Antipodes Subantarctic Islands tundra
Encyclopedia
The Antipodes Subantarctic Islands tundra ecoregion
, within the Tundra
Biome
, includes five remote island groups in the Southern Ocean
south of New Zealand
: the Bounty Islands
, Auckland Islands
, Antipodes Islands
and Campbell Island group
s of New Zealand, and Macquarie Island
of Australia
.
The Bounty Islands are small granite rocks (with a maximum height of 88 m (289 ft)), while the small Antipodes Islands group(maximum height 366m), the largest group the Aucklands (705 m (2,313 ft)) and Campbell Island (569 m (1,867 ft)) are volcanic in origin. Macquarie Island (433 m (1,421 ft)) is the furthest south and the coldest. Where present, soil
s are mainly bog
gy peat
s, up to 8 m (26.2 ft) deep in flat areas. None of the islands are inhabited although there are ongoing research projects including a permanent base of the Australian Antarctic Division
on Macquarie Island.
s of Southern Rata
in the more sheltered areas of the Aucklands and parts of Campbell Island
with tussock
grassland
, shrubland
, herbfield
, feldmark
and cushion plant
s elsewhere. The islands represent a transition zone between the Antarctic
to the south and temperate climates to the north. Individual species include many endemics, such as a Cyathea
tree fern, which are not found any further south in the world along with others that also occur in New Zealand and further north. Macquarie Island being colder (average annual temperature 5 °C (41 °F)) does not sustain any wooded plants while the small Bounty Islands lack soils and their flora is largely restricted to algae
and lichen
s on the rocks. The islands are home to a number of rare plants including a unique genus
the Auckland Island Pleurophyllum
, and the only subantarctic orchids, Nematoceras dienemum
and Nematoceras sulcatum
of Macquarie Island.
; the Southern Elephant Seal
, Australasian Fur Seal, Subantarctic Fur Seal
, Antarctic Fur Seal
and the rare New Zealand Sea Lion
of which 95% of the world's population breed on the Auckland Islands.
There are also large numbers of breeding penguins and other seabird
s including almost half of world's species of albatross
, especially the world's only breeding colonies of the Antipodean Albatross
(Diomedea exulans antipodensis), Southern Royal Albatross
(Diomedea epomophora epomophora), Campbell Albatross
(Thalassarche impavida), White-capped Albatross
(Thalassarche steadi), and Salvin's Albatross
(Thalassarche salvini). The large colonies of Salvin's Albatross on the Bounty Islands build nests of feathers as there is no vegetation to use. There are also isolated populations of land birds that have presumably settled here having been blown off course by ocean winds. Many of these have since evolved into unique species including two endemic parakeet
s on Antipodes Island; the Antipodes Parakeet (Cyanoramphus unicolor) and Reischek's Parakeet
(Cyanoramphus hochstetteri).
Similarly a high proportion of the Lepidoptera
and other insects of the islands have evolved into unique endemic species.
A number of species have disappeared since the islands were discovered by humans including the Macquarie Island Rail
, and the Macquarie Island Parakeet
.
are particularly damaging.
Current predators on the islands include rats and cats and these are being systematically removed while cautionary procedures are in place to prevent more alien species becoming established. All cats have now been removed from Macquarie Island and there appears to have been an immediate increase in some seabird populations. All the islands are nature reserves, World Heritage Sites and (except for the Bounty Islands) a Centre of Plant Diversity. Permission to land must be obtained from the Department of Conservation (New Zealand) for the New Zealand islands and the Tasmania Parks and Wildlife Service
for Macquarie.
Ecoregion
An ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural...
, within the Tundra
Tundra
In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...
Biome
Biome
Biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. Some parts of the earth have more or less the same kind of abiotic and biotic factors spread over a...
, includes five remote island groups in the Southern Ocean
Southern Ocean
The Southern Ocean comprises the southernmost waters of the World Ocean, generally taken to be south of 60°S latitude and encircling Antarctica. It is usually regarded as the fourth-largest of the five principal oceanic divisions...
south of New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
: the Bounty Islands
Bounty Islands
The Bounty Islands at are a small group of 13 granite islets and numerous rocks, with a combined area of , in the south Pacific Ocean that are territorially part of New Zealand. They are located between 47°44'35" and 47°46'10" S, and 179°01' and 179°04'20" E, southeast of the South Island of New...
, Auckland Islands
Auckland Islands
The Auckland Islands are an archipelago of the New Zealand Sub-Antarctic Islands and include Auckland Island, Adams Island, Enderby Island, Disappointment Island, Ewing Island, Rose Island, Dundas Island and Green Island, with a combined area of...
, Antipodes Islands
Antipodes Islands
The Antipodes Islands are inhospitable volcanic islands to the south of—and territorially part of—New Zealand...
and Campbell Island group
Campbell Island group
The Campbell Island group is a group of subantarctic islands, belonging to New Zealand. The group has a total area of , consisting of one big island, Campbell Island , and several small islets, notably Dent Island , Isle de Jeanette Marie , Jacquemart Island , and Monowai Island 1...
s of New Zealand, and Macquarie Island
Macquarie Island
Macquarie Island lies in the southwest corner of the Pacific Ocean, about half-way between New Zealand and Antarctica, at 54°30S, 158°57E. Politically, it has formed part of the Australian state of Tasmania since 1900 and became a Tasmanian State Reserve in 1978. In 1997 it became a world heritage...
of Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
.
Location and description
The islands comprising this ecoregion share a long history of isolation, both from other landmasses and each other. The isolation, combined with harsh climates characterised by low temperatures, strong westerly winds and few hours of sunlight in winter, have resulted in the evolution of many endemic plants and animals, though species richness is relatively low. Wind speeds reach an average of 40 km/h (25 mph) while even in summer the thick cloud cover prevents much sunlight from penetrating.The Bounty Islands are small granite rocks (with a maximum height of 88 m (289 ft)), while the small Antipodes Islands group(maximum height 366m), the largest group the Aucklands (705 m (2,313 ft)) and Campbell Island (569 m (1,867 ft)) are volcanic in origin. Macquarie Island (433 m (1,421 ft)) is the furthest south and the coldest. Where present, soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
s are mainly bog
Bog
A bog, quagmire or mire is a wetland that accumulates acidic peat, a deposit of dead plant material—often mosses or, in Arctic climates, lichens....
gy peat
Peat
Peat is an accumulation of partially decayed vegetation matter or histosol. Peat forms in wetland bogs, moors, muskegs, pocosins, mires, and peat swamp forests. Peat is harvested as an important source of fuel in certain parts of the world...
s, up to 8 m (26.2 ft) deep in flat areas. None of the islands are inhabited although there are ongoing research projects including a permanent base of the Australian Antarctic Division
Australian Antarctic Division
The Australian Antarctic Division is an agency of the Department of Sustainability, Environment, Water, Population and Communities . The division undertakes science programs and research projects to contribute to an understanding of Antarctica and the Southern Ocean...
on Macquarie Island.
Flora
Vegetation may include low forestForest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s of Southern Rata
Metrosideros umbellata
Southern rātā , is a tree endemic to New Zealand. It grows up to 15 m. or more tall with a trunk up to 1 m. or more in diameter. It produces masses of red flowers in summer...
in the more sheltered areas of the Aucklands and parts of Campbell Island
Campbell Island, New Zealand
Campbell Island is a remote, subantarctic island of New Zealand and the main island of the Campbell Island group. It covers of the group's , and is surrounded by numerous stacks, rocks and islets like Dent Island, Folly Island , Isle de Jeanette Marie, and Jacquemart Island, the latter being the...
with tussock
New Zealand tussock grasslands
Tussock grasslands form expansive and distinctive landscapes in the South Island and to a lesser extent in the central plateau region of the North Island of New Zealand...
grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
, shrubland
Shrubland
Shrubland, scrubland, scrub or brush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity...
, herbfield
Herbfield
Herbfields are plant communities dominated by herbaceous plants, especially forbs and grasses. They are found where climatic conditions do not allow large woody plants to grow, such as in subantarctic and alpine tundra environments...
, feldmark
Feldmark
Feldmark, also spelt fjaeldmark , is a plant community characteristic of sites where plant growth is severely restricted by extremes of cold and by exposure to wind, typical of alpine tundra and subantarctic environments.-Description:...
and cushion plant
Cushion plant
A cushion plant is a compact, low growing, mat forming plant that is found in alpine, subalpine, arctic, or subarctic environments around the world...
s elsewhere. The islands represent a transition zone between the Antarctic
Antarctic
The Antarctic is the region around the Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica and the ice shelves, waters and island territories in the Southern Ocean situated south of the Antarctic Convergence...
to the south and temperate climates to the north. Individual species include many endemics, such as a Cyathea
Cyathea
Cyathea is a genus of tree ferns, the type genus of the fern order Cyatheales. They are mostly terrestrial ferns, usually with a single tall stem. Rarely, the trunk may be branched or creeping. Many species also develop a fibrous mass of roots at the base of the trunk. The genus has a pantropical...
tree fern, which are not found any further south in the world along with others that also occur in New Zealand and further north. Macquarie Island being colder (average annual temperature 5 °C (41 °F)) does not sustain any wooded plants while the small Bounty Islands lack soils and their flora is largely restricted to algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
and lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
s on the rocks. The islands are home to a number of rare plants including a unique genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
the Auckland Island Pleurophyllum
Pleurophyllum
Pleurophyllum is a genus of flowering plants in the daisy family, Asteraceae. It contains three species and is native to the subantarctic islands of New Zealand and Australia .-Species:* Pleurophyllum criniferum Hook.f.* Pleurophyllum hookeri Buch.* Pleurophyllum speciosum Hook.f....
, and the only subantarctic orchids, Nematoceras dienemum
Nematoceras dienemum
Nematoceras dienemum , also known as the Windswept Helmet-orchid, is one of two helmet orchids endemic to Australia’s subantarctic Macquarie Island, and the first orchid to be found there...
and Nematoceras sulcatum
Nematoceras sulcatum
Nematoceras sulcatum, also known as the Grooved Helmet-orchid, is one of two helmet orchids endemic to Australia’s subantarctic Macquarie Island, and the second to be discovered. The specific epithet comes from the Latin sulcatus – “grooved”, with reference to the prominent groove in the labellum...
of Macquarie Island.
Fauna
There are no native land mammals, nor amphibians or reptiles. Marine mammals include five breeding species of sealPinniped
Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...
; the Southern Elephant Seal
Southern Elephant Seal
The Southern Elephant Seal is one of the two extant species of elephant seal. It is both the most massive pinniped and member of the order Carnivora living today...
, Australasian Fur Seal, Subantarctic Fur Seal
Subantarctic Fur Seal
The subantarctic fur seal is a fur seal found in the southern parts of the Indian and Atlantic Oceans. It was first described by Gray in 1872 from a specimen recovered in northern Australia—hence the inappropriate tropicalis specific name.- Description :The subantarctic fur seal is...
, Antarctic Fur Seal
Antarctic Fur Seal
The Antarctic fur seal is one of eight seals in the genus Arctocephalus, and one of nine fur seals in the subfamily Arctocephalinae. As its name suggests, the Antarctic fur seal is distributed in Antarctic waters. Around 95% of the world population breeds at the Island of South Georgia...
and the rare New Zealand Sea Lion
New Zealand Sea Lion
The New Zealand Sea Lion also known as Hooker's Sea Lion or Whakahao in Māori is a species of sea lion that breeds around the coast of New Zealand's South Island and Stewart Island/Rakiura to some extent, and to a greater extent around the New Zealand Sub-Antarctic Islands, especially the Auckland...
of which 95% of the world's population breed on the Auckland Islands.
There are also large numbers of breeding penguins and other seabird
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
s including almost half of world's species of albatross
Albatross
Albatrosses, of the biological family Diomedeidae, are large seabirds allied to the procellariids, storm-petrels and diving-petrels in the order Procellariiformes . They range widely in the Southern Ocean and the North Pacific...
, especially the world's only breeding colonies of the Antipodean Albatross
Antipodean Albatross
The Antipodean Albatross, Diomedea antipodensis, is a large seabird, from the albatross family. Antipodean Albatrosses are smaller than Wandering Albatrosses, and breed in predominantly brown plumage, but are otherwise difficult to distinguish from Wanderers.-Etymology:Diomedea antipodensis breaks...
(Diomedea exulans antipodensis), Southern Royal Albatross
Southern Royal Albatross
The Southern Royal Albatross, Diomedea epomophora, is a large seabird from the albatross family. At an average wingspan of around , it is the second largest albatross, behind the Wandering Albatross.-Taxonomy:...
(Diomedea epomophora epomophora), Campbell Albatross
Campbell Albatross
The Campbell Albatross or Campbell Mollymawk, Thalassarche impavida, is a medium-sized mollymawk in the albatross family. It breeds only on Campbell Island and the associated islet of Jeanette Marie, a small New Zealand island group in the South Pacific. It is sometimes considered a subspecies of...
(Thalassarche impavida), White-capped Albatross
White-capped Albatross
The White-capped Albatross, Thalassarche steadi, is a mollymawk that breeds on the islands off of New Zealand. Not all experts agree that this form should be recognized as a separate species to the Shy Albatross, Thalassarche cauta...
(Thalassarche steadi), and Salvin's Albatross
Salvin's Albatross
Salvin's Albatross, or Salvin's Mollymawk, Thalassarche salvini, is a large seabird that ranges across the Southern Ocean. A medium sized mollymawk in the albatross family, it was long considered to be a subspecies of the Shy Albatross...
(Thalassarche salvini). The large colonies of Salvin's Albatross on the Bounty Islands build nests of feathers as there is no vegetation to use. There are also isolated populations of land birds that have presumably settled here having been blown off course by ocean winds. Many of these have since evolved into unique species including two endemic parakeet
Parakeet
Parakeet is a term for any one of a large number of unrelated small to medium sized species of parrot, that generally have long tail feathers...
s on Antipodes Island; the Antipodes Parakeet (Cyanoramphus unicolor) and Reischek's Parakeet
Reischek's Parakeet
Reischek’s Parakeet is a small green parrot confined to 21 km2 Antipodes Island, one of New Zealand’s subantarctic islands, which it shares with a congener, the larger Antipodes Island Parakeet.-Taxonomy:...
(Cyanoramphus hochstetteri).
Similarly a high proportion of the Lepidoptera
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
and other insects of the islands have evolved into unique endemic species.
A number of species have disappeared since the islands were discovered by humans including the Macquarie Island Rail
Macquarie Island Rail
The Macquarie Island Rail, Gallirallus philippensis macquariensis, is an extinct subspecies of the Buff-banded Rail endemic to Macquarie Island, a subantarctic island part of the state of Tasmania, Australia...
, and the Macquarie Island Parakeet
Macquarie Island Parakeet
The Macquarie Parakeet , also known as the Macquarie Island Parakeet, is an extinct parrot from subantarctic Macquarie Island, an outlying part of Tasmania, Australia, in the Southern Ocean.-Taxonomy:...
.
Threats and preservation
Although the islands have been partially occupied at various times the habitats remain largely unspoilt. However introduced animals prey on native wildlife and graze on the plant cover while both mammals and seabirds are vulnerable to entanglement in deep-sea fishing equipment. Longline fishing for tuna and trawling for squidSquid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
are particularly damaging.
Current predators on the islands include rats and cats and these are being systematically removed while cautionary procedures are in place to prevent more alien species becoming established. All cats have now been removed from Macquarie Island and there appears to have been an immediate increase in some seabird populations. All the islands are nature reserves, World Heritage Sites and (except for the Bounty Islands) a Centre of Plant Diversity. Permission to land must be obtained from the Department of Conservation (New Zealand) for the New Zealand islands and the Tasmania Parks and Wildlife Service
Tasmania Parks and Wildlife Service
Tasmania Parks and Wildlife Service is the Tasmanian Government body responsible for the care and administration of Tasmania's National Parks and wildlife.-History:...
for Macquarie.