Biodiversity of New Zealand

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Biota of New Zealand
Close-up of a New Zealand wood pigeon or kereru
Biodiversity
Flora and Fauna
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Associated laws
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Related topics
Leiopelmatidae
is endemic to New Zealand.

The biodiversity of New Zealand, a large

elasmosaurs and plesiosaurs.[1] The ancient fauna is not well known, but at least one species of terrestrial mammal existed in New Zealand around 19 Ma. For at least several million years before the arrival of human and commensal species, the islands had no terrestrial mammals except for bats and seals, the main component of the terrestrial fauna being insects and birds. As recently as the 14th century a component has been introduced
by humans, including many terrestrial mammals.

New Zealand has developed a national

Biodiversity Action Plan
to address conservation of considerable numbers of threatened flora and fauna within New Zealand.

Evolution

Main article: Natural history of New Zealand
New Zealand's geckos, such as the Duvaucel's gecko, may have had their origins in New Caledonia although Australia is implicated in recent phylogenetic work.[2]

The break-up of the

southern beeches, but also a distinctive insect fauna, New Zealand's unusual frogs and the tuatara, as well as some of New Zealand's birds. It seems likely that some primitive mammals also were part of the original cargo. Whether or not any of these taxa are descendants of survivors of that ancient cargo remains unproven. Recent molecular evidence has shown that even the iconic Gondwanan plants the southern beeches (Nothofagus) arrived in New Zealand after separation of Zealandia from Gondwana. There is a high rate of interspecific and intraspecific hybridisation in New Zealand plants and animals.[7]

The two sources of New Zealand's biodiversity following separation from Gondwana have been speciation and air- or sea-borne immigration. Most of these immigrants have arrived from Australia, and have provided the majority of New Zealand's birds[8] and bats as well as some plant species (carried on the wind or inside the guts of birds). Some of these immigrants arrived long enough ago that their affinities to their Australian ancestors are uncertain; for example, the affinities of the unusual short-tailed bats (Mystacinidae) were unknown until fossils from the Miocene were found in Australia. Cyanoramphus parakeets are thought to have originated in New Caledonia and have been successful at reaching many islands in the region. The link between the two island groups also includes affinities between skink and gecko families.[9]

Elements

Floral biodiversity

Main article: Flora of New Zealand
The kauri of North Island were the largest trees in New Zealand, but were extensively logged and are much less common today.
Many species of southern bull kelp are found in New Zealand.

The history, climate and geology of New Zealand have created a great deal of diversity in New Zealand's vegetation types. The main two types of forest have been dominated by

southern beech. Podocarps (Podocarpaceae), an ancient evergreen gymnosperm family of trees, have changed little in the last 190 million years. Forests dominated by podocarps form a closed canopy with an understory of hardwoods and shrubs. The forests of southern beeches, from the genus Nothofagus, comprise a less diverse habitat, with the beeches of four species dominating the canopy and allowing a single understory. In the north of New Zealand the podocarp forests were dominated by the ancient giant kauri
. These trees are amongst the largest in the world, holding the record for the greatest timber volume of any tree. The value of this was not lost on early European settlers, and most of these trees were felled.

The remaining vegetation types in New Zealand are grassland of grass and tussock, usually associated with the subalpine areas, and the low shrublands between grasslands and forests. These shrublands are dominated by daisies, which can become woody and 3 m high. New Zealand had a 2019 Forest Landscape Integrity Index mean score of 7.12/10, ranking it 55th globally out of 172 countries.[10]

In addition to terrestrial plants, New Zealand is home to many species of algae. Many species of southern bull kelp are found along the coasts of the main islands, Chatham Islands and the Subantarctic Islands.[11][12]

Faunal diversity

See also: Fauna of New Zealand and Birds of New Zealand

Until 2006, it was thought that no mammals, other than bats and marine mammals, had reached New Zealand before humans did. The discovery of a femur and mandibles of an extinct non-volant (non-flying) mammal in Otago, dated at 16–19 million years old, has changed the view of New Zealand's evolutionary history, as it strongly suggests that mammals had been part of New Zealand's fauna since the break-up of Gondwana. The fossil has been called SB mammal. It is not known when, or why, land mammals became extinct in New Zealand but there were none present on New Zealand for several million years before the arrival of humans.

The short-tailed bats (from the monotypic family

vesper bat and several incertae sedis species.[13]

The extinct huia was a member of the endemic bird family Callaeidae (New Zealand wattlebirds).

Birds comprise the most important part of New Zealand's

passerines, splitting from the ancestral passerine stock at the time New Zealand become an isolated land mass. In the absence of mammals, birds diversified into the niches
usually filled by mammals in other ecosystems.

The moas, of which there were eleven species, were large browsers, and were in turn the prey species of the giant

rails, waders, owls, and seabirds (albeit often with a New Zealand twist). Of the 245 species of birds from the greater New Zealand (the main islands along with the offshore islands, also including Norfolk Island), 174 were endemic, roughly 71%. Of these, about 32% of the genera
were endemic.

The tuatara is a unique component of New Zealand's biodiversity and the only surviving species in the order Sphenodontia.

No

Sphenodontia. Frogs, which because of their intolerance for saltwater are assumed to have descended from ancestors that broke off from Gondwana, are one of the few exceptions to the rule that amphibians are never found on oceanic islands (another being the frogs of Fiji). New Zealand's few wholly freshwater fishes are derived from diadromous
species.

This Auckland tree wētā is about 7 cm long, excluding legs and antennae

New Zealand's terrestrial invertebrate community displays strong Gondwanan affinities, and has also diversified strongly, if unevenly. There are over a thousand species of snail, and many species of insect have become large and in many cases flightless, especially grasshoppers and beetles. There are, however, fewer than 12 species of ant. The most famous of New Zealand's insects, the wētā, are ground-living relatives of the crickets that often reach enormous proportions. Many endemic marine invertebrate species, particularly marine snails, have evolved in the seas surrounding New Zealand.[14][15][16]

Endemism

The siphon whelk Penion ormesi is a large, marine snail species endemic to New Zealand.

New Zealand has a high number of

endemic species,[17]
such as:

Of New Zealand's estimated 20,000 fungi species, only about 4,500 are known.

Maui's dolphin
.

Human impact

The common brushtail possum is one of the 33 species of land mammal introduced to New Zealand by humans.
Large areas of native bush has been logged and cleared for pasture in the past.
See also:
Environmental issues in New Zealand, Deforestation in New Zealand, and Invasive species in New Zealand

The arrival of humans in New Zealand has presented a challenge for the native species, causing the

Himalayas), which detrimentally affect native vegetation.[20]

The silvereye is one of several species of birds that have introduced themselves to New Zealand in the wake of human settlement.

The date of the first arrival of the

New Zealand greyling
), skinks, and geckos.

In some instances, the extinction of New Zealand's native fauna has brought about a natural colonisation from Australia. In the case of the

pūkeko and the swamp harrier is more interesting, mirroring the arrival of related species in the past, before they evolved into the takahē and the Eyles's harrier. Once these specialised birds declined and (in the case of the harrier) became extinct, their niches were available and colonisation could occur again.[24][25]

Management

The New Zealand government, through the

Tiritiri Matangi and Mangere Island
. Establishment of conservation areas is not restricted to islands however and several ecological islands have been established on the New Zealand mainland which are isolated by the use of pest-exclusion fences.

State of biodiversity 2020

State of biodiversity in New Zealand, 2020 [27]

See also

  • List of extinct animals of New Zealand
  • Landcare Research
    has biodiversity as one of its major research areas.
  • New Zealand dinosaurs
  • List of ecoregions of New Zealand

References

  1. ISBN 978-0-14-302088-2
    .
  2. PMID 21184833
    .
  3. doi:10.1111/j.1365-2699.2006.01643.x
    .
  4. ^ PDF Trewick SA, Morgan-Richards M. 2009 New Zealand Biology. Pages 665-673 in Encyclopedia of Islands (Eds R.G. Gillespie and D.A. Clague). University of California Press, Berkeley.
  5. Dominion Post. 29 September 2007. Archived
    from the original on 12 February 2009. Retrieved 9 October 2007. We cannot categorically say that there has always been land here. The geological evidence at present is too weak, so we are logically forced to consider the possibility that the whole of Zealandia may have sunk.
  6. ISBN 978-0-14-302088-2
    .
  7. doi:10.1080/03014220909510561
    .
  8. doi:10.1111/j.1474-919X.2010.01018.x
    .
  9. PMID 19674312
    .
  10. PMID 33293507
    .
  11. S2CID 18309093
    .
  12. PMID 31642057
    .
  13. S2CID 85925160
    .
  14. ISBN 0-00-216906-1
  15. ^ Beu, A.G. and Maxwell, P.A. 1990. Cenozoic Mollusca of New Zealand. New Zealand Geological Survey Bulletin, 58.
  16. PMID 28669812
    .
  17. ISBN 9781845935573
    .
  18. ISBN 978-1877257-60-5
  19. ^ "What happens in New Zealand... Stays in Vegas". New Zealand Trade and Enterprise. 11 March 2017. Retrieved 29 April 2017. [permanent dead link]
  20. ^ "Introduced Plants and Animals". Te Ara: The Encyclopedia of New Zealand. Retrieved 15 June 2022.
  21. ^ "Rat remains help date New Zealand's colonisation". New Scientist. 4 June 2008. Retrieved 30 June 2018.
  22. PMID 18523023
    .
  23. ^ Brockie, Bob (24 September 2007). "Native plants and animals – overview". Te Ara: The Encyclopedia of New Zealand. Retrieved 15 June 2022.
  24. ^ Trewick SA. 2011. Vicars and vagrants: Assembly of the New Zealand avifauna. Australasian Science 32: 24-27.
  25. ISBN 9780143568896
  26. ^ Cuvier Island restoration Archived 30 September 2007 at the Wayback Machine (from the Department of Conservation website)
  27. ISBN 978-0-9951392-4-4
    .

Further reading
Volume 1
ISBN 9781927145050
Journal articles

External links
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