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Tree Topping
Tree topping is the practice of removing whole tops of trees or large branches and/or trunks from the tops of trees, leaving stubs or lateral branches that are too small to assume the role of a terminal leader. Other common names for the practice include hat-racking, heading, rounding over, and tipping. Some species of trees are more likely to recover from topping than others. There are alternatives to topping that can help to achieve the same goals without damaging trees. Purpose Hundreds of large trees are topped each year, which causes significant stress and future safety issues. It has been shown through survey that the average person's knowledge on tree care is limited. Another popular misconception is that a topped tree will benefit from increased light penetration. The removal of a large portion of a tree's canopy can have detrimental effects. When a tree is topped, newly formed bark may be susceptible to sun scald. Prolonged exposure can severely damage the bark, thus cre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree
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 taxonomic group but include a 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 some three trillion mature trees in the world. A tree typically has many secondary branches supported clear of the ground by the trunk. This trunk typicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arborist
An arborist, tree surgeon, or (less commonly) arboriculturist, is a professional in the practice of arboriculture, which is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants in dendrology and horticulture. Arborists generally focus on the health and safety of individual plants and trees, rather than managing forests or harvesting wood ( forestry or silviculture). An arborist's scope of work is therefore distinct from that of either a forester or a logger. Scope of work In order for arborists to work near power wires, either additional training is required or they need to be certified as a Qualified Line Clearance Arborist or Utility Arborist (there may be different terminology for various countries). There is a variety of minimum distances that must be kept from power wires depending on voltage, however the common distance for low voltage lines in urban settings is 10 feet (about 3 metres). Arborists who cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topping (agriculture)
Topping is a process by which a mower or similar implement is used to "top", or remove, the aerial part of a crop, in order to prevent seed formation and distribution onto the soil. Typically, a set-aside cover crop is topped in July or August, to prevent seed production and subsequent soil contamination leading to germination and regrowth. For example, controlling the spread of Soft rush or Juncus Effusus on wet land, such as Purple Moor and Rush Pastures. A variation of topping is often employed in order to create a more stout and bushy plant, one that is suitable for thriving indoors. See also * Tree topping Tree topping is the practice of removing whole tops of trees or large branches and/or trunks from the tops of trees, leaving stubs or lateral branches that are too small to assume the role of a terminal leader. Other common names for the practice i ... Agricultural terminology {{Agri-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Amnesty
PlantAmnesty is a non-profit education and advocacy group based in Seattle, Washington. PlantAmnesty was founded by arborist Cass Turnbull on October 22, 1987, as a mock protest group intended to educate the public about the problems associated with pruning techniques which are biologically harmful to plants and counter productive to the goals of landscape design and management; most notably tree topping Tree topping is the practice of removing whole tops of trees or large branches and/or trunks from the tops of trees, leaving stubs or lateral branches that are too small to assume the role of a terminal leader. Other common names for the practice i .... The stated mission of the organization "is to end the senseless torture and mutilation of trees and shrubs." PlantAmnesty also provides an "adopt-a-plant" exchange for unwanted, healthy plants. References External links Plant Amnesty Horticultural organizations based in the United States Organizations established in 1987 Or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollarding
Pollarding is a pruning system involving the removal of the upper branches of a tree, which promotes the growth of a dense head of foliage and branches. In ancient Rome, Propertius mentioned pollarding during the 1st century BCE. The practice occurred commonly in Europe since medieval times, and takes place today in urban areas worldwide, primarily to maintain trees at a determined height or to place new shoots out of the reach of grazing animals. Traditionally, people pollarded trees for one of two reasons: for fodder to feed livestock or for wood. Fodder pollards produced "pollard hay" for livestock feed; they were pruned at intervals of two to six years so their leafy material would be most abundant. Wood pollards were pruned at longer intervals of eight to fifteen years, a pruning cycle tending to produce upright poles favored for fencing and boat construction. Supple young willow or hazel branches may be harvested as material for weaving baskets, fences, and garden constru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coppicing
Coppicing is a traditional method of woodland management which exploits the capacity of many species of trees to put out new shoots from their stump or roots if cut down. In a coppiced wood, which is called a copse, young tree stems are repeatedly cut down to near ground level, resulting in a stool. New growth emerges, and after a number of years, the coppiced tree is harvested, and the cycle begins anew. Pollarding is a similar process carried out at a higher level on the tree in order to prevent grazing animals from eating new shoots. '' Daisugi'' (台杉, where ''sugi'' refers to Japanese cedar), is a similar Japanese technique. Many silviculture practices involve cutting and regrowth; coppicing has been of significance in many parts of lowland temperate Europe. The widespread and long-term practice of coppicing as a landscape-scale industry is something that remains of special importance in southern England. Many of the English language terms referenced in this article are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arboriculture
Arboriculture () is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants. The science of arboriculture studies how these plants grow and respond to cultural practices and to their environment. The practice of arboriculture includes cultural techniques such as selection, planting, training, fertilization, pest and pathogen control, pruning, shaping, and removal. Overview A person who practices or studies arboriculture can be termed an ''arborist'' or an ''arboriculturist''. A ''tree surgeon'' is more typically someone who is trained in the physical maintenance and manipulation of trees and therefore more a part of the arboriculture process rather than an arborist. Risk management, legal issues, and aesthetic considerations have come to play prominent roles in the practice of arboriculture. Businesses often need to hire arboriculturists to complete "tree hazard surveys" and generally manage the trees on-site to fulfill oc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulmus Parvifolia
''Ulmus parvifolia'', commonly known as the Chinese elm or lacebark elm, is a species native to eastern Asia, including China, India, Japan, Korea, and Vietnam.Fu, L., Xin, Y. & Whittemore, A. (2002)Ulmaceae in Wu, Z. & Raven, P. (eds) ''Flora of China'', Vol. 5 (Ulmaceae through Basellaceae). Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis, USA; also available as It has been described as "one of the most splendid elms, having the poise of a graceful '' Nothofagus''".''Hilliers' Manual of Trees & Shrubs'', 4th edition, 1977, David & Charles, Newton Abbot, England The tree was introduced to the UK in 1794 by James Main, who collected in China for Gilbert Slater of Low Layton, Essex.Elwes, H. J. & Henry, A. (1913). The Trees of Great Britain & Ireland'. Vol. VII. 1848–1929. Republished 2004 Cambridge University Press, Bean, W. J. (1981). ''Trees and shrubs hardy in Great Britain'', 7th edition. Murray, London. Description A small to medium deciduous or se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Resistance
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers (or surfaces) or between a fluid and a solid surface. Unlike other resistive forces, such as dry friction, which are nearly independent of velocity, the drag force depends on velocity. Drag force is proportional to the velocity for low-speed flow and the squared velocity for high speed flow, where the distinction between low and high speed is measured by the Reynolds number. Even though the ultimate cause of drag is viscous friction, turbulent drag is independent of viscosity. Drag forces always tend to decrease fluid velocity relative to the solid object in the fluid's path. Examples Examples of drag include the component of the net aerodynamic or hydrodynamic force acting opposite to the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wire Rope
Steel wire rope (right hand lang lay) Wire rope is several strands of metal wire twisted into a helix forming a composite ''rope'', in a pattern known as ''laid rope''. Larger diameter wire rope consists of multiple strands of such laid rope in a pattern known as ''cable laid''. In stricter senses, the term ''wire rope'' refers to a diameter larger than , with smaller gauges designated cable or cords. Initially wrought iron wires were used, but today steel is the main material used for wire ropes. Historically, wire rope evolved from wrought iron chains, which had a record of mechanical failure. While flaws in chain links or solid steel bars can lead to catastrophic failure, flaws in the wires making up a steel cable are less critical as the other wires easily take up the load. While friction between the individual wires and strands causes wear over the life of the rope, it also helps to compensate for minor failures in the short run. Wire ropes were developed starting with mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind
Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few hours, to global winds resulting from the difference in absorption of solar energy between the climate zones on Earth. The two main causes of large-scale atmospheric circulation are the differential heating between the equator and the poles, and the rotation of the planet (Coriolis effect). Within the tropics and subtropics, thermal low circulations over terrain and high plateaus can drive monsoon circulations. In coastal areas the sea breeze/land breeze cycle can define local winds; in areas that have variable terrain, mountain and valley breezes can prevail. Winds are commonly classified by their spatial scale, their speed and direction, the forces that cause them, the regions in which they occur, and their effect. Winds have vario ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
