Sequoioideae

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Sequoioideae
Temporal range: Middle Jurassic–Present
US 199 Redwood Highway.jpg
Redwood Highway, California Sequoia sempervirens
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Gymnospermae
Division: Pinophyta
Class: Pinopsida
Order: Cupressales
Family: Cupressaceae
Subfamily: Sequoioideae
Genera

Sequoioideae, commonly referred to as redwoods, is a subfamily of coniferous trees within the family Cupressaceae, that range in the northern hemisphere. It includes the largest and tallest trees in the world. The trees in the subfamily are amongst the most notable trees in the world and are common ornamental trees.

Contents

Description

The three redwood subfamily genera are Sequoia from coastal California and Oregon, Sequoiadendron from California's Sierra Nevada, and Metasequoia in China. The redwood species contains the largest and tallest trees in the world. These trees can live for thousands of years. Threats include logging, fire suppression, [1] illegal marijuana cultivation, and burl poaching. [2] [3]

Only two of the genera, Sequoia and Sequoiadendron, are known for massive trees. Trees of Metasequoia , from the single living species Metasequoia glyptostroboides , are deciduous, grow much smaller (although are still large compared to most other trees) and can live in colder climates.[ citation needed ]

Taxonomy and evolution

Multiple studies of both morphological and molecular characters have strongly supported the assertion that the Sequoioideae are monophyletic. [4] [5] [6] [7] Most modern phylogenies place Sequoia as sister to Sequoiadendron and Metasequoia as the out-group. [5] [7] [8] However, Yang et al. went on to investigate the origin of a peculiar genetic component in Sequoioideae, the polyploidy of Sequoia—and generated a notable exception that calls into question the specifics of this relative consensus. [7]

Cladistic tree

A 2006 paper based on non-molecular evidence suggested the following relationship among extant species: [9]

Sequoioideae
Metasequoia

M. glyptostroboides (dawn redwood)

Sequoia

S. sempervirens (coast redwood)

Sequoiadendron

S. giganteum (giant sequoia)

Taxodioideae

A 2021 study using molecular evidence found the same relationships among Sequoioideae species, but found Sequoioideae to be the sister group to the Athrotaxidoideae (a superfamily presently known only from Tasmania) rather than to Taxodioideae. Sequoioideae and Athrotaxidoideae are thought to have diverged from each other during the Jurassic. [10]

Possible reticulate evolution in Sequoioideae

Reticulate evolution refers to the origination of a taxon through the merging of ancestor lineages. Polyploidy has come to be understood as quite common in plants—with estimates ranging from 47% to 100% of flowering plants and extant ferns having derived from ancient polyploidy. [11] Within the gymnosperms however it is quite rare. Sequoia sempervirens is hexaploid (2n= 6x= 66). To investigate the origins of this polyploidy Yang et al. used two single copy nuclear genes, LFY and NLY, to generate phylogenetic trees. Other researchers have had success with these genes in similar studies on different taxa. [7]

Several hypotheses have been proposed to explain the origin of Sequoia's polyploidy: allopolyploidy by hybridization between Metasequoia and some probably extinct taxodiaceous plant; Metasequoia and Sequoiadendron, or ancestors of the two genera, as the parental species of Sequoia; and autohexaploidy, autoallohexaploidy, or segmental allohexaploidy.[ citation needed ]

Yang et al. found that Sequoia was clustered with Metasequoia in the tree generated using the LFY gene but with Sequoiadendron in the tree generated with the NLY gene. Further analysis strongly supported the hypothesis that Sequoia was the result of a hybridization event involving Metasequoia and Sequoiadendron. Thus, Yang et al. hypothesize that the inconsistent relationships among Metasequoia, Sequoia, and Sequoiadendron could be a sign of reticulate evolution by hybrid speciation (in which two species hybridize and give rise to a third) among the three genera. However, the long evolutionary history of the three genera (the earliest fossil remains being from the Jurassic) make resolving the specifics of when and how Sequoia originated once and for all a difficult matter—especially since it in part depends on an incomplete fossil record. [8]

Extant species

Paleontology

Sequoioideae is an ancient taxon, with the oldest described Sequoioideae species, Sequoia jeholensis , recovered from Jurassic deposits. [12] [13] The fossil wood Medulloprotaxodioxylon , reported from the late Triassic of China, resembles Sequoiadendron giganteum and may represent an ancestral form of the Sequoioideae; this supports the idea of a Late Triassic Norian origin for this subfamily. [14]

The fossil record shows a massive expansion of range in the Cretaceous and dominance of the Arcto-Tertiary Geoflora, especially in northern latitudes. Genera of Sequoioideae were found in the Arctic Circle, Europe, North America, and throughout Asia and Japan. [15] A general cooling trend beginning in the late Eocene and Oligocene reduced the northern ranges of the Sequoioideae, as did subsequent ice ages. [16] Evolutionary adaptations to ancient environments persist in all three species despite changing climate, distribution, and associated flora, especially the specific demands of their reproduction ecology that ultimately forced each of the species into refugial ranges where they could survive.[ citation needed ]

The extinct genus Austrosequoia , known from the Late Cretaceous-Oligocene of the Southern Hemisphere, including Australia and New Zealand, has been suggested as a member of the subfamily. [17]

Young but already tall redwood trees (Sequoia sempervirens) in Oakland, California Redwood tree in Oakland California (person for comparison)IMG 4881.jpg
Young but already tall redwood trees ( Sequoia sempervirens ) in Oakland, California

Conservation

In 2024, it was estimated that there were about 500,000 redwoods in Britain, mostly brought as seeds and seedlings from the US in the Victorian era. [18] The entire subfamily is endangered. The IUCN Red List Category & Criteria assesses Sequoia sempervirens as Endangered (A2acd), Sequoiadendron giganteum as Endangered (B2ab) and Metasequoia glyptostroboides as Endangered (B1ab). In 2024 it was reported that over a period of two years about one-fifth of all giant sequoias were destroyed in extreme wildfires in California. [19]

See also

Related Research Articles

Sequoia, Sequoya or Sequoyah refers to a type of tree in the cypress family which includes the redwood trees. By extension the name may refer to:

<i>Sequoiadendron giganteum</i> Species of tree native to North America

Sequoiadendron giganteum, also known as the giant sequoia, giant redwood, Sierra redwood or Wellingtonia is a coniferous tree, classified in the family Cupressaceae in the subfamily Sequoioideae. Giant sequoia specimens are the most massive trees on Earth. They are native to the groves on the western slopes of the Sierra Nevada mountain range of California but have been introduced, planted, and grown around the world.

Taxodiaceae is a formerly recognized conifer family. It is today recognised as a paraphyletic grade of basal lineages within the Cupressaceae. It contains the following living genera:

<i>Metasequoia</i> Genus of conifers

Metasequoia, Dawen redwood, is a genus of fast-growing coniferous trees, one of three species of conifers known as redwoods. The living species Metasequoia glyptostroboides is native to Lichuan county in Hubei province, China. Although the shortest of the redwoods, it grows to at least 165 feet in height. Local villagers refer to the original tree from which most others derive as Shuǐshān (水杉), or "water fir", which is part of a local shrine. Since its rediscovery in 1944, the dawn redwood has become a popular ornamental, with examples found in various parks in a variety of countries. The genus was dominant near the North Pole during the Cretaceous.

<i>Metasequoia glyptostroboides</i> Species of conifer

Metasequoia glyptostroboides, the dawn redwood, is a fast-growing, endangered deciduous conifer. It is the sole living species of the genus Metasequoia, one of three genera in the subfamily Sequoioideae of the family Cupressaceae. It now survives in the wild only in wet lower slopes and montane river and stream valleys in the border region of Hubei and Hunan provinces and Chongqing municipality in south-central China, notably in Lichuan county in Hubei. Although the shortest of the redwoods, it can grow to 167 ft (51 m) in height.

<span class="mw-page-title-main">Cupressaceae</span> Cypress family of conifers

Cupressaceae or the cypress family is a family of conifers. The family includes 27–30 genera, which include the junipers and redwoods, with about 130–140 species in total. They are monoecious, subdioecious or (rarely) dioecious trees and shrubs up to 116 m (381 ft) tall. The bark of mature trees is commonly orange- to red-brown and of stringy texture, often flaking or peeling in vertical strips, but smooth, scaly or hard and square-cracked in some species. The family reached its peak of diversity during the mesozoic era.

<i>Cupressus</i> Several genera of evergreen conifers

Cupressus is one of several genera of evergreen conifers within the family Cupressaceae that have the common name cypress; for the others, see cypress. It is considered a polyphyletic group. Based on genetic and morphological analysis, the genus Cupressus is found in the subfamily Cupressoideae. The common name "cypress" comes via the Old French cipres from the Latin cyparissus, which is the latinisation of the Greek κυπάρισσος (kypárissos).

<i>Cunninghamia</i> Genus of conifers

Cunninghamia is a genus of one or two living species of evergreen coniferous trees in the cypress family Cupressaceae. They are native to China, northern Vietnam and Laos, and perhaps also Cambodia. They may reach 50 m (160 ft) in height. In vernacular use, it is most often known as Cunninghamia, but is also sometimes called "China-fir". The genus name Cunninghamia honours Dr. James Cunningham, a British doctor who introduced this species into cultivation in 1702 and botanist Allan Cunningham.

<i>Athrotaxis</i> Genus of conifers

Athrotaxis is a genus of two to three species of conifers in the cypress family, Cupressaceae. The genus is endemic to western Tasmania, where they grow in high-elevation temperate rainforests.

The Chester M Alter Arboretum is an arboretum located on the campus of the University of Denver, 2467 South Vine Street, Denver, Colorado.

<span class="mw-page-title-main">Redwood Mountain Grove</span>

Redwood Mountain Grove is the largest grove of giant sequoia trees on earth. It is located in Kings Canyon National Park and Giant Sequoia National Monument on the western slope of California's Sierra Nevada. The grove contains the world's tallest giant sequoia. The Hart Tree and Roosevelt Tree grow in the grove and are two of the 25 largest trees by volume in the world. The largest tree is the General Sherman Tree in the Giant Forest grove to the southeast.

<i>Sequoia sempervirens</i> Species of tree

Sequoia sempervirens is the sole living species of the genus Sequoia in the cypress family Cupressaceae. Common names include coast redwood, coastal redwood and California redwood. It is an evergreen, long-lived, monoecious tree living 1,200–2,200 years or more. This species includes the tallest living trees on Earth, reaching up to 115.9 m (380.1 ft) in height and up to 8.9 m (29 ft) in diameter at breast height. These trees are also among the longest-living trees on Earth. Before commercial logging and clearing began by the 1850s, this massive tree occurred naturally in an estimated 810,000 ha along much of coastal California and the southwestern corner of coastal Oregon within the United States. Being the tallest tree species, with a small range and an extremely long lifespan, many redwoods are preserved in various state and national parks; many of the largest specimens have their own official names.

<i>Sequoia</i> (genus) Genus of conifers in the cypress family Cupressaceae

Sequoia is a genus of redwood coniferous trees in the subfamily Sequoioideae of the family Cupressaceae. The only extant species of the genus is Sequoia sempervirens in the Northern California coastal forests ecoregion of Northern California and Southwestern Oregon in the United States. The two other genera in the subfamily Sequoioideae, Sequoiadendron and Metasequoia, are closely related to Sequoia. It includes the tallest trees, as well as the heaviest, in the world.

<i>Sequoiadendron chaneyi</i> Extinct species of conifer

Sequoiadendron chaneyi is an extinct species of tree in the Cupressaceae genus Sequoiadendron. Known from Miocene fossils found in Nevada and California, S. chaneyi is the oldest species of Sequoiadendron. The common use of the name "sequoia" generally refers to Sequoiadendron giganteum, which occurs naturally only in the various groves that exist on the western slopes of the Sierra Nevada of California. S. chaneyi is considered the probable direct ancestor to the extant Sequoiadendron giganteum.

<i>Sequoia affinis</i> Extinct species of conifer

Sequoia affinis is an extinct species of the genus Sequoia in the cypress family Cupressaceae.

<i>Sequoiadendron</i> Genus of conifers in the cypress family Cupressaceae

Sequoiadendron is a genus of evergreen trees, with three species, only one of which survives to the present:

<span class="mw-page-title-main">Stellenbosch University Botanical Garden</span> Oldest university botanical garden in South Africa

The Stellenbosch University Botanical Garden located in the historical center of Stellenbosch is the oldest university botanical garden in South Africa. The Garden is relatively small and houses an enormous diversity of plants, both indigenous to South Africa and introduced species. It is open to the public.

<i>Metasequoia occidentalis</i> Extinct species of conifer

Metasequoia occidentalis is an extinct redwood species of the family Cupressaceae that is found as fossils throughout the Northern Hemisphere. It is one of three extinct species of Metasequoia that are currently recognized as valid.

<i>Metasequoia heerii</i> Extinct species of conifer

Metasequoia heerii is an extinct redwood species of the family Cupressaceae that is found as fossils throughout the Northern Hemisphere. It is one of several proposed extinct species of Metasequoia that were previously referred to Sequoia.

References

  1. ↑ "Prescribed Fire at Redwood National and State Parks - Redwood National and State Parks (U.S. National Park Service)".
  2. ↑ "Why redwood burl poaching is so destructive". Christian Science Monitor. 5 March 2014.
  3. ↑ Kurland, Justin; Pires, Stephen F; Marteache, Nerea (2018). "The spatial pattern of redwood burl poaching and implications for prevention". Forest Policy and Economics. 94: 46–54. doi:10.1016/j.forpol.2018.06.009. S2CID   158505170.
  4. ↑ Brunsfeld, Steven J; Soltis, Pamela S; Soltis, Douglas E; Gadek, Paul A; Quinn, Christopher J; Strenge, Darren D; Ranker, Tom A (1994). "Phylogenetic Relationships Among the Genera of Taxodiaceae and Cupressaceae: Evidence from rbcL Sequences". Systematic Botany. 19 (2): 253. doi:10.2307/2419600. JSTOR   2419600.
  5. 1 2 Gadek, P.A.; Alpers, D.L.; Heslewod, M.M.; Quinn, C.J. (2000). "Relationships Within Cupressaceae Sensu Lato: A Combined Morphological and Molecular Approach". American Journal of Botany. 87 (7): 1044–57. doi: 10.2307/2657004 . JSTOR   2657004. PMID   10898782.
  6. ↑ Takaso, T.; Tomlinson, P.B. (1992). "Seed cone and ovule ontogeny in Metasequoia, Sequoia and Sequoiadendron (Taxodiaceae-Coniferales)". Botanical Journal of the Linnean Society. 109: 15–37. doi:10.1111/j.1095-8339.1992.tb00256.x.
  7. 1 2 3 4 Yang, Z.Y.; Ran, J.H.; Wang, X.Q. (2012). "Three Genome-based Phylogeny of Cupressaceae s.l: Further Evidence for the Evolution of Gymnosperms and Southern Hemisphere Biogeography". Molecular Phylogenetics and Evolution. 64 (3): 452–470. doi:10.1016/j.ympev.2012.05.004. PMID   22609823.
  8. 1 2 Mao, K.; Milne, R.I.; Zhang, L.; Peng, Y.; Liu, J.; Thomas, P.; Mill, R.R.; Renner, S.S. (2012). "Distribution of Living Cupressaceae Reflects the Breakup of Pangea". Proceedings of the National Academy of Sciences. 109 (20): 7793–7798. Bibcode:2012PNAS..109.7793M. doi: 10.1073/pnas.1114319109 . PMC   3356613 . PMID   22550176.
  9. ↑ Schulz; Stützel (August 2007). "Evolution of taxodiaceous Cupressaceae (Coniferopsida)". Organisms Diversity & Evolution. 7 (2): 124–135. doi: 10.1016/j.ode.2006.03.001 .
  10. ↑ Stull, Gregory W.; Qu, Xiao-Jian; Parins-Fukuchi, Caroline; Yang, Ying-Ying; Yang, Jun-Bo; Yang, Zhi-Yun; Hu, Yi; Ma, Hong; Soltis, Pamela S.; Soltis, Douglas E.; Li, De-Zhu (August 2021). "Gene duplications and phylogenomic conflict underlie major pulses of phenotypic evolution in gymnosperms". Nature Plants. 7 (8): 1015–1025. doi:10.1038/s41477-021-00964-4. ISSN   2055-0278. PMID   34282286. S2CID   236141481.
  11. ↑ Soltis, D.E.; Buggs, R.J.A.; Doyle, J.J.; Soltis, P.S. (2010). "What we still don't know about polyploidy". Taxon. 59 (5): 1387–1403. doi:10.1002/tax.595006. JSTOR   20774036.
  12. ↑ Ma, Qing-Wen; K. Ferguson, David; Liu, Hai-Ming; Xu, Jing-Xian (2020). "Compressions of Sequoia (Cupressaceae sensu lato) from the Middle Jurassic of Daohugou, Ningcheng, Inner Mongolia, China". Palaeobiodiversity and Palaeoenvironments. 1 (9): 1. doi:10.1007/s12549-020-00454-z. S2CID   227180592 . Retrieved 9 March 2021.
  13. ↑ Ahuja M. R. and D. B. Neale. 2002. Origins of polyploidy in coast redwood (Sequoia sempervirens) and relationship of coast redwood (Sequoia sempervirens) to other genera of Taxodiaceae. Archived 2 January 2014 at the Wayback Machine Silvae Genetica 51: 93–99.
  14. ↑ Wan, Mingli; Yang, Wan; Tang, Peng; Liu, Lujun; Wang, Jun (2017). "Medulloprotaxodioxylon triassicum gen. Et sp. Nov., a taxodiaceous conifer wood from the Norian (Triassic) of northern Bogda Mountains, northwestern China". Review of Palaeobotany and Palynology. 241: 70–84. doi:10.1016/j.revpalbo.2017.02.009.
  15. ↑ Chaney, Ralph W. (1950). "Revision of Fossil Sequoia and Taxodium in Western North America Based on the Recent Discovery of Metasequoia". Transactions of the American Philosophical Society. 40 (3). Philadelphia: 172–236. doi:10.2307/1005641. ISBN   978-1422377055. JSTOR   1005641 . Retrieved 1 January 2014.
  16. ↑ Jagels, Richard; Equiza, María A. (2007). "Why did Metasequoia disappear from North America but not from China?". Bulletin of the Peabody Museum of Natural History. 48 (2): 281–290. doi:10.3374/0079-032x(2007)48[281:wdmdfn]2.0.co;2. S2CID   129649877.
  17. ↑ Mays, Chris; Cantrill, David J.; Stilwell, Jeffrey D.; Bevitt, Joseph J. (28 May 2018). "Neutron tomography of Austrosequoia novae-zeelandia e comb. nov. (Late Cretaceous, Chatham Islands, New Zealand): implications for Sequoioideae phylogeny and biogeography". Journal of Systematic Palaeontology. 16 (7): 551–570. doi:10.1080/14772019.2017.1314898. ISSN   1477-2019.
  18. ↑ Tapper, James (16 March 2024). "Hidden giants: how the UK's 500,000 redwoods put California in the shade". The Guardian.
  19. ↑ Sommer, Lauren; Kellman, Ryan (26 February 2024). "Wildfires are killing California's ancient giants. Can seedlings save sequoia trees?". NPR. Retrieved 16 March 2024.
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