Fagus sylvatica

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Fagus sylvatica, the European beech or common beech, is a large, graceful deciduous tree in the beech family with smooth silvery-gray bark, large leaf area, and a short trunk with low branches.[3]

Fagus sylvatica
Alpine forest (Italy)
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Fagales
Family: Fagaceae
Genus: Fagus
Species:
F. sylvatica
Binomial name
Fagus sylvatica
Distribution map
  Fagus sylvatica

  Fagus orientalis (syn. F. sylvatica subsp. orientalis)

Synonyms[2]
  • Castanea fagus Scop.
  • Fagus aspleniifolia (Dum.Cours.) Raf.
  • Fagus comptoniifolia Desf.
  • Fagus cuprea Hurter ex A.DC.
  • Fagus echinata Gilib.
  • Fagus incisa Dippel
  • Fagus laciniata A.DC.
  • Fagus purpurea (Aiton) Dum.Cours.
  • Fagus purpurea var. roseomarginata Cripps
  • Fagus purpurea tricolor (Simon-Louis ex K.Koch) Pynaert
  • Fagus sylvatica var. aenea Dum.Cours.
  • Fagus sylvatica var. albovariegata Weston
  • Fagus sylvatica f. albovariegata (Weston) Domin
  • Fagus sylvatica var. aspleniifolia Dum.Cours.
  • Fagus sylvatica f. aspleniifolia (Dum.Cours.) C.K.Schneid.
  • Fagus sylvatica var. atropunicea Weston
  • Fagus sylvatica f. atropunicea (Weston) Domin
  • Fagus sylvatica f. aureovariegata C.K.Schneid.
  • Fagus sylvatica f. bornyensis Simon-Louis ex Beissn.
  • Fagus sylvatica var. cochleata Dippel
  • Fagus sylvatica var. colorata A.DC.
  • Fagus sylvatica var. coriacea Wallr.
  • Fagus sylvatica var. cristata Dum.Cours.
  • Fagus sylvatica f. cristata (Dum.Cours.) Schelle
  • Fagus sylvatica f. fastigiata Simon-Louis ex K.Koch
  • Fagus sylvatica var. foliis-striatis Dippel
  • Fagus sylvatica var. grandidentata Dippel
  • Fagus sylvatica var. heterophylla Loudon
  • Fagus sylvatica var. laciniata Vignet
  • Fagus sylvatica f. laciniata (Vignet) Domin
  • Fagus sylvatica var. latifolia Loudon
  • Fagus sylvatica f. luteovariegata (Weston) Domin
  • Fagus sylvatica var. luteovariegata Weston
  • Fagus sylvatica var. miltonensis A.Henry
  • Fagus sylvatica pendula (Dum.Cours.) Lodd.
  • Fagus sylvatica var. pendula Dum.Cours.
  • Fagus sylvatica f. pendula (Dum.Cours.) Schelle
  • Fagus sylvatica pendula-purpurea Graebener
  • Fagus sylvatica var. purpurea Aiton in Hortus Kew. 3: 362 (1789)
  • Fagus sylvatica f. purpurea (Aiton) Schelle
  • Fagus sylvatica purpurea-latifolia Jacob-Makoy
  • Fagus sylvatica purpurea-pendula Van Geert
  • Fagus sylvatica var. purpureopendula H.Jaeger
  • Fagus sylvatica f. purpureopendula (H.Jaeger) Rehder
  • Fagus sylvatica var. pyramidalis Dippel
  • Fagus sylvatica f. quercifolia C.K.Schneid.
  • Fagus sylvatica var. quercifolia (C.K.Schneid.) Geerinck
  • Fagus sylvatica var. quercoides Pers.
  • Fagus sylvatica f. quercoides (Pers.) Aug.DC.
  • Fagus sylvatica var. remillyensis (Simon-Louis) A.Henry
  • Fagus sylvatica remillyensis Simon-Louis
  • Fagus sylvatica f. retroflexa Dippel
  • Fagus sylvatica rohanii Körb.
  • Fagus sylvatica f. rohanii (Körb.) C.K.Schneid.
  • Fagus sylvatica f. roseomarginata (Cripps) Domin
  • Fagus sylvatica f. roseomarginatis Dippel
  • Fagus sylvatica rotundifolia Jackman
  • Fagus sylvatica f. rotundifolia (Jackman) Rehder
  • Fagus sylvatica f. salicifolia Dippel
  • Fagus sylvatica var. sanguinea Amo
  • Fagus sylvatica subsp. Sanguinea (Amo) Arcang.
  • Fagus sylvatica var. suentelensis Schelle
  • Fagus sylvatica var. suntalensis Beissn.
  • Fagus sylvatica var. tortuosa Pépin
  • Fagus sylvatica proles tortuosa (Pépin) Rouy
  • Fagus sylvatica f. tortuosa (Pépin) Hegi
  • Fagus sylvatica f. tricolor Simon-Louis ex K.Koch
  • Fagus sylvatica var. variegata Dippel
  • Fagus sylvatica var. vulgaris Aiton
  • Fagus sylvatica var. zlatia Späth ex E.Goeze
  • Fagus sylvatica f. zlatia (Späth ex E.Goeze) Schelle
  • Fagus sylvestris Gaertn.
  • Fagus tortuosa (Dippel) F.Boden

Description

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Copper beech in autumn
 
Shoot with nut cupules

Fagus sylvatica is a large tree, capable of reaching heights of up to 50 metres (160 feet) tall[4] and 3 m (10 ft) trunk diameter, though more typically 25–35 m (82–115 ft) tall and up to 1.5 m (5 ft) trunk diameter. A 10-year-old sapling will stand about 4 m (13 ft) tall. Undisturbed, the European beech has a lifespan of 300 years; one tree at the Valle Cervara site was more than 500 years old—the oldest known in the northern hemisphere.[5] In cultivated forest stands trees are normally harvested at 80–120 years of age.[6] 30 years are needed to attain full maturity (as compared to 40 for American beech). Like most trees, its form depends on the location: in forest areas, F. sylvatica grows to over 30 m (100 ft), with branches being high up on the trunk. In open locations, it will become much shorter (typically 15–24 m or 50–80 ft) and more massive.

The leaves are alternate, simple, and entire or with a slightly crenate margin, 5–10 centimetres (2–4 inches) long and 3–7 cm broad, with 6–7 veins on each side of the leaf (as opposed to 7–10 veins in F. orientalis). When crenate, there is one point at each vein tip, never any points between the veins. The buds are long and slender, 15–30 millimetres (581+18 in) long and 2–3 mm (33218 in) thick, but thicker (to 4–5 mm) where the buds include flower buds.

The leaves of beech are often not abscissed (dropped) in the autumn and instead remain on the tree until the spring. This process is called marcescence. This particularly occurs when trees are saplings or when plants are clipped as a hedge (making beech hedges attractive screens, even in winter), but it also often continues to occur on the lower branches when the tree is mature.

Small quantities of seeds may be produced around 10 years of age, but not a heavy crop until the tree is at least 30 years old. F. sylvatica male flowers are borne in the small catkins which are a hallmark of the Fagales order (beeches, chestnuts, oaks, walnuts, hickories, birches, and hornbeams). The female flowers produce beechnuts, small triangular nuts 15–20 mm (5834 in) long and 7–10 mm (1438 in) wide at the base; there are two nuts in each cupule, maturing in the autumn 5–6 months after pollination. Flower and seed production is particularly abundant in years following a hot, sunny and dry summer, though rarely for two years in a row.

Distribution and habitat

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Fagus sylvatica pliocenicaMuseum of Toulouse

The European beech is the most abundant hardwood species in Austrian, German and Swiss forests.[7] The native range extends from the north, in Sweden, Denmark, Norway, Germany, Poland, Switzerland, Bulgaria, eastern parts of Russia, Romania, through Europe to France, southern England, Spain (on the Cantabrian, Iberian and Central mountain ranges),[8] and east to northwest Turkey,[2] where it exhibits an interspecific cline with the oriental beech (Fagus orientalis), which replaces it further east. In the Balkans, it shows some hybridisation with oriental beech; these hybrid trees are named Fagus × taurica Popl. [Fagus moesiaca (Domin, Maly) Czecz.]. In the southern part of its range around the Mediterranean, and Sicily,[9] it grows only in mountain forests, at 600–1,800 m (1,969–5,906 ft) altitude.

Although often regarded as native in southern England, recent evidence suggests that F. sylvatica did not arrive in England until about 4000 BC, or 2,000 years subsequent to the English Channel forming following the ice ages; it could have been an early introduction by Stone Age humans, who used the nuts for food.[10] The beech is classified as a native in the south of England and as a non-native in the north where it is often removed from 'native' woods.[11] Localised pollen records have been recorded in the North of England from the Iron Age by Sir Harry Godwin. Changing climatic conditions may put beech populations in southern England under increased stress and while it may not be possible to maintain the current levels of beech in some sites it is thought that conditions for beech in north-west England will remain favourable or even improve. It is often planted in Britain. Similarly, the nature of Norwegian beech populations is subject to debate. If native, they would represent the northern range of the species. However, molecular genetic analyses support the hypothesis that these populations represent intentional introduction from Denmark before and during the Viking Age.[12] However, the beech in Vestfold and at Seim north of Bergen in Norway is now spreading naturally and regarded as native.[13]

Though not demanding of its soil type, the European beech has several significant requirements: a humid atmosphere (precipitation well distributed throughout the year and frequent fogs) and well-drained soil (being intolerant of excessive stagnant water). It prefers moderately fertile ground, calcified or lightly acidic, therefore it is found more often on the side of a hill than at the bottom of clayey basin. It tolerates rigorous winter cold, but is sensitive to spring frost. In Norway's oceanic climate planted trees grow well north to Bodø Municipality, and produce seedlings and can spread naturally in Trondheim.[14] In Sweden, beech trees do not grow as far north as in Norway.[15]

A beech forest is very dark and few species of plant are able to survive there, where the sun barely reaches the ground. Young beeches prefer some shade and may grow poorly in full sunlight. In a clear-cut forest a European beech will germinate and then die of excessive dryness. Under oaks with sparse leaf cover it will quickly surpass them in height and, due to the beech's dense foliage, the oaks will die from lack of sunlight.

Ecology

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The root system is shallow, even superficial, with large roots spreading out in all directions. European beech forms ectomycorrhizas with a range of fungi including many Russula species, as well as Laccaria amethystina,[16] and with the species Ramaria flavosaponaria.[17] Tomentella Pat. species and Cenococcum geophilum have been found in Danish and Spanish beech forests. These fungi are important in enhancing uptake of water and nutrients from the soil.[16]

In the woodlands of southern Britain, beech is dominant over oak and elm south of a line from about north Suffolk across to Cardigan. Oak are the dominant forest trees north of this line. One of the most beautiful European beech forests called Sonian Forest (Forêt de Soignes/Zoniënwoud) is found in the southeast of Brussels, Belgium. Beech is a dominant tree species in France and constitutes about 10% of French forests. The largest virgin forests made of beech trees are Uholka-Shyrokyi Luh (8,800 hectares or 22,000 acres) in Ukraine[18] and Izvoarele Nerei (5,012 ha or 12,380 acres in one forest body) in Semenic-Cheile Carașului National Park, Romania. These habitats are the home of Europe's largest predators, (the brown bear, the grey wolf and the lynx).[19][20][21] Many trees are older than 350 years in Izvoarele Nerei[22] and even 500 years in Uholka-Shyrokyi Luh.[18]

Spring leaf budding by the European beech is triggered by a combination of day length and temperature. Bud break each year is from the middle of April to the beginning of May, often with remarkable precision (within a few days). It is more precise in the north of its range than the south, and at 600 m (2,000 ft) than at sea level.[23]

The European beech invests significantly in summer and autumn for the following spring. Conditions in summer, particularly good rainfall, determine the number of leaves included in the buds. In autumn, the tree builds the reserves that will sustain it into spring. Given good conditions, a bud can produce a shoot with ten or more leaves. The terminal bud emits a hormonal substance in the spring that halts the development of additional buds. This tendency, though very strong at the beginning of their existence, becomes weaker in older trees.

It is only after the budding that root growth of the year begins. The first roots to appear are very thin (with a diameter of less than 0.5 mm). Later, after a wave of above ground growth, thicker roots grow in a steady fashion.

Diseases and pathogens

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Fagus sylvatica and other beeches are prone to false heartwood ('red heart') a condition where drought, nutrient deficient soil, branch breakage, pathogen infestation or other stressor induces formation of protection wood.[24] False heartwood often manifests in the areas of the trunk associated with symplastless branches. As branch symplast dies, the trunk wood becomes depleted of nitrogen-containing molecules essential for life; this increases risk of catastrophic trunk failure.[25]

As the European beech exhibits deterministic leaf and shoot development and has a larger leaf area than other European hardwood trees, it is relatively more sensitive to drought and may respond to a dry summer with pre-senescent leafdrop.[26]

 
Detail of the tarcrust's structure

Biscogniauxia nummularia (beech tarcrust) is an ascomycete primary pathogen of beech trees, causing strip-canker and wood rot. It can be found at all times of year and is not edible.[27]

Cultivation

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A look down a steep gorge with European beech leading down to the ocean at Møns Klint, Denmark

European beech is a very popular ornamental tree in parks and large gardens in temperate regions of the world. In North America, they are preferred for this purpose over the native F. grandifolia, which despite its tolerance of warmer climates, is slower growing, taking an average of 10 years longer to attain maturity. The town of Brookline, Massachusetts has one of the largest, if not the largest, grove of European beech trees in the United States. The 2.5-acre (1 ha) public park, called 'The Longwood Mall', was planted sometime before 1850 qualifying it as the oldest stand of European beeches in the United States.[28]

It is frequently kept clipped to make attractive hedges.

Since the early 19th century there have been numerous cultivars of European beech made by horticultural selection, often repeatedly; they include:

  • copper beech or purple beech (Fagus sylvatica purpurea)[29] – a mutation of the European beech which was first noted in 1690 in the "Possenwald" forest near the town of Sondershausen in Thuringia, Germany. It is assumed that about 99% of all copper beeches in the world are descendants of this copper beech. Its leaves are purple, in many selections turning deep spinach green by mid-summer. In the United States Charles Sprague Sargent noted the earliest appearance in a nurseryman's catalogue in 1820, but in 1859 "the finest copper beech in America... more than fifty feet high" was noted in the grounds of Thomas Ash, Esq., Throggs Neck, New York;[30] it must have been more than forty years old at the time.
  • fern-leaf beech (Fagus sylvatica Heterophylla Group) – leaves deeply serrated to thread-like
  • dwarf beech (Fagus sylvatica Tortuosa Group) – distinctive twisted trunk and branches
  • weeping beech (Fagus sylvatica Pendula Group) – branches pendulous
  • Dawyck beech (Fagus sylvatica 'Dawyck') – fastigiate (columnar) growth – occurs in green, gold and purple forms; named after Dawyck Botanic Garden in the Scottish Borders
  • golden beech (Fagus sylvatica 'Zlatia') – leaves golden in spring

Cultivars

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The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:-[31]

  • F. sylvatica[32]
  • 'Dawyck'[33]
  • 'Dawyck Gold'[34]
  • 'Dawyck Purple'[35]
  • 'Pendula' (weeping beech)[36]
  • 'Riversii'[37]
  • F. sylvatica var. heterophylla 'Aspleniifolia'[38]

Uses

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The nuts are eaten by humans and animals.[39] Slightly toxic to humans if eaten in large quantities due to the tannins and alkaloids they contain, the nuts were nonetheless pressed to obtain an oil in 19th-century England that was used for cooking and in lamps. They were also ground to make flour, which could be eaten after the tannins were leached out by soaking.[40][41][42]

Primary Product AM 01, a smoke flavouring, is produced from Fagus sylvatica.[43]

Timber

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The wood of the European beech is used in the manufacture of numerous objects and implements. Its fine and short grain makes it an easy wood to work with, easy to soak, dye, varnish and glue. Steaming makes the wood even easier to machine. It has an excellent finish and is resistant to compression and splitting and it is stiff when flexed. Milling is sometimes difficult due to cracking. The density of the wood is 720 kilograms (1,590 pounds) per cubic metre.[44] It is particularly well suited for minor carpentry, particularly furniture. From chairs to parquetry (flooring) and staircases, the European beech can do almost anything other than heavy structural support, so long as it is not left outdoors. Its hardness make it ideal for making wooden mallets and workbench tops. The wood rots easily if it is not protected by a tar based on a distillate of its own bark (as used in railway sleepers).[45][46] It is better for paper pulp than many other broadleaved trees though is only sometimes used for this, the high cellulose content can also be spun into modal, which is used as a textile akin to cotton. The code for its use in Europe is fasy (from FAgus SYlvatica). Common beech is also considered one of the best firewoods for fireplaces.[47]

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References

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  1. ^ Barstow, M.; Beech, E. (2018). "Fagus sylvatica". IUCN Red List of Threatened Species. 2018: e.T62004722A62004725. doi:10.2305/IUCN.UK.2018-1.RLTS.T62004722A62004725.en. Retrieved 21 July 2023.
  2. ^ a b "Fagus sylvatica L." Plants of the World Online. Royal Botanic Gardens, Kew. Archived from the original on 15 April 2023. Retrieved 1 June 2023.
  3. ^ "European beech". The Morton Arboretum. Retrieved 20 October 2023.
  4. ^ "Tall Trees". Bomeninfo.nl. Archived from the original on 2014-07-17. Retrieved 2010-08-30.
  5. ^ Packham, John R.; Hobson, Peter R.; Norris, Catherine (June 2013). "Common beech Fagus sylvatica L; survival and longevity in changing times". Arboricultural Journal. 35 (2): 64–73. Bibcode:2013ArbJ...35...64P. doi:10.1080/03071375.2013.767078.
  6. ^ Wühlisch, G. (2008). "European beech – Fagus sylvatica" (PDF). EUFORGEN Technical Guidelines for Genetic Conservation and Use. Archived from the original (PDF) on 2019-08-19. Retrieved 2016-10-20.
  7. ^ Pramreiter, Maximilian; Grabner, Michael (11 July 2023). "The Utilization of European Beech Wood (Fagus sylvatica L.) in Europe". Forests. 14 (7): 1419. doi:10.3390/f14071419.
  8. ^ "Fagus sylvatica" (PDF). Flora Iberica. Retrieved 19 November 2023.
  9. ^ Brullo, S.; Guarino, R.; Minissale, P.; Siracusa, G.; Spampinato, G. (1999). "Syntaxonomical analysis of the beech forests from Sicily". Annali di Botanica. 57: 121–132. ISSN 2239-3129. Archived from the original on 2013-12-13. Retrieved 5 December 2013.
  10. ^ Harris, E. (2002) Goodbye to Beech? Farewell to Fagus? Quarterly Journal of Forestry 96 (2):97.
  11. ^ International foresters study Lake District's 'greener, friendlier forests' Archived 2010-01-28 at the Wayback Machine forestry.gov.uk
  12. ^ Myking, T.; Yakovlev, I.; Ersland, G. A. (2011). "Nuclear genetic markers indicate Danish origin of the Norwegian beech (Fagus sylvatica L.) populations established in 500–1,000 AD". Tree Genetics & Genomes. 7 (3): 587–596. doi:10.1007/s11295-010-0358-y. S2CID 27550587.
  13. ^ Bøk – en kulturvekst? Archived 2017-03-12 at the Wayback Machine (in Norwegian)
  14. ^ Eli Fremstad. "Lade i Trondheim: naturtyper, flora og grunnlag for skjøtselsplan". Ntnu.no (in Norwegian). Archived from the original on 2021-06-13. Retrieved 2022-04-02.
  15. ^ Laurie, James; Balbi, Adriano (1842-01-01). System of Universal Geography: Founded on the Works of Malte-Brun and Balbi: Embracing a Historical Sketch of the Progress of Geographical Discovery …. A. and C. Black.
  16. ^ a b Packham, John R.; Thomas, Peter A.; Atkinson, Mark D.; Degen, Thomas (19 October 2012). "Biological Flora of the British Isles: Fagus sylvatica". Journal of Ecology. 100 (6): 1557–1608. Bibcode:2012JEcol.100.1557P. doi:10.1111/j.1365-2745.2012.02017.x. S2CID 85095298.
  17. ^ Agerer, Reinhard, ed. (1987–2012). "Tables of identified ectomycorrhizae". Colour Atlas of Ectomycorrhizae. Schwäbisch Gmünd: Einhorn-Verlag. ISBN 978-3-921703-77-9. OCLC 263940450. Archived from the original on 30 December 2012. Retrieved 19 July 2018. Ramaria flavo-saponaria + Fagus selvatica (Raidl, Scattolin)
  18. ^ a b Commarmot, Brigitte; Brändli, Urs-Beat; Hamor, Fedir; Lavnyy, Vasyl (2013). Inventory of the Largest Primeval Beech Forest in Europe (PDF). Swiss Federal Institute for Forest, Snow and Landscape Research WSL. Archived from the original (PDF) on 2013-08-14.
  19. ^ Romania & Moldova. Lonely Planet. 1998-01-01. ISBN 978-0-86442-329-0.
  20. ^ Romanescu, Gheorghe; Stoleriu, Cristian Constantin; Enea, Andrei (2013-05-23). Limnology of the Red Lake, Romania: An Interdisciplinary Study. Springer Science & Business Media. ISBN 9789400767577.
  21. ^ Apollonio, Marco; Andersen, Reidar; Putman, Rory (2010-02-04). European Ungulates and Their Management in the 21st Century. Cambridge University Press. ISBN 978-0-521-76061-4. Archived from the original on 2023-09-02. Retrieved 2020-10-07.
  22. ^ "Zone de conservare – Parcul National Semenic Cheile-Carasului". Pnscc.ro. Archived from the original on 2022-03-09. Retrieved 2 April 2022.
  23. ^ Efe, Recep (2014-03-17). Environment and Ecology in the Mediterranean Region II. Cambridge Scholars Publishing. ISBN 978-1-4438-5773-4.
  24. ^ Dzurenda, Ladislav; Dudiak, Michal; Kučerová, Viera (29 May 2023). "Differences in Some Physical and Chemical Properties of Beechwood with False Heartwood, Mature Wood and Sapwood". Forests. 14 (6): 1123. doi:10.3390/f14061123.
  25. ^ Hörnfeldt, Roland; Drouin, Myriam; Woxblom, Lotta (2010). "False heartwood in beech Fagus sylvatica, birch Betula pendula, B. papyrifera and ash Fraxinus excelsior - an overview". Ecological Bulletins (53): 61–76. JSTOR 41442020.
  26. ^ Leuschner, Christoph (December 2020). "Drought response of European beech (Fagus sylvatica L.)—A review". Perspectives in Plant Ecology, Evolution and Systematics. 47: 125576. Bibcode:2020PPEES..4725576L. doi:10.1016/j.ppees.2020.125576.
  27. ^ Blanchette, Robert; Biggs, Alan (2013-11-11). Defense Mechanisms of Woody Plants Against Fungi. Springer Science & Business Media. ISBN 978-3-662-01642-8. Archived from the original on 2023-09-02. Retrieved 2020-10-07.
  28. ^ "Longwood Mall". Brookline, MA. Archived from the original on 2019-12-20. Retrieved 2015-10-17.
  29. ^ "Copper Beech". Tree-Guide.com. Archived from the original on 6 October 2017. Retrieved 5 October 2017.
  30. ^ Andrew Jackson Downing and Henry Winthrop Sargent, A Treatise on the Theory and Practice of Landscape Gardening, Adapted to North America 1859:150.
  31. ^ "AGM Plants – Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 38. Archived (PDF) from the original on 3 May 2020. Retrieved 26 February 2018.
  32. ^ "Fagus sylvatica AGM". Royal Horticultural Society. Archived from the original on 1 July 2020. Retrieved 1 July 2020.
  33. ^ "Fagus sylvatica 'Dawyck' AGM". Royal Horticultural Society. Archived from the original on 3 July 2020. Retrieved 1 July 2020.
  34. ^ "Fagus sylvatica 'Dawyck Gold' AGM". Royal Horticultural Society. Archived from the original on 2 July 2020. Retrieved 1 July 2020.
  35. ^ "Fagus sylvatica 'Dawyck Purple' AGM". Royal Horticultural Society. Archived from the original on 2 July 2020. Retrieved 1 July 2020.
  36. ^ "Fagus sylvatica 'Pendula' AGM". Royal Horticultural Society. Archived from the original on 1 July 2020. Retrieved 1 July 2020.
  37. ^ "Fagus sylvatica (Atropurpurea Group) 'Riversii' AGM". Royal Horticultural Society. Archived from the original on 2 July 2020. Retrieved 1 July 2020.
  38. ^ "Fagus sylvatica var heterophylla 'Aslpeniifolia' AGM". Royal Horticultural Society. Archived from the original on 2 July 2020. Retrieved 1 July 2020.
  39. ^ Little, Elbert L. (1994) [1980]. The Audubon Society Field Guide to North American Trees: Western Region (Chanticleer Press ed.). Knopf. p. 390. ISBN 0394507614.
  40. ^ Fergus, Charles; Hansen, Amelia (2005-01-01). Trees of New England: A Natural History. Globe Pequot. ISBN 978-0-7627-3795-6.[permanent dead link]
  41. ^ Fergus, Charles (2002-01-01). Trees of Pennsylvania and the Northeast. Stackpole Books. ISBN 978-0-8117-2092-2. Archived from the original on 2023-09-02. Retrieved 2016-03-16.
  42. ^ Lyle, Susanna (2006-03-20). Fruit & nuts: a comprehensive guide to the cultivation, uses and health benefits of over 300 food-producing plants. Timber Press. ISBN 9780881927597.
  43. ^ European Food Safety Authority (EFSA) Scientific Opinion on Safety of smoke flavour – Primary Product – AM 01 Archived 2018-05-04 at the Wayback Machine 8 January 2010
  44. ^ Steamed Beech Archived 2010-11-11 at the Wayback Machine. Niche Timbers. Accessed 20-08-2009.
  45. ^ Association, American Wood-Preservers' (1939-01-01). Railroad Tie Decay: Comprising The Decay of Ties in Storage, by C. J. Humphrey ... Defects in Cross Ties, Caused by Fungi, by C. Audrey Richards. American wood-preservers' association.
  46. ^ Goltra, William Francis (1912-01-01). Some Facts about Treating Railroad Ties. Press of The J.B. Savage Company.
  47. ^ "The burning properties of wood" (PDF). Scoutbase (Scout Information Centre). Scout Association. Archived from the original (PDF) on 23 December 2012. Retrieved 26 July 2013.
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