Overview of New Zealand's Ecology and Biodiversity
The isolated ark evolves….
The islands of New Zealand have been likened to an ark which carried a distinctive load of evolving plants and animals (nearly all birds and insects) in isolation for about 80 million years, between becoming separate from the great landmass of Gondwanaland and, prior to the arrival of humans less than 1,000 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 predators. Another feature of many New Zealand bird and reptile species that had evolved in isolation over a long time, was the development of longer life spans and slower and less frequent breeding patterns. Some species like the Kakapo only breed every few years. The long period of isolation and slow and specialised evolution and breeding patterns meant that many of these plants and animals were especially vulnerable to sudden changes.
About one thousand years ago New Zealand was one of the last large land areas on earth to be settled by humans. The many mammalian species that arrived with humans were particularly hard on the native species. Along with major loss of habitat that occurred through land clearance by humans, many animal species became extinct quite quickly through predation by humans, dogs, rats, stoats and possums and other introduced species. Many more have survived on but are threatened, and some may well become extinct in the future as predations by pests like stoats and rats continues to prevent successful breeding.
Whats happening today….
The 1997 "State of New Zealand's Environment Report" produced by central government claimed that the decline of the country's native biodiversity was the most serious and pervasive environmental issue. In response, the "New Zealand Biodiversity Strategy" was published in 2000, in an attempt to establish national goals for halting the steady decline of our biodiversity. LINK to Ministry of Environment website.
The GRAPH from the Biodiversity Strategy shows the steady decline of biodiversity over the twentieth century and the proportion of effort required to halt that rate of decline.
A number of laws provide a level of protection for native plants and animals and their habitats. However, the reality is that the practical management of on the ground issues like loss of habitat and pest control, will need to be improved, if many habitats and species are to survive in the long term on the ark that they once evolved on.
Many New Zealanders, including iwi groups, private and public agencies and landowners, understand or are beginning to understand, the urgency of this protection and are working towards the sort of practical management that will make a difference. Marlborough is no exception.
The Marlborough District Council has a variety of roles in this work. These include policy development, regulation through rules and resource consents, practical management through its roles as manager of river, road and recreation reserves, and a role in working alongside iwi, community groups and individuals to help promote the protection of the ecology and biodiversity of the Marlborough region.
