Pine Explained

A pine is any conifer in the genus Pinus (^[1]) of the family Pinaceae. Pinus is the sole genus in the subfamily Pinoideae. The species are evergreen trees or shrubs with their leaves in bunches, usually of 2 to 5 needles. The seeds are carried on woody cones, with two seeds to each cone scale.

Pines are widely distributed in the Northern Hemisphere; they occupy large areas of taiga (boreal forest), but are found in many habitats, including the Mediterranean Basin, and dry tropical forests in southeast Asia and Central America. Some are fire-resistant or fire-dependent.

Pine trees provide one of the most extensively used types of timber. The pine nuts are used to make dishes such as pesto, while retsina wine is flavoured with pine resin.

Description

Tree

Pine trees are evergreen, coniferous resinous trees (or, rarely, shrubs) growing 3– tall, with the majority of species reaching 15– tall.^[2] The smallest are Siberian dwarf pine and Potosi pinyon, and the tallest is an 83.45m (273.79feet) tall sugar pine (Pinus lambertiana) located in Yosemite National Park.^[3]

Pines are long lived and typically reach ages of 100–1,000 years, some even more. The longest-lived is the Great Basin bristlecone pine (Pinus longaeva). One individual in the White Mountains of California, dubbed "Methuselah", is among the world's oldest living organisms at around 4,800 years old.^[4] An older tree near Wheeler Peak, now cut down, was dated at 4,900 years old.^{[5] [6]}

The spirals of branches, needles, and cone scales are arranged in Fibonacci number ratios.^{[7] [8]}

Bark

The bark of most pines is thick and scaly, but some species have thin, flaky bark. The branches are produced in "pseudo-whorls", actually a very tight spiral but appearing like a ring of branches arising from the same point. Many pines are uninodal, producing just one such whorl of branches each year, from buds at the tip of the year's new shoot, but others are multinodal, producing two or more whorls of branches per year.^[9]

Foliage

Pines have four types of leaf:^[9]

• Seed leaves (cotyledons) on seedlings are borne in a whorl of 4–24.
• Juvenile leaves, which follow immediately on seedlings and young plants, are NaNcm (-2,147,483,648inches) long, single, green or often blue-green, and arranged spirally on the shoot. These are produced for six months to five years, rarely longer.
• Scale leaves, similar to bud scales, are small, brown and not photosynthetic, and arranged spirally like the juvenile leaves.
• Needles, the adult leaves, are green (photosynthetic) and bundled in clusters called fascicles. The needles can number from one to seven per fascicle, but generally number from two to five. Each fascicle is produced from a small bud on a dwarf shoot in the axil of a scale leaf. These bud scales often remain on the fascicle as a basal sheath. The needles persist for 1.5–40 years, depending on species. If a shoot's growing tip is damaged (e.g. eaten by an animal), the needle fascicles just below the damage generate a stem-producing bud, which can then replace the lost growth tip.

Cones

Pines are monoecious, having the male and female cones on the same tree.^[10] The male cones are small, typically 1–5 cm long, and only present for a short period (usually in spring, though autumn in a few pines), falling as soon as they have shed their pollen. The female cones take 1.5–3 years (depending on species) to mature after pollination, with actual fertilisation delayed one year. At maturity, the female cones are 3–60 cm long. Each cone has numerous spirally-arranged scales, with two seeds on each fertile scale; the scales at the base and tip of the cone are small and sterile without seeds.^[9]

The seeds (pine nuts) are mostly small and winged, and are anemochorous (wind-dispersed). Some are larger, have only a vestigial wing, and are bird-dispersed. Female cones are woody and sometimes armed to protect developing seeds from foragers. At maturity, the cones usually open to release the seeds. In some of the bird-dispersed species, for example whitebark pine,^[11] the seeds are only released by the bird breaking the cones open. In others, the seeds are stored in closed cones for many years until an environmental cue triggers the cones to open, releasing the seeds. This is called serotiny. The most common form of serotiny is pyriscence, in which resin binds the cones shut until the resin is melted by a forest fire, for example in P. radiata and P. muricata. The seeds are then released after the fire, enabling them to colonise the burnt ground with minimal competition from other plants.^{[9] [12]}

Naming

The modern English name "pine" derives from Latin pinus, traced to the Indo-European base *pīt- 'resin'.^[13] Before the 19th century, pines were often called firs, a name now applied to another genus, Abies. In some European languages, Germanic cognates of the Old Norse name are still in use for pines, as in Danish fyr and German Föhre.^[14] The genus Pinus was named by Carl Linnaeus in 1753. Pinus sylvestris, the Scots pine, was later chosen as the type species.^{[15] [16]}

Several other conifers are commonly known as pines, such as the Norfolk Island pine (Araucaria heterophylla); however, they belong to other genera.^[17]

Evolution

Fossil history

The Pinaceae, the pine family, first appeared in the Jurassic period.^[18] The genus Pinus first appeared during the Early Cretaceous; the oldest verified fossil is Pinus yorkshirensis from the Hauterivian-Barremian boundary (~130-125 million years ago) from the Speeton Clay, England.^[19] However, there are possible records of the genus from the Jurassic.^[20]

External phylogeny

Based on transcriptome analysis, Pinus is most closely related to the genus Cathaya, which in turn is closely related to the genus Picea, the spruces. These genera, with firs and larches, form the pinoid clade of the Pinaceae.

Internal phylogeny

The evolutionary history of the genus Pinus has been complicated by hybridisation. Pines are prone to inter-specific breeding. Wind pollination, long life spans, overlapping generations, large population size, and weak reproductive isolation make breeding across species more likely. As the pines have diversified, gene transfer between different species has created a complex history of genetic relatedness.^{[21] [22]} Research using large genetic datasets has clarified these relationships. Two 21st century phylogenies are given below; the differences between them demonstrate these complications:

Taxonomy

See main article: List of ''Pinus'' species.

Pines are gymnosperms. The genus is divided into two subgenera based on the number of fibrovascular bundles in the needle, and the presence or absence of a resin seal on the scales of the mature cones before opening. The subgenera can be distinguished by cone, seed, and leaf characters:^[9]

• Pinus subg. Pinus, the yellow, or hard pine group, with cones with a resin seal on the scales, and generally with harder wood; the needle fascicles mostly have a persistent sheath (two exceptions, Pinus leiophylla and Pinus lumholtzii, have deciduous sheaths).^[9]
• Pinus subg. Strobus, syn. Pinus subg. Ducampopinus, the white or soft pine, and pinyon pine groups, with cones without a resin seal on the scales, and usually have softer wood; the needle fascicles mostly have a deciduous sheath (one exception, Pinus nelsonii, has a persistent sheath).^[9]

Phylogenetic evidence indicates that the subgenera diverged anciently from one another.^[24] Each subgenus is further divided into sections and subsections.^[25]

World Flora Online accepts 134 species-rank taxa (119 species and 15 nothospecies) of pines as current, with additional synonyms,^[26] and Plants of the World Online 126 species-rank taxa (113 species and 13 nothospecies),^[27] making it the largest genus among the conifers. The highest species diversity of pines is found in Mexico.^{[28] [29] [30]}

Distribution

See also: List of pines by region.

Pines are native to the Northern Hemisphere, with the most species in North America, some in Asia, and a few in Europe. Only two species, Pinus sylvestris and Pinus sibirica, occur in more than one of those regions (Asia and Europe).^[31] They occupy large areas of boreal forest (taiga) in latitudes between 50° and 60° N; about a third of this biome is in North America and Scandinavia, the rest in Siberia.^[32] The northernmost species is Scots pine, reaching just north of 70° N in Stabbursdalen National Park in Norway;^[33] One species, Pinus merkusii, crosses the equator in Sumatra to 2°S.^[34] In North America, various species occur in regions at latitudes from as far north as 66° N^[34] to as far south as 12°N.^[35]

Various species have been introduced to temperate and subtropical regions of both hemispheres, where they are grown as timber or cultivated as ornamental plants in parks and gardens. A number of such introduced species have become naturalised, and species such as Pinus radiata are considered invasive in some regions.^[36]

Ecology

Environmental factors

Pines grow in a very large variety of environments, ranging from semi-arid desert to rainforests, from sea level up to 5200m (17,100feet), from the coldest to the hottest environments on Earth. They often occur in mountainous areas with favourable soils.^[37]

Pinus contorta is a fire-dependent species, requiring wildfires to maintain healthy populations of diverse ages.^[38] Pinus canariensis is highly fire-resistant,^[39] with adaptations such as growing epicormic sprouts after losing its needles in a fire.^[40] Some species such as Pinus muricata need fire to open their cones, allowing them to disperse their seeds.^[41] Other pines such as Pinus mugo^[42] and Pinus yunnanensis can grow at high elevation.^[43] Some pines, such as Pinus sabiniana, are adapted to growth in hot, dry semidesert climates.^[44]

Species interactions

Pine needles serve as food for the caterpillar larvae of several moth species including the pine beauty, a pest of mature stands of pine trees,^[45] and the pine hawk-moth, a large species which causes only occasional damage.^[46] Some moths, notably the pine processionary, whose caterpillars can completely defoliate pine trees,^{[47] [48] [49]} and the pine-tree lappet, are serious pests of commercial forestry.^[50]

Several species of pine are attacked by nematodes, causing pine wilt disease, which can quickly kill trees.^{[51] [52]} The sawfly Diprion pini is likewise a serious commercial pest of pine forestry, especially of Pinus sylvestris.^[53] Some birds such as nutcrackers are specialist feeders on pine seeds, and are important in distributing the seeds widely.^{[54] [55]} Crossbills rely on Pinus sylvestris seeds in Scotland, and similarly help significantly to disperse the seeds, whereas red squirrels feed on the seeds but do little for seed dispersal.^[56] Pine pollen may contribute to food webs involving detritivores. Nutrients from pollen aid detritivores in development, growth, and maturation, and may enable fungi to decompose plant litter which is low in nutrients.^[57] The edible^[58] basidiomycete fungus Boletus pinophilus (pine bolete) forms an ectomycorrhizal association with pines such as P. cembra, P. nigra, and P. sylvestris.^[59]

Uses

Timber

Pines are among the most commercially important tree species, valued for their timber and wood pulp throughout the world.^{[60] [61]} In temperate and tropical regions, they are fast-growing softwoods that grow in relatively dense stands. Commercial pines are grown in plantations for timber that is denser and therefore more durable than spruce (Picea). Pine wood is widely used in high-value carpentry items such as furniture, window frames, panelling, floors, and roofing due to its abundance and low cost.^[62]

As pine wood has little resistance to insects or decay after logging, in its untreated state it is generally recommended for indoor construction purposes only, such as indoor drywall framing. It is commonly used in Canadian Lumber Standard graded wood.^[63] For outside use, pine needs to be treated with copper azole, chromated copper arsenate or other suitable chemical preservatives.^[64]

Ornamental uses

Many pine trees make attractive ornamental plantings for parks and larger gardens, while dwarf cultivars are suitable for smaller spaces. There are at least 818 named cultivars (or trinomials) recognised by the American Conifer Society ACS.

Food

The seeds (pine nuts) are generally edible; the young male cones can be cooked and eaten, as can the bark of young twigs.^[65] Some species have large pine nuts, which are harvested and sold for cooking and baking. They are an ingredient of pesto alla genovese.^[66]

The soft, moist, white inner bark (cambium) beneath the woody outer bark is edible and very high in vitamins A and C.^[67] It can be eaten raw in slices as a snack or dried and ground up into a powder for use as an ersatz flour or thickener in stews, soups, and other foods, such as bark bread.^[68] The use of pine cambium gave the Adirondack Indians their name, from the Mohawk Indian word atirú:taks, meaning "tree eaters".^[68]

A herbal tea is made by steeping young, green pine needles in boiling water (known as tallstrunt in Sweden). In eastern Asia, pine and other conifers are accepted among consumers as a beverage product, and used in teas, as well as wine.^[69] In Greece, the wine retsina is flavoured with resin from Pinus halepensis (Aleppo pine).^[70]

Other uses

Turpentine oil, traditionally used as a solvent in paints, resins and varnishes, is extracted from pine resin^[71] or pine wood.^[72] Pine needles are woven into baskets in Latin America.^[73] In traditional Chinese medicine, pine resin is used for burns, wounds and skin complaints.^[74] Chinese ink sticks for calligraphy are often made of pine soot, producing a matt black ink when mixed with water.^[75] Pine needles have been used by Latvian designer Tamara Orjola to create biodegradable products including paper, furniture, textiles and dyestuffs.^[76]

Culture

In ancient Egypt, the god Osiris was honoured with an image placed in a cavity inside a pine tree. In ancient Greece, the goddess Pitthea was linked with pines, while in ancient Rome, the tree was worshipped in the festival of the god Attis and the goddess Cybele. The Greek god of wine, Dionysus (also called Bacchus), was associated with pine as a symbol of fertility, and his devotees carried a stick topped with a pine cone (a thyrsus), a phallic symbol. The Buryat people of Siberia revered groves of Pinus sylvestris, while ancient Celtic Druids marked the midwinter solstice with fires of the same species.^[77]

In 1924, the Italian composer Ottorino Respighi completed his tone poem Pines of Rome. Each of its four movements depicts a pine-clad setting in the city of Rome, namely the Villa Borghese gardens, near a catacomb, on the Janiculum Hill, and along the Appian Way.^[78]

Pines are often featured in paintings. A 2021 study lists over a hundred works: many are by artists from the Mediterranean region, such as Paul Cézanne and Jean-Baptiste-Camille Corot; Northern Europe, such as Akseli Gallen-Kallela and James William Giles; and North America, with works by Tom Thomson and others. The paintings often depict Pinus pinea by the Mediterranean sea; other species include P. sylvestris and P. pinaster.^[79] The pine is a particular motif in Chinese art and literature, which sometimes combines painting and poetry in the same work. The pine symbolises longevity and steadfastness, as it retains its green needles throughout the year. Sometimes the pine and cypress are paired. At other times the pine, plum, and bamboo are considered as the "Three Friends of Winter".^[80]

See also

• El Pino (The Pine Tree)
• Pine barrens
• Pine-cypress forest
• Pine Tree Flag
• Tree of Peace

Further reading

• Book: Farjon, A. . 2005 . 2nd . Pines . E. J. Brill . 90-04-13916-8 . none.
• Little . Elbert L., Jr. . Critchfield . W.B. . 1969 . Subdivisions of the Genus Pinus (Pines) . US Department of Agriculture . Misc. Publ. 1144 (Superintendent of Documents Number: A 1.38:1144) . none.
• Book: Richardson . D. M. . 1998 . Ecology and Biogeography of Pinus . Cambridge University Press . 530 . 0-521-55176-5 . none.
• Book: Sulavik, Stephen B. . 2007 . Adirondack; Of Indians and Mountains, 1535-1838 . Purple Mountain Press . 244 pages . 978-1-930098-79-4 . none.
• Book: Mirov, N. T. . 1967 . The Genus Pinus . Ronald Press . none .
• Web site: Classification of pines . The Lovett Pinetum Charitable Foundation . 17 January 2004 . 3 June 2004 . https://web.archive.org/web/20040603181329/http://www.pinetum.org/Lovett/classification.htm . live . none .
• Mirov . N. T. . Stanley . R.G. . 10.1146/annurev.pp.10.060159.001255 . The Pine Tree . Annual Review of Plant Physiology . 10 . 223–238 . 1959 . none.
• Book: Philips, Roger . Trees of North America and Europe . . 0-394-50259-0 . 1979 . registration . none .

External links

• 40 Species of Pine Trees You Can Grow by The Spruce
• , covers Californian species
• Pinus in Flora of North America
• Pinus in the USDA Plants Database
• Conifer Database

Notes and References

1. Encyclopedia: Medical Definition of PINUS . Pinus . Merriam-Webster Medical Dictionary .
2. News: Tallest of the tall . Fattig . Paul . 23 January 2011 . . 27 January 2011 . https://web.archive.org/web/20120923095326/http://www.mailtribune.com/apps/pbcs.dll/article?AID=%2F20110123%2FNEWS%2F101230353%2F . 23 September 2012 .
3. News: 3 Sierra sugar pines added to list of 6 biggest in world . Associated Press . 31 Jan 2021. 13 Feb 2023.
4. Ryan . Michael . Richardson . David M. . The Complete Pine . BioScience . December 1999 . 49 . 12 . 1023–1024 . 10.2307/1313736 . 1313736.
5. News: Miranda . Carolina A. . 28 February 2015 . Follow-up: More tales of the Prometheus tree and how it died . . 16 October 2020.
6. Eveleth . Rose . Rose Eveleth . 15 November 2012 . How One Man Accidentally Killed the Oldest Tree Ever . . . 16 October 2020.
7. Zeng . Lanling . Wang . Guozhao . Modeling golden section in plants . Progress in Natural Science . 2009 . 19 . 2 . 255–260 . 10.1016/j.pnsc.2008.07.004 . The ratio between two pine needles is 0.618 [...] the angle between the two neighbors is about 135° and the angle between the main stem and each branch is close to 34.4° which is the golden section of 90° . free. 2009PNSMI..19..255Z .
8. Web site: Pinus (Pine) Notes . Bracewell . Ronald . Rawlings . John . Trees of Stanford . 2 February 2020.
9. Book: Royal Horticultural Society Dictionary of Gardening . Macmillan Press

   Stockton Press

   . 1992 . 1-56159-001-0 . 3 . 582–594.
10. Book: W.S. . Judd . C.S. . Campbell . E.A. . Kellogg . P.F. . Stevens . M.J. . Donoghue . 2002 . Plant systematics, a phylogenetic approach . 2 . . 0-87893-403-0 . 205.
11. Tomback . Diana F. . Diana Tomback . June 1982 . Dispersal of Whitebark Pine seeds by Clark's Nutcracker: a mutualism hypothesis . The Journal of Animal Ecology . 51 . 2 . 451–467 . 10.2307/3976 . 3976 . 1982JAnEc..51..451T .
12. Book: Rushforth, Keith . 1987 . Conifers . . London, England, UK . 0-7470-2801-X . 158–192.
13. Web site: Where Are You From? - Credo Reference . credoreference.com.
14. Book: Vedel . Helge . Lange . Johan . Trees and Bushes in Wood and Hedgerow . 1960 . . 123–124.
15. Book: Linnaeus, Carolus . 1753 . Species plantarum: exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas. Tomus I & II. . Impensis Laurentii Salvii . 1000.
16. Book: Price . R. A. . Liston . A. . Strauss . S. H. . 1998 . Phylogeny and systematics of Pinus . 49–68 . Richardson . D. M. . Ecology and Biogeography of Pinus . . 978-0-521-55176-2.
17. Web site: Norfolk Island Pine – Gardening Solutions . 28 January 2026.
18. Ran . Jin-Hua . Shen . Ting-Ting . Wu . Hui . Gong . Xun . Wang . Xiao-Quan . December 2018 . Phylogeny and evolutionary history of Pinaceae updated by transcriptomic analysis . Molecular Phylogenetics and Evolution . 129 . 106–116 . 10.1016/j.ympev.2018.08.011 . 30153503 . 2018MolPE.129..106R . 52110440.
19. Ryberg . Patricia E. . Rothwell . Gar W. . Stockey . Ruth A. . Hilton . Jason . Mapes . Gene . Riding . James B. . 2012 . Reconsidering Relationships among Stem and Crown Group Pinaceae: Oldest Record of the Genus Pinus from the Early Cretaceous of Yorkshire, United Kingdom . International Journal of Plant Sciences . 173 . 8 . 917–932 . 10.1086/667228 . 2012IJPlS.173..917R . 85402168.
20. Web site: Ralikhomo tracksite (zone C/3) (Jurassic of Lesotho) . PBDB.org.
21. Hernández-León . Sergio . Gernandt . David S. . Pérez de la Rosa . Jorge A. . Jardón-Barbolla . Lev . 30 July 2013 . Phylogenetic relationships and species delimitation in Pinus section Trifoliae inferred from plastid DNA . PLOS ONE . 8 . 7 . e70501 . 2013PLoSO...870501H . 10.1371/journal.pone.0070501 . 3728320 . 23936218 . free.
22. Flores-Rentería . Lluvia . Wegier . Ana . Ortega Del Vecchyo . Diego . Ortíz-Medrano . Alejandra . Piñero . Daniel . Whipple . Amy V. . Molina-Freaner . Francisco . Domínguez . César A. . 5 . Genetic, morphological, geographical and ecological approaches reveal phylogenetic relationships in complex groups, an example of recently diverged pinyon pine species (Subsection Cembroides) . Molecular Phylogenetics and Evolution . 69 . 3 . 940–9 . December 2013 . 23831459 . 10.1016/j.ympev.2013.06.010 . 2013MolPE..69..940F .
23. Phylogenomic and ecological analyses reveal the spatiotemporal evolution of global pines . Jin . Wei-Tao . Gernandt . David S. . Wehenkel . Christian . Xia . Xiao-Mei . Wei . Xiao-Xin . Wang . Xiao-Quan . PNAS . May 2021 . 10.1073/pnas.2022302118 . 118 . 20 . e2022302118 . 33941644 . 8157994 . 2021PNAS..11822302J . free.
24. Stull . Gregory W. . Qu . Xiao-Jian . Parins-Fukuchi . Caroline . Yang . Ying-Ying . Yang . Jun-Bo . Yang . Zhi-Yun . Hu . Yi . Ma . Hong . Soltis . Pamela S. . Soltis . Douglas E. . Li . De-Zhu . 5 . 19 July 2021 . Gene duplications and phylogenomic conflict underlie major pulses of phenotypic evolution in gymnosperms . Nature Plants . 7 . 8 . 1015–1025 . 10.1038/s41477-021-00964-4 . 34282286 . 2021NatPl...7.1015S . 236141481 . 2055-0278 . 10 January 2022 . 10 January 2022 . https://web.archive.org/web/20220110174725/https://www.nature.com/articles/s41477-021-00964-4/ . live. subscription .
25. Gernandt . David S. . López . Gretel Geada . García . Sol Ortiz . Liston . Aaron . Phylogeny and classification of Pinus . Taxon . 54 . 1 . 2005 . 10.2307/25065300 . free . 29–42 . 25065300 . 2005Taxon..54...29G .
26. Web site: Pinus (L.) . 2022 . . 14 August 2022.
27. Web site: Plants of the World Online . Plants of the World Online . 14 October 2013 . 20 January 2025.
28. Web site: Wehenkel . C. . Mariscal-Lucero . S. . Jaramillo-Correa . J.P. . López-Sánchez . C.A. . Genetic diversity and conservation of Mexican forest trees . Forest Service . . 1 November 2024.
29. Biodiversity of Pinus (Pinaceae) in Mexico: speciation and palaeo-endemism . . 1996 . 121 . 4 . 365–384 . 10.1111/j.1095-8339.1996.tb00762.x . 1 November 2024 . Farjon . Aljos . 1996BJLS..121..365F .
30. Romero-Sanchez . Martin Enrique . Perez-Miranda . Ramiro . Gonzalez-Hernandez . Antonio . Valerio Velasco-Garcia . Mario . Velasco-Bautista . Efraín . Andrés . Flores . Current and Potential Spatial Distribution of Six Endangered Pine Species of Mexico: Towards a Conservation Strategy . Forests . 2018 . 9 . 12 . 767 . 10.3390/f9120767 . 2018Fore....9..767R . free .
31. Nobis . Michael P. . Traiser . Christopher . Roth-Nebelsick . Anita . Latitudinal variation in morphological traits of the genus Pinus and its relation to environmental and phylogenetic signals . Plant Ecology & Diversity . 5 . 1 . 1 March 2012 . 10.1080/17550874.2012.687501 . 1–11 . 2012PlEcD...5....1N .
32. Web site: The forest biome . . 12 May 2019 . https://web.archive.org/web/20190620145416/https://ucmp.berkeley.edu/exhibits/biomes/forests.php#boreal . 20 June 2019 .
33. Web site: Stabbursdalen Nasjonalpark . 20 January 2025.
34. Book: Critchfield . William B. . Little . Elbert L. . Geographic Distribution of the Pines of the World . 1966 . USDA Forest Service.
35. Singh . Surendra P. . Inderjit . Singh . Jamuna S. . Majumdar . Sudipto . Moyano . Jaime . Nuñez . Martin A. . Richardson . David M. . 21 September 2018 . Insights on the persistence of pines (Pinus species) in the Late Cretaceous and their increasing dominance in the Anthropocene . Ecology and Evolution . 8 . 20 . 10345–10359 . 10.1002/ece3.4499 . free . 6206191 . 30398478 . 2018EcoEv...810345S . free .
36. Web site: Pinus ssp. (tree), General Impact . Invasive Species Specialist Group . 13 March 2006 . Global Invasive Species Database . 2 March 2011 . https://web.archive.org/web/20110726195335/http://www.issg.org/database/species/impact_info.asp?si=890&fr=1&sts=sss&lang=EN . 26 July 2011 .
37. Web site: Pine Trees . 30 August 2020 . Basic Biology . 31 October 2019.
38. Schoennagel . Tania . Tania Schoennagel . Veblen . Thomas . The Interaction of Fire, Fuels and Climate across Rocky Mountain Forests . BioScience . 54 . 7 . 2004 . 661–676 . 10.1641/0006-3568(2004)054[0661:TIOFFA]2.0.CO;2 . free.
39. Web site: 9 January 2017 . The most fire-resistant pine in the world . 23 September 2022 . Forest Monitor.
40. Clarke . P. J. . Lawes . M. J. . Midgley . J. J. . Lamont . B. B. . Ojeda . F. . Burrows . G. E. . Enright . N. J. . Knox . K. J. E. . 5 . January 2013 . Resprouting as a key functional trait: how buds, protection and resources drive persistence after fire . . 197 . 1 . 19–35 . 10.1111/nph.12001 . 23110592 . 2013NewPh.197...19C . free.
41. Book: Moore . Gerry . Kershner, Bruce . Craig Tufts . Daniel Mathews . Gil Nelson . Spellenberg, Richard . Thieret, John W. . Terry Purinton . Block, Andrew . 5 . National Wildlife Federation Field Guide to Trees of North America . Sterling . 2008 . 90 . 978-1-4027-3875-3.
42. Solár . Jaroslav . Janiga . Marián . Long-term Changes in Dwarf Pine (Pinus mugo) Cover in the High Tatra Mountains, Slovakia . Mountain Research and Development . 33 . 1 . 2013 . 10.1659/MRD-JOURNAL-D-12-00079.1 . free . 51–62 . 2013MRDev..33...51S .
43. Sun . Yan-Qiang . Zhao . Wei . Xu . Chao-Qun . Xu . Yulan . El-Kassaby . Yousry A. . De La Torre . Amanda R. . Mao . Jian-Feng . Genetic Variation Related to High Elevation Adaptation Revealed by Common Garden Experiments in Pinus yunnanensis . Frontiers in Genetics . 10 . 11 February 2020 . 1405 . 32117429 . 7027398 . 10.3389/fgene.2019.01405 . free.
44. Web site: Pinus sabiniana Dougl . 4 May 2022 . www.srs.fs.usda.gov.
45. Hicks . B. J. . Barbour . D. A. . Evans . H. F. . Heritage . S. . Leather . S. R. . Milne . R. . Watt . A. D. . The history and control of the pine beauty moth, Panolis flammea (D. & S.) (Lepidoptera: Noctuidae), in Scotland from 1976 to 2000 . Agricultural and Forest Entomology . 3 . 3 . 2001 . 10.1046/j.1461-9555.2001.00106.x . free . 161–168.
46. Web site: Sphinx pinastri: Pine hawk-moth . Forest Pests Europe . 2 September 2025.
47. Web site: Thaumetopoea pityocampa Pine processionary moth . Forest Pests Europe . 2 September 2025.
48. La Processionnaire du Pin . fr . The Pine Processionary . INRA . Stantari . 14 (August–October 2008) . 2008 . 2 October 2021 . Bonnet . Catherine . Martin . Jean-Claude . Mazet . René . 29–33 . https://web.archive.org/web/20111004145101/http://www.prodinra.inra.fr/prodinra/pinra/data/2008/07/PROD20086c1fb7e_20080709010355455.pdf . 4 October 2011 .
49. Kerdelhué . Carole . Zane . Lorenzo . Simonato . Mauro . Salvato . Paola . Rousselet . Jérôme . Roques . Alain . Battisti . Andrea . Quaternary history and contemporary patterns in a currently expanding species . BMC Evolutionary Biology . 9 . 1 . 2009 . 220 . 10.1186/1471-2148-9-220 . 19732434 . 2753568 . 2009BMCEE...9..220K . free .
50. Web site: Pine tree lappet moth in Scotland . Scottish Forestry . 1 September 2025.
51. http://nematode.unl.edu/bursaphelenchusxylo.htm Bursaphelenchus xylophilus, Pine Wilt Nematode.
52. http://plpnemweb.ucdavis.edu/nemaplex/Taxadata/G145S1.HTM Bursaphelenchus xylophilus.
53. Web site: Diprion pini . Cooperative Agricultural Pest Survey . 19 August 2025 . July 2015.
54. Book: Lanner, Ronald M. . Made for each other: A symbiosis of birds and pines . 1996 . . 0-19-508-903-0 . 61–75.
55. Book: Tomback . Diana F. . Diana Tomback . Sekercioglu . Cagan . Wenny . Daniel G. . Whelan . Christopher J. . Why birds matter: avian ecological function and ecosystem services . 2016 . . 978-0-226-38263-0 . 201 . 7.
56. Summers . Ron W. . Patterns of exploitation of annually varying Pinus sylvestris cone crops by seed-eaters of differing dispersal ability . Ecography . 34 . 5 . 2011 . 10.1111/j.1600-0587.2010.06498.x . 723–728 . 2011Ecogr..34..723S .
57. Filipiak . Michał . 1 January 2016 . Pollen Stoichiometry May Influence Detrital Terrestrial and Aquatic Food Webs . Frontiers in Ecology and Evolution . 4 . 138 . 10.3389/fevo.2016.00138 . 2016FrEEv...4..138F . free .
58. Sitta . Nicola . Floriani . Marco . 2008 . Nationalization and globalization trends in the wild mushroom commerce of Italy with emphasis on porcini (Boletus edulis and allied species) . . 62 . 3 . 307–22 . 10.1007/s12231-008-9037-4. 2008EcBot..62..307S . 44274570 .
59. Book: Gallardi, Matteo . Diversity, Biogeographic Distribution, Ecology, and Ectomycorrhizal Relationships of the Edible Porcini Mushrooms (Boletus s. str., Boletaceae) Worldwide: State of the Art and an Annotated Checklist . Mushrooms, Humans and Nature in a Changing World: Perspectives from Ecological, Agricultural and Social Sciences . Pérez-Moreno, Jesús . Guerin-Laguette, Alexis . Arzú, Roberto Flores . Yu, Fu-Qiang . 2020 . Springer . 978-3-030-37378-8 . 236–237 . https://books.google.com/books?id=M3DgDwAAQBAJ&pg=PA237.
60. News: Choosing a Timber Species - Timber Frame HQ . Timber Frame HQ . 4 January 2018.
61. Web site: Trees for pulp . Paper.org . 4 January 2018 . 18 November 2017 . https://web.archive.org/web/20171118044645/http://www.paper.org.uk/information/factsheets/trees.pdf .
62. Wiemann, M. C. (2010). Characteristics and Availability of Commercially Important Woods. In Wood handbook: Wood as an engineering material (pp. 2-2-2–45). Chapter, Forest Products Laboratory; For sale by the Supt. of Docs., U.S. Govt. https://research.fs.usda.gov/treesearch/37440
63. Web site: Jenkins . Steve . What is CLS timber and what DIY projects is it good for? . Homebuilding & Renovating . 3 September 2023 . 22 August 2024.
64. Web site: Timber treatment . weathertight.org.nz . 18 May 2019 . 18 October 2010 .
65. Book: The Complete Guide to Edible Wild Plants . . . 2009 . 978-1-60239-692-0 . 78 . 277203364 .
66. Web site: Campionato Mondiale Pesto al Mortaio . Pesto's official recipe. 16 May 2021 . 16 May 2021 . https://web.archive.org/web/20210516204546/https://www.pestochampionship.it/championships-recipe/?lang=en . live.
67. Web site: Pinus / pine: Conifer Genus . American Conifer Society . 1 March 2022.
68. Book: Angier, Bradford . Field Guide to Edible Wild Plants . . 1974 . 0-8117-0616-8 . 166–167 . 799792 . Bradford Angier.
69. Zeng . Wei-Cai . Jia . Li-Rong . Zhang . Yan . Cen . Jia-Qi . Chen . Xi . Gao . Hong . Feng . Su . Huang . Yi-Na . 5 . Antibrowning and antimicrobial activities of the water-soluble extract from pine needles of Cedrus deodara . Journal of Food Science . 76 . 2 . C318–23 . March 2011 . 21535752 . 10.1111/j.1750-3841.2010.02023.x .
70. Book: J. . Robinson . 2006 . The Oxford Companion to Wine . Third . . 568–569 . 0-19-860990-6.
71. Chalier . Pascale . Martinez-Lopez . Brais . Lacour . Marie Agnès . Rigou . Peggy . Extraction of turpentine essential oil from Pinus pinaster ait: Comparison of yield and composition between conventional- or microwave assisted-hydro-distillation and vacuum distillation . Sustainable Chemistry and Pharmacy . 41 . 2024 . 10.1016/j.scp.2024.101702 . 101702 . 2024SusCP..4101702C .
72. Web site: Turpentine Production and Processing . . 1 September 2025.
73. Web site: Culture Trunks . College of Liberal Arts, University of Texas . 1 September 2025.
74. Ulukanli . Zeynep . KaraböRklü . Salih . Bozok . Fuat . Ates . Burhan . Erdogan . Selim . Cenet . Menderes . Karaaslan . Merve Göksin . 5 . Chemical composition, antimicrobial, insecticidal, phytotoxic and antioxidant activities of Mediterranean Pinus brutia and Pinus pinea resin essential oils . Chinese Journal of Natural Medicines . 12 . 12 . 901–910 . December 2014 . 25556061 . 10.1016/s1875-5364(14)60133-3 .
75. Web site: What Ink Stick Should You Choose For Japanese Calligraphy? . The Art of Calligraphy . 1 September 2025.
76. Web site: Solanki . Seetal . 5 radical material innovations that will shape tomorrow . 2018-12-17 . CNN Style . 17 December 2018.
77. Web site: Scots pine mythology and folklore . Trees for Life . 2 September 2025.
78. Web site: Dotsey . Calvin . The March of Time: Respighi's Pines of Rome . 7 January 2020 . . 19 April 2022.
79. Pinon . Jean . Les Pins vus par les peintres . Pines seen by Painters . Revue forestière française . 2021 . 73 . 5 . 583–596 . 10.20870/revforfr.2021.7109 . fr. free .
80. [Wolfram Eberhard|Eberhard, Wolfram]