Fraser fir

The Fraser fir (Abies fraseri) is an endangered species of fir native to the Appalachian Mountains of the Southeastern United States. They are endemic to only seven montane regions in the Appalachian Mountains. [4]

Fraser fir
Foliage and cone

Imperiled  (NatureServe)[2]
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Gymnosperms
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Pinaceae
Genus: Abies
Section: Abies sect. Balsamea
Species:
A. fraseri
Binomial name
Abies fraseri
Natural range of Abies fraseri
Close-up of natural range of Abies fraseri
Synonyms[3]
  • Abies humilis Bach.Pyl.
  • Picea fraseri (Pursh) Loudon
  • Picea hudsonia Gordon
  • Pinus fraseri Pursh

Taxonomy

Abies fraseri is closely related to Abies balsamea (balsam fir), 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).[5][6][7][8] 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.[6]

Names
Fraser fir on the slopes of Clingmans Dome

The species Abies fraseri is named after the Scottish botanist John Fraser (1750–1811), who made numerous botanical collections in the region.[6] 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,[9] in contrast to the "he balsam" (or Picea rubens, the red spruce) which could not be milked. It has also occasionally been called balsam fir, inviting confusion with A. balsamea.[10]

Description
Close-up view of Fraser fir foliage

Abies fraseri is a small evergreen coniferous tree typically growing between 30 and 50 ft (10 and 20 m) tall, but rarely to 80 ft (20 m), with a trunk diameter of 16–20 in (41–51 cm), but rarely 30 in (80 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 two rows on each twig; they are 10–23 mm (3⁄8–7⁄8 in) long and 2–2.2 mm (5⁄64–3⁄32 in) 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 two silvery white stomatal bands abaxially (on their undersides). Their strong fragrance resembles that of turpentine.

The cones are erect; cylindrical; 3.5–7 cm (1+1⁄2–2+3⁄4 in) long, rarely 8 cm (3+1⁄4 in), and 2.5–3 cm (1–1+1⁄8 in) broad, rarely 4 cm (1+1⁄2 in) 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.[5][6][7]

Ecology

Reproduction and growth

Fraser fir is monoecious, meaning that both male and female cones (strobili) occur on the same tree.[11] 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.[12]

Distribution and habitat
Fraser fir forest, with many trees killed by balsam woolly adelgid

Abies 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 ft (1,200 m) to the summit of Mount Mitchell, the highest point in the region at 6,684 ft (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.[5][6]

Pests

Abies fraseri can be severely damaged by a non-native insect, the balsam woolly adelgid (Adelges piceae) from Europe. 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 was 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 endangered spruce-fir moss spider (Microhexura montivaga), an obligate of Fraser fir-red spruce stands.[8]

By the late 1990s, the adelgid population had decreased. While two-thirds of adult trees had been killed by the 1980s, a study of the Great Smoky Mountains National Park showed that as of 2020, the number of adult trees had increased over the previous 30 years, with three times as many on Clingmans Dome, Tennessee's highest peak.[13]

Threats

The Fraser fir is an endangered species.[14] Threats include climate change and the aforementioned balsam woolly adelgid.

Cultivation and uses

Although not important as a source of timber, the combination of dense natural pyramidal form, strong limbs, soft long-retained needles, dark blue-green color, pleasant scent and excellent shipping characteristics, has led to Fraser fir being widely used as a Christmas tree.[15] Fraser fir has been used more times as the White House Christmas tree than any other tree.

The Christmas decoration trade is a multimillion-dollar business in the southern Appalachians. North Carolina produces the majority of Fraser fir Christmas trees.[16] It requires from seven to ten years in the field to produce a 6–7-foot-tall (1.8–2.1-meter) tree. In 2005, the North Carolina General Assembly passed legislation making the Fraser fir the official Christmas tree of North Carolina.

The Fraser fir is cultivated from seedlings in several northern states in the USA and across the border in adjacent parts of the Canadian province of Quebec, especially for the Christmas tree trade.[14] It is also grown in Bedgebury National Pinetum and other collections in the United Kingdom.[14]

See also

References
  1. Farjon, A. (2013). "Abies fraseri". IUCN Red List of Threatened Species. 2013: e.T32101A2810241. doi:10.2305/IUCN.UK.2013-1.RLTS.T32101A2810241.en. Retrieved 19 November 2021.
  2. "NatureServe Explorer 2.0". explorer.natureserve.org. Retrieved 18 June 2022.
  3. "The Plant List: A Working List of All Plant Species". Retrieved 3 October 2014.
  4. Kaylor, S. (September 2016). "Recovery Trends and Predictions of Fraser Fir (Abies fraseri) Dynamics in the Southern Appalachian Mountains". Canadian Journal of Forest Research. 47 (1): 125-133.
  5. Farjon, A. (1990). Pinaceae. Drawings and Descriptions of the Genera. Koeltz Scientific Books ISBN 3-87429-298-3.
  6. Liu, T.-S. (1971). A Monograph of the Genus Abies. National Taiwan University.
  7. Flora of North America: Abies fraseri
  8. Gymnosperm Database: Abies fraseri
  9. Frankenberg, D. (2000). Exploring North Carolina's Natural Areas: Parks, Nature Preserves, and Hiking Trails. Chapel Hill: University of North Carolina Press. ISBN 978-0-8078-4851-7. p343
  10. Sutton, M. & Sutton, A. (1985). Eastern forests (Audubon Society Nature Guides). New York: Knopf. ISBN 978-0-394-73126-1. p363
  11. Abies fraseri (Pursh) Poir Archived 2016-10-25 at the Wayback Machine, Silviculture Manual, Volume 1, US Department of Agriculture Forest Service, Retrieved 20 October 2014
  12. Abies fraseri (Pursh) Poir. Archived 2016-04-25 at the Wayback Machine The National Christmas Tree Association, Retrieved 20 Oct 2014
  13. McDarris, Anne (April 22, 2020). "Earth Day: After decades of devastation, a comeback for WNC forests". Asheville Citizen-Times. Retrieved April 22, 2020.
  14. "Fraser Fir". Global Trees. Retrieved 2021-05-07.
  15. Hendrix, Steve, "A Christmas tree’s remarkable journey", The Washington Post, December 21, 2011.
  16. "Fraser Fir". North Carolina Department of Agriculture. Retrieved 24 November 2010.
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