| 词条 | Fraser fir |
| 释义 |
| image = Abies fraseri cone.jpg | image_caption = Foliage and cone | status = EN | status_system = IUCN3.1 | status_ref = [1] | genus = Abies | parent = Abies sect. Balsamea | species = fraseri | authority = (Pursh) Poir. | range_map = Abies fraseri range map 2.png | range_map_caption = Natural range of Abies fraseri | range_map2 = Abies fraseri range map 4.png | range_map2_caption = Close-up of natural range of Abies fraseri |synonyms =
|synonyms_ref = [2] }} The Fraser fir (Abies fraseri) is a species of fir native to the Appalachian Mountains of the Southeastern United States. Abies fraseri is closely related to balsam fir (Abies balsamea), of which it has occasionally been treated as a subspecies (as A. balsamea subsp. fraseri (Pursh) E.Murray) or a variety (as A. balsamea var. fraseri (Pursh) Spach).[3][4][5][6]NamesThe species Abies fraseri is named after the Scottish botanist John Fraser (1750–1811), who made numerous botanical collections in the region.[4] It is sometimes misspelled "Frasier," "Frazer" or "Frazier." In the past, it was also sometimes known as "she-balsam" because resin could be "milked" from its bark blisters,[7] in contrast to the "he balsam" (red spruce) which could not be milked. It has also occasionally been called balsam fir, inviting confusion with A. balsamea.[8] DescriptionAbies fraseri is a small evergreen coniferous tree typically growing between 30 and 50 feet (10–15 m) tall, but rarely to 80 ft (25 m), with a trunk diameter of 16 to 20 inches (40–50 cm), but rarely 30 in (75 cm). The crown is conical, with straight branches either horizontal or angled upward at 40° from the trunk; it is dense when the tree is young and more open in maturity. The bark is thin, smooth, grayish brown, and has numerous resinous blisters on juvenile trees, becoming fissured and scaly in maturity. The leaves are needle-like; arranged spirally on the twigs but twisted at their bases to form 2 rows on each twig; they are 0.4-0.9 inches (10–23 mm) long and 79-87 mil (2–2.2 mm) broad; flat; flexible; rounded or slightly notched at their apices (tips); dark to glaucous green adaxially (above); often having a small patch of stomata near their apices; and having 2 silvery white stomatal bands abaxially (on their undersides). Their strong fragrance resembles turpentine. The cones are erect; cylindrical; 1.4 to 2.75 inches (3.5–7 cm) long, rarely 3.2 in (8 cm), and 1-1.2 inches (2.5–3 cm) broad, rarely 1.5 in (4 cm) broad; dark purple, turning pale brown when mature; often resinous; and with long reflexed green, yellow, or pale purple bract scales. The cones disintegrate when mature at 4–6 months old to release the winged seeds.[3][4][5] Some botanists regard the variety of Balsam fir named Abies balsamea var. phanerolepis as a natural hybrid with Fraser fir, denominated Abies × phanerolepis (Fernald) Liu.[4] EcologyReproduction and growthFraser fir is monoecious, meaning that both male and female cones (strobili) occur on the same tree.[9] Cone buds usually open from mid-May to early June. Female cones are borne mostly in the top few feet of the crown and on the distal ends of branches. Male cones are borne below female cones, but mostly in the upper half of the crown. Seed production may begin when trees are 15 years old. Seeds germinate well on mineral soil, moss, peat, decaying stumps and logs, and even on detritus or litter that is sufficiently moist.[10] DistributionAbies fraseri is restricted to the southeastern Appalachian Mountains in southwestern Virginia, western North Carolina and eastern Tennessee, where it occurs at high elevations, from 3,900 feet to the summit of Mount Mitchell, the highest point in the region at 6,683 feet (1,200 m up to 2,037 m). It lives in acidic moist but well-drained sandy loam, and is usually mixed with Picea rubens (red spruce). Other trees it grows with include Tsuga caroliniana (Carolina hemlock), Betula alleghaniensis (yellow birch), Betula papyrifera (paper birch), and Acer saccharum (sugar maple). The climate is cool and moist, with short, cool summers and cold winters with heavy snowfall.[3][4]PestsAbies fraseri is severely damaged by a non-native insect, the balsam woolly adelgid (Adelges piceae). The insect's introduction and spread led to a rapid decline in Fraser fir across its range, with over 80 percent of mature trees having been killed. The rapid regeneration of seedlings with lack of canopy has led to good regrowth of healthy young trees where the mature forests once stood. However, when these young trees get old enough for the bark to develop fissures, they may be attacked and killed by the adelgids as well. For this reason, the future of the species is still uncertain, though the Mount Rogers (Virginia) population has largely evaded adelgid mortality. The decline of the Fraser fir in the southern Appalachians has contributed to loss of moss habitat which supports the spruce-fir moss spider.[6] ThreatsThe Fraser fir is an endangered species. Threats include climate change, balsam woolly adelgid and destruction of trees for Christmas trees and timber. Cultivation and usesAlthough not important as a source of timber, Fraser fir is widely used as a Christmas tree. Its mild fragrance, shape, strong limbs, and ability to retain its soft needles (which do not prick easily when hanging ornaments) for a long time when cut make it one of the best trees for this purpose.[11] Fraser fir has been used more times as the White House Christmas tree (the official Christmas tree of the President of the United States's White House) than any other tree.{{citation needed|date = February 2012}} It is grown in plantations in Scotland and sold by the thousands throughout the United Kingdom and Ireland.{{citation needed|date = February 2012}} It is also cultivated from seedlings in several northern states in the USA and adjacent parts of Quebec province, especially for the Christmas tree trade.{{citation needed|date = February 2012}} The combination of form, needle retention, dark blue-green color, pleasant scent and excellent shipping characteristics has led to Fraser fir being a most popular Christmas tree species. Growing and harvesting this species for Christmas trees and boughs is a multimillion-dollar business in the southern Appalachians. North Carolina produces the majority of Fraser fir Christmas trees.[12] It requires from 7 to 10 years in the field to produce a {{convert|6-7|ft|m}} high tree. In 2005, the North Carolina General Assembly passed legislation making the Fraser fir the official Christmas tree of North Carolina. See also
References1. ^{{Cite journal | author = Farjon, A. | title = Abies fraseri | journal = The IUCN Red List of Threatened Species | volume = 2013 | page = e.T32101A2810241 | date = 2013 | url = http://www.iucnredlist.org/details/32101/0 | doi = 10.2305/IUCN.UK.2013-1.RLTS.T32101A2810241.en | access-date = 14 January 2018}} 2. ^{{cite web|url=http://www.theplantlist.org/tpl1.1/record/kew-2609865|title=The Plant List: A Working List of All Plant Species|accessdate=3 October 2014}} 3. ^1 2 Farjon, A. (1990). Pinaceae. Drawings and Descriptions of the Genera. Koeltz Scientific Books {{ISBN|3-87429-298-3}}. 4. ^1 2 3 4 Liu, T.-S. (1971). A Monograph of the Genus Abies. National Taiwan University. 5. ^1 Flora of North America: Abies fraseri 6. ^1 Gymnosperm Database: Abies fraseri 7. ^{{cite book |author=Frankenberg, D. |title=Exploring North Carolina's Natural Areas: Parks, Nature Preserves, and Hiking Trails |publisher=University of North Carolina Press |location=Chapel Hill |year=2000 |pages= |isbn=978-0-8078-4851-7 |oclc= |doi=}} p343 8. ^{{cite book |author1=Sutton, M. |author2= Sutton, A. |last-author-amp=yes |title=Eastern forests (Audubon Society Nature Guides) |publisher=Knopf |location=New York |year=1985 |pages= |isbn=978-0-394-73126-1 |oclc= |doi=}} p363 9. ^Abies fraseri (Pursh) Poir, Silviculture Manual, Volume 1, US Department of Agriculture Forest Service, Retrieved 20 October 2014 10. ^Abies fraseri (Pursh) Poir. The National Christmas Tree Association, Retrieved 20 Oct 2014 11. ^Hendrix, Steve, "[https://www.washingtonpost.com/lifestyle/magazine/the-remarkable-journey-of-a-single-christmas-tree/2011/12/01/gIQALVuZ9O_story.html A Christmas tree’s remarkable journey]", The Washington Post, December 21, 2011. 12. ^Fraser Fir North Carolina Department of Agriculture. Retrieved 24 November 2010 External links{{Commons category|Abies fraseri|Abies fraseri (Fraser fir)}}
7 : Abies|Endemic flora of the United States|Flora of the Appalachian Mountains|Trees of the Southeastern United States|Natural history of the Great Smoky Mountains|Taxa named by Frederick Traugott Pursh|Endangered flora of the United States |
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