Background
New Zealand's biodiversity gives our country a unique character and is internationally important. Isolated from other landmasses for roughly 80 million years, many of our native species evolved separately from those elsewhere in the world. As a result, New Zealand makes a significant contribution to global biodiversity.
Biodiversity also benefits New Zealand from a social, cultural, and economic aspect through, for example, recreational opportunities, tourism, research, education, provision of ecosystem services and natural resources for primary industry, and customary and medical uses.
Go to New Zealand Biodiversity Strategy 2020
Internationally Unique
New Zealand's native plants and animals (biodiversity) are internationally important and unique, but are also very vulnerable due to a multitude of influences, such as:
- Our plants and animals evolved in isolation on an island land mass for roughly 80 million years, prior to the arrival of humans about 700 years ago. The only mammals were bats and marine animals, so birds and insects adapted to fit most ecological niches and roles on land, with many becoming flightless and ground-dwelling and naïve to the danger from mammalian predators.
- Many species of bird and reptile that had evolved in isolation over a long time period developed longer life spans and slower, less frequent breeding patterns. Some species, like the kakapo, only breed once every few years. This slow and specialised evolution and breeding pattern results in these species being vulnerable to change and disruption.
- A large proportion of the species are endemic to New Zealand, occurring nowhere else in the world. If they become extinct, they are lost to the world, unlike many species in other countries. About 90% of New Zealand insects, 80% of trees, ferns and flowering plants, 25% of bird species, 100% of our 123 reptile species, four remaining frog species and two species of bat are endemic.
- A large number of mammal species have been introduced into the New Zealand environment by humans and our native species are not generally adapted to cope with the competition for resources and heavy predation that has resulted.
Human Arrival
New Zealand was one of the last large land areas to be settled by humans, roughly 700 years ago (estimated 1200-1300 CE) with the arrival of Polynesians and 500 years later with the first Europeans.
Changes were rapid as habitats were altered, vegetation cleared by fire and the introduction of numerous animal and plant species which competed with, and predated on, many of the native plants and animals which had evolved over a long period of time.
Many animal species became extinct quite quickly through predation by humans, dogs, rats, stoats, possums, and other introduced species. Over 45 species of native bird have become extinct and over 1,000 species of plants, animals and fungi are considered threatened today, with further extinctions likely.
The Marlborough environment is split into two distinct areas in relation to ecology and biodiversity. The Wairau River is the approximate divider between the drier, less forested South Marlborough area (about 700,000 ha) and the wetter, more forested North Marlborough and Sounds area (about 250,000 ha). Together, these areas form a distinctive part of New Zealand's natural environment. The diversity of the region in terms of climate, geology, topography, and its central location within the country mean that a large variety of plants and animals occur here, a number these being at their northern or southern limits of distribution.
North Marlborough
North Marlborough has a moister climate and steeper terrain and was less modified by human arrival. A significant amount of original forest cover remains, and vigorous native regeneration is well underway on land cleared for pastoral farming from 1850 to 1940. Forest birds like tui, bellbird and kereru are common and other species like weka, native freshwater fish, snails and frogs are still present. The Department of Conservation has a strong presence in the Marlborough Sounds and a number of islands are used for conservation projects to protect threatened species through the use of island sanctuaries.
