Ecology

Overview of Ecology and Biodiversity in Marlborough and New Zealand

Background

New Zealand’s biodiversity gives our country a unique character and is internationally important. Many of our native species are not found anywhere else in the world and therefore make a significant contribution to global biodiversity.

Biodiversity also provides social, cultural and economic benefits through, for example, recreational opportunities, tourism, research, education, provision of ecosystem services and natural resources for primary industry, and customary and medical uses.

Internationally Unique

New Zealand’s native plants and animals (biodiversity) are internationally important and unique, but also very vulnerable because:

• A large proportion of the species are endemic to New Zealand, occurring nowhere else in the world. So, if they become extinct here, 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, all 60 reptile species, four remaining frog species and two species of bat, are endemic. Britain, in contrast, has only two endemic species; one plant and one animal.
• Our plants and animals evolved in isolation on an island land mass for about 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 unaware of 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 and 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 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.

700 Years Ago

New Zealand was one of the last large land areas on Earth to be settled by humans only 700 years ago.

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 and possums and other introduced species. Over 45 species of native bird have become extinct and over 1,000 species of plant, animal and fungi are considered threatened today, with further extinctions likely.