Abies fraseri
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Fraser Fir | ||||||||||||||
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Abies fraseri (Pursh) Poir. |
Abies fraseri (Fraser Fir) is a species of fir native to the mountains of the eastern United States. It 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).[2][3][4][5]
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[edit] Morphology
It is a small evergreen coniferous tree growing to 10–15 m (rarely to 25 m) tall with a trunk 40–50 cm (rarely to 75 cm) diameter. The crown is conical, with straight branches from horizontal to angled 40° upward from the trunk; it is dense when the tree is young, but becomes more open as it ages. The bark is thin and smooth, gray-brown with numerous resin blisters on young trees, becoming fissured and scaly with age. The foliage is strongly turpentine-scented. The leaves are needle-like, arranged spirally on the twigs but twisted at the base to spread in two rows; they are 10–23 mm long and 2–2.2 mm broad, flat and flexible with a rounded or slightly notched tip, dark green to glaucous green above, often with a small patch of stomata near the tip, and with two silvery white stomatal bands on the underside. The cones are erect, cylindric, 3.5-7 cm (rarely 8 cm) long and 2.5–3 cm (rarely 4 cm) broad, dark purple, turning light brown when mature, with long reflexed green, yellow or pale purple bract scales, and often resinous. The cones disintegrate when mature at 4–6 months old to release the winged seeds.[2][3][4]
The Balsam Fir variety Abies balsamea var. phanerolepis is regarded by some botanists as a natural hybrid between Balsam Fir and Fraser Fir, as Abies × phanerolepis (Fernald) Liu.[3]
[edit] Distribution and ecology
It is restricted to the southeastern Appalachian Mountains in southwestern Virginia, western North Carolina and eastern Tennessee, where it occurs at high elevations, from 1200 m up to 2,037 m (the summit of Mount Mitchell, the highest point in the region). 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.[2][3]
The species severely is 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% of mature trees having been killed. The rapid regeneration of seedlings with lack of canopy has led to good regrowth of new, healthy young trees where the mature forests once stood. However, when these young trees get old enough for the bark to develop fissures, they will likely be attacked and killed by the adelgids as well. For this reason, the future of the species is still uncertain. The decline of the Fraser Fir in the southern Appalachians has contributed to loss of moss habitat which supports the Spruce-fir moss spider.[5]
[edit] Cultivation and uses
Fraser Fir is widely used as a Christmas tree. Its fragrance, appearance, strong twigs, and ability to retain its soft needles for a long time when cut (which do not prick easily when hanging ornaments) make it an excellent choice for this purpose.
[edit] Etymology
The species is named after the Scottish botanist John Fraser (1750–1811), who made numerous botanical collections in the region.[3] It is sometimes mis-spelled as "Frazer" or "Frazier". In the past, it was also sometimes known as "she-balsam" because resin could be "milked" from its bark blisters,[6] 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.[7]
[edit] References and external links
- ^ Conifer Specialist Group (1998). Abies fraseri. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Listed as Vulnerable (VU D2 v2.3)
- ^ a b c Farjon, A. (1990). Pinaceae. Drawings and Descriptions of the Genera. Koeltz Scientific Books ISBN 3-87429-298-3.
- ^ a b c d e Liu, T.-S. (1971). A Monograph of the Genus Abies. National Taiwan University.
- ^ a b Flora of North America: Abies fraseri
- ^ a b Gymnosperm Database: Abies fraseri
- ^ Frankenberg, D. (2000). Exploring North Carolina's Natural Areas: Parks, Nature Preserves, and Hiking Trails. Chapel Hill: University of North Carolina Press. ISBN 0-8078-4851-4. p343
- ^ Sutton, M., & Sutton, A. (1985). Eastern forests (Audubon Society Nature Guides). New York: Knopf. ISBN 0-394-73126-3. p363