Portal:Trees
The Trees Portal
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees.
Trees are not a monophyletic taxonomic group but consist of a wide variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight. The majority of tree species are angiosperms or hardwoods; of the rest, many are gymnosperms or softwoods. Trees tend to be long-lived, some reaching several thousand years old. Trees have been in existence for 370 million years. It is estimated that there are around three trillion mature trees in the world.
A tree typically has many secondary branches supported clear of the ground by the trunk, which typically contains woody tissue for strength, and vascular tissue to carry materials from one part of the tree to another. For most trees it is surrounded by a layer of bark which serves as a protective barrier. Below the ground, the roots branch and spread out widely; they serve to anchor the tree and extract moisture and nutrients from the soil. Above ground, the branches divide into smaller branches and shoots. The shoots typically bear leaves, which capture light energy and convert it into sugars by photosynthesis, providing the food for the tree's growth and development.
Trees usually reproduce using seeds. Flowers and fruit may be present, but some trees, such as conifers, instead have pollen cones and seed cones. Palms, bananas, and bamboos also produce seeds, but tree ferns produce spores instead.
Trees play a significant role in reducing erosion and moderating the climate. They remove carbon dioxide from the atmosphere and store large quantities of carbon in their tissues. Trees and forests provide a habitat for many species of animals and plants. Tropical rainforests are among the most biodiverse habitats in the world. Trees provide shade and shelter, timber for construction, fuel for cooking and heating, and fruit for food as well as having many other uses. In much of the world, forests are shrinking as trees are cleared to increase the amount of land available for agriculture. Because of their longevity and usefulness, trees have always been revered, with sacred groves in various cultures, and they play a role in many of the world's mythologies. (Full article...)
The Webster Sycamore (alternatively known as the Webster Springs Sycamore and the Big Sycamore Tree) was an American sycamore (Platanus occidentalis) in the U.S. state of West Virginia. Long recognized for its size, the Webster Sycamore was the largest living American sycamore tree in West Virginia until its felling in 2010. The tree stood approximately 4.5 miles (7.2 km) east of Webster Springs in Webster County, in a moist flood plain along the banks of the Back Fork Elk River, a tributary stream of the Elk River.
The Webster Sycamore reached a tree height measurement of 112 feet (34 m), a tree crown measurement of 90 feet (27 m), and a circumference of 25.75 feet (7.85 m) at breast height. In 1955, the American Forests Association declared the tree the largest of its species in the United States. It only held the title for three weeks, before the association identified a larger American sycamore in Maryland. Despite losing its national title, the sycamore remained the largest American sycamore in West Virginia. Following a 1963 survey of large trees in West Virginia, the Webster Sycamore was named the second-largest tree after a white oak (Quercus alba) in Randolph County. (Full article...)Did you know? -
- ... that the Top 10 New Species of the past year include a 40 foot (12 m) tall tree (pictured), a crustacean that looks like a skeleton, a protist that acts like a sponge, and a fungus named after the King of the Netherlands?
- ... that the Pass Christian Light was deactivated in part because neighboring property owners refused to trim their trees?
- ... that Cossinia trifoliata trees endemic to New Caledonia have become vulnerable to extinction, according to the International Union for Conservation of Nature's 1998 assessment?
- ... that the Hanlon Expressway is named after Felix Hanlon, who helped cut the first tree to inaugurate Guelph, Ontario?
- ... that British architect Richard Feilden was killed by a falling tree whilst creating a woodland memorial for his recently deceased father?
- ... that according to tradition the Church of the Holy Archangels, Rogoz was built from two huge elm trees?
- ... that the oak tree under which Goethe allegedly wrote Faust's Walpurgis Night scene stood inside Buchenwald concentration camp and was sketched by French Volontaires de la Liberté member and camp inmate Léon Delarbre?
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The stone pine, botanical name Pinus pinea, also known as the Italian stone pine, Mediterranean stone pine, umbrella pine and parasol pine, is a tree from the pine family (Pinaceae). The tree is native to the Mediterranean region, occurring in Southern Europe and the Levant. The species was introduced into North Africa millennia ago, and is also naturalized in the Canary Islands, South Africa and New South Wales.
Stone pines have been used and cultivated for their edible pine nuts since prehistoric times. They are widespread in horticultural cultivation as ornamental trees, planted in gardens and parks around the world. This plant has gained the Royal Horticultural Society's Award of Garden Merit. (Full article...)General images
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