Welcome to the Midnight Collective Broadsheet 156
Actively
supporting NZ’s endangered wetland birds
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| Up and away - willow in the wetland |
Over the past few months willow
saplings have gone forth and multiplied down on the western side of the
M2PP expressway near the
Wharemauku stream. This is a noxious weed that was previously unknown in the
area so how did it get in here and can it be contained?
Don't believe that its noxious? - This is taken from the DoC website
Willow – the scourge of wetlands
More than 90% of New Zealand wetlands have been
drained. Crack and grey willow are a scourge in most
of those that remain, shading out native plant species,
choking water bodies and even ‘pumping’ wetlands
dry through their leaves. This leads to a loss of plant
diversity, a lack of open waterways and the drying of
wetlands that affects the birds, fish and insects that rely
on them.
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| An abundance of seedlings |
There are four likely sources.
The first is wind blown and an occasional poplar seedling coming through can be traced to a poplar
stand bordering the swamp. There are however no similar stands of willow close
to this area, so we can rule that out.
The second source is flooding.
The area has been opened up and drained, but is regularly inundated now from
both sides.
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| Flooding in willow infested area...poplar stand in background |
This is the traditional source of willow weeds. However both sides of the expressway get
flooded but only the western swamp is infested. There are a few seedlings on
the town side, but some of these are above the flood line.
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| Willow growing out of planting above flood line |
Flooding will be a
source, but it can’t account for the level of infestation we are seeing, especially
in the south western zone.
This leaves two prime suspects.
New weeds have been appearing
here since the work on the M2PP was completed a year ago and some of these are garden botanical specimens like this sweet pea.
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| Pretty in pink - a sweet pea amongst the willows |
These garden plants and the
occasional willow, can be spotted growing up through some of the native plantings
potted soil, so the nursery stock is one source of contamination.
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| Spot the willows |
The primary source however must
be in contaminated topsoil trucked into the area by NZTA contractors. This fits
with the spread of the seedlings which are clumped together in blocks along the
cycle way and then along the south eastern end.
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| Willow felled and ringbarked at back of airport - now regenerating |
This infestation is very
pernicious and will turn what should be a regenerating native swamp area, into
a drained willow forest, if it isn’t stopped now. But how likely is that?
There are gangs around trying to keep on top of
the runaway weed proliferation but when I approached one, they were working to
clear areas around the native seedlings to give them breathing space. The theory is that the native plantings will grow in size to smoother the weeds, so they
weren’t pulling weeds. They were working right next to a growing sea of willow seedlings, but were completely unaware of the issue.
So who will clean this up?
Well, the
NZTA is still in charge but are way too busy putting up signage to show what a
great job they have done to take an interest. Besides there are
only a couple of years left in the weeding contract, at which point it will presumably
devolve back under District and Regional Council jurisdiction. But their
scientists don’t get out in the field much anymore. It’s too far away from head
office, the lab, and the coffee machine so they keep an eye on things via
google maps and Wikipedia. Meanwhile the land itself appears to have been
contracted out to a contractor charged with contracting out the contract to a contractor. And his name? Mr Nobody.
Track we were listening to while
posting this? We are back to John Lennon and his plaintive Bob Dylan influenced
Nowhere Man…
He's as blind as he can be
Just sees what he wants to see
Nowhere man, can you see me at all
Nowhere man don't worry
Take your time, don't hurry
Leave it all till somebody else
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