| 词条 | Juniperus bermudiana |
| 释义 |
| name = Bermuda cedar | status = CR | status_system = IUCN3.1 | status_ref = [1] | image = Image-Juniperus bermudiana - mature.jpg | image_caption = | regnum = Plantae | divisio = Pinophyta | classis = Pinopsida | ordo = Pinales | familia = Cupressaceae | genus = Juniperus | species = J. bermudiana | binomial = Juniperus bermudiana | binomial_authority = L. }} Juniperus bermudiana is a species of juniper endemic to Bermuda. This species is most commonly known as Bermuda cedar, but is also referred to as Bermuda juniper. Historically, this tree formed woodland that covered much of Bermuda. Settlers cleared part of the forest and the tree was used for many purposes including building construction and was especially prized for shipbuilding. However scale insects introduced during World War II devastated the forests, killing over 99% of the Bermuda cedar. Since then, the salt tolerant casuarina has been planted as a replacement species, and a small number of Bermuda cedars have been found to be resistant to the scale insects. Populations of certain endemic birds which had co-evolved with the tree have plummeted as a result of its demise. DescriptionThe Bermuda cedar is an evergreen tree growing up to 15 m tall with a trunk up to 60 cm thick (larger specimens existed in the past) and thin bark that exfoliates in strips. The foliage is produced in blue-green sprays, with the individual shoots 1.3–1.6 mm wide, four-sided (quadriform) in section. The leaves are scale-like 1.5–2.5 mm long (up to 4 mm long on strong-growing shoots) and 1-1.5 mm broad, with an inconspicuous gland; they are arranged in opposite decussate pairs, occasionally decussate whorls of three. Juvenile plants bear needle-like leaves 4–8 mm long. The seed cones are irregularly globose to broad pyriform, 4–6 mm long and 5–8 mm broad, soft and berry-like, green at first, maturing bluish-purple about 8 months after pollination; they contain one or two (rarely three) seeds. The male cones are 4–6 mm long, yellow, turning brown after pollen release in early spring. EcologyA threat to the continued existence of Bermuda's cedars arose in the mid-1940s when the species was attacked by two species of scale insects, Lepidosaphes newsteadi and Carulaspis minima, which were unintentionally introduced from the United States' mainland during the wartime construction of US airbases in Bermuda. By 1978, these parasites had killed 99% of Bermuda's cedars, some 8 million trees. However, the remaining 1% of the trees proved somewhat resistant to the scale insects, and efforts by Bermuda's Department of Agriculture, Fisheries and Parks to plant young cedars from this resistant strain throughout Bermuda have saved the trees from extinction. In the 1950s and 1960s, the casuarina (Casuarina equisetifolia, also known as horsetail tree and Australian pine), native to Australia, was introduced into Bermuda to replace the Bermuda cedar's windbreak functions. However, in Bermuda, casuarinas have proved to be highly aggressive, and no other plants are able to survive beneath them. Still, like the Bermuda cedar, the casuarina's foliage is resistant to wind and salt, and these features have made casuarinas popular with gardeners in Bermuda. Other species introduced in an attempt to replace the cedar forest included the bay grape (Coccoloba uvifera). Along with the casuarina, the cedar's main introduced competitor for space is the Brazilian pepper (Schinus terebinthifolius). The species is occasionally grown as an ornamental tree outside of Bermuda, and may have become naturalised on Hawaii and Saint Helena. It is reported that more than 6,500 of them were planted in Hawaii between 1921 and 1953, and that it has established wild populations there.[2] The Bermuda cedar forests that covered Bermuda fed and housed many species of bird that had evolved and adapted to live amongst them, and thus became endemic to Bermuda. With the loss of so many trees the populations of such species have plummeted to near extinction. These birds include the Bermuda white-eyed vireo, and a possible subspecies of eastern bluebird. Efforts by the public and the government have been made to boost their populations along with the populations of the Bermuda cedar. However the Bermuda cedar may take 200 years to reach full maturity, and the birds may not survive this long. With recent sea level rises, some low-lying old-growth cedars are being infiltrated with seawater and are beginning to die off. Uses and historyIt is known for its heavy, sweet aroma, useful and attractive reddish timber, significant role in Bermuda's history, and notable presence in Bermuda's historic homes. When English settlers arrived in Bermuda, forests of Bermuda cedar flourished throughout the islands, and the species continued to thrive even as settlers developed the land. The wood was utilized by settlers for widely varying purposes, including home, church, jail, and shipbuilding, interior woodworking, furniture construction, coffin-making, and export for sale. In addition, the cones were used by settlers as food for both themselves and their animals, and to prepare cedarberry syrup as a treatment for toothaches and coughs. Settlers also boiled the shoots in water to create an elixir for lowering fevers. Furthermore, the wood was found to repel moths and fleas as well as prevent mildew and rot, so many Bermuda residents used the wood to line closets and drawers. The wood was especially prized by shipbuilders. It could be worked as soon as it was felled, and was naturally resistant to rot and woodworms. It was as strong as oak, but much lighter, contributing to the speed and maneouverability for which Bermudian ships were noted and prized. Its abundance enabled Bermudians to turn wholesale to a maritime economy after the dissolution of the Somers Isles Company in 1684. In 1627, in an effort to conserve Bermuda's cedar forests, the local assembly passed legislation to restrict export of Bermuda cedar for shipbuilding. In addition, between 1693 and 1878, the Bermuda legislature passed sixteen further acts placing restrictions on the uses of Bermuda cedar. Despite these Acts, the shipbuilding industry eventually denuded much of Bermuda's landscape by the 1830s. Only the dawn of the age of steam-driven, steel-hulled ships allowed the forest to recover. Many historic homes in Bermuda feature interior woodwork and furnishings made from Bermuda cedar. Examples of these homes include the Mayflower House, Camden House, Tucker House, and Verdmont House, the latter of which, according to the Bermuda National Trust, contains the colony's finest collection of antique Bermuda cedar furnishings. Because it is now both scarce, and expensive, and it is featured in many grand homes, its scent has come to be associated with wealth. The Bermuda hedge fund Juniperus Capital is named after this species.[3] External links{{Commons}}
References1. ^{{cite journal |author=Wingate, D.B. |author2=Adams, R. |author3=Gardner, M. |last-author-amp=yes |title=Juniperus bermudiana |journal=The IUCN Red List of Threatened Species |volume=2011 |page=e.T30376A9532928 |publisher=IUCN |year=2011 |url=http://www.iucnredlist.org/details/30376/0 |doi=10.2305/IUCN.UK.2011-2.RLTS.T30376A9532928.en |access-date=9 November 2017}} 2. ^{{cite book | last = Little Jr. | first = Elbert L. | title = Common Forest Trees of Hawaii (Native and Introduced) | publisher = U.S. Dept. of Agriculture, Forest Service | year = 1989 | page = 321 }} 3. ^{{cite web|url=http://www.juniperuscapital.com/about/origin_of_the_juniperus_name |title=Origin of the Juniperus Name |publisher=Juniperus Capital |date= |accessdate=January 17, 2011}}
5 : Juniperus|Trees of Bermuda|Plants described in 1753|Critically endangered flora of North America|Taxa named by Carl Linnaeus |
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