Betula chichibuensis

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Betula chichibuensis
Betula chichibuensis kz02.jpg
Chichibu birch specimen at the Botanischer Garten Halle, Germany
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Fagales
Family: Betulaceae
Genus: Betula
Species:
B. chichibuensis
Binomial name
Betula chichibuensis

Betula chichibuensis, commonly known as Chichibu birch (Chichibu-Minebari in Japanese [1] ), is a species of birch native exclusively to limestone outcrops in the Okuchichibu and Kitakami Mountains of central and northeast Honshu, Japan. [2] The tree is rated as Critically Endangered on the IUCN Red List due to its extreme rarity and limited range. [1]

Contents

In 1993, only 21 B. chichibuensis trees existed in the wild. Although several other small populations of the tree were discovered in the 2010s, including the Kitakami populations, [3] [4] the Chichibu birch remains very rare. Ex situ conservation efforts to prevent the species' extinction are ongoing, including at the University of Liverpool's Ness Botanic Gardens [1] and the Bedgebury National Pinetum. [5]

Description

Betula chichibuensis is a multi-stemmed shrub or small deciduous tree that reaches 8–10 meters (26–33 ft) tall in the wild and about 5 meters (16 ft) tall in captivity. [3] The Chichibu birch is very long-lived due to its sprouting habit, but its self-incompatibility means two individuals must be close enough together to cross-pollinate, making seed production unreliable in smaller populations. [1]

The bark of the Chichibu birch is light brown and flaky with horizontal lenticels. Twigs from it are nearly hairless and can reach up to 3 mm in diameter. The leaves are alternately placed on the stem, and their shape is ovate, acute, rounded or slightly cordate at the base. They are 30–75 mm long by 15–45 mm wide, glabrous and green on their upper surface, and have white hairs on the underside. They have up to 18 pairs of deep veins and are serrated, with 1–3 teeth between each tooth ending a secondary vein. Chichibu birch is monoecious: an individual has both male and female catkins. Female catkins are red-violet and erect, while male catkins expand in the spring with tiny nutlet fruits that are chestnut brown in color and about 0.15 mm wide. [1] [3]

Taxonomy

Betula chichibuensis has relatively little taxonomic differences from its closest relatives, including Betula schmidtii and Betula chinensis , [6] but its soft leaves with 18 pairs of veins make it visually distinct from other birches. [3] Recent research in Japan has sought to assemble the full chloroplast genome of B. chichibuensis and further investigate its genetic structure. [2] [7]

Distribution and habitat

The Okuchichibu Mountains, where B. chichibuensis is found Okuchichibu.jpg
The Okuchichibu Mountains, where B. chichibuensis is found

Chichibu birches are extremely rare in the wild, growing only on a handful of limestone outcrops in the mountains of the Japanese island of Honshu. From their first description as a distinct species by Hiroshi Hara in 1965 [8] up until roughly 2015, B. chichibuensis had been found exclusively in a single stand in the Okuchichibu Mountains (Chichibu Tama Kai National Park), where only 21 Chichibu birches were counted in 1993. [1] As of 2017, at least eight additional small stands of B. chichibuensis were found by Dr. Toshihide Hirao, mostly in the Kitakami Mountains of northeast Honshu. [2] [3]

A 2014 expedition to the Okuchichibu Mountains location found B. chichibuensis growing on an exposed limestone mountain face near the Karisaka Tunnel, alongside plants including Sasa bamboo, Chamaecyparis obtusa cypresses, Juniperus rigida junipers, and Acer pictum maples. [9]

Conservation

Betula chichibuensis is considered a Critically Endangered species by the IUCN Red List. [1] In addition to the Chichibu birch's self-incompatibility and low seed viability (around 1%, by some estimates [3] ), the species is also threatened by habitat degradation and deforestation in the Chichibu District, and its small population size makes it particularly vulnerable to natural disasters and disease. [9]

Ness Botanic Gardens, UK, site of the first B. chichibuensis ex situ conservation program outside Japan Ness Botanic Gardens, Wirral - geograph.org.uk - 290784.jpg
Ness Botanic Gardens, UK, site of the first B. chichibuensis ex situ conservation program outside Japan

Serious ex situ conservation efforts to prevent the Chichibu birch's extinction began in 1986, when Tetsuo Satomi collected seeds from the Okuchichibu Mountains site and sent them to Hugh McAllister, a botanist at the University of Liverpool's Ness Botanic Gardens. Eight of the seeds germinated, clippings from which were then used to create all Chichibu birches growing in captivity up until the 2010s. [4] Cultivated specimens vary significantly in appearance, with some clones showing a spreading habit and others growing more upright. [3]

In 2014, an Anglo-Japanese expedition to the Okuchichibu Mountains collected roughly 1,000 B. chichibuensis seeds (of which around 100 germinated) in order to increase the genetic diversity of cultivated specimens. [10] As of 2015, more than 30 gardens worldwide grow Chichibu birches, including the Bedgebury National Pinetum [5] and Harvard University's Arnold Arboretum. [4] Specimens at the Ness Botanic Gardens have been reported to have seed viabilities of up to 40 percent. [3]

Related Research Articles

<span class="mw-page-title-main">Birch</span> Genus of flowering plants in the family Betulaceae

A birch is a thin-leaved deciduous hardwood tree of the genus Betula, in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus Betula contains 30 to 60 known taxa of which 11 are on the IUCN 2011 Red List of Threatened Species. They are typically short-lived pioneer species and are widespread in the Northern Hemisphere, particularly in northern areas of temperate climates and in boreal climates. Birch wood, the wood of the birch, is used for a wide range of purposes.

<span class="mw-page-title-main">Betulaceae</span> Family of flowering plants comprising hazel and birch trees

Betulaceae, the birch family, includes six genera of deciduous nut-bearing trees and shrubs, including the birches, alders, hazels, hornbeams, hazel-hornbeam, and hop-hornbeams numbering a total of 167 species. They are mostly natives of the temperate Northern Hemisphere, with a few species reaching the Southern Hemisphere in the Andes in South America. Their typical flowers are catkins and often appear before leaves.

<span class="mw-page-title-main">Hornbeam</span> Genus of flowering plants

Hornbeams are hardwood trees in the plant genus Carpinus in the family Betulaceae. The 30–40 species occur across much of the temperate regions of the Northern Hemisphere.

<span class="mw-page-title-main">Bedgebury National Pinetum</span>

Bedgebury National Pinetum at Bedgebury, Kent, in the United Kingdom, is a recreational and conservational arboretum managed by Forestry England that was established as the National Conifer Collection in 1925 and is now recognised as the most complete collection of conifers on one site anywhere in the world. The collection has over 10,000 trees growing across 320 acres (1.3 km2), including rare, endangered and historically important specimens. Bedgebury National Pinetum conducts conservation work, is home to some 56 vulnerable or critically endangered species, and houses five National Plant Collections.

<i>Alnus glutinosa</i> Species of flowering plant in the birch family Betulaceae

Alnus glutinosa, the common alder, black alder, European alder, European black alder, or just alder, is a species of tree in the family Betulaceae, native to most of Europe, southwest Asia and northern Africa. It thrives in wet locations where its association with the bacterium Frankia alni enables it to grow in poor quality soils. It is a medium-sized, short-lived tree growing to a height of up to 30 metres (98 feet). It has short-stalked rounded leaves and separate male and female flowers in the form of catkins. The small, rounded fruits are cone-like and the seeds are dispersed by wind and water.

<i>Betula pendula</i> Species of birch

Betula pendula, commonly known as silver birch, warty birch, European white birch, or East Asian white birch, is a species of tree in the family Betulaceae, native to Europe and parts of Asia, though in southern Europe, it is only found at higher altitudes. Its range extends into Siberia, China, and southwest Asia in the mountains of northern Turkey, the Caucasus, and northern Iran. It has been introduced into North America, where it is known as the European white birch or weeping birch and is considered invasive in some states in the United States and parts of Canada. The tree can also be found in more temperate regions of Australia.

<i>Betula pubescens</i> Species of birch

Betula pubescens, commonly known as downy birch and also as moor birch, white birch, European white birch or hairy birch, is a species of deciduous tree, native and abundant throughout northern Europe and northern Asia, growing farther north than any other broadleaf tree. It is closely related to, and often confused with, the silver birch, but grows in wetter places with heavier soils and poorer drainage; smaller trees can also be confused with the dwarf birch.

<i>Betula nigra</i> Species of birch

Betula nigra, the black birch, river birch or water birch, is a species of birch native to the Eastern United States from New Hampshire west to southern Minnesota, and south to northern Florida and west to Texas. It is one of the few heat-tolerant birches in a family of mostly cold-weather trees which do not thrive in USDA Zone 6 and up. B. nigra commonly occurs in floodplains and swamps.

<i>Betula papyrifera</i> Species of tree

Betula papyrifera is a short-lived species of birch native to northern North America. Paper birch is named after the tree's thin white bark, which often peels in paper-like layers from the trunk. Paper birch is often one of the first species to colonize a burned area within the northern latitudes, and is an important species for moose browsing. Primary commercial uses for paper birch wood are as boltwood and sawlogs, while secondary products include firewood and pulpwood. It is the provincial tree of Saskatchewan and the state tree of New Hampshire.

<i>Betula alleghaniensis</i> Species of flowering plant in the birch family Betulaceae

Betula alleghaniensis, the yellow birch, golden birch, or swamp birch, is a large tree and an important lumber species of birch native to northeastern North America. Its vernacular names refer to the golden color of the tree's bark. In the past its scientific name was Betula lutea, the yellow birch.

<i>Betula lenta</i> Species of plant

Betula lenta is a species of birch native to eastern North America, from southern Maine west to southernmost Ontario, and south in the Appalachian Mountains to northern Georgia.

<span class="mw-page-title-main">Fraser fir</span> Species of conifer

The Fraser fir, sometimes spelled Frasier fir, 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.

<i>Betula populifolia</i> Species of birch

Betula populifolia, known as the gray birch, is a deciduous tree in the family Betulaceae. It is native to eastern North America and is most commonly found in the northeast United States as well as southern Quebec, New Brunswick, and Nova Scotia. The tree is a pioneer species that is commonly found in sites following disturbance, such as fire or logging. Gray birches don't have as much economic value as other birch species but are still commonly used as ornamental trees.

<i>Athrotaxis selaginoides</i> Growth Patterns

Athrotaxis selaginoides is a species of Athrotaxis, endemic to Tasmania in Australia, where it grows at 400–1,120 m elevation. In its habitat in the mountains, snow in winter is very usual. It is often called King Billy pine or King William pine, although it is not a true pine.

<i>Betula ermanii</i> Species of tree

Betula ermanii, or Erman's birch, is a species of birch tree belonging to the family Betulaceae. It is an extremely variable species and can be found in Northeast China, Korea, Japan, and Russian Far East. It can grow to 20 metres (66 ft) tall. It is noted for its peeling bark, which can sometimes be removed in sheets, but usually shreds and hangs from the trunk and under branches. Yellow-brown male catkins appear with the leaves in spring.

<i>Betula cordifolia</i> Species of birch

Betula cordifolia, the mountain paper birch or heartleaf birch is a birch species native to Eastern Canada and the Northeastern United States. Until recently it was considered a variety of Betula papyrifera, with which it shares many characteristics, and it was classified as B. papyrifera var. cordifolia (Regel) Fern.

<i>Betula albosinensis</i> Species of birch

Betula albosinensis, the Chinese red birch, syn. B. bhojpattra var. sinensis, B. utilis var. sinensis, is a species of birch in the family Betulaceae, native to Western China. It is a deciduous tree growing to 25 metres (82 ft). A particular feature is the peeling brown bark. In fact the Latin specific name albosinensis means "white, from China". Brown catkins are produced in Spring.

<i>Betula chinensis</i> Species of plant

Betula chinensis, commonly known as dwarf small-leaf birch, is a species of birch that can be found in China and Korea on the elevation of 700–3,000 metres (2,300–9,800 ft).

Betula murrayana commonly known as Murray birch, is a critically endangered species of small birch that is endemic to Washtenaw County, Michigan in the United States and St. Williams, Norfolk County, Ontario, in Canada.

References

  1. 1 2 3 4 5 6 7 8 Shaw, Kirsty; Shyamali, Roy; Wilson, Becky (2014-08-01). "IUCN Red List of Threatened Species: Betula chichibuensis". IUCN Red List of Threatened Species. Archived from the original on 2018-10-28. Retrieved 2021-06-29.
  2. 1 2 3 Igarashi, Yuji; Aihara, Hiroki; Handa, Yoshihiro; Katsumata, Hiroshi; Fujii, Masanori; Nakano, Koichiro; Hirao, Toshihide (May 2017). "Development and Evaluation of Microsatellite Markers for the Critically Endangered Birch Betula chichibuensis (Betulaceae)". Applications in Plant Sciences. 5 (5): 1700016. doi:10.3732/apps.1700016. ISSN   2168-0450. PMC   5435406 . PMID   28529833.
  3. 1 2 3 4 5 6 7 8 McAllister, Hugh (2019). "924. Betula Chichibuensis". Curtis's Botanical Magazine. 36 (4): 365–374. doi:10.1111/curt.12305. ISSN   1467-8748. S2CID   212925397.
  4. 1 2 3 Nuwer, Rachel (2015-10-26). "Saving a Rare Tree Worlds Away". The New York Times. ISSN   0362-4331 . Retrieved 2021-06-29.
  5. 1 2 "Conservation at Bedgebury". Forestry England. Retrieved 2021-06-29.
  6. Wang, Nian; Kelly, Laura J.; McAllister, Hugh A.; Zohren, Jasmin; Buggs, Richard J.A. (2021-07-01). "Resolving phylogeny and polyploid parentage using genus-wide genome-wide sequence data from birch trees". Molecular Phylogenetics and Evolution. 160: 107126. doi: 10.1016/j.ympev.2021.107126 . ISSN   1055-7903. PMID   33647400. S2CID   232091362.
  7. Yoshida, Takuya; Igarashi, Yuji; Hirao, Toshihide (2020-07-02). "Characterization of the complete chloroplast genome of Betula chichibuensis (Betulaceae), a critically endangered limestone birch". Mitochondrial DNA Part B. 5 (3): 2166–2167. doi:10.1080/23802359.2020.1768932. PMC   7510759 . PMID   33366954.
  8. "World Checklist of Selected Plant Families: Royal Botanic Gardens, Kew". wcsp.science.kew.org. Retrieved 2021-07-27.
  9. 1 2 "Oxford University Plants 400: Betula chichibuensis". herbaria.plants.ox.ac.uk. Retrieved 2021-07-27.
  10. "UK team germinates critically endangered Japanese birch". BBC News. 2015-09-29. Retrieved 2021-07-27.