Tree

==Uses==

===Food===
{{further|nut (fruit)|fruit}}

Trees are the source of many of the world's best known fleshy fruits. Apples, pears, plums, cherries and citrus are all grown commercially in temperate climates and a wide range of edible fruits are found in the tropics. Other commercially important fruit include dates, figs and olives. [[Palm oil]] is obtained from the fruits of the oil palm (''[[Elaeis guineensis]]''). The fruits of the cocoa tree (''[[Theobroma cacao]]'') are used to make [[cocoa solids|cocoa]] and chocolate and the berries of coffee trees, ''[[Coffea arabica]]'' and ''[[Coffea canephora]]'', are processed to extract the coffee beans. In many rural areas of the world, fruit is gathered from forest trees for consumption.<ref>{{cite web |url=http://www.fao.org/docrep/X5325e/x5325e0c.htm |title=Monetary valuation of tree-based resources in Zimbabwe |author=Campbell, B. |year=1993 |publisher=FAO: Forestry Department |access-date=13 September 2012 |archive-date=1 May 2013 |archive-url=https://web.archive.org/web/20130501225016/http://www.fao.org/docrep/X5325e/x5325e0c.htm |url-status=live }}</ref> Many trees bear edible nuts which can loosely be described as being large, oily kernels found inside a hard shell. These include [[coconut]]s (''Cocos nucifera''), [[Brazil nut]]s (''Bertholletia excelsa''), [[pecan]]s (''Carya illinoinensis''), [[Hazel|hazel nuts]] (''Corylus''), [[almond]]s (''Prunus dulcis''), [[walnut]]s (''Juglans regia''), [[pistachio]]s (''Pistacia vera'') and many others. They are high in nutritive value and contain high-quality protein, vitamins and minerals as well as dietary fibre.<ref>{{cite news |title=Walnuts are the healthiest nut, say scientists |url=https://www.bbc.co.uk/news/health-12865291 |newspaper=BBC News: Health |date=28 March 2011 |access-date=21 September 2014 |archive-date=24 September 2017 |archive-url=https://web.archive.org/web/20170924113046/http://www.bbc.co.uk/news/health-12865291 |url-status=live }}</ref> A variety of [[List of vegetable oils#Nut oils|nut oils]] are extracted by pressing for culinary use; some such as walnut, pistachio and hazelnut oils are prized for their distinctive flavours, but they tend to spoil quickly.<ref>{{cite book |url=https://archive.org/details/isbn_9780740769764 |url-access=registration |title=Things Cooks Love |author=Simmons, Marie |publisher=Andrews McMeel |year=2008 |page=[https://archive.org/details/isbn_9780740769764/page/295 295] |isbn=978-0-7407-6976-4}}</ref>

[[File:Maple syrup taps.jpg|thumb|left|Sugar maple (''[[Acer saccharum]]'') tapped to collect sap for [[maple syrup]]]]

In temperate climates there is a sudden movement of sap at the end of the winter as trees prepare to burst into growth. In North America, the sap of the sugar maple (''[[Acer saccharum]]'') is most often used in the production of a sweet liquid, [[maple syrup]]. About 90% of the sap is water, the remaining 10% being a mixture of various sugars and certain minerals. The sap is harvested by drilling holes in the trunks of the trees and collecting the liquid that flows out of the inserted spigots. It is piped to a sugarhouse where it is heated to concentrate it and improve its flavour. Similarly in northern Europe the spring rise in the [[Birch sap|sap]] of the silver birch (''Betula pendula'') is tapped and collected, either to be drunk fresh or fermented into an alcoholic drink. In Alaska, the sap of the sweet birch (''[[Betula lenta]]'') is made into a syrup with a sugar content of 67%. Sweet birch sap is more dilute than maple sap; a hundred litres are required to make one litre of birch syrup.<ref>{{cite web |url=http://www.alaskabirchsyrup.com/abbisy.html |title=About birch syrup |publisher=Alaska Wild Harvest |access-date=27 July 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120815013022/http://www.alaskabirchsyrup.com/abbisy.html |archive-date=15 August 2012 }}</ref>

Various parts of trees are used as spices. These include [[cinnamon]], made from the bark of the cinnamon tree (''[[Cinnamomum zeylanicum]]'') and [[allspice]], the dried small fruits of the pimento tree (''[[Pimenta dioica]]''). [[Nutmeg]] is a seed found in the fleshy fruit of the nutmeg tree (''[[Myristica fragrans]]'') and [[clove]]s are the unopened flower buds of the clove tree (''[[Syzygium aromaticum]]'').<ref name=spices/>

Many trees have flowers rich in [[nectar]] which are attractive to bees. The production of forest honey is an important industry in rural areas of the developing world where it is undertaken by small-scale beekeepers using traditional methods.<ref>{{cite web |url=http://www.tropicalforest.com/Tropical_Forest/Tropical_Forest_home.html |archive-url=https://web.archive.org/web/20111015230522/http://www.tropicalforest.com/Tropical_Forest/Tropical_Forest_home.html |archive-date=15 October 2011 |title=Honey |publisher=Tropical Forest |access-date=28 July 2012 |url-status=dead }}</ref> The flowers of the elder (''[[Sambucus]]'') are used to make [[elderflower cordial]] and petals of the plum (''[[Prunus]] spp.'') can be candied.<ref>{{cite web |url=http://extension.colostate.edu/topic-areas/yard-garden/edible-flowers-7-237/ |title=Edible flowers |author1=Newman, S. E. |author2=O'Connor, A. Stoven |date=November 2009 |publisher=Colorado State University Extension |access-date=28 July 2012 |archive-date=11 October 2015 |archive-url=https://web.archive.org/web/20151011151626/http://extension.colostate.edu/topic-areas/yard-garden/edible-flowers-7-237/ |url-status=live }}</ref> [[Sassafras]] oil is a flavouring obtained from distilling bark from the roots of the sassafras tree (''[[Sassafras albidum]]'').

The leaves of trees are widely gathered as fodder for livestock and some can be eaten by humans but they tend to be high in tannins which makes them bitter. Leaves of the curry tree (''[[Murraya koenigii]]'') are eaten, those of [[kaffir lime]] (''Citrus × hystrix'') (in [[Thai food]])<ref name=thaitravel>{{cite web |last=Loha-unchit |first=Kasma |title=Kaffir Lime: Magrood |work=Thai Food and Travel |url=http://www.thaifoodandtravel.com/ingredients/klime.html |access-date=16 May 2012 |archive-date=9 May 2019 |archive-url=https://web.archive.org/web/20190509021529/http://www.thaifoodandtravel.com/ingredients/klime.html |url-status=live }}</ref> and ''[[Ailanthus]]'' (in [[Korean food|Korean]] dishes such as [[bugak]]) and those of the European bay tree (''[[Laurus nobilis]]'') and the California bay tree (''[[Umbellularia californica]]'') are used for flavouring food.<ref name=spices>{{cite web |url=http://waynesword.palomar.edu/ecoph16.htm |title=Allspice, Bay Rum, Bay Leaves, Capers, Cloves, Cinnamon, Camphor, Witch Hazel & Nutmeg |last=Armstrong |first=Wayne P. |date=1 June 2012 |work=Wayne's Word |access-date=28 July 2012 |archive-date=10 August 2012 |archive-url=https://web.archive.org/web/20120810131037/http://waynesword.palomar.edu/ecoph16.htm |url-status=live }}</ref> ''[[Camellia sinensis]]'', the source of tea, is a small tree but seldom reaches its full height, being heavily pruned to make picking the leaves easier.<ref>{{cite web |url=http://www.upasitearesearch.org/tea-cultivation-practices/ |title=Tea cultivation and practices |publisher=Upasi Tea Research Foundation |access-date=13 September 2012 |archive-date=17 October 2012 |archive-url=https://web.archive.org/web/20121017032147/http://www.upasitearesearch.org/tea-cultivation-practices/ |url-status=live }}</ref>

[[Smoking (cooking)|Wood smoke]] can be used to preserve food. In the hot smoking process the food is exposed to smoke and heat in a controlled environment. The food is ready to eat when the process is complete, having been tenderised and flavoured by the smoke it has absorbed. In the cold process, the temperature is not allowed to rise above {{convert | 100 | °F | °C | abbr=on}}. The flavour of the food is enhanced but raw food requires further cooking. If it is to be preserved, meat should be [[Curing (food preservation)|cured]] before cold smoking.<ref>{{cite news |title=The rise and rise of smoking food |last=Mackenzie |first=Sophie |url=https://www.theguardian.com/lifeandstyle/wordofmouth/2012/jan/30/rise-of-smoking-food |newspaper=The Guardian |date=30 January 2012 |access-date=27 July 2012 |location=London |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304052854/http://www.theguardian.com/lifeandstyle/wordofmouth/2012/jan/30/rise-of-smoking-food |url-status=live }}</ref>

===Fuel===
{{main | Wood fuel}}
[[File:Selling fuelwood.jpeg|thumb|Selling firewood at a market]]

Wood has traditionally been used for fuel, especially in rural areas. In less developed nations it may be the only fuel available and collecting firewood is often a time-consuming task as it becomes necessary to travel further and further afield in the search for fuel.<ref>{{cite web |url=https://www.un.org/womenwatch/feature/idrw/index-2008.html |title=Women watch: International Day of Rural Women |date=15 October 2008 |publisher=United Nations Inter-agency Network on Women and Gender Equality |access-date=1 August 2012 |archive-date=17 December 2011 |archive-url=https://web.archive.org/web/20111217142532/http://www.un.org/womenwatch/feature/idrw/index-2008.html |url-status=live }}</ref> It is often burned inefficiently on an open fire. In more developed countries other fuels are available and burning wood is a choice rather than a necessity. Modern [[wood-burning stove]]s are very fuel efficient and new products such as [[wood pellet]]s are available to burn.<ref>{{cite web |url=http://www.epa.gov/burnwise/ |title=Burn Wise |publisher=United States Environmental Protection Agency |access-date=27 July 2012 |date=8 May 2013 |archive-date=19 March 2021 |archive-url=https://web.archive.org/web/20210319140434/https://www.epa.gov/burnwise |url-status=live }}</ref>

[[Charcoal]] can be made by slow [[pyrolysis]] of wood by heating it in the absence of air in a [[kiln]]. The carefully stacked branches, often oak, are burned with a very limited amount of air. The process of converting them into charcoal takes about fifteen hours. Charcoal is used as a fuel in [[barbecue]]s and by [[blacksmith]]s and has many industrial and other uses.<ref>{{cite web |url=http://www.woodlands.co.uk/blog/practical-guides/how-do-you-make-charcoal/ |title=How do you make charcoal? |work=Woodlands.co.uk |publisher=Woodland Investment Management |access-date=27 July 2012 |archive-date=4 June 2012 |archive-url=https://web.archive.org/web/20120604175105/http://www.woodlands.co.uk/blog/practical-guides/how-do-you-make-charcoal/ |url-status=live }}</ref>

===Timber===
{{main|Wood|Timber}}
[[File:Timberwork2.JPG|thumb|upright=1.2<!--fmt for low image-->|left|Roof trusses made from softwood]]

Timber, "trees that are grown in order to produce wood"<ref>{{cite web|title = timber {{!}} trees that are grown in order to produce wood|url = http://www.merriam-webster.com/dictionary/timber|website = www.merriam-webster.com|access-date = 3 September 2015|archive-date = 19 September 2015|archive-url = https://web.archive.org/web/20150919081941/http://www.merriam-webster.com/dictionary/timber|url-status = live}}</ref> is cut into lumber (sawn wood) for use in construction. Wood has been an important, easily available material for construction since humans started building shelters. [[Engineered wood]] products are available which bind the particles, fibres or [[Wood veneer|veneers]] of wood together with adhesives to form [[composite material]]s. Plastics have taken over from wood for some traditional uses.<ref>{{cite web |url=http://www.fao.org/docrep/004/Y3609E/Y3609E00.HTM |title=Environmental and energy balances of wood products and substitutes |last1=Scharai-Rad |first1=Mohammad |author2=Welling, Johannes |year=2002 |publisher=Food and Agriculture Organization of the United Nations |access-date=30 July 2012 |archive-date=9 November 2012 |archive-url=https://web.archive.org/web/20121109163747/http://www.fao.org/docrep/004/y3609e/y3609e00.htm |url-status=live }}</ref>

Wood is used in the construction of buildings, bridges, trackways, piles, poles for power lines, masts for boats, pit props, railway sleepers, fencing, hurdles, shuttering for concrete, pipes, scaffolding and pallets. In housebuilding it is used in joinery, for making joists, roof trusses, roofing shingles, thatching, staircases, doors, window frames, floor boards, parquet flooring, panelling and cladding.<ref name=Appalachian>{{cite web |url=http://www.appalachianwood.org/utilization.htm |title=Wood utilization |publisher=Appalachian Hardwood Manufacturers |access-date=27 July 2012 |archive-date=28 July 2012 |archive-url=https://web.archive.org/web/20120728010824/http://www.appalachianwood.org/utilization.htm |url-status=live }}</ref>

[[File:Claude Monet, Weeping Willow.JPG|thumb|upright|Trees in art: ''[[Weeping Willow (painting)|Weeping Willow]]'', [[Claude Monet]], 1918]]

Wood is used to construct carts, farm implements, boats, dugout canoes and in shipbuilding. It is used for making furniture, tool handles, boxes, ladders, musical instruments, bows, weapons, matches, clothes pegs, brooms, shoes, baskets, turnery, carving, toys, pencils, rollers, cogs, wooden screws, barrels, coffins, skittles, veneers, artificial limbs, oars, skis, wooden spoons, sports equipment and wooden balls.<ref name=Appalachian/>

Wood is pulped for paper and used in the manufacture of cardboard and made into engineered wood products for use in construction such as [[Medium-density fibreboard|fibreboard]], [[hardboard]], [[Particle board|chipboard]] and [[plywood]].<ref name=Appalachian/> The wood of conifers is known as [[softwood]] while that of broad-leaved trees is [[hardwood]].<ref>{{cite web |url=http://www.dnr.state.md.us/forests/gloss.html |archive-url=https://web.archive.org/web/20120712173543/http://www.dnr.state.md.us/forests/gloss.html |archive-date=12 July 2012 |title=Glossary of Forestry Terms |last=Pywell |first=Nancy |date=7 October 2003 |access-date=30 July 2012 |url-status=dead }}</ref>

===Art===

Besides inspiring artists down the centuries, trees have been used to create art. Living trees have been used in [[bonsai]] and in [[tree shaping]], and both living and dead specimens have been sculpted into sometimes fantastic shapes.<ref>{{cite magazine |url=http://mentalfloss.com/article/30098/10-artists-who-work-trees |title=10 Artists Who Work in Trees |author=Cellania, Miss<!--NOT LAST, FIRST--> |date=28 February 2012 |magazine=Mental Floss |access-date=20 September 2014 |archive-date=3 August 2014 |archive-url=https://web.archive.org/web/20140803191336/http://mentalfloss.com/article/30098/10-artists-who-work-trees |url-status=live }}</ref>

====Bonsai====
[[File:Dwarf Japanese Juniper, 1975-2007.jpg|thumb|upright|Informal upright style of [[bonsai]] on a [[juniper]] tree]]
{{main|Bonsai}}

{{Nihongo |Bonsai | 盆栽 | | lit. "Tray planting"}}<ref>{{cite book | last=Gustafson |first=Herbert L. | title=Miniature Bonsai | publisher=Sterling Publishing Company, Inc. | year=1995 | isbn=0-8069-0982-X | page=[https://archive.org/details/miniaturebonsai00gust/page/9 9] | url-access=registration | url=https://archive.org/details/miniaturebonsai00gust/page/9 }}</ref> is the practice of [[Hòn Non Bộ|''hòn non bộ'']] originated in China and spread to Japan more than a thousand years ago, there are similar practices in other cultures like the living miniature landscapes of Vietnam ''hòn non bộ''. The word ''bonsai'' is often used in English as an [[umbrella term]] for all miniature trees in containers or pots.<ref>{{cite book |first=David |last=Squire |title=The Bonsai Specialist |url=https://books.google.com/books?id=7IrFEu13suIC&pg=PA3 |year=2004 |publisher=New Holland Publishers |isbn=978-1-84330-543-9 |page=3 |access-date=28 February 2016 |archive-date=4 March 2017 |archive-url=https://web.archive.org/web/20170304193243/https://books.google.com/books?id=7IrFEu13suIC&pg=PA3 |url-status=live }}</ref>

The purposes of bonsai are primarily contemplation (for the viewer) and the pleasant exercise of effort and ingenuity (for the grower).<ref name="bonsai_masterclass_peter_chan">{{cite book |last=Chan |first=Peter |title=Bonsai Masterclass |publisher=Sterling Publishing Co., Inc. |year=1987 |isbn=978-0-8069-6763-9 |ref=bonsai_masterclass_peter_chan}}</ref> Bonsai practice focuses on long-term cultivation and shaping of one or more small trees growing in a container, beginning with a cutting, seedling, or small tree of a species suitable for bonsai development. Bonsai can be created from nearly any [[perennial]] woody-stemmed tree or shrub species<ref name="the_bonsai_identifier">{{cite book |last=Owen |first=Gordon |title=The Bonsai Identifier |publisher=Quintet Publishing Ltd. |year=1990 |isbn=978-0-88665-833-5 |page=[https://archive.org/details/bonsaiidentifier0000owen/page/11 11] |url=https://archive.org/details/bonsaiidentifier0000owen/page/11 }}</ref> that produces true branches and can be cultivated to remain small through pot confinement with crown and root pruning. Some [[List of species used in bonsai|species]] are popular as bonsai material because they have characteristics, such as small leaves or needles, that make them appropriate for the compact visual scope of bonsai and a miniature deciduous forest can even be created using such species as [[Japanese maple]], [[Zelkova serrata|Japanese zelkova]] or [[hornbeam]].<ref>{{cite book |first=David |last=Squire |title=The Bonsai Specialist |url=https://books.google.com/books?id=7IrFEu13suIC&pg=PA66 |year=2004 |publisher=New Holland Publishers |isbn=978-1-84330-543-9 |page=66 |access-date=28 February 2016 |archive-date=4 March 2017 |archive-url=https://web.archive.org/web/20170304135627/https://books.google.com/books?id=7IrFEu13suIC&pg=PA66 |url-status=live }}</ref>

====Tree shaping====
{{main|Tree shaping}}
[[File:Person-tree.jpg|thumb|left|''People trees'', by Pooktre]]

Tree shaping is the practice of changing living trees and other woody plants into man made shapes for art and useful structures. There are a few different methods<ref name="CottageGarden">{{Cite journal |first=Mörður |last=Gunnarsson |title=Living Furniture |journal=Cottage and Garden |pages=28–29 |year=2012 }}</ref> of shaping a tree. There is a gradual method and there is an instant method. The gradual method slowly guides the growing tip along predetermined pathways over time whereas the instant method bends and weaves saplings {{convert|2|to|3|m|ft|abbr=on}} long into a shape that becomes more rigid as they thicken up.<ref name="LLC2007">{{cite book |author=Dwell, LLC |title=Dwell |url=https://books.google.com/books?id=f8YDAAAAMBAJ&pg=PA96 |date=February 2007 |publisher=Dwell, LLC |page=96 |issn=1530-5309 |access-date=28 February 2016 |archive-date=4 March 2017 |archive-url=https://web.archive.org/web/20170304135950/https://books.google.com/books?id=f8YDAAAAMBAJ&pg=PA96 |url-status=live }}</ref> Most artists use grafting of living trunks, branches, and roots, for art or functional structures and there are plans to grow "living houses" with the branches of trees knitting together to give a solid, weatherproof exterior combined with an interior application of straw and clay to provide a [[stucco]]-like inner surface.<ref name="LLC2007"/>

Tree shaping has been practised for at least several hundred years, the oldest known examples being the [[living root bridges]] built and maintained by the [[Khasi people|Khasi]] people of [[Meghalaya]], India using the roots of the [[Ficus elastica|rubber tree]] (''Ficus elastica'').<ref>{{cite web |url=http://www.picturesw.com/2012/08/the-natural-root-bridges-of-cherrapunji.html |title=The natural root bridges of Cherrapunji, India |date=7 August 2012 |publisher=Pictures World |access-date=17 September 2014 |archive-date=24 September 2014 |archive-url=https://web.archive.org/web/20140924180958/http://www.picturesw.com/2012/08/the-natural-root-bridges-of-cherrapunji.html |url-status=live }}</ref><ref>{{cite web |url=http://www.treehugger.com/sustainable-product-design/living-bridges-in-india-have-grown-for-500-years-pics.html |title=Living Bridges in India Have Grown for 500 Years |last=Merchant |first=Brian |date=28 September 2010 |work=Treehugger |access-date=17 September 2014 |archive-date=23 October 2014 |archive-url=https://web.archive.org/web/20141023050359/http://www.treehugger.com/sustainable-product-design/living-bridges-in-india-have-grown-for-500-years-pics.html |url-status=live }}</ref>

===Bark===
[[File:CorkOakStripped.jpg|thumb|upright|Recently stripped cork oak (''[[Quercus suber]]'')]]
{{further|Bark (botany)}}

[[Cork (material)|Cork]] is produced from the thick bark of the cork oak (''[[Quercus suber]]''). It is harvested from the living trees about once every ten years in an environmentally sustainable industry.<ref>{{cite web |url=http://www.azom.com/news.aspx?newsID=4951 |title=Cork Flooring is Environmentally Sustainable |date=27 February 2006 |publisher=AZoM.com |access-date=26 July 2012 |archive-date=7 November 2012 |archive-url=https://web.archive.org/web/20121107104856/http://www.azom.com/news.aspx?newsID=4951 |url-status=live }}</ref> More than half the world's cork comes from Portugal and is largely used to make stoppers for wine bottles.<ref name=cork>{{cite web |url=http://people.uwec.edu/ivogeler/Travel/Portugal/cork-article2.htm |title=The cork industry in Portugal |author1=Calheiros e Meneses |author2=J. L. |publisher=University of Wisconsin |access-date=26 July 2012 |archive-date=14 September 2014 |archive-url=https://web.archive.org/web/20140914040935/http://people.uwec.edu/ivogeler/Travel/Portugal/cork-article2.htm |url-status=live }}</ref> Other uses include floor tiles, bulletin boards, balls, footwear, cigarette tips, packaging, insulation and joints in woodwind instruments.<ref name=cork/>

The bark of other varieties of oak has traditionally been used in Europe for the [[Tanning (leather)|tanning]] of hides though bark from other species of tree has been used elsewhere. The active ingredient, [[tannin]], is extracted and after various preliminary treatments, the skins are immersed in a series of vats containing solutions in increasing concentrations. The tannin causes the hide to become supple, less affected by water and more resistant to bacterial attack.<ref>{{cite web |title=3. Tanneries, Description of the Tanning Process |access-date=26 July 2012 |publisher=Food and Agriculture Organization of the United Nations |url=http://www.fao.org/WAIRDOCS/LEAD/X6114E/x6114e05.htm#b1-3.1.%20Description%20of%20the%20tanningprocess |archive-date=22 August 2011 |archive-url=https://web.archive.org/web/20110822080512/http://www.fao.org/WAIRDOCS/LEAD/X6114E/x6114e05.htm#b1-3.1.%20Description%20of%20the%20tanningprocess |url-status=live }}</ref>

At least 120 drugs come from [[medicinal plant|plant sources]], many of them from the bark of trees.<ref name=rainforest>{{cite web |url=http://rainforest-database.com/plants/plantdrugs.htm |title=Plant Based Drugs and Medicines |author=Taylor, Leslie |date=13 October 2000 |work=The Healing Power of Rainforest Herbs |access-date=27 July 2012 |archive-date=29 June 2012 |archive-url=https://web.archive.org/web/20120629144821/http://rainforest-database.com/plants/plantdrugs.htm |url-status=live }}</ref> [[Quinine]] originates from the cinchona tree (''[[Cinchona]]'') and was for a long time the remedy of choice for the treatment of [[malaria]].<ref>{{cite web |title=Guidelines for the treatment of malaria |publisher=World Health Organization |url=http://apps.who.int/iris/bitstream/10665/162441/1/9789241549127_eng.pdf?ua=1&ua=1 |year=2006 |access-date=26 July 2012 |archive-date=13 October 2015 |archive-url=https://web.archive.org/web/20151013193459/http://apps.who.int/iris/bitstream/10665/162441/1/9789241549127_eng.pdf?ua=1&ua=1 |url-status=live }}</ref> [[Aspirin]] was synthesised to replace the [[sodium salicylate]] derived from the bark of willow trees (''[[Salix]]'') which had unpleasant side effects.<ref>{{Cite journal |last1=Sneader |first1=W. |title=The discovery of aspirin: A reappraisal |journal=BMJ (Clinical Research Ed.) |volume=321 |issue=7276 |pages=1591–1594 |year=2000 |pmid=11124191 |pmc=1119266 |doi=10.1136/bmj.321.7276.1591}}</ref> The anti-cancer drug [[Paclitaxel]] is derived from taxol, a substance found in the bark of the Pacific yew (''[[Taxus brevifolia]]'').<ref>{{cite book |last1=Goodman |first1=Jordan |last2=Walsh |first2=Vivien |title=The Story of Taxol: Nature and Politics in the Pursuit of an Anti-Cancer Drug |publisher=Cambridge University Press |year=2001 |isbn=978-0-521-56123-5 |page=[https://archive.org/details/storyoftaxolnatu00jord/page/17 17] |url=https://archive.org/details/storyoftaxolnatu00jord/page/17 }}</ref> Other tree based drugs come from the paw-paw (''[[Carica papaya]]''), the cassia ([[Cassia (genus)|''Cassia'' spp.]]), the cocoa tree (''Theobroma cacao''), the tree of life (''[[Camptotheca acuminata]]'') and the downy birch (''[[Betula pubescens]]'').<ref name=rainforest/>

The papery bark of the white birch tree (''[[Betula papyrifera]]'') was used extensively by [[Indigenous peoples of the Americas|Native Americans]]. [[Wigwam]]s were covered by it and [[canoe]]s were constructed from it. Other uses included food containers, hunting and fishing equipment, musical instruments, toys and sledges.<ref>{{cite web |url=http://www.nativetech.org/brchbark/brchbark.htm |title=Uses for birch bark |author=Prindle, Tara |year=1994 |publisher=NativeTech: Native American Technology and Art |access-date=27 July 2012 |archive-date=18 September 2012 |archive-url=https://web.archive.org/web/20120918040348/http://www.nativetech.org/brchbark/brchbark.htm |url-status=live }}</ref> Nowadays, bark chips, a by-product of the timber industry, are used as a mulch and as a growing medium for epiphytic plants that need a soil-free compost.<ref>{{cite web |url=http://www.orchid-growing-secrets.com/choosing-the-right-potting-media-for-your-orchid/ |archive-url=https://web.archive.org/web/20121115211019/http://www.orchid-growing-secrets.com/choosing-the-right-potting-media-for-your-orchid/ |archive-date=15 November 2012 |title=Choosing the right potting media for your orchid |author=Johnson, Aidan |date=25 January 2011 |work=Orchid growing secrets |access-date=27 July 2012 |url-status=dead }}</ref>

[[File:Fontaine-l'Eveque JPG01c.jpg|thumb|left|[[Avenue (landscape)|Alleé]] of [[Platanus × acerifolia|London plane trees (''Platanus'' × ''acerifolia'')]] in garden]]

===Ornamental trees===
{{main|Ornamental trees}}
Trees create a visual impact in the same way as do other landscape features and give a sense of maturity and permanence to park and garden. They are grown for the beauty of their forms, their foliage, flowers, fruit and bark and their siting is of major importance in creating a landscape. They can be grouped informally, often surrounded by plantings of bulbs, laid out in stately avenues or used as specimen trees. As living things, their appearance changes with the season and from year to year.<ref>{{cite book |title=The Royal Horticultural Society Encyclopedia of Gardening |editor-last=Brickell |editor-first=Christopher  |year=1992 |publisher=Dorling Kindersley |chapter=Ornamental trees |isbn=978-0-86318-979-1 |pages=32–33}}</ref>

Trees are often planted in town environments where they are known as street trees or amenity trees. They can provide shade and cooling through [[evapotranspiration]], absorb greenhouse gases and pollutants, intercept rainfall, and reduce the risk of flooding. Scientific studies show that street trees help cities be more sustainable, and improve the physical and mental wellbeing of the citizens.<ref>{{Cite journal |last1=Turner-Skoff|first1=J. |last2=Cavender|first2=N. |title=The Benefits of Trees for Livable and Sustainable Communities |journal=Plants, People, Planet  |volume=1 |issue=4 |pages=323–335 |year=2019 |doi=10.1002/ppp3.39|doi-access=free }}</ref> It has been shown that they are beneficial to humans in creating a sense of well-being and reducing stress. Many towns have initiated tree-planting programmes.<ref>{{cite web |url=http://www.forestry.gov.uk/fr/urgc-7EKEC8 |title=Street trees |work=Greenspace initiative |publisher=Forestry Commission |access-date=20 September 2014 |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304110933/http://www.forestry.gov.uk/fr/urgc-7EKEC8 |url-status=live }}</ref> In London for example, there is an initiative to plant 20,000 new street trees and to have an increase in tree cover of 5% by 2025, equivalent to one tree for every resident.<ref>{{cite web |url=https://www.london.gov.uk/WHAT-WE-DO/environment/parks-green-spaces-and-biodiversity/releaf-partnership |title=The RE:LEAF Partnership|work=Greening London |publisher=Mayor of London |access-date=20 September 2014 |date=10 August 2015 |archive-date=24 April 2016 |archive-url=https://web.archive.org/web/20160424163422/https://www.london.gov.uk/what-we-do/environment/parks-green-spaces-and-biodiversity/releaf-partnership |url-status=live }}</ref>

===Other uses===
[[File:Sri Lanka-Rubber plantation (5).JPG|thumb|upright|[[Latex]] collecting from a [[Hevea brasiliensis|rubber tree (''Hevea brasiliensis'')]]]]
{{further|Resin|Latex|Camphor}}

Latex is a sticky defensive secretion that protects plants against [[herbivore]]s. Many trees produce it when injured but the main source of the latex used to make [[natural rubber]] is the Pará rubber tree (''Hevea brasiliensis''). Originally used to create bouncy balls and for the waterproofing of cloth, natural rubber is now mainly used in tyres for which synthetic materials have proved less durable.<ref>{{cite web |url=http://www.azom.com/article.aspx?ArticleID=2101 |title=Natural rubber: History and Developments in the Natural Rubber Industry |author=Baker, C |year=1997 |work=Materials World |publisher=AZoM.com |access-date=26 July 2012 |archive-date=28 July 2012 |archive-url=https://web.archive.org/web/20120728170522/http://www.azom.com/article.aspx?ArticleID=2101 |url-status=live }}</ref> The latex exuded by the balatá tree (''[[Manilkara bidentata]]'') is used to make [[golf ball]]s and is similar to [[gutta-percha]], made from the latex of the "getah perca" tree ''[[Palaquium]]''. This is also used as an insulator, particularly of undersea cables, and in dentistry, walking sticks and gun butts. It has now largely been replaced by synthetic materials.<ref>{{cite web |url=http://www.atlantic-cable.com/Article/GuttaPercha/ |title=The Gutta Percha Company |author=Burns, Bill |date=15 February 2010 |work=History of the Atlantic Cable and Undersea Communications |access-date=26 July 2012 |archive-date=23 April 2018 |archive-url=https://web.archive.org/web/20180423170435/http://atlantic-cable.com/Article/GuttaPercha/ |url-status=live }}</ref>

Resin is another plant exudate that may have a defensive purpose. It is a viscous liquid composed mainly of volatile [[terpene]]s and is produced mostly by coniferous trees. It is used in varnishes, for making small castings and in [[ten-pin bowling]] balls. When heated, the terpenes are driven off and the remaining product is called "rosin" and is used by stringed instrumentalists on their [[Bow (music)|bows]]. Some resins contain [[essential oil]]s and are used in [[incense]] and [[aromatherapy]]. Fossilised resin is known as amber and was mostly formed in the Cretaceous (145 to 66 million years ago) or more recently. The resin that oozed out of trees sometimes trapped insects or spiders and these are still visible in the interior of the amber.<ref>{{cite web |url=http://gurukul.ucc.american.edu/ted/amber.htm |title=Amber Trade and the Environment in the Kaliningrad Oblast |author=Jacobson, Douglas |year=1997 |work=The Mandala Projects |access-date=26 July 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120706182814/http://gurukul.ucc.american.edu/ted/amber.htm |archive-date=6 July 2012 }}</ref>

The camphor tree (''[[Cinnamomum camphora]]'') produces an essential oil<ref name=spices/> and the eucalyptus tree (''[[Eucalyptus globulus]]'') is the main source of [[eucalyptus oil]] which is used in medicine, as a fragrance and in industry.<ref>{{cite web |url=http://www.fao.org/docrep/v5350e/v5350e07.htm |publisher=Food and Agriculture Organization of the United Nations |title=Chapter 5: Eucalyptus oil |work=Flavours and fragrances of plant origin |access-date=19 March 2015 |archive-date=2 May 2012 |archive-url=https://web.archive.org/web/20120502162220/http://www.fao.org/docrep/V5350E/V5350e07.htm |url-status=live }}</ref>