Nothofagus

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Nothofagus
Temporal range: 72–0Ma
Late Campanian–Present
The roble beech (Nothofagus obliqua) from South America
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Fagales
Family: Nothofagaceae
Kuprian.[1]
Genus: Nothofagus
Blume
Species

See text

The range of Nothofagus.
Shoots, leaves, and cupules of N. obliqua

Nothofagus, also known as the southern beeches, is a genus of 36 species of trees and shrubs native to the temperate oceanic to tropical Southern Hemisphere in southern South America (Chile, Argentina) and Australasia (east and southeast Australia, New Zealand, New Guinea and New Caledonia). Fossils have recently been found in Antarctica.[2]

In the past, they were included in the family Fagaceae, but genetic tests by the Angiosperm Phylogeny Group revealed them to be genetically distinct, and they are now included in their own family, the Nothofagaceae.

The leaves are toothed or entire, evergreen or deciduous. The fruit is a small, flattened or triangular nut, borne in cupules containing two to seven nuts.

Nothofagus species are used as food plants by the larvae of hepialid moths of the genus Aenetus, including A. eximia and A. virescens.

Many individual trees are extremely old, and at one time it was believed that some populations could not reproduce in present-day conditions at the location where they were growing, except by suckering (clonal reproduction), being remnant forest from a cooler time. It has since been shown that sexual reproduction may occur,[3] but distribution in cool, isolated high-altitude environments at temperate and tropical latitudes is consistent with the theory that the genus was more prolific in a cooler age.[4]

Taxonomy[edit]

The genus is classified in the following sections:[5]

Sect. Brassospora (type Nothofagus brassi)
Sect. Fuscospora (type Nothofagus fusca)
Beech trees in New Zealand
Sect. Lophozonia (type Nothofagus menziesii)
Sect. Nothofagus (type Nothofagus antarctica)

The generic classification of the Nothofagaceae was recently revised, and the 4 subgenera were elevated to full genera.[6] It remains to be seen if this work will gain wide acceptance.

Nothofagus is a plant genus that illustrates Gondwanan distribution, having originated on the supercontinent and persisting in current day Australia, New Guinea, New Zealand, New Caledonia, Argentina and Chile. Recently fossils also have been found in Antarctica.[7]

Distribution[edit]

The pattern of distribution around the southern Pacific Rim suggests the dissemination of the genus dates to the time when Antarctica, Australia and South America were connected, a common land-mass or supercontinent referred to as Gondwana.[8]

In South America, the northern genus limit can be construed as La Campana National Park and the Vizcachas Mountains in the central part of Chile.[9]

Beech mast[edit]

Every four to six years or so Nothofagus produces a heavier crop of seeds and is known as the beech mast. In New Zealand the beech mast causes an increase in the population of introduced mammals such as mice, rats and stoats. When the rodent population collapses, the stoats begin to prey on native bird species, many of which are threatened with extinction.[10] Main article here Stoats in New Zealand


See also[edit]

  • Cyttaria, genus of ascomycete fungi found on or associated with Nothofagus
  • Misodendron, a family of specialist parasites of Nothofagus

References[edit]

  1. ^ Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III" (PDF). Botanical Journal of the Linnean Society 161 (2): 105–121. doi:10.1111/j.1095-8339.2009.00996.x. Retrieved 2013-06-26. 
  2. ^ Li, H. M.; Zhou, Z. K. (2007). "Fossil nothofagaceous leaves from the Eocene of western Antarctica and their bearing on the origin, dispersal and systematics of Nothofagus". Science China Earth Sciences 50 (10): 1525–1535. 
  3. ^ http://cgi.cse.unsw.edu.au/~lambert/cgi-bin/clim/2005/07/
  4. ^ Dawson, J. W. (1966). "Observations on Nothofagus in New Caledonia". Tuatara 14 (1). 
  5. ^ Nothofagus website (in French)
  6. ^ Heenan, P.B.; Smissen, R.D. 2013: Revised circumscription of Nothofagus and recognition of the segregate genera Fuscospora, Lophozonia, and Trisyngyne (Nothofagaceae). Phytotaxa, 146(1): 1-31. doi:10.11646/phytotaxa.146.1.1
  7. ^ H.M. Li and Z.K. Zhou (2007) Fossil nothofagaceous leaves from the Eocene of western Antarctica and their bearing on the origin, dispersal and systematics of Nothofagus. Science in China. 50(10): 1525-1535.
  8. ^ Native Forest Network (2003) Gondwana Forest Sanctuary
  9. ^ C. Michael Hogan (2008) Chilean Wine Palm: Jubaea chilensis, GlobalTwitcher.com, ed. Nicklas Stromberg
  10. ^ "Beech forest: Native plants". Department of Conservation. Retrieved 26 August 2012.