Champion trees

The world's champion trees can be considered on several factors; height, trunk diameter or girth, total size, and age. It is significant that in each case, the top position is always held by a conifer, though a different species in each case; in most measures, the second to fourth places are also held by conifers.

Tallest trees

The heights of the tallest trees in the world have been the subject of considerable dispute and much (often wild) exaggeration. Modern verified measurement with laser rangefinders combined with tape drop measurements made by tree climbers, carried out by the U.S. Eastern Native Tree Society has shown that most older measuring methods and measurements are unreliable, often producing exaggerations of 5% to 15% above the real height. Historical claims of trees of 117 meters (384 ft), 130 meters (427 ft), and even 150 meters (492 ft), are now largely disregarded as unreliable, fantasy or outright fraud. The following are now accepted as the top five tallest reliably measured species:
Coast Redwood Sequoia sempervirens: 115.55 m (379.1 ft), Redwood National Park, California, United States
Coast Douglas-fir Pseudotsuga menziesii: 99.4 m (326.1 ft), Brummit Creek, Coos County, Oregon, United States
Australian Mountain-ash Eucalyptus regnans: 97.0 m (318.2 ft), Styx Valley, Tasmania, Australia
Sitka Spruce Picea sitchensis: 96.7 m (317.3 ft), Prairie Creek Redwoods State Park, California, United States
Giant Sequoia Sequoiadendron giganteum: 94.9 m (311.4 ft), Redwood Mountain Grove, Kings Canyon National Park, California, United States

A view of a tree from below; this may exaggerate apparent height

More about the coast redwood that is the tallest tree in the world.

Stoutest trees

The girth (circumference) of a tree is much easier to measure than the height, as it is a simple matter of stretching a tape round the trunk, and pulling it taut to find the circumference. Despite this, UK tree author Alan Mitchell made the following comment about measurements of yew trees in the British Isles:
"The aberrations of past measurements of yews are beyond belief. For example, the tree at Tisbury has a well-defined, clean, if irregular bole at least 1.5 m long. It has been found to have a girth which has dilated and shrunk in the following way: 11.28 m (1834 Loudon), 9.3 m (1892 Lowe), 10.67 m (1903 Elwes and Henry), 9.0 m (1924 E. Swanton), 9.45 m (1959 Mitchell) .... Earlier measurements have therefore been omitted".[citation needed]

As a general standard, tree girth is taken at 'breast height' (gbh); this is defined differently in different situations, with most foresters measuring girth at 1.3 meters (51 in) above ground, while ornamental tree measurers usually measure at 1.5 meters (59 in) above ground; in most cases this makes little difference to the measured girth. In the United States, measurements are mostly done at a height of 1.3 meters (51 in), while in the United Kingdom this is mostly done at 1.5 meters (59 in). On sloping ground, the "above ground" reference point is usually taken as the highest point on the ground touching the trunk, but some use the average between the highest and lowest points of ground. Some of the inflated old measurements may have been taken at ground level. Some past exaggerated measurements also result from measuring the complete next-to-bark measurement, pushing the tape in and out over every crevice and buttress.

Modern trends are to cite the tree's diameter rather than the circumference; this is obtained by dividing the measured circumference by π; it assumes the trunk is circular in cross-section (an oval or irregular cross-section would result in a mean diameter slightly greater than the assumed circle). This is cited as dbh (diameter at breast height) in tree literature.

A further problem with measuring baobabs Adansonia is that these trees store large amounts of water in the very soft wood in their trunks. This leads to marked variation in their girth over the year, swelling to a maximum at the end of the rainy season, minimum at the end of the dry season. Although baobabs have some of the highest girth measurements of any trees, no accurate measurements are currently available, but probably do not exceed 10-11 meter (33–36 ft) diameter.

An addition problem lies in cases where multiple trunks (whether from an individual tree or multiple trees) grow together. A good example of the difficulty of such cases is the Árbol del Tule, an 11.42 meter (37.5 ft) diameter Montezuma Cypress Taxodium mucronatum in Oaxaca, Mexico. Whether or not it is comprised of multiple trunks has long been a source of controversy. It is now known to be genetically a single organism (Dorado et al, 1996), but whether it is a single trunk or simply fused trunks/branches is not known[1][verification needed]. The Sacred Fig is another notorious example of this. A single tree can have hundreds of trunks, leading to diameter measurements of hundreds of meters.

The stoutest single-trunk species in diameter, excluding baobabs, are:
Kauri Agatha australis: 16.41 metres (54 feet) Te Matua Ngahere, Waipoua Forest of Northland Region, New Zealand
Jequitibá Cariniana excelsa Casar.: 10.5 m (34.4 ft) (http://www.cr.nps.gov/history/online_books/science/hartesveldt/chap2.htm)Template:Verify sourcedate
Giant Sequoia Sequoiadendron giganteum: 8.85 m (29 ft), General Grant tree, Grant Grove, California, United States
Coast Redwood Sequoia sempervirens: 7.44 m (24.4 ft), Prairie Creek Redwoods State Park, California, United States [citation needed]
Kauri Agathis australis: 7.25 m (23.8 ft) , Mercury Bay, New Zealan
Eucalyptus obliqua: 6.72 m (22 ft) , Reynolds Falls Nature Reserve, Tasmania, Australia (E. regnans has similarly large diameters)
Western Redcedar: Thuja plicata, 5.94 m (19.5 ft), Lake Quinault, Washington (Van Pelt, 2001)

Charles Darwin reported finding Fitzroya cupressoides with trunk circumferences of up to 40 meters (130 ft)[3], implying a diameter of about 12 meters (40 ft), but this may be an anomaly as the largest known measurements are about 4.5 meters (15 ft).

Largest trees

The largest trees in total volume are those which are both tall and of large diameter, and in particular, which hold a large diameter high up the trunk. Measurement is very complex, particularly if branch volume is to be included as well as the trunk volume, so measurements have only been made for a small number of trees, and generally only for the trunk. No attempt has ever been made to include root volume.

The top four species measured so far are:
Giant Sequoia Sequoiadendron giganteum: 1,489 m³ (55,040 cu ft), General Sherman
Coast Redwood Sequoia sempervirens: 1,045 m³ (36,890 cu ft), Del Norte Titan tree
Western Redcedar Thuja plicata: 500 m³ (17,650 cu ft ), Quinault Lake Redcedar
Kauri Agathis australis: circa 400 m³ (15,000 cu ft), Tane Mahuta tree (total volume, including branches, 516.7 m³/18,247 cu ft)

However, the Alerce Fitzroya cupressoides, as yet un-measured, may well slot in at third or fourth place, and Montezuma Cypress Taxodium mucronatum and other giants are also likely to be high in the list. The largest angiosperm tree is a Mountain Ash (Eucalyptus regnans) in Tasmania, known as the 'Two Towers' tree, with a volume of 430 cubic meters (15,185 cu ft).[12]

Oldest trees

The oldest trees are determined by growth rings, which can be seen if the tree is cut down or in cores taken from the edge to the center of the tree. Accurate determination is only possible for trees which produce growth rings, generally those which occur in seasonal climates; trees in uniform non-seasonal tropical climates grow continuously and do not have distinct growth rings. It is also only possible for trees which are solid to the center of the tree; many very old trees become hollow as the dead heartwood decays away. For some of these species, age estimates have been made on the basis of extrapolating current growth rates, but the results are usually little better than guesswork or wild speculation. White (1998)[13] proposes a method of estimating the age of large and veteran trees in the United Kingdom through the correlation between a tree's stem diameter, growth character and age.

The verified oldest measured ages are (Gymnosperm Database):
Great Basin Bristlecone Pine Pinus longaeva: 4844 years
Alerce Fitzroya cupressoides: 3622 years
Giant Sequoia Sequoiadendron giganteum: 3266 years
Huon-pine Lagarostrobos franklinii: 2500 years
Rocky Mountains Bristlecone Pine Pinus aristata: 2435 years

Other species suspected of reaching exceptional age include European Yew Taxus baccata (probably over 3000 years) and Western Redcedar Thuja plicata.

The oldest verified age for an angiosperm tree is 2293 years for the Sri Maha Bodhi Sacred Fig (Ficus religiosa) planted in 288 BC at Anuradhapura, Sri Lanka; this is also the oldest human-planted tree with a known planting date.

Trees in culture

The tree has been and still is a popular cultural symbol in most of the world. Common icons are the World tree, for instance Yggdrasil, and the tree of life. The tree often represents nature or the environment itself. A tree can also symbolize investment for humans, and is featured in insignia of some banks, for instance Swedbank.