The history of science and the discoveries made by some of the most famous scientists are the themes of a new competition for secondary school students being run by the Royal Society of New Zealand.
Weedbusters, a public awareness and education programme about invasive
weeds, has launched a new website, with the aim of helping Kiwis understand
more about the problem of weeds.
“I think people just don’t realise that it is, effectively, environmental litter,” says
Amber Bill, the national coordinator of the Weedbusters programme.
According to the Weedbusters website, there are more introduced plant species
growing wild — 2221 — in New Zealand than there are native plants species
which number 1896. Weeds are the main threat to the existence of 61 native
animal and plant species but so far only 7 species of invasive weeds have been successfully eradicated from NZ, the
Weeds, the website points out, threaten the long-term survival of some native animals by changing or destroying their
habitat, reducing the availability of food or breeding sites, or influencing the way native and introduced animals behave.
Weeds are also a risk to nearly 600,000 hectares of protected natural areas. Freshwater, wetlands, coastal habitats,
lowland forest, shrubland and native grasslands are all particularly vulnerable areas.
Says Department of Conservation weed ecologist Clayson Howell: “The main reason that we are concerned is that weeds
competitively displace indigenous plants. In some instances they can impact whole systems by accumulating large
amounts of biomass where usually there is very little.”
Half of the weeds in New Zealand are trees and shrubs, but weeds can range from mosses, to palms and everything
between. Two thirds of environmental weeds were brought into New Zealand for ornamental use. “Plants that establish
readily, grow quickly, and require little care sound ideal for the garden, but these are also characteristics of many of our
most invasive weed,” Mr Howell says.
The conservation agency, which manages eight million hectares or about 30 per cent of New Zealand’s land area, helped
establish the Weedbusters programme late last year with the aim of raising the profile of the problem and to support the
many community groups doing weed control work.
“Part of what we are doing is trying to raise that profile and acknowledge the work that is already going on that shows the
sort of ground swell there already is,” says Ms Bill.
Weeds, the Weedbusters website argues, is one conservation area where all New Zealanders can make a real difference.
“If we want to look out for a new weed we want as many eyes on the lookout as possible,” says Ms Bill. “Also if we are
trying to eradicate a weed from an area, often the weeds we deal with have been introduced for ornamental reasons and
are what we call garden escapes, so they will be lurking in a lot of people’s gardens.
“So there is not point in trying to eradicate them unless you can get the public to help.”
According to DOC, some of the weediest places are often close to towns. Around Auckland alone there are four garden
escapes every year, adding to the more than 300 seriously invasive weeds managed by DOC.
People tend to spread invasive weeds by growing them in their gardens, dumping rubbish from gardens or fish tanks, or
accidentally spreading seeds and fragments — activities that the Weedbusters programme hopes to help slow or stop.