Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 

Attitude change prescribed for weedy Auckland


Doctors prescribe attitude change for World’s weediest city

Researchers say responding to the threat of weeds early rather than waiting until plants become weeds is crucial for curbing Auckland’s rampaging weed problem.

The Auckland Regional Council has proposed a ban on sales of Phoenix, bangalow and Chinese fan palm trees, as these are spreading into and threatening native bush. Palm enthusiasts have expressed disbelief that the trees are a threat now, after more than a century in New Zealand. They also say self-sown palms can easily be weeded out.


A Phoenix palm discovered growing in a native bush patch in Auckland. Photo: Landcare Research


Nikau palm and bangalow palm seedlings - spot the difference. Photo: Landcare Research

Landcare Research botanist Dr Peter Williams says many weeds establish when people fail to act on early signs that exotics are spreading.

“New Zealanders tend to wait to assess how a potential weed will impact on the environment. But by then it’s too late, because the plant has often already spread and become a weed.

“The didymo alga is an extreme example of how quickly a weed can spread. Rapid response may not always stop aggressive invaders, but it does improve our chances.

“We need a shift in culture towards taking pre-emptive action, even if that means erring on the side of caution.”

Dr Williams says invasive species which spread slowly are known as “sleeper” weeds. Like secret agents, sleeper weeds appear benign and relatively inactive, sometimes for decades. Palms take many decades to establish because they are slow to produce seeds. But once they do, birds distribute the seeds far and wide and the trees’ spread is inexorable.

“Just because palms spread slowly, this does not make them less of a threat,” Dr Williams says.

“Hieracium and old man’s beard took decades to begin to spread.”

Landcare Research scientist Dr Margaret Stanley agrees, and says that weeding out stray palm trees is not as easy as many believe.

“It means extra time and expense for community groups who are weeding native forests.

“Also, bangalow palm seedlings appear identical to those of our native nikau palm, which causes considerable confusion.

“Nipping weeds in the bud is by far the best approach.”

Facts on Auckland’s weedy woes:

Auckland has the dubious honour of being the weediest city in the world, with 220 weeds (and climbing). It has more than 10 000 exotic plant species (compared with about 400 natives), and each year an average of four species naturalise (escape cultivation and reproduce in the wild – with great weedy potential.) There are currently 1100 naturalised exotic species in Auckland. Weeds displace native plants, alter soil chemistry, and drastically reduce food for native animals.

ENDS

© Scoop Media

 
 
 
Business Headlines | Sci-Tech Headlines

 

Media Mega Merger: StuffMe Hearing Argues Over Moveable Feast

New Zealand's two largest news publishers are appealing against the Commerce Commission's rejection of the proposal to merge their operations. More>>

Elsewhere:


Approval: Northern Corridor Decision Released

The approval gives the green light to construction of the last link of Auckland’s Western Ring Route, providing an alternative route from South Auckland to the North Shore. More>>

ALSO:


Crown Accounts: $4.1 Billion Surplus

The New Zealand Government has achieved its third fiscal surplus in a row with the Crown accounts for the year ended 30 June 2017 showing an OBEGAL surplus of $4.1 billion, $2.2 billion stronger than last year, Finance Minister Steven Joyce says. More>>

ALSO:

Mycoplasma Bovis: One New Property Tests Positive

The newly identified property... was already under a Restricted Place notice under the Biosecurity Act. More>>

Accounting Scandal: Suspension Of Fuji Xerox From All-Of-Government Contract

General Manager of New Zealand Government Procurement John Ivil says, “FXNZ has been formally suspended from the Print Technology and Associated Services (PTAS) contract and terminated from the Office Supplies contract.” More>>