Hardwood

Hardwood is wood from dicot trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood contrasts with softwood (which is from gymnosperm trees).

Fagus wood
Beech is a popular hardwood

Characteristics

Hard Soft Wood
SEM images showing the presence of pores in hardwoods (oak, top) and absence in softwoods (pine, bottom)

Hardwoods are produced by angiosperm trees that reproduce by flowers, and have broad leaves. Many species are deciduous. Those of temperate regions lose their leaves every autumn as temperatures fall and are dormant in the winter, but those of tropical regions may shed their leaves in response to seasonal or sporadic periods of drought. Hardwood from deciduous species, such as oak, normally shows annual growth rings, but these may be absent in some tropical hardwoods.

Hardwoods have a more complex structure than softwoods and are often much slower growing as a result. The dominant feature separating "hardwoods" from softwoods is the presence of pores, or vessels.[1] The vessels may show considerable variation in size, shape of perforation plates (simple, scalariform, reticulate, foraminate), and structure of cell wall, such as spiral thickenings.

As the name suggests, the wood from these trees is generally harder than that of softwoods, but there are significant exceptions. In both groups there is an enormous variation in actual wood hardness, with the range in density in hardwoods completely including that of softwoods; some hardwoods (e.g., balsa) are softer than most softwoods, while yew is an example of a hard softwood.

Applications

Hardwoods are employed in a large range of applications, including fuel, tools, construction, boat building, furniture making, musical instruments, flooring, cooking, barrels, and manufacture of charcoal. Solid hardwood joinery tends to be expensive compared to softwood. In the past, tropical hardwoods were easily available, but the supply of some species, such as Burma teak and mahogany, is now becoming scarce due to over-exploitation. Cheaper "hardwood" doors, for instance, now consist of a thin veneer bonded to a core of softwood, plywood or medium-density fibreboard (MDF). Hardwoods may be used in a variety of objects, but are most frequently seen in furniture or musical instruments because of their density which adds to durability, appearance, and performance. Different species of hardwood lend themselves to different end uses or construction processes. This is due to the variety of characteristics apparent in different timbers, including density, grain, pore size, growth and fibre pattern, flexibility and ability to be steam bent. For example, the interlocked grain of elm wood (Ulmus spp.) makes it suitable for the making of chair seats where the driving in of legs and other components can cause splitting in other woods.

Cooking

There is a correlation between density and calories/volume. This makes the denser hardwoods like oak, cherry, and apple more suited for camp fires, cooking fires, and smoking meat, as they tend to burn hotter and longer than softwoods like pine or cedar whose low-density construction and highly-flammable sap make them burn quickly and without producing quite as much heat.

See also

References

  1. ^ CRC Handbook of Materials Science, Vol IV, pg 15

Further reading

  • Schweingruber, F.H. (1990) Anatomie europäischer Hölzer—Anatomy of European woods. Eidgenössische Forschungsanstalt für Wald, Schnee und Landscaft, Birmensdorf (Hrsg,). Haupt, Bern und Stuttgart.
  • Timonen, Tuuli (2002). Introduction to Microscopic Wood Identification. Finnish Museum of Natural History, University of Helsinki.
  • Wilson, K., and D.J.B. White (1986). The Anatomy of Wood: Its Diversity and variability. Stobart & Son Ltd, London.

External links

Ballroom

A ballroom or ballhall is a large room inside a building, the primary purpose of which is holding large formal parties called balls. Traditionally, most balls were held in private residences; many mansions contain one or more ballrooms. In other large houses, a large room such as the main drawing room, long gallery, or hall may double as a ballroom, but a good ballroom should have the right type of flooring, such as hardwood flooring or stone flooring (usually marble). In later times the term ballroom has been used to describe nightclubs where customers dance, the Top Rank Suites in the United Kingdom for example were also often referred to as ballrooms. The phrase "having a ball" has grown to encompass many events where person(s) are having fun, not just dancing.

Ballrooms are generally quite large, and may have ceilings higher than other rooms in the same building. The large amount of space for dancing, as well as the highly formal tone of events have given rise to ballroom dancing. The largest balls are now nearly always held in public buildings, and many hotels have a ballroom. They are also designed large to help the sound of orchestras carry well throughout the whole room.

A special case is the annual Vienna Opera Ball, where, just for one night, the auditorium of the Vienna State Opera is turned into a large ballroom. On the eve of the event, the rows of seats are removed from the stalls, and a new floor, level with the stage, is built.

Sometimes ballrooms have stages in the front of the room where the host or a special guest can speak. That stage can also be used for instrumentalists and musical performers.

Certified wood

Certified wood and paper products come from responsibly managed forests – as defined by a particular standard. With third-party forest certification, an independent organization develops standards of good forest management, and independent auditors issue certificates to forest operations that comply with those standards.

Engineered wood

Engineered wood, also called mass timber, composite wood, man-made wood, or manufactured board, includes a range of derivative wood products which are manufactured by binding or fixing the strands, particles, fibres, or veneers or boards of wood, together with adhesives, or other methods of fixation to form composite material. The panels vary in size but can range upwards of 64 by 8 feet (20m x 2.4m) and in the case of CLT can be of any thickness from a few inches to 16 inches or more. These products are engineered to precise design specifications which are tested to meet national or international standards. Engineered wood products are used in a variety of applications, from home construction to commercial buildings to industrial products. The products can be used for joists and beams that replace steel in many building projects. The term Mass Timber to describe this group of building materials was popularized by architect Michael Green (Michael Green Architecture), a prominent champion of engineered timber construction. Typically, engineered wood products are made from the same hardwoods and softwoods used to manufacture lumber. Sawmill scraps and other wood waste can be used for engineered wood composed of wood particles or fibers, but whole logs are usually used for veneers, such as plywood, MDF or particle board. Some engineered wood products, like oriented strand board (OSB), can use trees from the poplar family, a common but non-structural species.

Alternatively, it is also possible to manufacture similar engineered bamboo from bamboo; and similar engineered cellulosic products from other lignin-containing materials such as rye straw, wheat straw, rice straw, hemp stalks, kenaf stalks, or sugar cane residue, in which case they contain no actual wood but rather vegetable fibers.

Flat pack furniture is typically made out of man-made wood due to its low manufacturing costs and its low weight.

Gavel

A gavel is a small ceremonial mallet commonly made of hardwood, typically fashioned with a handle. It is used almost exclusively in the United States in legislatures and courts of law, but is used worldwide for auctions. It can be used to call for attention or to punctuate rulings and proclamations and is a symbol of the authority and right to act officially in the capacity of a presiding officer. It is often struck against a sound block, a striking surface typically also made of hardwood, to enhance its sounding qualities. According to tradition, Vice President John Adams used a gavel as a call to order in the first U.S. Senate in New York in the spring of 1789. Since then, it has remained customary to tap the gavel against a lectern or desk to indicate the opening and closing of proceedings, and it is also used to keep the meeting itself calm and orderly.

Great Smoky Mountains

The Great Smoky Mountains are a mountain range rising along the Tennessee–North Carolina border in the southeastern United States. They are a subrange of the Appalachian Mountains, and form part of the Blue Ridge Physiographic Province. The range is sometimes called the Smoky Mountains and the name is commonly shortened to the Smokies. The Great Smokies are best known as the home of the Great Smoky Mountains National Park, which protects most of the range. The park was established in 1934, and, with over 11 million visits per year, it is the most visited national park in the United States.The Great Smokies are part of an International Biosphere Reserve. The range is home to an estimated 187,000 acres (76,000 ha) of old growth forest, constituting the largest such stand east of the Mississippi River. The cove hardwood forests in the range's lower elevations are among the most diverse ecosystems in North America, and the Southern Appalachian spruce-fir forest that coats the range's upper elevations is the largest of its kind. The Great Smokies are also home to the densest black bear population in the Eastern United States and the most diverse salamander population outside of the tropics.Along with the Biosphere reserve, the Great Smokies have been designated a UNESCO World Heritage Site. The U.S. National Park Service preserves and maintains 78 structures within the national park that were once part of the numerous small Appalachian communities scattered throughout the range's river valleys and coves. The park contains five historic districts and nine individual listings on the National Register of Historic Places.

The name "Smoky" comes from the natural fog that often hangs over the range and presents as large smoke plumes from a distance. This fog is caused by the vegetation exhaling volatile organic compounds, chemicals that have a high vapor pressure and easily form vapors at normal temperature and pressure.

Hardcourt

A hardcourt (or hard court) is a surface or floor on which a sport is played, most usually in reference to tennis courts. They are typically made of rigid materials such as asphalt or concrete, and covered with acrylic material to seal the surface and mark the playing lines, while providing some cushioning. Historically, hardwood surfaces were also in use in indoor settings, similar to an indoor basketball court, but these surfaces are rare now.

Lumber

Lumber (North American English) or timber (used in the rest of the English-speaking world) is a type of wood that has been processed into beams and planks, a stage in the process of wood production. Lumber is mainly used for structural purposes but has many other uses as well.

There are two main types of lumber. It may be supplied either rough-sawn, or surfaced on one or more of its faces. Besides pulpwood, rough lumber is the raw material for furniture-making and other items requiring additional cutting and shaping. It is available in many species, usually hardwoods; but it is also readily available in 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 is more commonly made from softwood than hardwoods, and 80% of lumber comes from softwood.

Northern hardwood forest

The northern hardwood forest is a general type of North American forest ecosystem found over much of southeastern and south central Canada, Ontario and Quebec, extending south into the United States in northern New England, New York, and Pennsylvania, and west along the Great Lakes to Minnesota and western Ontario. Some ecologists consider it a transitional forest because it contains species common to both the oak-hickory forest community to the south and the Boreal forest community to the north. The trees and shrub species of the Northern Hardwood Forest are known for their brilliant fall colors, making the regions that contain this forest type popular fall foliage tourist destinations.

Sugar maple, yellow birch, American beech, and White Ash are the common key indicator tree and shrub species in the Northern Hardwood Forest. Other species include eastern hemlock and eastern white pine. Herb and heath species include wintergreen, wild sarsaparilla, and wood sorrel. Birds and animals common to the Northern Hardwood Forest include the black-capped chickadee, white-throated sparrow, cedar waxwing, porcupine, snowshoe hare, white-tailed deer, and American Red Squirrel.

Most of the Northern Hardwood Forest is not virgin forest, it is regrowth following centuries of commercial timber harvesting and the clearing of land for agricultural purposes. This is particularly true of New England, New York, and Eastern Canada, where the land was cleared to make room for farms in the 17th and 18th centuries and subsequently abandoned in the 19th century when farming interests migrated to the midwestern United States and central Canada.

The Northern Hardwood Forest is indigenous to several well-known parks and national forests, including the Boundary Waters region of Minnesota, New York's Adirondack Park, the White Mountain National Forest in New Hampshire, the Green Mountain National Forest in Vermont, Baxter State Park and Acadia National Park in Maine, and Fundy National Park in New Brunswick. The Berkshires region of western Massachusetts is very typical of a Northern Hardwood Forest ecosystem. Northern hardwood stands are also found in the higher elevations of the southern Blue Ridge Mountains, typically between 4,500 feet (1,400 m) and 5,500 feet (1,700 m), where climatic conditions resemble those in northern states and southern Canada.

Plywood

Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured boards which includes medium-density fibreboard (MDF) and particle board (chipboard).

All plywoods bind resin and wood fibre sheets (cellulose cells are long, strong and thin) to form a composite material. This alternation of the grain is called cross-graining and has several important benefits: it reduces the tendency of wood to split when nailed in at the edges; it reduces expansion and shrinkage, providing improved dimensional stability; and it makes the strength of the panel consistent across all directions. There is usually an odd number of plies, so that the sheet is balanced—this reduces warping. Because plywood is bonded with grains running against one another and with an odd number of composite parts, it has high stiffness perpendicular to the grain direction of the surface ply.

Smaller, thinner, and lower-quality plywoods may only have their plies (layers) arranged at right angles to each other. Some better-quality plywood products will by design have five plies in steps of 45 degrees (0, 45, 90, 135, and 180 degrees), giving strength in multiple axes.

The word ply derives from the French verb plier, "to fold", from the Latin verb plico, from the ancient Greek verb πλέκω.

Richard J. Dorer Memorial Hardwood State Forest

The Richard J. Dorer Memorial Hardwood State Forest is a 1,016,204 acres (4,112.43 km2) reserve of current and former forest in Minnesota's Driftless Area. Only 45,000 acres (180 km2) of the land is state owned, with the remainder owned by private individuals and community groups, governed by easements. Non-contiguous units are spread over seven counties ( Dakota, Fillmore, Goodhue, Olmsted, Houston, Wabasha, and Winona Counties), generally in areas just west of the Mississippi River, but extending much further west into the valleys of the Root and Zumbro Rivers.

A wide variety of recreational activities are offered: camping, fishing, horseback riding trails (including horse picket lines and corrals); an extensive network of hiking and nature trails (including a wheelchair-accessible trail), and off-highway vehicle trails.

It is named in honor of a former Commissioner of Conservation.

Rubberwood

Rubberwood is a light-colored medium-density tropical hardwood obtained from the Pará rubber tree (Hevea brasiliensis), usually from trees grown in rubber plantations. Rubberwood is commonly advertised as an "environmentally friendly" wood, as it makes use of plantation trees that have already served a useful function.

Softwood

Softwood is wood from gymnosperm trees such as conifers, as well as Amborella. The term is opposed to hardwood, which is the wood from angiosperm trees.

Temperate broadleaf and mixed forest

Temperate broadleaf and mixed forest is a temperate climate terrestrial habitat type defined by the World Wide Fund for Nature, with broadleaf tree ecoregions, and with conifer and broadleaf tree mixed coniferous forest ecoregions.These forests are richest and most distinctive in central China and eastern North America, with some other globally distinctive ecoregions in the Caucasus, the Himalayas, Southern Europe, and the Russian Far East.

The Hardwood Pile

"The Hardwood Pile" is a contemporary fantasy story by American writer L. Sprague de Camp. It was first published in the magazine Unknown for September, 1940. It first appeared in book form in the collection The Reluctant Shaman and Other Fantastic Tales (Pyramid, 1970); it later appeared in the collection The Best of L. Sprague de Camp (Doubleday, 1978), and the anthology Bestiary! (Ace Books, 1985) The story has been translated into French and German.

Veneer saw

The veneer saw is a small double-edged tool for cutting thin hardwood veneer. Its narrow curved blade facilitates precision work, and its elevated offset handle makes it possible to cut flush with a surface. The blade is usually 3 or 4 inches long and it has 13 tpi (teeth per inch).

A similarly shaped tool, known as a French flush-cut saw is designed for trimming the ends of dowels, tenons, and other protrusions flush with a surface.

Wood flooring

Wood flooring is any product manufactured from timber that is designed for use as flooring, either structural or aesthetic. Wood is a common choice as a flooring material and can come in various styles, colors, cuts, and species. Bamboo flooring is often considered a form of wood flooring, although it is made from a grass (bamboo) rather than a timber.

Woodworking

Woodworking is the activity or skill of making items from wood, and includes cabinet making (cabinetry and furniture), wood carving, joinery, carpentry, and woodturning.

Wyalusing State Park

Wyalusing State Park is a 2,628-acre (1,064 ha) Wisconsin state park at the confluence of the Mississippi and Wisconsin rivers in the town of Wyalusing, just south of Prairie du Chien. Wyalusing means "home of the warrior" in the Lenape language spoken by Munsee-Delaware tribes who settled in the area in the 19th century after being displaced from farther east. 500-foot-high (150 m) bluffs dotted with prehistoric Native American mounds look out over the river valleys. Two park resources have been recognized nationally: the Wyalusing Hardwood Forest is a National Natural Landmark and the Wyalusing State Park Mounds Archaeological District is on the National Register of Historic Places.

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