“List of endemic species of the British Isles”的意思、由来-开放百科全书

The British Isles have few endemic species due to past frequent glaciations and because of the proximity to Continental Europe and former land bridges which enabled species to re-colonise the islands from the continent following glaciations.{{citation needed|date=August 2017}} Most endemic species to the British Isles are considered to be subspecies of a larger species, with mutations or adaptations slightly changing the species in the islands or in certain localities.

British Conservationists often describe this as a “wiped clean effect” {{who|date=August 2017}}{{citation needed|date=August 2017}}with repeated glaciations forcing many species out of the modern area of the islands to more southern latitudes in Europe and perhaps even driving some species extinct.

Some species which were present in Britain before past glaciations, often during periods with a warmer climate than now failed to return after the Last Glacial Maximum. Amongst these are Rhododendron ponticum and rabbits, now considered invasive and non-native.

A species is only deemed native if it reached the British Isles without human intervention (either intentional or unintentional). That means that to be native the species must have reached Britain before the land bridge joining Britain to the continent was submerged. Alternatively species can also be native when they have flown or swum to Britain as is the case with many bird species which arrived after the submersion of the land bridge, a recent example is the collared dove which arrived in the 1950s, this also applies for plants which spread seed in the wind.

A few endemic species are Arctic-Alpine species, survivors of Arctic species of plants and animals which either adapted to the warming climate or became isolated in suitable areas of mountains or lakes which still retained a suitable micro-climate. A common misconception is that the entirety of the British Isles was under glaciers and was uninhabitable both for humans, plants and animals. Whilst unsuitable for most species, a number of Arctic species survived in the areas not under glaciers in southern areas of England, Wales and south west Ireland and were either driven to extinction in the British Isles or to micro-climatic refuges as the climate warmed and the Arctic conditions retreated north.

Most endemic species or subspecies however date to more recent, post-glacial times, many having spread via land bridges or along the Atlantic seaboard of Europe.

Types of endemic species

Fungi

Bryophytes

Plants

Subsequently, Sorbus pseudomeinichii was discovered on the island of Arran in 2007.^[5]

Spiders

Amphipoda (freshwater)

Insects

Birds

Britain has few endemic species of birds but quite a few subspecies. A few Arctic-Alpine species have subspecies in the British Isles, some have been in the islands since the last Ice Age, but many spread in the immediate Sub-Arctic conditions as the ice retreated.

Further more these species were latter reinforced by newer arrivals as the climate assumed temperatures and conditions more similar to the present day.

Mammals

Britain has a few subspecies of mammals but no endemic species. Many again are Ice Age survivors that adapted to the new conditions; others arrived in warmer conditions whilst the land bridge still existed.

Aquatic fauna

Cnidaria

The Cnidaria are a group of animals found exclusively in aquatic and mostly marine environments. They include sea anemones, sea pen and corals and their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey.^[12]^[13]

Fish

In some areas of uplands in the British Isles the retreating glaciers left melt water in hollows which had been carved out by the movement of ice. In these, Arctic species of fish survived, due often to the sheer depth of the lakes and the colder temperatures. For the young endemic fish varieties of the British Isles, it is usually controversial whether they should be considered as distinct taxa (species or subspecies) or just as isolated populations of their ancestral species.

As global warming affects the British climate there is some concern for these species, some confined to a handful of lakes. Action has been taken to protect them, as is the case with vendace which has been moved to tarns in nearby mountains due to the cooler temperatures. It is hoped that these will act as refuges should the species die-out in the lower-level lakes where they occur naturally.

Extinct

Distribution

The distribution of endemic species seems to have a North Western bias and with endemic species on the whole showing an oceanic / alpine distribution with most endemics being found in upland areas or islands.

Endemic livestock breeds

Human bred-animals are not usually classified as distinct subspecies but rather breeds which is a similar concept. However some animals such as Iron Age pigs are classified as a distinct species from their wild relatives.

See also

References

1. ^{{cite journal|last1=Blackman|first1=Stuart|title=New Species of the month|journal=BBC Wildlife|date=July 2015|volume=33|issue=402|page=17}}
2. ^{{cite book|last=Holyoak|first=David T|title=Bryophytes: Liverworts (Marchantiophyta), Hornworts (Anthocerotophyta) and Mosses (Bryophyta). In Red Data Book for Cornwall and the Isles of Scilly|year=2009|publisher=Croceago Press|location=Praze-an-Beeble|isbn=978-1-901685-01-5|pages=72–104}}
3. ^{{cite journal |author1=T. G. C. Rich |author2=G. Hutchinson |author3=R. Randall |author4=R. G. Ellis |title=List of Plants Endemic to the British Isles |year=1999 |journal=BSBI News |volume=80 | pages=23–27 | url=http://archive.bsbi.org.uk/bsbi_news_3.html}}
4. ^{{cite book |author1=M. O. Hill |author2=J. O. Mountford |author3=D. B. Roy |author4=R. G. H. Bunce |year=1999 |title=Ellenberg's indicator values for British plants |id=ECOFACT Volume 2 Technical Annex |location=Huntingdon |publisher=Institute of Terrestrial Ecology |url=http://nora.nerc.ac.uk/6411/ |isbn=1-870393-48-1}}
5. ^{{cite web|title=New species of tree discovered on Arran|date=14 June 2007|url=http://www.snh.org.uk/press/detail.asp?id=1724|publisher=Scottish Natural Heritage|accessdate=6 November 2013}}
6. ^{{cite web|title=Britain’s rarest spider found at new site, and photographed|url=https://www.buglife.org.uk/news-%26-events/news/britain%E2%80%99s-rarest-spider-found-at-a-new-site-and-photographed|website=buglife|accessdate=10 February 2016}}
7. ^{{cite book|last1=Gainey|first1=P A|title=Amphipoda. In Red Data Book For Cornwall And The Isles Of Scilly|publisher=Croago Press|location=Praze-an-Beeble|page=177|edition=2nd}}
8. ^{{cite web|title=202 Eudarcia richardsoni|url=https://ukmoths.org.uk/show.php?id=6680|publisher=UKmoths|accessdate=7 May 2012}}
9. ^{{cite book|last=Alexander|first=Keith N A T|title=Hemiptera. In Red Data Book for Cornwall and the Isles of Scilly|year=2009|publisher=Croceago Press|location=Praze-an-Beeble|isbn=978-1-901685-01-5|pages=214–232}}
10. ^{{cite journal|last=Beavis|first=Ian|title=Bees, Wasps and Ants of Scilly|journal=Isles of Scilly Bird and Natural History Review 2002|year=2003|pages=168–183}}
11. ^{{Cite journal | doi = 10.1046/j.1365-2745.2000.00477.x| title = Coincya wrightii (O.E. Schulz) Stace (Rhynchosinapis wrightii (O.E. Schulz) Dandy ex A.R. Clapham)| journal = Journal of Ecology| volume = 88| issue = 3| pages = 535| year = 2000| last1 = Compton | first1 = S. G.| last2 = Key | first2 = R. S.}}
12. ^{{cite book|last=Gainey|first=Paul T|title=Hydroids, Sea Anemones and Jellyfish (Cindaria). In Red Data Book for Cornwall and the Isles of Scilly|year=2009|publisher=Croceago Press|location=Praze-an-Beeble|isbn=978-1-901685-01-5|pages=449–456}}
13. ^{{cite journal |author1=Holstein T. |author2=Tardent P. | title =An ultrahigh-speed analysis of exocytosis: nematocyst discharge | journal =Science | volume =223 | issue =4638 | pages =830–833 | year =1984 | url = | doi =10.1126/science.6695186 | pmid =6695186 }}