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Old Main, University of Arizona 3
Image by Ken Lund
The University of Arizona (also referred to as UA, U of A, or Arizona) is a land-grant and space-grant public institution of higher education and research located in Tucson, Arizona, United States. The University of Arizona was the first university in the state of Arizona, founded in 1885 (twenty-seven years before the Arizona Territory achieved statehood), and is considered a Public Ivy. UA includes the only medical school in Arizona that grants M.D. degrees. In 2006, total enrollment was 36,805 students. UA is governed by the Arizona Board of Regents.
The University of Arizona was approved by the Arizona Territory’s Thieving Thirteenth Legislature in 1885. The city of Tucson had hoped to receive the appropriation for the territory’s mental hospital, which carried a 0,000 allocation instead of the ,000 allotted to the territory’s only university (Arizona State University was also chartered in 1885, but at the time it was created as Arizona’s normal school, and not a university). Tucson’s contingent of legislators was delayed in reaching Prescott due to flooding on the Salt River and by the time they arrived back-room deals allocating the most desirable territorial institutions had already been made. Tucson was largely disappointed at receiving what was viewed as an inferior prize. With no parties willing to step forth and provide land for the new institution, the citizens of Tucson prepared to return the money to the Territorial Legislature until two gamblers and a saloon keeper decided to donate the land necessary to build the school. Classes met for the first time in 1891 with 32 students in Old Main, the first building constructed on campus, and still in use to this day.[2]
Because there were no high schools in Arizona Territory, the University maintained separate preparatory classes for the first 23 years of operation.
The main campus sits on 380 acres (1.5 km2) in central Tucson, about one mile (1.6 km) northeast of downtown. There are 179 buildings on the main campus. Many of the early buildings, including the Arizona State Museum buildings (one of them the 1927 main library) and Centennial Hall, were designed by Roy Place, a prominent Tucson architect. It was Place’s use of red brick that set the tone for the red brick facades that are a basic and ubiquitous part of nearly all UA buildings, even those built in recent decades. Indeed, almost every UA building has red brick as a major component of the design, or at the very least, a stylistic accent to harmonize it with the other buildings on campus. [3][4]
The campus is roughly divided into quadrants. The north and south sides of campus are delineated by a grassy expanse called the Mall, which stretches from Old Main eastward to the campus’ eastern border at Campbell Avenue (a major north-south arterial street). The west and east sides of campus are separated roughly by Highland Avenue and the Student Union Memorial Center (see below).
The science and mathematics buildings tend to be clustered in the southwest quadrant; the intercollegiate athletics facilities to the southeast; the arts and humanities buildings to the northwest (with the dance department being a major exception as its main facilities are far to the east end of campus), with the engineering buildings in the north central area. The optical and space sciences buildings are clustered on the east side of campus near the sports stadiums and the (1976) main library.
Speedway Boulevard, one of Tucson’s primary east-west arterial streets, traditionally defined the northern boundary of campus but since the 1980s, several university buildings have been constructed north of this street, expanding into a neighborhood traditionally filled with apartment complexes and single-family homes. The University has purchased a handful of these apartment complexes for student housing in recent years. Sixth Street typically defines the southern boundary, with single-family homes (many of which are rented out to students) south of this street.
Park Avenue has traditionally defined the western boundary of campus, and there is a stone wall which runs along a large portion of the east side of the street, leading to the old Main Gate, and into the driveway leading to Old Main.
Along or adjacent to all of these major streets are a wide variety of retail facilities serving the student, faculty and staff population: shops, bookstores, bars, banks, credit unions, coffeehouses and major chain fast-food restaurants such as Burger King and Chick-fil-A. The area near University Boulevard and Park Avenue, near the Main Gate, has long been a major center of such retail activity; many of the shops have been renovated since the late 1990s and a nine-story Marriott hotel was built in this immediate district in 1996.
The oldest campus buildings are located west of Old Main. Most of the buildings east of Old Main date from the 1940s to the 1980s, with a few recent buildings constructed in the years since 1990.
The Student Union Memorial Center, located on the north side of the Mall east of Old Main, was completely reconstructed between 2000 and 2003, replacing a 270,000-square-foot (25,000 m2) structure originally opened in 1951 (with additions in the 1960s). The new million student union has 405,000 square feet (37,600 m2) of space on four levels, including 14 restaurants (including a food court with such national chains as Burger King, Panda Express, Papa John’s Pizza and Chick-fil-A), a new two-level bookstore (that includes a counter for Clinique merchandise as well as an office supplies section sponsored by Staples with many of the same Staples-branded items found in their regular stores), 23 meeting rooms, eight lounge areas (including one dedicated to the USS Arizona), a computer lab, a U.S. Post Office, a copy center named Fast Copy, and a video arcade.
For current museum hours, fees, and directions see "campus visitor’s guide" in the external links.
Much of the main campus has been designated an arboretum. Plants from around the world are labeled along a self-guided plant walk. The Krutch Cactus Garden includes the tallest Boojum tree in the state of Arizona.[6] (The university also manages Boyce Thompson Arboretum State Park, located c. 85 miles (137 km) north of the main campus.)
Two herbaria are located on the University campus and both are referred to as "ARIZ" in the Index Herbariorum
The University of Arizona Herbarium – contains roughly 400,000 specimens of plants.
The Robert L. Gilbertson Mycological Herbarium – contains more than 40,000 specimens of fungi.
The Arizona State Museum is the oldest anthropology museum in the American Southwest.
The Center for Creative Photography features rotating exhibits. The permanent collection includes over 70,000 photos, including many Ansel Adams originals.
University of Arizona Museum of Art.
The Arizona Historical Society is located one block west of campus.
Flandrau Science Center has exhibits, a planetarium, and a public-access telescope.
The University of Arizona Mineral Museum is located inside Flandrau Science Center. The collection dates back to 1892 and contains over 20,000 minerals from around the world, including many examples from Arizona and Mexico.
The University of Arizona Poetry Center
The Stevie Eller Dance Theatre, opened in 2003 (across the Mall from McKale Center) as a 28,600-square-foot (2,660 m2) dedicated performance venue for the UA’s dance program, one of the most highly regarded university dance departments in the United States. Designed by Gould Evans, a Phoenix-based architectural firm, the theatre was awarded the 2003 Citation Award from the American Institute of Architects, Arizona Chapter. [7]
The football stadium has the Navajo-Pinal-Sierra dormitory in it. The dorm rooms are underneath the seats along the South and East sides of the stadium.
Academics
[edit] Academic subdivisions
The University of Arizona offers 334 fields of study at four levels: bachelor’s, masters, doctoral, and first professional.
Academic departments and programs are organized into colleges and schools. Typically, schools are largely independent or separately important from their parent college. In addition, not all schools are a part of a college. The university maintains a current list of colleges and schools at www.arizona.edu/index/colleges.php. [10]
[edit] Admissions
The UA is considered a "selective" university by U.S. News and World Report.[11] In the fall semester of 2007, the UA matriculated 6,569 freshmen, out of 16,853 freshmen admitted, from an application pool of 21,199 applicants. The average person admitted to the university as a freshman in fall 2007 had a weighted GPA of 3.31 and an average score of 1102 out of 1600 on the SAT admissions test. Sixty-nine of these freshman students were National Merit Scholars.[12]
UA students hail from all states in the U.S. While nearly 72% of students are from Arizona, nearly 10% are from California, followed by a significant student presence from Illinois, Texas, Washington, and New York (2007).[13] The UA has over 2,200 international students representing 122 countries. International students comprise approximately 6% of the total enrollment at UA.[13]
[edit] Academic and research reputation
Among the strongest programs at UA are optical sciences, astronomy, astrophysics, planetary sciences, hydrology, Earth Sciences, hydrogeology, linguistics, philosophy, sociology, architecture and landscape architecture, engineering, and anthropology.
Arizona is classified as a Carnegie Foundation "RU/VH: Research Universities (very high research activity)" university (formerly "Research 1" university).
The university receives more than 0 million USD annually in research funding, generating around two thirds of the research dollars in the Arizona university system.[14] 26th highest in the U.S. (including public and private institutions).[15] The university has an endowment of 6.7 million USD as of 2006(2006 NACUBO Endowment Study).[16]
UA is awarded more NASA grants for space exploration than any other university nationally.[17] The UA was recently awarded over 5 million USD for its Lunar and Planetary Laboratory (LPL) to lead NASA’s 2007-08 mission to Mars to explore the Martian Arctic. The LPL’s work in the Cassini spacecraft orbit around Saturn is larger than that of any other university globally. The UA laboratory designed and operated the atmospheric radiation investigations and imaging on the probe.[18] The UA operates the HiRISE camera, a part of the Mars Reconnaissance Orbiter.
The Eller College of Management McGuire Entrepreneurship program is currently the number 1 ranked undergraduate program in the country. This ranking was made by The Princeton Review and Entrepreneur Magazine.
The Council for Aid to Education ranked the UA 12th among public universities and 24th overall in financial support and gifts.[citation needed] Campaign Arizona, an effort to raise over billion USD for the school, exceeded that goal by 0 million a year earlier than projected.[19]
The National Science Foundation ranks UA 16th among public universities, and 26th among all universities nationwide in research funding.[19]
UA receives more NASA grants annually than the next nine top NASA-Jet Propulsion Laboratory-funded universities combined.[19]
UA students have been selected as Flinn, Truman, Rhodes, Goldwater, Fulbright, and National Merit scholars.[20]
According to The Chronicle of Higher Education, UA is among the top 25 producers of Fulbright awards in the U.S.[19]
[edit] World rankings
Academic Ranking of World Universities (Shanghai Jiao Tong University, China): 77th (2008).
Webometrics Ranking of World Universities (Cybermetrics Lab, National Research Council of Spain): 18th (2008).
The G-Factor International University Ranking (Peter Hirst): 15th (2006).
Professional Ranking of World Universities (École nationale supérieure des mines de Paris, France): 35th (2008).
Performance Ranking of Scientific Papers for World Universities (Higher Education Evaluation and Accreditation Council of Taiwan): 37th (2008).
Global University Ranking by Wuhan University (Wuhan University, China): 43rd (2007).
[edit] Notable associations
UA is a member of the Association of Universities for Research in Astronomy, a consortium of institutions pursuing research in astronomy. The association operates observatories and telescopes, notably Kitt Peak National Observatory located just outside of Tucson.
UA is a member of the Association of American Universities, and the sole representative from Arizona to this group.
[edit] Notable rankings
The Eller College of Management’s programs in Accounting, Entrepreneurship, Management Information Systems, and Marketing are ranked in the nation’s top 25 by U.S. News & World Report. The Masters in MIS program has been ranked in the top 5 by U.S. News & World Report since the inception of the rankings.[21] It is one of three programs to have this distinction.
The Eller MBA program has ranked among the top 50 programs for 11 straight years by U.S. News & World Report. In 2005 the MBA program was ranked 40th by U.S. News & World Report. Forbes Magazine ranked the Eller MBA program 33rd overall for having the best Return on Investment (ROI), in its fourth biennial rankings of business schools 2005. The MBA program was ranked 24th by The Wall Street Journal’s 2005 Interactive Regional Ranking.[22]
Out of 30 accredited graduate programs in landscape architecture in the country, DesignIntelligence ranked the College’s School of Landscape Architecture as the No. 1 graduate program in the western region. For 2009 the Undergraduate Program in Architecture was ranked 12th in the nation for all universities, public and private.
The James E. Rogers College of Law was ranked 38th nationally by U.S. News & World Report in 2008.[23]
According to the National Academy of Sciences, the Graduate Program in Ecology and Evolutionary Biology is one of the top-rated research departments in ecology and evolutionary biology in the U.S.
The Systems and Industrial Engineering (SIE) Department is ranked 18th in the ‘America’s Best Graduate Schools 2006′ by US News and World Report.
The analytical chemistry program at UA is ranked 4th nationally by U.S. News & World Report (2006).[22]
The Geosciences program is ranked 7th nationally by U.S. News & World Report in 2006.[22]
The Doctor of Pharmacy program is ranked 4th nationally by U.S. News & World Report in 2005.[22]
The Photography program is ranked 9th nationally, also by U.S. News & World Report in 2008.
The Master of Fine Arts (MFA) program in Creative Writing at the University of Arizona has ranked in the top ten consistently according to U.S. News & World Report.
In the Philosophical Gourmet rankings of philosophy departments, the graduate program in Philosophy is ranked 13th nationally. The political philosophy program at the University of Arizona is top ranked first in the English speaking world, according to the same report.
Many programs in the College of Agriculture and Life Sciences have ranked in the top ten in the U.S. according to Faculty Scholarly Productivity Index: Agricultural Sciences — No. 1, Agronomy and Crop Sciences — No. 1, Entomology — No. 2, Botany and Plant Biology — No. 4, Nutrition — No. 10.
In 2005, the Association of Research Libraries, in its "Ranked Lists for Institutions for 2005" (the most recent year available), ranked the UA libraries as the 33rd overall university library in North America (out of 113) based on various statistical measures of quality; this is one rank below the library of Duke University, one rank ahead of that of Northwestern University[24] (both these schools are members, along with the UA, of the Association of American Universities).
As of 2006, the UA’s library system contains nearly five million volumes.
The Main Library, opened in 1976, serves as the library system’s reference, periodical, and administrative center; most of the main collections and special collections are housed here as well. The Main Library is located on the southeast quadrant of campus near McKale Center and Arizona Stadium.
In 2002, a million, 100,000-square-foot (10,000 m2) addition, the Integrated Learning Center (ILC), was completed; it is a home base for first-year students (especially those undecided on a major) which features classrooms, auditoriums, a courtyard with an alcove for vending machines, and a greatly expanded computer lab (the Information Commons) with several dozen Gateway and Apple Macintosh G5 workstations (these computers are available for use by the general public (with some restrictions) as well as by UA students, faculty and staff). Much of the ILC was constructed underground, underneath the east end of the Mall; the ILC connects to the basement floor of the Main Library through the Information Commons. As part of the project, additional new office space for the Library was constructed on the existing fifth floor.
The Science and Engineering Library is in a nearby building from the 1960s that houses volumes and periodicals from those fields. The Music Building (on the northwest quadrant of campus where many of the fine arts disciplines are clustered) houses the Fine Arts Library, including reference collections for architecture, music (including sheet music, recordings and listening stations), and photography. There is a small library at the Center for Creative Photography, also in the fine arts complex, devoted to the art and science of photography. The Law Library is in the law building.
The libraries at University of Arizona are expecting a 15 percent budget cut for the 2009 fiscal year. They will begin to explore the possibilities of cutting staff, cutting online modules, and closing some libraries. The biggest threat is the possible closure of 11 libraries. The staff is projected to decline from 180 employees to 155 employees. They also intend to cut face-face instructional program that teaches students in English 101 and 102 how to navigate the library. This will now be taught online.
[edit] Athletics
Main article: Arizona Wildcats
Like many large public universities in the U.S., sports are a major activity on campus, and receive a large operating budget. Arizona’s athletic teams are nicknamed the Wildcats, a name derived from a 1914 football game with then California champions Occidental College, where the L.A. Times asserted that, "the Arizona men showed the fight of wildcats."[25] The University of Arizona participates in the NCAA’s Division I-A in the Pacific-10 Conference, which it joined in 1978.
[edit] Men’s basketball
Main article: Arizona Wildcats men’s basketball
The men’s basketball team has been one of the nation’s most successful programs since Lute Olson was hired as head coach in 1983, and is still known as a national powerhouse in Division I men’s basketball.[26] As of 2009, the team has reached the NCAA Tournament 25 consecutive years, which is the longest active and second-longest streak in NCAA history (University of North Carolina at Chapel Hill had the longest streak with 27).[27] The Wildcats have reached the Final Four of the NCAA tournament in 1988, 1994, 1997, and 2001. In 1997, Arizona defeated the University of Kentucky, the defending national champions, to win the NCAA National Championship (NCAA Men’s Division I Basketball Championship) by a score of 84–79 in overtime; Arizona’s first national championship victory. The 1997 championship team became the first and only in NCAA history to defeat three number-one seeds en route to a national title (Kansas, North Carolina and Kentucky — the North Carolina game being the final game for longtime UNC head coach Dean Smith). Point guard Miles Simon was chosen as 1997 Final Four MVP (Simon was also an assistant coach under Olson from 2005–08). The Cats also boast the third highest winning percentage over the last twenty years. Arizona has won a total of 21 conference championships in its’ programs history.
The Wildcats play their home games at the McKale Center in Tucson. A number of former Wildcats have gone on to pursue successful professional NBA careers (especially during the Lute Olson era), including Gilbert Arenas, Richard Jefferson, Mike Bibby, Jason Terry, Sean Elliott, Damon Stoudamire, Luke Walton, Hassan Adams, Salim Stoudamire, Andre Iguodala, Channing Frye, Brian Williams (later known as Bison Dele), Sean Rooks, Jud Buechler, Michael Dickerson and Steve Kerr. Kenny Lofton, now best known as a former Major League Baseball star, was a four year letter winner as a Wildcat basketball player (and was on the 1988 Final Four team), before one year on the Arizona baseball team. Another notable former Wildcat basketball player is Eugene Edgerson, who played on the 1997 and 2001 Final Four squads, and is currently one of the primary stars of the Harlem Globetrotters as "Wildkat" Edgerson.
Before Lute Olson’s hire in 1983, Arizona was the first major Division I school to hire an African American head coach in Fred Snowden, in 1972. After a 25-year tenure as Arizona head coach, Olson announced his retirement from the Arizona basketball program in October 2008. After two seasons of using interim coaches, Arizona named Sean Miller, head coach at Xavier University, as its new head basketball coach in April 2009.
The football team began at The University of Arizona in 1899 under the nickname "Varsity" (a name kept until the 1914 season when the team was deemed the "Wildcats").[28]
The football team was notably successful in the 1990s, under head coach Dick Tomey; his "Desert Swarm" defense was characterized by tough, hard-nosed tactics. In 1993, the team had its first 10-win season and beat the University of Miami Hurricanes in the Fiesta Bowl by a score of 29–0. It was the bowl game’s only shutout in its then 23-year history. In 1998, the team posted a school-record 12–1 season and made the Holiday Bowl in which it defeated the Nebraska Cornhuskers. Arizona ended that season ranked 4th nationally in the coaches and API poll. The 1998 Holiday Bowl was televised on ESPN and set the now-surpassed record of being the most watched of any bowl game in that network’s history (the current record belongs to the 2005 Alamo Bowl between Michigan and Nebraska). The program is led by Mike Stoops, brother of Bob Stoops, the head football coach at the University of Oklahoma.
[edit] Baseball
Main article: Arizona Wildcats baseball
The baseball team had its first season in 1904. The baseball team has captured three national championship titles in 1976, 1980, and 1986, all coached by Jerry Kindall. Arizona baseball teams have appeared in the NCAA National Championship title series a total of six times, including 1956, 1959, 1963, 1976, 1980, and 1986 (College World Series). The team is currently coached by Andy Lopez; aided by Assistant Coach Mark Wasikowski, Assistant Coach Jeff Casper and Volunteer Assistant Coach Keith Francis. Arizona baseball also has a student section named The Hot Corner. Famous UA baseball alums include current Boston Red Sox manager Terry Francona, Cleveland Indian Kenny Lofton, Yankee Shelley Duncan, Brewers closer Trevor Hoffman, Diamondbacks third-base coach Chip Hale, former 12-year MLB pitcher and current minor league coach Craig Lefferts, longtime MLB standout J. T. Snow, star MLB pitchers Don Lee, Carl Thomas, Mike Paul, Dan Schneider, Rich Hinton and Ed Vosberg, NY Giants slugger Hank Leiber, Yankee catcher Ron Hassey, and Red Sox coach Brad Mills. Former Angels and Cardinals (among others) pitcher Joe Magrane is also a UA alum.
[edit] Softball
The Arizona softball team is among the top programs in the country and a perennial powerhouse. The softball team has won eight NCAA Women’s College World Series titles, in 1991, 1993, 1994, 1996, 1997, 2001, 2006 and 2007 under head coach Mike Candrea (NCAA Softball Championship). Arizona defeated the University of Tennessee in the 2007 National Championship series in Oklahoma City. The team has appeared in the NCAA National Championship in 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 2001, 2002, 2006, and 2007 (a feat second only to UCLA), and has reached the College World Series 19 of the past 20 years. Coach Candrea, along with former Arizona pitcher Jennie Finch, led the 2004 U.S. Olympic softball team to a gold medal in Athens, Greece. The Wildcat softball team plays at Rita Hillenbrand Memorial Stadium.
[edit] Men’s and women’s golf
The university’s golf teams have also been notably successful. The men’s team won a national championship in 1992 (NCAA Division I Men’s Golf Championships), while the women’s team won national championships in 1996 and 2000 (NCAA Women’s Golf Championship).
A strong athletic rivalry exists between the University of Arizona and Arizona State University located in Tempe. The UA leads the all-time record against ASU in men’s basketball (138-73), football (44–35–1), and baseball (224–189–1) as of January 2006. The football rivalry game between the schools is known as "The Duel in the Desert." The trophy awarded after each game, the Territorial Cup, is the nation’s oldest rivalry trophy, distinguished by the NCAA. Rivalries have also been created with other Pac-10 teams, especially University of California, Los Angeles which has provided a worthy softball rival and was Arizona’s main basketball rival in the early and mid-1990s.
[edit] Mascot
The University mascot is an anthropomorphized wildcat named Wilbur. The identity of Wilbur is kept secret through the year as the mascot appears only in costume. In 1986, Wilbur married his longtime wildcat girlfriend, Wilma. Together, Wilbur and Wilma appear along with the cheerleading squad at most Wildcat sporting events.[29] Wilbur was originally created by Bob White as a cartoon character in the University’s humor magazine, Kitty Kat. From 1915 through the 1950s the school mascot was a live bobcat, a species known locally as a wildcat. This succession of live mascots were known by the common name of Rufus Arizona, originally named after Rufus von Kleinsmid, president of the university from 1914 to 1921. 1959 marked the creation of the first incarnated Wilbur, when University student John Paquette and his roommate, Dick Heller, came up with idea of creating a costume for a student to wear. Ed Stuckenhoff was chosen to wear the costume at the homecoming game in 1959 against Texas Tech and since then it has become a long-standing tradition. Wilbur will celebrate his 50th birthday in November 2009.
Officially implemented in 2003, Zona Zoo is the official student section and student ticketing program for the University of Arizona Athletics. The Zona Zoo program is co-owned by the Associated Students of the University of Arizona (ASUA) and Arizona Athletics, the program is run by a team of spirited individuals called the Zona Zoo Crew. Zona Zoo is one of the largest and most spirited student sections in NCAA Division I Athletics.
Notable venues
McKale Center, opened in 1973, is currently used by men’s and women’s basketball, women’s gymnastics, and women’s volleyball. The official capacity has changed often. The largest crowd to see a game in McKale was 15,176 in 1976 for a game against the University of New Mexico, a main rival during that period. In 2000, the floor in McKale was dubbed Lute Olson Court, for the basketball program’s winningest coach. During a memorial service in 2001 for Lute’s wife, Bobbi, who died after a battle with ovarian cancer, the floor was renamed Lute and Bobbi Olson Court. In addition to the playing surface, McKale Center is host to the offices of the UA athletic department. McKale Center is named after J.F. Pop McKale, who was athletic director and coach from 1914 through 1957. Joe Cavaleri ("The Ooh-Aah Man") made his dramatic and inspiring appearances there.
Arizona Stadium, built in 1928 and last expanded in 1976, seats over 56,000 patrons. It hosts American football games and has also been used for university graduations. The turf is bermuda grass, taken from the local Tucson National Golf Club. Arizona football’s home record is 258-139-12. The largest crowd ever in Arizona Stadium was 59,920 in 1996 for a game against Arizona State University.
Jerry Kindall Field at Frank Sancet Stadium hosts baseball games.
Rita Hillenbrand Memorial Stadium hosts softball games.
en.wikipedia.org/wiki/University_of_Arizona
wood
Image by Joost J. Bakker IJmuiden
Wood is a hard, fibrous tissue found in many plants. It has been used for centuries for both fuel and as a construction material for several types of living areas such as houses. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. In the strict sense wood is produced as secondary xylem in the stems of trees (and other woody plants). In a living tree it transfers water and nutrients to the leaves and other growing tissues, and has a support function, enabling woody plants to reach large sizes or to stand up for themselves. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or wood chips or fiber.
People have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. Wood can be dated by carbon dating and in some species by dendrochronology to make inferences about when a wooden object was created. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time.
Formation
Wood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. Technically this is known as secondary growth; it is the result of cell division in the vascular cambium, a lateral meristem, and subsequent expansion of the new cells.
Growth rings
Where there are clear seasons, growth can occur in a discrete annual or seasonal pattern, leading to growth rings; these can usually be most clearly seen on the end of a log, but are also visible on the other surfaces. If these seasons are annual these growth rings are referred to as annual rings. Where there is no seasonal difference growth rings are likely to be indistinct or absent.
If there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earlywood or springwood. The outer portion formed later in the season is then known as the latewood or summerwood. However, there are major differences, depending on the kind of wood.
Knots
A knot on a tree at the Garden of the Gods public park in Colorado Springs, Colorado (October 2006).A knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually for the worse, but may be exploited for artistic effect. In a longitudinally sawn plank, a knot will appear as a roughly circular "solid" (usually darker) piece of wood around which the grain of the rest of the wood "flows" (parts and rejoins). Within a knot, the direction of the wood (grain direction) is up to 90 degrees different from the grain direction of the regular wood.
In the tree a knot is either the base of a side branch or a dormant bud. A knot (when the base of a side branch) is conical in shape (hence the roughly circular cross-section) with the tip at the point in stem diameter at which the plant’s cambium was located when the branch formed as a bud.
During the development of a tree, the lower limbs often die, but may persist for a time, sometimes years. Subsequent layers of growth of the attaching stem are no longer intimately joined with the dead limb, but are grown around it. Hence, dead branches produce knots which are not attached, and likely to drop out after the tree has been sawn into boards.
In grading lumber and structural timber, knots are classified according to their form, size, soundness, and the firmness with which they are held in place. This firmness is affected by, among other factors, the length of time for which the branch was dead while the attaching stem continued to grow.
Knots materially affect cracking (known in the US as checking, and the UK as shakes) and warping, ease in working, and cleavability of timber. They are defects which weaken timber and lower its value for structural purposes where strength is an important consideration. The weakening effect is much more serious when timber is subjected to forces perpendicular to the grain and/or tension than where under load along the grain and/or compression. The extent to which knots affect the strength of a beam depends upon their position, size, number, and condition. A knot on the upper side is compressed, while one on the lower side is subjected to tension. If there is a season check in the knot, as is often the case, it will offer little resistance to this tensile stress. Small knots, however, may be located along the neutral plane of a beam and increase the strength by preventing longitudinal shearing. Knots in a board or plank are least injurious when they extend through it at right angles to its broadest surface. Knots which occur near the ends of a beam do not weaken it. Sound knots which occur in the central portion one-fourth the height of the beam from either edge are not serious defects.
Knots do not necessarily influence the stiffness of structural timber, this will depend on the size and location. Stiffness and elastic strength are more dependent upon the sound wood than upon localised defects. The breaking strength is very susceptible to defects. Sound knots do not weaken wood when subject to compression parallel to the grain.
In some decorative applications, wood with knots may be desirable to add visual interest. In applications where wood is painted, such as skirting boards, fascia boards, door frames and furniture, resins present in the timber may continue to ‘bleed’ through to the surface of a knot for months or even years after manufacture and show as a yellow or brownish stain. A Knot Primer paint or solutuion, correctly applied during preparation, may do much to reduce this problem but it is difficult to control completely, especially when using massproduced kiln-dried timber stocks
Heartwood and sapwood
A section of a Yew branch showing 27 annual growth rings, pale sapwood and dark heartwood, and pith (centre dark spot). The dark radial lines are small knots.Heartwood is wood that, as a result of tylosis, has become more resistant to decay. Tylosis is the deposition of chemical substances (a genetically programmed process). Once heartwood formation is complete, the heartwood is dead. Some uncertainty still exists as to whether heartwood is truly dead, as it can still chemically react to decay organisms, but only once (Shigo 1986, 54).
Usually heartwood looks different; in that case it can be seen on a cross-section, usually following the growth rings in shape. Heartwood may (or may not) be much darker than living wood. It may (or may not) be sharply distinct from the sapwood. However, other processes, such as decay, can discolor wood, even in woody plants that do not form heartwood, with a similar color difference, which may lead to confusion.
Sapwood is the younger, outermost wood; in the growing tree it is living wood, and its principal functions are to conduct water from the roots to the leaves and to store up and give back according to the season the reserves prepared in the leaves. However, by the time they become competent to conduct water, all xylem tracheids and vessels have lost their cytoplasm and the cells are therefore functionally dead. All wood in a tree is first formed as sapwood. The more leaves a tree bears and the more vigorous its growth, the larger the volume of sapwood required. Hence trees making rapid growth in the open have thicker sapwood for their size than trees of the same species growing in dense forests. Sometimes trees (of species that do form heartwood) grown in the open may become of considerable size, 30 cm or more in diameter, before any heartwood begins to form, for example, in second-growth hickory, or open-grown pines.
The term heartwood derives solely from its position and not from any vital importance to the tree. This is evidenced by the fact that a tree can thrive with its heart completely decayed. Some species begin to form heartwood very early in life, so having only a thin layer of live sapwood, while in others the change comes slowly. Thin sapwood is characteristic of such species as chestnut, black locust, mulberry, osage-orange, and sassafras, while in maple, ash, hickory, hackberry, beech, and pine, thick sapwood is the rule. Others never form heartwood.
There is no definite relation between the annual rings of growth and the amount of sapwood. Within the same species the cross-sectional area of the sapwood is very roughly proportional to the size of the crown of the tree. If the rings are narrow, more of them are required than where they are wide. As the tree gets larger, the sapwood must necessarily become thinner or increase materially in volume. Sapwood is thicker in the upper portion of the trunk of a tree than near the base, because the age and the diameter of the upper sections are less.
When a tree is very young it is covered with limbs almost, if not entirely, to the ground, but as it grows older some or all of them will eventually die and are either broken off or fall off. Subsequent growth of wood may completely conceal the stubs which will however remain as knots. No matter how smooth and clear a log is on the outside, it is more or less knotty near the middle. Consequently the sapwood of an old tree, and particularly of a forest-grown tree, will be freer from knots than the inner heartwood. Since in most uses of wood, knots are defects that weaken the timber and interfere with its ease of working and other properties, it follows that a given piece of sapwood, because of its position in the tree, may well be stronger than a piece of heartwood from the same tree.
It is remarkable that the inner heartwood of old trees remains as sound as it usually does, since in many cases it is hundreds, and in a few instances thousands, of years old. Every broken limb or root, or deep wound from fire, insects, or falling timber, may afford an entrance for decay, which, once started, may penetrate to all parts of the trunk. The larvae of many insects bore into the trees and their tunnels remain indefinitely as sources of weakness. Whatever advantages, however, that sapwood may have in this connection are due solely to its relative age and position.
If a tree grows all its life in the open and the conditions of soil and site remain unchanged, it will make its most rapid growth in youth, and gradually decline. The annual rings of growth are for many years quite wide, but later they become narrower and narrower. Since each succeeding ring is laid down on the outside of the wood previously formed, it follows that unless a tree materially increases its production of wood from year to year, the rings must necessarily become thinner as the trunk gets wider. As a tree reaches maturity its crown becomes more open and the annual wood production is lessened, thereby reducing still more the width of the growth rings. In the case of forest-grown trees so much depends upon the competition of the trees in their struggle for light and nourishment that periods of rapid and slow growth may alternate. Some trees, such as southern oaks, maintain the same width of ring for hundreds of years. Upon the whole, however, as a tree gets larger in diameter the width of the growth rings decreases.
Different pieces of wood cut from a large tree may differ decidedly, particularly if the tree is big and mature. In some trees, the wood laid on late in the life of a tree is softer, lighter, weaker, and more even-textured than that produced earlier, but in other trees, the reverse applies. This may or may not correspond to heartwood and sapwood. In a large log the sapwood, because of the time in the life of the tree when it was grown, may be inferior in hardness, strength, and toughness to equally sound heartwood from the same log. In a smaller tree, the reverse may be true.
Hard and soft woods
There is a strong relationship between the properties of wood and the properties of the particular tree that yielded it. For every tree species there is a range of density for the wood it yields. There is a rough correlation between density of a wood and its strength (mechanical properties). For example, while mahogany is a medium-dense hardwood which is excellent for fine furniture crafting, balsa is light, making it useful for model building. The densest wood may be black ironwood.
It is common to classify wood as either softwood or hardwood. The wood from conifers (e.g. pine) is called softwood, and the wood from dicotyledons (usually broad-leaved trees, e.g. oak) is called hardwood. These names are a bit misleading, as hardwoods are not necessarily hard, and softwoods are not necessarily soft. The well-known balsa (a hardwood) is actually softer than any commercial softwood. Conversely, some softwoods (e.g. yew) are harder than many hardwoods.
Engineered wood products have properties that usually differ from those of natural timbers. (see below)
Color
In species which show a distinct difference between heartwood and sapwood the natural color of heartwood is usually darker than that of the sapwood, and very frequently the contrast is conspicuous (see section of yew log above). This is produced by deposits in the heartwood of chemical substances, so that a dramatic color difference does not mean a dramatic difference in the mechanical properties of heartwood and sapwood, although there may be a dramatic chemical difference.
Some experiments on very resinous Longleaf Pine specimens indicate an increase in strength, due to the resin which increases the strength when dry. Such resin-saturated heartwood is called "fat lighter". Structures built of fat lighter are almost impervious to rot and termites; however they are very flammable. Stumps of old longleaf pines are often dug, split into small pieces and sold as kindling for fires. Stumps thus dug may actually remain a century or more since being cut. Spruce impregnated with crude resin and dried is also greatly increased in strength thereby.
Since the latewood of a growth ring is usually darker in color than the earlywood, this fact may be used in judging the density, and therefore the hardness and strength of the material. This is particularly the case with coniferous woods. In ring-porous woods the vessels of the early wood not infrequently appear on a finished surface as darker than the denser latewood, though on cross sections of heartwood the reverse is commonly true. Except in the manner just stated the color of wood is no indication of strength.
Abnormal discoloration of wood often denotes a diseased condition, indicating unsoundness. The black check in western hemlock is the result of insect attacks. The reddish-brown streaks so common in hickory and certain other woods are mostly the result of injury by birds. The discoloration is merely an indication of an injury, and in all probability does not of itself affect the properties of the wood. Certain rot-producing fungi impart to wood characteristic colors which thus become symptomatic of weakness; however an attractive effect known as spalting produced by this process is often considered a desirable characteristic. Ordinary sap-staining is due to fungous growth, but does not necessarily produce a weakening effect.
Structure
Wood is a heterogeneous, hygroscopic, cellular and anisotropic material. It is composed of cells, and the cell walls are composed of micro-fibrils of cellulose (40% – 50%) and hemicellulose (15% – 25%) impregnated with lignin (15% – 30%).
Sections of tree trunk
A tree trunk as found at the Veluwe, NetherlandsIn coniferous or softwood species the wood cells are mostly of one kind, tracheids, and as a result the material is much more uniform in structure than that of most hardwoods. There are no vessels ("pores") in coniferous wood such as one sees so prominently in oak and ash, for example.
The structure of hardwoods is more complex. The water conducting capability is mostly taken care of by vessels: in some cases (oak, chestnut, ash) these are quite large and distinct, in others (buckeye, poplar, willow) too small to be seen without a hand lens. In discussing such woods it is customary to divide them into two large classes, ring-porous and diffuse-porous. In ring-porous species, such as ash, black locust, catalpa, chestnut, elm, hickory, mulberry, and oak, the larger vessels or pores (as cross sections of vessels are called) are localised in the part of the growth ring formed in spring, thus forming a region of more or less open and porous tissue. The rest of the ring, produced in summer, is made up of smaller vessels and a much greater proportion of wood fibers. These fiber are the elements which give strength and toughness to wood, while the vessels are a source of weakness.
In diffuse-porous woods the pores are evenly sized so that the water conducting capability is scattered throughout the growth ring instead of being collected in a band or row. Examples of this kind of wood are basswood, birch, buckeye, maple, poplar, and willow. Some species, such as walnut and cherry, are on the border between the two classes, forming an intermediate group.
Earlywood and latewood in softwood
earlywood and latewood in a softwood; radial view, growth rings closely spaced in a Pseudotsuga taxifoliaIn temperate softwoods there often is a marked difference between latewood and earlywood. The latewood will be denser than that formed early in the season. When examined under a microscope the cells of dense latewood are seen to be very thick-walled and with very small cell cavities, while those formed first in the season have thin walls and large cell cavities. The strength is in the walls, not the cavities. Hence the greater the proportion of latewood the greater the density and strength. In choosing a piece of pine where strength or stiffness is the important consideration, the principal thing to observe is the comparative amounts of earlywood and latewood. The width of ring is not nearly so important as the proportion and nature of the latewood in the ring.
If a heavy piece of pine is compared with a lightweight piece it will be seen at once that the heavier one contains a larger proportion of latewood than the other, and is therefore showing more clearly demarcated growth rings. In white pines there is not much contrast between the different parts of the ring, and as a result the wood is very uniform in texture and is easy to work. In hard pines, on the other hand, the latewood is very dense and is deep-colored, presenting a very decided contrast to the soft, straw-colored earlywood.
It is not only the proportion of latewood, but also its quality, that counts. In specimens that show a very large proportion of latewood it may be noticeably more porous and weigh considerably less than the latewood in pieces that contain but little. One can judge comparative density, and therefore to some extent strength, by visual inspection
No satisfactory explanation can as yet be given for the exact mechanisms determining the formation of earlywood and latewood. Several factors may be involved. In conifers, at least, rate of growth alone does not determine the proportion of the two portions of the ring, for in some cases the wood of slow growth is very hard and heavy, while in others the opposite is true. The quality of the site where the tree grows undoubtedly affects the character of the wood formed, though it is not possible to formulate a rule governing it. In general, however, it may be said that where strength or ease of working is essential, woods of moderate to slow growth should be chosen.
Earlywood and latewood in ring-porous woods
Earlywood and latewood in a ring-porous wood (ash) in a Fraxinus excelsior ; tangential view, wide growth ringsIn ring-porous woods each season’s growth is always well defined, because the large pores formed early in the season abut on the denser tissue of the year before.
In the case of the ring-porous hardwoods there seems to exist a pretty definite relation between the rate of growth of timber and its properties. This may be briefly summed up in the general statement that the more rapid the growth or the wider the rings of growth, the heavier, harder, stronger, and stiffer the wood. This, it must be remembered, applies only to ring-porous woods such as oak, ash, hickory, and others of the same group, and is, of course, subject to some exceptions and limitations.
In ring-porous woods of good growth it is usually the latewood in which the thick-walled, strength-giving fibers are most abundant. As the breadth of ring diminishes, this latewood is reduced so that very slow growth produces comparatively light, porous wood composed of thin-walled vessels and wood parenchyma. In good oak these large vessels of the earlywood occupy from 6 to 10 per cent of the volume of the log, while in inferior material they may make up 25 per cent or more. The latewood of good oak is dark colored and firm, and consists mostly of thick-walled fibers which form one-half or more of the wood. In inferior oak, this latewood is much reduced both in quantity and quality. Such variation is very largely the result of rate of growth.
Wide-ringed wood is often called "second-growth", because the growth of the young timber in open stands after the old trees have been removed is more rapid than in trees in a closed forest, and in the manufacture of articles where strength is an important consideration such "second-growth" hardwood material is preferred. This is particularly the case in the choice of hickory for handles and spokes. Here not only strength, but toughness and resilience are important. The results of a series of tests on hickory by the U.S. Forest Service show that:
"The work or shock-resisting ability is greatest in wide-ringed wood that has from 5 to 14 rings per inch (rings 1.8-5 mm thick), is fairly constant from 14 to 38 rings per inch (rings 0.7-1.8 mm thick), and decreases rapidly from 38 to 47 rings per inch (rings 0.5-0.7 mm thick). The strength at maximum load is not so great with the most rapid-growing wood; it is maximum with from 14 to 20 rings per inch (rings 1.3-1.8 mm thick), and again becomes less as the wood becomes more closely ringed. The natural deduction is that wood of first-class mechanical value shows from 5 to 20 rings per inch (rings 1.3-5 mm thick) and that slower growth yields poorer stock. Thus the inspector or buyer of hickory should discriminate against timber that has more than 20 rings per inch (rings less than 1.3 mm thick). Exceptions exist, however, in the case of normal growth upon dry situations, in which the slow-growing material may be strong and tough."
The effect of rate of growth on the qualities of chestnut wood is summarised by the same authority as follows:
"When the rings are wide, the transition from spring wood to summer wood is gradual, while in the narrow rings the spring wood passes into summer wood abruptly. The width of the spring wood changes but little with the width of the annual ring, so that the narrowing or broadening of the annual ring is always at the expense of the summer wood. The narrow vessels of the summer wood make it richer in wood substance than the spring wood composed of wide vessels. Therefore, rapid-growing specimens with wide rings have more wood substance than slow-growing trees with narrow rings. Since the more the wood substance the greater the weight, and the greater the weight the stronger the wood, chestnuts with wide rings must have stronger wood than chestnuts with narrow rings. This agrees with the accepted view that sprouts (which always have wide rings) yield better and stronger wood than seedling chestnuts, which grow more slowly in diameter."
Earlywood and latewood in diffuse-porous woods
In the diffuse-porous woods, the demarcation between rings is not always so clear and in some cases is almost (if not entirely) invisible to the unaided eye. Conversely, when there is a clear demarcation there may not be a noticeable difference in structure within the growth ring.
In diffuse-porous woods, as has been stated, the vessels or pores are even-sized, so that the water conducting capability is scattered throughout the ring instead of collected in the earlywood. The effect of rate of growth is, therefore, not the same as in the ring-porous woods, approaching more nearly the conditions in the conifers. In general it may be stated that such woods of medium growth afford stronger material than when very rapidly or very slowly grown. In many uses of wood, total strength is not the main consideration. If ease of working is prized, wood should be chosen with regard to its uniformity of texture and straightness of grain, which will in most cases occur when there is little contrast between the latewood of one season’s growth and the earlywood of the next.
Monocot wood
Trunks of the Coconut palm, a monocot, in Java. From this perspective these look not much different from trunks of a dicot or coniferStructural material that roughly (in its gross handling characteristics) resembles ordinary, "dicot" or conifer wood is produced by a number of monocot plants, and these also are usually called wood. Of these, bamboo, botanically a member of the grass family, has considerable economic importance, larger culms being widely used as a building and construction material in their own right and, these days, in the manufacture of engineered flooring, panels and veneer. Another major plant group that produce material that often is called wood are the palms. Of much less importance are plants such as Pandanus, Dracaena and Cordyline. With all this material, the structure and composition of the structural material is quite different from ordinary wood.
Water content
The churches of Kizhi, Russia are among a handful of World Heritage Sites built entirely of wood, without metal joints.Water occurs in living wood in three conditions, namely: (1) in the cell walls, (2) in the protoplasmic contents of the cells, and as free water in the cell cavities and spaces. In heartwood it occurs only in the first and last forms. Wood that is thoroughly air-dried retains from 8-16% of water in the cell walls, and none, or practically none, in the other forms. Even oven-dried wood retains a small percentage of moisture, but for all except chemical purposes, may be considered absolutely dry.
The general effect of the water content upon the wood substance is to render it softer and more pliable. A similar effect of common observation is in the softening action of water on paper or cloth. Within certain limits, the greater the water content, the greater its softening effect.
Drying produces a decided increase in the strength of wood, particularly in small specimens. An extreme example is the case of a completely dry spruce block 5 cm in section, which will sustain a permanent load four times as great as that which a green (undried) block of the same size will support.[citation needed]
The greatest increase due to drying is in the ultimate crushing strength, and strength at elastic limit in endwise compression; these are followed by the modulus of rupture, and stress at elastic limit in cross-bending, while the modulus of elasticity is least affected.
Fuel
Main article: Wood fuel
Wood has a long history of being used as fuel, which continues to this day, mostly in rural areas of the world. Hardwood is preferred over softwood because it creates less smoke and burns longer. Adding a woodstove or fireplace to a home is often felt to add ambiance and warmth.
Construction
Wood can be cut into straight planks and made into a wood flooring.
The Saitta House, Dyker Heights, Brooklyn, New York built in 1899 is made of and decorated in wood.[8]Wood has been an important construction material since humans began building shelters, houses and boats. Nearly all boats were made out of wood until the late 19th century, and wood remains in common use today in boat construction.
Wood to be used for construction work is commonly known as lumber in North America. Elsewhere, lumber usually refers to felled trees, and the word for sawn planks ready for use is timber.
New domestic housing in many parts of the world today is commonly made from timber-framed construction. Engineered wood products are becoming a bigger part of the construction industry. They may be used in both residential and commercial buildings as structural and aesthetic materials.
In buildings made of other materials, wood will still be found as a supporting material, especially in roof construction, in interior doors and their frames, and as exterior cladding.
Wood is also commonly used as shuttering material to form the mould into which concrete is poured during reinforced concrete construction.
Engineered wood
Wood used in construction includes products such as glued laminated timber (glulam), laminated veneer lumber (LVL), parallam and I-joists. On the one hand these allow the use of smaller pieces, and on the other hand allow bigger spans. They may also be selected for specific projects such as public swimming pools or ice rinks where the wood will not deteriorate in the presence of certain chemicals. These engineered wood products prove to be more environmentally friendly, and sometimes cheaper, than building materials such as steel or concrete.
Wood unsuitable for construction in its native form may be broken down mechanically (into fibers or chips) or chemically (into cellulose) and used as a raw material for other building materials such as chipboard, engineered wood, hardboard, medium-density fiberboard (MDF), oriented strand board (OSB). Such wood derivatives are widely used: wood fibers are an important component of most paper, and cellulose is used as a component of some synthetic materials. Wood derivatives can also be used for kinds of flooring, for example laminate flooring.
Next generation wood products
Further developments include new lignin glue applications, recyclable food packaging, rubber tire replacement applications, anti-bacterial medical agents, and high strength fabrics or composites. As scientists and engineers further learn and develop new techniques to extract various components from wood, or alternatively to modify wood, for example by adding components to wood, new more advanced products will appear on the marketplace.
Furniture and utensils
Wood has always been used extensively for furniture, including chairs and beds. Also for tool handles and cutlery, such as chopsticks, toothpicks, and other utensils, like the wooden spoon.
In the arts
Artists can use wood to create delicate sculptures.
Stringed instrument bows are often made from pernambuco or brazilwood.Main article: Wood as a medium
Wood has long been used as an artistic medium. It has been used to make sculptures and carvings for millennia. Examples include the totem poles carved by North American indigenous people from conifer trunks, often Western Red Cedar (Thuja plicata), and the Millennium clock tower , now housed in the National Museum of Scotland[ in Edinburgh.
It is also used in woodcut printmaking, and for engraving.
Certain types of musical instruments, such as those of the violin family, the guitar, the clarinet and recorder, the xylophone, and the marimba, are made mostly or entirely of wood. The choice of wood may make a significant difference to the tone and resonant qualities of the instrument, and tonewoods have widely differing properties, ranging from the hard and dense african blackwood (used for the bodies of clarinets) to the light but resonant European spruce (Picea abies) (traditionally used for the soundboards of violins). The most valuable tonewoods, such as the ripple sycamore (Acer pseudoplatanus), used for the backs of violins, combine acoustic properties with decorative color and grain which enhance the appearance of the finished instrument.
Sports and recreational equipment
Many types of sports equipment are made of wood, or were constructed of wood in the past. For example, cricket bats are typically made of white willow. The baseball bats which are legal for use in Major League Baseball are frequently made of ash wood or hickory, and in recent years have been constructed from maple even though that wood is somewhat more fragile. In softball, however, bats are more commonly made of aluminium (this is especially true for fastpitch softball).
Many other types of sports and recreation equipment, such as skis, ice hockey sticks, lacrosse sticks and archery bows, were commonly made of wood in the past, but have since been replaced with more modern materials such as aluminium, fiberglass, carbon fiber, titanium, and composite materials. One noteworthy example of this trend is the golf club commonly known as the wood, the head of which was traditionally made of persimmon wood in the early days of the game of golf, but is now generally made of synthetic materials.
Medicine
In January 2010 Italian scientists announced that wood could be harnessed to become a bone substitute. It is likely to take at least five years until this technique will be applied for humans.
