Nothofagus

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Southern beeches
Temporal range: 72–0 Ma
Late Campanian–Present
Roble (Nothofagus obliqua).JPG
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
Nothofagus Distribution.svg
The range of Nothofagus.
Synonyms[2]
  • Fagaster Spach
  • Cliffortioides Dryand. ex Hook.
  • Myrtilloides Banks & Sol. ex Hook.
  • Calucechinus Hombr. & Jacquinot ex Decne. in J.S.C.Dumont d'Urville
  • Calusparassus Hombr. & Jacquinot ex Decne. in J.S.C.Dumont d'Urville
  • Lophozonia Turcz.
  • Trisyngyne Baill.
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 Southern Hemisphere in southern South America (Chile, Argentina) and Australasia (east and southeast Australia, New Zealand, New Guinea and New Caledonia). The species are ecological dominants in many temperate forests in these regions. Some species are reportedly naturalized in Germany and Great Britain.[2] The genus has a rich fossil record of leaves, cupules and pollen, with fossils extending into the late Cretaceous and occurring in Australia, New Zealand, Antarctica and South America.[3] In the past, they were included in the family Fagaceae, but genetic tests revealed them to be genetically distinct,[4] and they are now included in their own family, the Nothofagaceae (literally meaning "false beeches" or "bastard beeches").[5]

The leaves are toothed or entire, evergreen or deciduous. The fruit is a small, flattened or triangular nut, borne in cupules containing one 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, some populations were thought to be unable to reproduce in present-day conditions at the location where they were growing, except by suckering (clonal reproduction), being remnant forest from a cooler time. Sexual reproduction has since been shown to be possible,.[6] Although the genus now mostly occurs in cool, isolated, high-altitude environments at temperate and tropical latitudes the fossil record shows that it survived in climates that appear to be much warmer than those that Nothofagus now occupies.[7]

Taxonomy[edit]

The genus is classified in these sections:[8]

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)
Section uncertain

It was recently proposed that the generic classification of the Nothofagaceae should be revised, with the four subgenera elevated to full genera.[13] This proposed change is not taxonomically essential and it remains to be seen if this work will gain wide acceptance.[2][14]

The Nothofagus plant genus illustrates the distribution on fragments of the old supercontinent Gondwana Australia, New Guinea, New Zealand, New Caledonia, Argentina and Chile. Fossils show that the genus originated on the supercontinent.

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 in a common land-mass or supercontinent referred to as Gondwana.[15] However, genetic evidence using molecular dating methods has been used to argue that the species in New Zealand and New Caledonia evolved from species that arrived in these landmasses by dispersal across oceans.[16] There is uncertainty in molecular dates and controversy rages as to whether the distribution of Nothofagus derives from the break-up of Gondwana (i.e. vicariance), or if there has been long distance dispersal across oceans. 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.[17]

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.[18] This phenomenon is covered in more detail in the article on stoats in New Zealand.

See also[edit]

  • Cyttaria, genus of ascomycete fungi found on or associated with Nothofagus
  • Misodendrum, 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. ^ a b c Kew World Checklist of Selected Plant Families
  3. ^ a b c d e f g h i j k l m n o Hill, Robert (2001). "Biogeography, evolution and palaeoecology of Nothofagus (Nothofagaceae): The contribution of the fossil record.". Australian Journal of Botany 49: 321. doi:10.1071/BT00026. 
  4. ^ Manos PS, Steele KP (1997) Phylogenetic analyses of 'higher' Hamamelididae based on plastid sequence data. American Journal of Botany 84, 1407-1419. Stable URL: http://www.jstor.org/stable/2446139
  5. ^ Manos, Paul (1997). "Phylogenetic analyses of 'higher' Hamamelididae based on plastid sequence data". American Journal of Botany 84: 1407–1419. doi:10.2307/2446139. JSTOR 2446139. 
  6. ^ http://cgi.cse.unsw.edu.au/~lambert/cgi-bin/clim/2005/07/
  7. ^ Carpenter, RJ; Jordan, GJ; Macphail, MK; Hill, RS (2012). "Near-tropical early eocene terrestrial temperatures at the Australo-Antarctic margin, western Tasmania". Geology 40: 267–270. doi:10.1130/G32584.1. 
  8. ^ Nothofagus website (in French)
  9. ^ Carpenter, RJ; Bannister, JM; Lee, DE; Jordan, GJ (2014). "Nothofagus subgenus Brassospora (Nothofagaceae) leaf fossils from New Zealand: A link to Australia and New Guinea?". Botanical Journal of the Linnean Society 174: 503–515. doi:10.1111/boj.12143. 
  10. ^ Jordan, GJ (1999). "A new Early Pleistocene species of Nothofagus and the climatic implications of co-occurring Nothofagus fossils". Australian Systematic Botany 12: 757–765. doi:10.1071/sb98025. 
  11. ^ Neogene Period (23–0.05 mya)
  12. ^ Nothofagus beardmorensis Nothofagaceae, a new species based on leaves from the Pliocene Sirius Group, Transantarctic Mountains, Antarctica
  13. ^ 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. 
  14. ^ Hill, RS; Jordan, GJ; Macphail, MK (2015). "Why we should retain Nothofagus sensu lato". Australian Systematic Botany 28: 190–193. doi:10.1071/sb15026. 
  15. ^ Native Forest Network (2003) Gondwana Forest Sanctuary
  16. ^ Knapp, M; Stockler, K; Havell, D; Delsuc, F; Sebastiani, F; Lockhart, PJ (2005). "Relaxed molecular clock provides evidence for long-distance dispersal of Nothofagus (Southern Beech)". PLoS Biology 3: 38–43. doi:10.1371/journal.pbio.0030014. 
  17. ^ C. Michael Hogan (2008) Chilean Wine Palm: Jubaea chilensis, GlobalTwitcher.com, ed. Nicklas Stromberg
  18. ^ "Beech forest: Native plants". Department of Conservation. Retrieved 26 August 2012.