Shorea
{{Short description|Genus of trees}}
{{Automatic taxobox
| fossil_range = {{fossil range|Early Eocene|present}}
| image = Shorea roxburghii.jpg
| image_caption = Shorea roxburghii
| taxon = Shorea
| authority = Roxb. ex C.F.Gaertn. (1805)
| synonyms =
- Caryolobis {{small|Gaertn. (1788)}}
- Isoptera {{small|Scheff. ex Burck (1887)}}
- Pachychlamys {{small|Dyer ex Ridley (1922)}}
- Parahopea {{small|F.Heim (1892)}}
|synonyms_ref = {{cite web |title=Shorea Roxb. ex C.F.Gaertn. |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:14402-1 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=18 September 2024}}
}}
file:Dipterocarp Winged Seed (Shorea sp.) (15866621516).jpg
Shorea is a genus of about 47 species of mainly rainforest trees in the family Dipterocarpaceae. The timber of trees of the genus is sold under the common names lauan, luan, lawaan, meranti, seraya, balau, bangkirai, and Philippine mahogany.[https://www.wood-database.com/lauan/ Lauan - The Wood Database]
Description
The tallest documented tropical angiosperm is a {{convert|100.8|m|ft|abbr=on}} Shorea faguetiana found in the Danum Valley Conservation Area, in Sabah, Malaysia (Borneo). In Sabah's Tawau Hills National Park, at least five other species of the genus have been measured to be over {{Convert|80|m|abbr=on}} tall: S. argentifolia, S. gibbosa, S. johorensis, S. smithiana, and S. superba.{{cite web | url = http://www.nativetreesociety.org/worldtrees/sea_ei/borneo_ii.htm | title = Borneo | publisher = Eastern Native Tree Society | access-date= 2008-06-21}} Borneo is also the hotspot of Shorea diversity with 138 species, of which 91 are endemic to the island.Ashton, P. S. "Dipterocarpaceae". In Tree Flora of Sabah and Sarawak, Volume 5, 2004. Soepadmo, E.; Saw, L. G. and Chung, R. C. K. eds. Government of Malaysia, Kuala Lumpur, Malaysia. {{ISBN|983-2181-59-3}}
= Reproduction =
The majority of Shorea spp. are general flowering species, which is an event occurring at irregular intervals of 3–10 years, in which nearly all dipterocarp species together with species of other families bloom heavily.{{cite journal |last=Sakai |first=Shoko |author2=K Momose |author3=T Yumoto |author4=T Nagamitsu |author5=H Nagamasu |author6=A A Hamid |author7=T Nakashizuka |year=1999 |title=Plant reproductive phenology over four years including an episode of general flowering in a lowland dipterocarp forest, Sarawak, Malaysia |journal=American Journal of Botany |volume=86 |issue=10 |pages=1414–36 |doi=10.2307/2656924 |jstor=2656924 |pmid=10523283|bibcode=1999AmJB...86.1414S }} General flowering is thought to have evolved to satiate seed predators{{cite journal |last=Curran |first=Lisa M. |author2=M. Leighton |year=2000 |title=Vertebrate responses to spatiotemporal variation in seed production of mast-fruiting Dipterocarpaceae |journal=Ecological Monographs |volume=70 |issue=1 |pages=101–128 |doi=10.1890/0012-9615(2000)070[0101:VRTSVI]2.0.CO;2 |hdl-access=free |hdl=2027.42/116363}} and/or to facilitate pollination. Both explanations apparently hold merit.{{cite journal |last=Maycock |first=Colin R. |author2=R. N. Thewlis |author3=J. Ghazoul |author4=R. Nilus |author5=David F. R. P. Burslem |year=2005 |title=Reproduction of dipterocarps during low intensity masting events in a Bornean rain forest |journal=Journal of Vegetation Science |volume=16 |issue=6 |pages=635–46 |doi=10.1658/1100-9233(2005)016[0635:RODDLI]2.0.CO;2}} Flowering is thought to be triggered by droughts that occur during transition periods from La Niña to El Niño.{{cite journal |last=Sakai |first=Shoko |author2=Rhett D. Harrison |author3=Kuniyasu Momose |author4=Koichiro Kuraji |author5=Hidetoshi Nagamasu |author6=Tetsuzo Yasunari |author7=Lucy Chong |author8=Tohru Nakashizuka |year=2006 |title=Irregular droughts trigger mass flowering in aseasonal tropical forests in Asia |journal=American Journal of Botany |volume=93 |issue=8 |pages=1134–39 |doi=10.3732/ajb.93.8.1134 |pmid=21642179|bibcode=2006AmJB...93.1134S }} The magnitude of a flowering event is suggested to be dependent on the timing of the droughts associated with the El Niño southern oscillation cycle, with the largest events occurring after an interval of several years with no flowering.
Shorea spp. are insect pollinated. A variety of insects have been identified as pollinators, with species within the sections of Shorea sharing the same insect pollinators. Flowering within a section is sequential within one habitat and species association to prevent competition for pollinators.{{cite journal |last=LaFrankie |first=James V. Jr. |author2=H. T. Chan |date=June 1991 |title=Confirmation of Sequential Flowering in Shorea (Dipterocarpaceae) |journal=Biotropica |volume=23 |issue=2 |pages=200–203 |bibcode=1991Biotr..23..200L |doi=10.2307/2388308 |jstor=2388308}}
Seed predation and mortality have an impact on the reproduction process of dipterocarps such as Shorea. In Singapore, crab-eating macaque and moth larvae are known seed predators.{{cite journal |last1=Chong |first1=Kwek Yan |last2=Chong |first2=Rie |last3=Tan |first3=Lorraine W.A. |last4=Yee |first4=Alex T.K. |last5=Chua |first5=Marcus A.H. |last6=Wong |first6=Khoon Meng |last7=Tan |first7=Hugh T.W. |date=1 November 2016 |title=Seed production and survival of four dipterocarp species in degraded forests in Singapore |journal=Plant Ecology & Diversity |volume=9 |issue=5–6 |pages=483–490 |bibcode=2016PlEcD...9..483C |doi=10.1080/17550874.2016.1266404 |s2cid=89849984}}
Taxonomy
Shorea fossils (linked with the modern sal, S. robusta, which is still a dominant tree species in Indian forests) are known from as early as the Eocene of Gujarat, India. They are identifiable by the amber fossils formed by their dammar resin.{{Cite journal |last1=Sahni |first1=A. |last2=Patnaik |first2=R. |date=2022-06-01 |title=An Eocene Greenhouse Forested India: Were Biotic Radiations Triggered by Early Palaeogene Thermal Events? |url=https://www.researchgate.net/publication/361230160 |journal=Journal of the Geological Society of India |language=en |volume=98 |issue=6 |pages=753–759 |bibcode=2022JGSI...98..753S |doi=10.1007/s12594-022-2064-4 |issn=0974-6889 |s2cid=249536528}} Other fossils include a Miocene-aged fossilized fruit from the same region; this fruit most closely resembles the extant S. macroptera of the Malay Peninsula.{{Cite journal |last1=SHUKLA |first1=ANUMEHA |last2=GULERIA |first2=J. S. |last3=MEHROTRA |first3=R. C. |date=2012-02-01 |title=A fruit wing of Shorea Roxb. from the Early Miocene sediments of Kachchh, Gujarat and its bearing on palaeoclimatic interpretation |journal=Journal of Earth System Science |language=en |volume=121 |issue=1 |pages=195–201 |bibcode=2012JESS..121..195S |doi=10.1007/s12040-012-0142-5 |issn=0973-774X |doi-access=free}}
= Sections and selected species =
{{Main|List of Shorea species|label 1=List of Shorea species}}
- Shorea agamii P.S.Ashton
;Brachypterae
- Shorea smithiana Symington
- Shorea zeylanica (Thwaites) P.S.Ashton
;Mutica
- Shorea argentifolia Symington
- Shorea parvifolia Dyer
;Neohopea
- Shorea isoptera P.S.Ashton
;Ovalis
- Shorea ovalis (Korth.) Blume
;Pachycarpae
- Shorea macrophylla (de Vriese) P.S.Ashton
- Shorea siamensis Miq.
;Richetioides
- Shorea richetia Symington
;Rubella
- Shorea albida Symington
;Shorea
- Shorea guiso (Blanco) Blume
;Not placed
- Shorea robusta C.F.Gaertn. (sal tree)
- Shorea thorelii Pierre ex Laness.
= Etymology =
The genus is named after Sir John Shore, the governor-general of the British East India Company, 1793–1798.
Distribution and habitat
Shorea spp. are native to Southeast Asia, from northern India to Malaysia, Indonesia, and the Philippines. In west Malesia and the Philippines, this genus dominates the skyline of the tropical forests.
Conservation
{{See also|List of Shorea species|label 1=List of Shorea species}}
Of the 148 species of Shorea currently listed on the IUCN Redlist, most are listed as being critically endangered.{{cite web |year=2012 |title=IUCN Red List of Threatened Species, Shorea search results |url=http://www.iucnredlist.org/search |access-date=3 January 2013 |publisher=IUCN}} Some concerns exist regarding the IUCN's listing of dipterocarps, as the criteria used to assess the level of threat are based mainly on animal population characteristics. This is thought to overstate the threat assessment, when applied to long-lived, habitat-specific organisms such as trees.
class="wikitable"
|+ Conservation status of Shorea spp. |
IUCN red list category
! Number of species |
---|
Extinct
| align="center" |1 |
Critically endangered
| align="center" |102 |
Endangered
| align="center" |34 |
Vulnerable
| align="center" |3 |
Least concern
| align="center" |6 |
Data deficient
| align="center" |2 |
Not evaluated
| align="center" |~48 |
Uses
Many economically important timber trees belong to Shorea. They are sold under various trade names including "lauan", "lawaan", "meranti", "seraya", "balau", "bangkirai", and "Philippine mahogany". The "Philippine mahogany" sold in North America is not a true mahogany at all, but a mixture of woods from the genus Shorea.
Other products from Shorea spp. include dammar and illipe. Dammar is a resin collected from a variety of species. It varies in colour among the different taxonomic groups. Shorea wiesneri is listed in many websites as an important source of dammar;{{cite encyclopedia |url= http://www.britannica.com/eb/article-9028654/dammar |title = Dammar |encyclopedia = Encyclopædia Britannica |access-date= 2007-11-14}} however, this appears to be either a trade name or a synonym.{{cite web | url = http://193.62.154.38/diptero/diptax.html | title = Dipterocarpaceae Data Base—Taxonomic Information | publisher = Royal Botanical Gardens, Edinburgh | access-date = 2007-11-14 | archive-date = 2007-05-20 | archive-url = https://web.archive.org/web/20070520031520/http://193.62.154.38/diptero/diptax.html | url-status = dead }}{{cite web | url = http://www.kew.org/searchepic/summaryquery.do;jsessionid=BD255C82F8006D581ED0D08C7CBC1300?scientificName=Shorea+wiesneri+&searchAll=true&categories=names&categories=bibl&categories=colln&categories=taxon&categories=flora&categories=misc | title = Electronic Plant Information Centre | publisher = Royal Botanical Gardens, Kew | access-date= 2007-11-14}}
Borneo tallow nut oil is extracted from the egg-shaped, winged fruit of Shorea species.{{cite web|title=Minor oil crops - Individual monographs (Balanites-Borneo tallow nut-Brazil nut-Caryocar spp)|url=http://www.fao.org/docrep/X5043E/x5043E05.htm#Borneo%20tallow%20nut|website=www.fao.org|publisher=FAO|access-date=15 April 2017}}
References
{{Reflist|25em}}
External links
- {{Wikispecies-inline}}
- {{Commons category-inline}}
{{Woodworking}}
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