Arthropods and alpine bogs, bacteria and butterflies, chromosomes and centipedes, eels and estuaries, forests and fumaroles, genes and geckos, wetlands and whales these are all components of our biodiversity. Biodiversity includes individual species, the genes they comprise and the ecosystems they collectively form.
All of these plants, animals and micro-organisms depend on one another for survival. Each species provides another species with something it needs to live along with healthy soil, water and air.
Why do we need biodiversity?
Biodiversity is our living heritage providing us with fresh air, fertile soil and clean water, food, clothing, housing as well as cultural significance and spiritual renewal.
We used to think of our native plants and animals as just out there somewhere, something to inspire us on the occasional bush walk or drive through the country. But we are now realising that we rely on biodiversity in every part of our lives:
Our food and medicines come from biodiversity
Genetic diversity in crops enables us to produce new varieties
Biodiversity is a source of future pharmaceutical discoveries
Native, birds, bats and insects pollinate our gardens
Forests trap silt and we breathe the oxygen produced by trees
Bacteria break down our green waste into fertile soil
Marine organisms clean up the sewage we put into oceans
Biodiversity is the basis of the burgeoning eco-tourism industry.
What's so special about New Zealand's biodiversity?
New Zealand's diverse plants, animals and landscapes set us apart and help define us as a nation the land of the silver fern and kiwi. Maori culture is built on things like flax, totara and kai moana which are unique to New Zealand. Because of our relative isolation many of our flora and fauna have unusual features, such as the world's only flightless parrot (the kakapo) and primitive frogs that bear live young. Ninety percent of New Zealand's plants and animals are endemic they are found nowhere else in the world.
Yet New Zealand has about 600 threatened species, a rate higher per person than any country in the world. Habitat destruction (such as forest clearance and drainage of wetlands), over-harvesting and successive waves of plant and animal pests and diseases have decimated New Zealand's biodiversity. What has taken millions of years to evolve is now being destroyed at a breathtaking rate:
11 percent of the world's endangered species are found in New Zealand (the highest rate in the world)
Two thirds of our native forest cover has gone in the past 900 years
90% of our wetlands have been lost
Coastal dunes and lakes are now only tiny remnants.
What happens when species are lost and ecosystems are destroyed?
Biodiversity can be likened to a spider's web. The loss of one or two threads does not destroy the web, just weakens it unnoticeably. However, if more threads are destroyed the web disintegrates, its essential elements are gone and it is eventually ruined. Natural communities and their member species are the same. Every organism, no matter how small or unattractive, has its place in the ecosystem. Species contribute to valued ecosystem services (which we don't often appreciate) such as contributing to the cycling of energy, water and nutrients.
These ecosystem services are vital to human welfare.
The loss of biodiversity may take many forms but at its most fundamental and irreversible it involves the extinction of species. Without a diversity of life to call on we could not adapt to changing environmental conditions. To maintain biodiversity is to maintain our future options.
What can we do?
As we look around we know that biodiversity is under threat, yet often it seems there is little any individual can do. But positive action is needed at a personal level, as well as a national and regional level, to retain indigenous biodiversity.
There are a number of things that individuals and private landowners can do to help maintain our unique biodiversity:
Growing native plants in gardens and on farms to support native wildlife.
Not growing weeds like buddleia or wild ginger and removing them when they do appear.
Ensuring garden plants do not spread into native bush.
Disposing carefully of wastes animal effluent, rubbish, offal, farm chemicals, silage leachate which can harm and destroy natural areas such as streams and estuaries.
Controlling animal pests such as possums, rats and stoats.
Controlling and desexing pets, which kill many native birds and wildlife each year.
Throwing back under-sized fish and not catching more than needed.
Fencing and covenanting bush and wetland remnants.
Setting developments back from waterways and protecting and planting riparian margins.
Increasing awareness of biodiversity in others, especially our children.
Start or become involved in a Landcare group or help with a species recovery programme in your area e.g. kiwi care, stream planting or native bat monitoring.
Joining in events such as community planting days and working bees to help with weeding nature reserves.