-evaluated lumber are readily available for end-uses where high strength

4320-416: Is whether the forests are composed predominantly of broadleaf trees, coniferous (needle-leaved) trees, or mixed. The number of trees in the world, according to a 2015 estimate, is 3 trillion, of which 1.4 trillion are in the tropics or sub-tropics, 0.6 trillion in the temperate zones, and 0.7 trillion in the coniferous boreal forests. The 2015 estimate is about eight times higher than previous estimates, and

4428-517: The American Lumber Standard Committee , appointed by the U.S. Secretary of Commerce . Design values for most species and grades of visually graded structural products are determined in accordance with ASTM standards, which consider the effect of strength reducing characteristics, load duration, safety, and other influencing factors. The applicable standards are based on results of tests conducted in cooperation with

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4536-728: The American colonies began in 1607 when the Jamestown settlers cut timber to build the first settlement in the new world. America's first sawmill was built at the Falls of Piscatauqua , on the line between the Province of Maine and the Province of New Hampshire , in 1634. Unauthenticated records, however, claim that as early as 1633 several mills were operating in New Netherland . The American colonies were essential to England in

4644-606: The Equator , and temperate forests at the middle latitudes . Forests form in areas of the Earth with high rainfall, while drier conditions produce a transition to savanna . However, in areas with intermediate rainfall levels, forest transitions to savanna rapidly when the percentage of land that is covered by trees drops below 40 to 45 percent. Research conducted in the Amazon rainforest shows that trees can alter rainfall rates across

4752-651: The Medieval Latin foresta , denoting "open wood", Carolingian scribes first used foresta in the capitularies of Charlemagne , specifically to denote the royal hunting grounds of the king. The word was not endemic to the Romance languages , e.g., native words for forest in the Romance languages derived from the Latin silva , which denoted "forest" and " wood(land) " ( cf. the English sylva and sylvan ;

4860-592: The Proto-Germanic * furhísa- , * furhíþija- , denoting "a fir-wood , coniferous forest", from the Proto-Indo-European * perk u- , denoting "a coniferous or mountain forest , wooded height" all attest to the Frankish * forhist . Uses of forest in English to denote any uninhabited and unenclosed area are presently considered archaic. The Norman rulers of England introduced the word as

4968-554: The Special Report on Global Warming of 1.5 °C of the Intergovernmental Panel on Climate Change , to avoid temperature rise by more than 1.5 degrees above pre-industrial levels, there will need to be an increase in global forest cover equal to the land area of Canada (10 million square kilometres (3.9 million square miles)) by 2050. China instituted a ban on logging, beginning in 1998, due to

5076-558: The USDA Forest Products Laboratory. Design Values for Wood Construction, which is a supplement to the ANSI/AF&;PA National Design Specification® for Wood Construction, provides these lumber design values, which are recognized by the model building codes. Canada has grading rules that maintain a standard among mills manufacturing similar woods to assure customers of uniform quality. Grades standardize

5184-592: The World Resources Institute recorded that only 20% of the world's original forests remained in large intact tracts of undisturbed forest. More than 75% of these intact forests lie in three countries: the boreal forests of Russia and Canada, and the rainforest of Brazil. According to Food and Agriculture Organization 's (FAO) Global Forest Resources Assessment 2020 , an estimated 420 million hectares (1.0 billion acres) of forest have been lost worldwide through deforestation since 1990, but

5292-418: The boreal region and in the seasonally dry tropics. At high latitudes, north of the main zone of boreal forestland, growing conditions are not adequate to maintain a continuously closed forest cover , so tree cover is both sparse and discontinuous. This vegetation is variously called open taiga , open lichen woodland, and forest tundra. A savanna is a mixed woodland – grassland ecosystem characterized by

5400-407: The equator are mostly covered in tropical rainforest , and the latitudes between 53°N and 67°N have boreal forest . As a general rule, forests dominated by angiosperms ( broadleaf forests ) are more species-rich than those dominated by gymnosperms ( conifer , montane , or needleleaf forests ), although exceptions exist. The trees that form the principal structural and defining component of

5508-408: The slash and burn practices of swidden agriculture or shifting cultivation . The loss and re-growth of forests lead to a distinction between two broad types of forest: primary or old-growth forest and secondary forest . There are also many natural factors that can cause changes in forests over time, including forest fires , insects , diseases , weather, competition between species, etc. In 1997,

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5616-404: The "quarter" system in specifications as a vogue of insider knowledge, though the materials being specified are finished lumber, thus conflating the separate systems and causing confusion. Hardwoods cut for furniture are cut in the fall and winter, after the sap has stopped running in the trees. If hardwoods are cut in the spring or summer the sap ruins the natural color of the lumber and decreases

5724-429: The 1990s to 4.7 million hectares (12 million acres) per year during 2010–2020. In absolute terms, the global forest area decreased by 178 million hectares (440 million acres; 1,780,000 square kilometres; 690,000 square miles) between 1990 and 2020, which is an area about the size of Libya. Forests provide a diversity of ecosystem services including: The main ecosystem services can be summarized in

5832-521: The 1990s. In 2015, a study for Nature Climate Change showed that the trend has recently been reversed, leading to an "overall gain" in global biomass and forests. This gain is due especially to reforestation in China and Russia. New forests are not equivalent to old growth forests in terms of species diversity, resilience, and carbon capture. On 7 September 2015, the FAO released a new study stating that over

5940-409: The 4×4 (89 mm × 89 mm), are common lumber sizes used in modern construction. They are the basic building blocks for such common structures as balloon-frame or platform-frame housing. Dimensional lumber made from softwood is typically used for construction, while hardwood boards are more commonly used for making cabinets or furniture. Lumber's nominal dimensions are larger than

6048-459: The Earth's plant biomass . Net primary production is estimated at 21.9 gigatonnes of biomass per year for tropical forests , 8.1 for temperate forests , and 2.6 for boreal forests . Forests form distinctly different biomes at different latitudes and elevations, and with different precipitation and evapotranspiration rates. These biomes include boreal forests in subarctic climates, tropical moist forests and tropical dry forests around

6156-725: The Italian, Spanish, and Portuguese selva ; the Romanian silvă ; the Old French selve ). Cognates of forest in Romance languages—e.g., the Italian foresta , Spanish and Portuguese floresta , etc.—are all ultimately derivations of the French word. The precise origin of Medieval Latin foresta is obscure. Some authorities claim the word derives from the Late Latin phrase forestam silvam , denoting "the outer wood"; others claim

6264-452: The U.S. state of Wisconsin , forests managed by indigenous people have more plant diversity, fewer invasive species, higher tree regeneration rates, and higher volume of trees. Forest management has changed considerably over the last few centuries, with rapid changes from the 1980s onward, culminating in a practice now referred to as sustainable forest management . Forest ecologists concentrate on forest patterns and processes, usually with

6372-828: The UK), 2×6 , and 4×4 . The length of a board is usually specified separately from the width and depth. It is thus possible to find 2×4s that are four, eight, and twelve feet in length. In Canada and the United States, the standard lengths of lumber are 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24 feet (1.8, 2.4, 3.0, 3.7, 4.3, 4.9, 5.5, 6.1, 6.7 and 7.3 m). For wall framing, precut "stud" lengths are available, and are commonly used. For ceilings heights of 8, 9 or 10 feet (2.4, 2.7 or 3.0 m), studs are available in 92 + 5 ⁄ 8 inches (2.35 m), 104 + 5 ⁄ 8 inches (2.66 m), and 116 + 5 ⁄ 8 inches (2.96 m). The length of

6480-509: The United States began with the publication of the American Lumber Standard in 1924, which set specifications for lumber dimensions, grade, and moisture content; it also developed inspection and accreditation programs. These standards have changed over the years to meet the changing needs of manufacturers and distributors, with the goal of keeping lumber competitive with other construction products. Current standards are set by

6588-422: The actual standard dimensions of finished lumber. Historically, the nominal dimensions were the size of the green (not dried), rough (unfinished) boards that eventually became smaller finished lumber through drying and planing (to smooth the wood). Today, the standards specify the final finished dimensions and the mill cuts the logs to whatever size it needs to achieve those final dimensions. Typically, that rough cut

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6696-460: The aim of elucidating cause-and-effect relationships. Foresters who practice sustainable forest management focus on the integration of ecological, social, and economic values, often in consultation with local communities and other stakeholders . Humans have generally decreased the amount of forest worldwide. Anthropogenic factors that can affect forests include logging, urban sprawl , human-caused forest fires , acid rain , invasive species , and

6804-420: The basis of the variation of physiognomy corresponding to changes in altitude. Tropical dry forests are characteristic of areas in the tropics affected by seasonal drought. The seasonality of rainfall is usually reflected in the deciduousness of the forest canopy, with most trees being leafless for several months of the year. Under some conditions, such as less fertile soils or less predictable drought regimes,

6912-590: The canopy; but other taxa are also important. In the Southern Hemisphere , most coniferous trees (members of Araucariaceae and Podocarpaceae ) occur mixed with broadleaf species, and are classed as broadleaf-and-mixed forests. Temperate broadleaf and mixed forests include a substantial component of trees of the Anthophyta group. They are generally characteristic of the warmer temperate latitudes, but extend to cool temperate ones, particularly in

7020-423: The children live. Canada has about 4 million square kilometres (1.5 million square miles) of forest land. More than 90% of forest land is publicly owned and about 50% of the total forest area is allocated for harvesting. These allocated areas are managed using the principles of sustainable forest management, which include extensive consultation with local stakeholders. About eight percent of Canada's forest

7128-402: The conversion of log timber into planks 30 times faster than previously. The circular saw, as used in modern sawmills, was invented by an Englishman named Miller in 1777. It was not until the nineteenth century, however, that it was generally applied, and its great work belongs to that period. The first insertable teeth for this saw were invented by W. Kendal, an American, in 1826. Logging in

7236-408: The countries with significant sawmilling industries. Historical wood-frame home building regions are: Europe, North America, Japan. Different areas of the world are recognized as significant timber suppliers; however, these areas (Indonesia, Sarawak, New Guinea, etc.) are exporters of raw logs and do not have a significant domestic lumber producing industry. The largest lumber manufacturing regions in

7344-517: The cutoff points are between a forest, woodland , and savanna . Under some definitions, to be considered a forest requires very high levels of tree canopy cover, from 60% to 100%, which excludes woodlands and savannas, which have a lower canopy cover . Other definitions consider savannas to be a type of forest, and include all areas with tree canopies over 10%. Some areas covered with trees are legally defined as agricultural areas, for example Norway spruce plantations, under Austrian forest law, when

7452-418: The density of trees, area of tree canopy cover, or area of the land occupied by the cross-section of tree trunks ( basal area ) meeting a particular threshold. This type of definition depends upon the presence of trees sufficient to meet the threshold, or at least of immature trees that are expected to meet the threshold once they mature. Under land-cover definitions, there is considerable variation on where

7560-411: The eastern United States , in which only 0.1% of land was left undisturbed. Almost half of Earth's forest area (49 percent) is relatively intact, while 9 percent is found in fragments with little or no connectivity. Tropical rainforests and boreal coniferous forests are the least fragmented, whereas subtropical dry forests and temperate oceanic forests are among the most fragmented. Roughly 80 percent of

7668-522: The erosion and flooding that it caused. In addition, ambitious tree-planting programmes in countries such as China, India, the United States, and Vietnam – combined with natural expansion of forests in some regions – have added more than 7 million hectares (17 million acres) of new forests annually. As a result, the net loss of forest area was reduced to 5.2 million hectares (13 million acres) per year between 2000 and 2010, down from 8.3 million hectares (21 million acres) annually in

7776-465: The evolution of cladoxylopsid plants like Calamophyton . Appeared in the Late Devonian , Archaeopteris was both tree-like and fern -like plant, growing to 20 metres (66 ft) in height or more. It quickly spread throughout the world, from the equator to subpolar latitudes. It is the first species known to cast shade due to its fronds and forming soil from its roots. Archaeopteris

7884-417: The forest ecosystem. Since 2002, the amount of land that is legally owned by or designated for indigenous peoples has broadly increased, but land acquisition in lower-income countries by multinational corporations, often with little or no consultation of indigenous peoples, has also increased. Research in the Amazon rainforest suggests that indigenous methods of agroforestry form reservoirs of biodiversity. In

7992-415: The fourteenth century, English texts used the word in all three of its senses: common, legal, and archaic. Other English words used to denote "an area with a high density of trees" are firth , frith , holt , weald , wold , wood , and woodland . Unlike forest , these are all derived from Old English and were not borrowed from another language. Some present classifications reserve woodland for denoting

8100-542: The higher latitudes of the Northern Hemisphere , as well as some warm temperate areas, especially on nutrient-poor or otherwise unfavourable soils. These forests are composed entirely, or nearly so, of coniferous species ( Coniferophyta ). In the Northern Hemisphere, pines Pinus , spruces Picea , larches Larix , firs Abies , Douglas firs Pseudotsuga , and hemlocks Tsuga make up

8208-469: The lands on which they lived as part of global colonialism . Indigenous lands contain 36% or more of intact forest worldwide, host more biodiversity, and experience less deforestation. Indigenous activists have argued that degradation of forests and indigenous peoples' marginalization and land dispossession are interconnected. Other concerns among indigenous peoples include lack of Indigenous involvement in forest management and loss of knowledge related for

8316-493: The last 25 years the global deforestation rate has decreased by 50% due to improved management of forests and greater government protection. There is an estimated 726 million hectares (1.79 billion acres) of forest in protected areas worldwide. Of the six major world regions, South America has the highest share of forests in protected areas, at 31 percent. The area of such areas globally has increased by 191 million hectares (470 million acres) since 1990, but

8424-543: The modern era; a 1st class timber during the Sui was reconstructed as 15×10 (Sui dynasty inches, or 29.4 mm). Defects occurring in lumber are grouped into the following four divisions: During the process of converting timber to commercial forms of lumber the following defects may occur: Fungi attack wood (both timber and lumber) when these conditions are all present: Wood with less than 25% moisture (dry weight basis) can remain free of decay for centuries. Similarly, wood submerged in water may not be attacked by fungi if

8532-991: The montane forests of Africa, South America, Southeast Asia, and lowland forests of Australia, coastal Brazil, the Caribbean islands, Central America, and insular Southeast Asia have many species with small geographical distributions. Areas with dense human populations and intense agricultural land use, such as Europe, parts of Bangladesh, China, India, and North America, are less intact in terms of their biodiversity. Northern Africa, southern Australia, coastal Brazil, Madagascar, and South Africa are also identified as areas with striking losses in biodiversity intactness. A forest consists of many components that can be broadly divided into two categories: biotic (living) and abiotic (non-living). The living parts include trees , shrubs , vines , grasses and other herbaceous (non-woody) plants, mosses , algae , fungi , insects , mammals , birds , reptiles , amphibians , and microorganisms living on

8640-491: The most common and widely used method of sawing logs. Plain sawn lumber is produced by making the first cut on a tangent to the circumference of the log. Each additional cut is then made parallel to the one before. This method produces the widest possible boards with the least amount of log waste. Lumber manufacturing globally is determined by the preferred style of building; areas with a "wood building culture" (homes were built from wood rather than other materials like brick) are

8748-530: The next table: Some researchers state that forests do not only provide benefits, but can in certain cases also incur costs to humans. Forests may impose an economic burden, diminish the enjoyment of natural areas, reduce the food-producing capacity of grazing land and cultivated land, reduce biodiversity, reduce available water for humans and wildlife, harbour dangerous or destructive wildlife, and act as reservoirs of human and livestock disease. An important consideration regarding carbon sequestration

8856-411: The plants and animals and in the soil, connected by mycorrhizal networks . The main layers of all forest types are the forest floor , the understory, and the canopy. The emergent layer, above the canopy, exists in tropical rainforests. Each layer has a different set of plants and animals, depending upon the availability of sunlight, moisture, and food. In botany and countries like Germany and Poland,

8964-512: The population belongs to forest-dependent communities, which live in close proximity to forests and practice agroforestry as a principal part of their livelihood. People of Ghana who rely on timber and bushmeat harvested from forests and Indigenous peoples of the Amazon rainforest are also examples of forest-dependent people. Though forest-dependence by more common definitions is statistically associated with poverty and rural livelihoods, elements of forest-dependence exist in communities with

9072-615: The proportion of evergreen species increases and the forests are characterised as " sclerophyllous ". Thorn forest , a dense forest of low stature with a high frequency of thorny or spiny species, is found where drought is prolonged, and especially where grazing animals are plentiful. On very poor soils, and especially where fire or herbivory are recurrent phenomena, savannas develop. Sparse trees and savanna are forests with sparse tree- canopy cover. They occur principally in areas of transition from forested to non-forested landscapes. The two major zones in which these ecosystems occur are in

9180-505: The quality of lumber at different levels and are based on moisture content, size, and manufacture at the time of grading, shipping, and unloading by the buyer. The National Lumber Grades Authority (NLGA) is responsible for writing, interpreting and maintaining Canadian lumber grading rules and standards. The Canadian Lumber Standards Accreditation Board (CLSAB) monitors the quality of Canada's lumber grading and identification system. Their common grade abbrievation, CLS, Canadian Lumber Standard

9288-428: The rate of forest loss has declined substantially. In the most recent five-year period (2015–2020), the annual rate of deforestation was estimated at 10 million hectares (25 million acres), down from 12 million hectares (30 million acres) annually in 2010–2015. The transition of a region from forest loss to net gain in forested land is referred to as the forest transition. This change occurs through

9396-465: The rate of annual increase slowed in 2010–2020. Smaller areas of woodland in cities may be managed as urban forestry , sometimes within public parks. These are often created for human benefits; Attention Restoration Theory argues that spending time in nature reduces stress and improves health, while forest schools and kindergartens help young people to develop social as well as scientific skills in forests. These typically need to be close to where

9504-460: The region and habitat. In contrast, secondary forest is forest regrowing following timber harvest and may contain species originally from other regions or habitats. Different global forest classification systems have been proposed, but none has gained universal acceptance. UNEP - WCMC 's forest category classification system is a simplification of other, more complex systems (e.g. UNESCO 's forest and woodland 'subformations'). This system divides

9612-672: The role of supplier of lumber for the British fleet. By the 1790s, New England was exporting 36 million feet of pine boards and at least 300 ship masts per year to the British Empire. The timber supply began to dwindle at the start of the twentieth century due to significant harvest volumes, so the logging industry was forced to seek timber elsewhere; hence, the expansion into the American West. Logs are converted into lumber by being sawn, hewn , or split . Sawing with

9720-525: The rules of the Sciages Avivés Tropicaux Africains (SATA) and is based on clear cuttings – established by the percentage of the clear surface. In North America, market practices for dimensional lumber made from hardwoods varies significantly from the regularized standardized ' dimension lumber ' sizes used for sales and specification of softwoods – hardwood boards are often sold totally rough cut, or machine planed only on

9828-501: The settlers started clearing the huge expanses of forest in order to grow crops. Felled trees were made into planks by water-powered mills and the timber (cedar and yew) was shipped to Portugal and Spain. About 1427, the first sawmill in Germany was built. Cornelis Corneliszoon (or Krelis Lootjes) was a Dutch windmill owner from Uitgeest who invented the first mechanical sawmill, which was wind-powered, on 15 December 1593. This made

9936-616: The southern hemisphere. They include such forest types as the mixed deciduous forests of the United States and their counterparts in China and Japan; the broadleaf evergreen rainforests of Japan, Chile , and Tasmania ; the sclerophyllous forests of Australia, central Chile, the Mediterranean , and California; and the southern beech Nothofagus forests of Chile and New Zealand. There are many different types of tropical moist forests , with lowland evergreen broad-leaf tropical rainforests : for example várzea and igapó forests and

10044-690: The terra firme forests of the Amazon Basin ; the peat swamp forests ; dipterocarp forests of Southeast Asia ; and the high forests of the Congo Basin . Seasonal tropical forests , perhaps the best description for the colloquial term " jungle ", typically range from the rainforest zone 10 degrees north or south of the equator , to the Tropic of Cancer and Tropic of Capricorn . Forests located on mountains are also included in this category, divided largely into upper and lower montane formations, on

10152-476: The trees are being grown as Christmas trees and are below a certain height. The word forest derives from the Old French forest (also forès ), denoting "forest, vast expanse covered by trees"; forest was first introduced into English as the word denoting wild land set aside for hunting without necessarily having trees on the land. Possibly a borrowing, probably via Frankish or Old High German , of

10260-425: 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 that consists primarily of grasses. Savannas maintain an open canopy despite a high tree density. Forest plantations are generally intended for the production of timber and pulpwood . Commonly mono-specific, planted with even spacing between

10368-403: The trees, and intensively managed, these forests are generally important as habitat for native biodiversity . Some are managed in ways that enhance their biodiversity protection functions and can provide ecosystem services such as nutrient capital maintenance, watershed and soil structure protection and carbon storage. The annual net loss of forest area has decreased since 1990, but the world

10476-453: The two (broader) face sides. When hardwood boards are also supplied with planed faces, it is usually both by random widths of a specified thickness (normally matching milling of softwood dimensional lumber) and somewhat random lengths. But besides those older (traditional and normal) situations, in recent years some product lines have been widened to also market boards in standard stock sizes; these usually retail in big-box stores and using only

10584-505: The type of vegetation that grows upon the land; an area can be legally designated "forest" even if no trees grow on it. Land-use definitions are based on the primary purpose the land is used for. Under a land-use definition, any area used primarily for harvesting timber, including areas that have been cleared by harvesting, disease, fire, or for the construction of roads and infrastructure, are still defined as forests, even if they contain no trees. Land-cover definitions define forests based upon

10692-459: The value of the wood for furniture. Engineered lumber is lumber created by a manufacturer and designed for a certain structural purpose. The main categories of engineered lumber are: In the United States, pilings are mainly cut from southern yellow pines and Douglas-fir . Treated pilings are available in chromated copper arsenate retentions of 0.60, 0.80 and 2.50 pounds per cubic foot (9.6, 12.8 and 40.0 kg/m ) if treatment

10800-626: The word forest is commonly used, there is no universally recognised precise definition, with more than 800 definitions of forest used around the world. Although a forest is usually defined by the presence of trees, under many definitions an area completely lacking trees may still be considered a forest if it grew trees in the past, will grow trees in the future, or was legally designated as a forest regardless of vegetation type. There are three broad categories of definitions of forest in use: administrative, land use , and land cover . Administrative definitions are legal designations, and may not reflect

10908-461: The word is a Latinisation of the Frankish * forhist , denoting "forest, wooded country", and was assimilated to forestam silvam , pursuant to the common practice of Frankish scribes. The Old High German forst denoting "forest"; Middle Low German vorst denoting "forest"; Old English fyrhþ denoting "forest, woodland, game preserve, hunting ground" (English frith ); and Old Norse fýri , denoting " coniferous forest "; all of which derive from

11016-424: The world are: China (18%); United States (17%); Canada (10%); Russia (9%); Germany (5%); Sweden (4%). In early periods of society, to make wood for building, the trunks of trees were split with wedges into as many and as thin pieces as possible. If it was necessary to have them still thinner, they were hewn, by some sharp instrument, on both sides, to the proper size. This simple but wasteful manner of making boards

11124-579: The world's forest area is found in patches larger than 1 million hectares (2.5 million acres). The remaining 20 percent is located in more than 34 million patches around the world – the vast majority less than 1,000 hectares (2,500 acres) in size. Human society and forests can affect one another positively or negatively. Forests provide ecosystem services to humans and serve as tourist attractions. Forests can also affect people's health. Human activities, including unsustainable use of forest resources, can negatively affect forest ecosystems. Although

11232-416: The world's forests into 26 major types, which reflect climatic zones as well as the principal types of trees. These 26 major types can be reclassified into 6 broader categories: temperate needleleaf, temperate broadleaf and mixed, tropical moist, tropical dry, sparse trees and parkland, and forest plantations. Each category is described in a separate section below. Temperate needleleaf forests mostly occupy

11340-420: The world's land area in 2020. Forests are the largest terrestrial ecosystems of Earth by area, and are found around the globe. 45 percent of forest land is in the tropical latitudes . The next largest share of forests are found in subarctic climates , followed by temperate , and subtropical zones. Forests account for 75% of the gross primary production of the Earth's biosphere , and contain 80% of

11448-525: Was 13 ⁄ 16  in (21 mm). In 1928, that was reduced by 4%, and yet again by 4% in 1956. In 1961, at a meeting in Scottsdale, Arizona, the Committee on Grade Simplification and Standardization agreed to what is now the current U.S. standard: in part, the dressed size of a 1-inch (nominal) board was fixed at 3 ⁄ 4  inch; while the dressed size of 2 inch (nominal) lumber

11556-436: Was deciduous , dropping its fronds onto the forest floor, the shade, soil, and forest duff from the dropped fronds creating the early forest. The shed organic matter altered the freshwater environment, slowing its flow and providing food. This promoted freshwater fish. Forests account for 75% of the gross primary productivity of the Earth's biosphere , and contain 80% of the Earth's plant biomass. Biomass per unit area

11664-516: Was reduced from 1 + 5 ⁄ 8  inch to the current 1 + 1 ⁄ 2  inch. Dimensional lumber is available in green, unfinished state, and for that kind of lumber, the nominal dimensions are the actual dimensions. Individual pieces of lumber exhibit a wide range in quality and appearance with respect to knots, slope of grain, shakes and other natural characteristics. Therefore, they vary considerably in strength, utility, and value. The move to set national standards for lumber in

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