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Biodiversity Hotspots
New Zealand
About…
• New Zealand is an archipelago in the southern Pacific, 2000km south east
of Australia
• Mainly mountainous but has a variety of different landscapes including
alluvial plains and forest.
• Annual rainfall ranges from 12,000 mm (one of the highest rainfall rates in
the world) on the western slopes of the Southern Alps, to less than 300
mm in the rain-shadow areas east of the Southern Alps.
• About 75 percent of the hotspot's land area is above 200 meters in
altitude
• Tectonically Active
• One of the most diverse places on earth with 1,865 endemic plant species
Why is New Zealand so Diverse?
• Animal and plant life evolved in isolation for 80 million years,
before people arrived, it had the longest period of isolation of
any non-polar landmass on earth.
• Climate is variable, which has affected biodiversity
distribution; Kermadec islands are subtropical, whereas
Chatham islands are cloudy and humid with cold winters. The
different types of climate and habitat means that a huge
variety of life can be supported.
• New Zealand has extraordinary levels of endemic species. Many of
its mammals, amphibians, or reptiles are found nowhere else in the
world.
• Unlike other land masses new Zealand had very few mammals.
There are only two endemic land mammals and both are bats.
• For 65 million years, birds dominated the land. Flightless birds and
giant insects (such as the weta) filled roles small mammals filled
elsewhere .
• As a result of evolving with few predators, native species developed
strange characteristics such as flightlessness, gigantism and some
species became long-lived and slow breeding. For 65 million years,
birds dominated the land. Flightless birds and giant insects (such as
the weta) filled roles small mammals filled elsewhere .
Endemic Animals
Endemic plants
Human Threats –Habitat Destruction
The biggest threats to biodiversity are habitat destruction and invasive
species.
• New Zealand’s temperate forests have been greatly depleted.
Native forest has been logged and cleared for pasture. The hotspot
originally extended up to and area of 270,197km squared, but has
now been reduced to 59,443 km.
• Forest covered 85% of the island before humans settled, it is now
23%. It has happened in three ways
1)Whole ecosystems have been converted into farmland, exotic forests
and settlements.
2)They have been partially removed, creating ‘islands’ surrounded by
farmland.
3)Ecosystems have been degraded by the loss of species and
disruption of their ecological processes.
Human Threats – Invasive Species
• Mammals began to arrive in numbers about 1000 years ago
in the form of human settlers who bought with them mammal
predators such as rats and possums. Without these natural
predators, the native species had evolved to be slow, flightless
and unprotected, they were easy targets and quickly under
threat.
• For many of the invasive species introduced there were no
natural native predators which allowed them to thrive and
compete.
• Invasive species pose the most serious threat to the flora and
fauna of New Zealand’s islands, and the hotspot has suffered
50 bird extinctions since the island’s colonization by humans
700 years ago.
Human Impact
Many of New Zealand’s native species are now
endangered:
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63 Endemic Threatened Birds
3 Endemic Threatened Mammals
4 Endemic Threatened Amphibians
23 Extinct Species since 1500
Protecting biodiversity
• The Department of Conservation manages eight million hectares of land,
about 30% of New Zealand's land area. DOC is responsible for preserving
and protecting these areas, including managing threats from invasive
pests and diseases.
• To stop the threat of animal pests on native species methods such as
introducing natural predators. Ground control -using traps, bait stations or
culling -is the most widely used method.
• The 2008 New Zealand Biodiversity Strategy has been put in place to
encourage conservation.
• They have established marine Protected Areas (MPAs) which ban fishing
and allow marine areas to recover from human activity.
Biosecurity
• Biosecurity is about keeping New Zealand free
of unwanted organisms and for controlling,
managing or eradicating them should they
arrive in the country. This helps to protect and
preserve New Zealand’s biodiversity.
• The Government released New Zealand's first
Biosecurity Strategy in August 2003 to deal
with the mounting pressures on the biosecurity
system. The strategy raises public awareness
and understanding of biosecurity.