Very few of our native species have any form of browse-resistance and hardly any of them can invade well-developed farmland.
Such vegetation was able to develop because, apart from bats, there was not one land mammal native to New Zealand. In many parts of the country, the bush floor species have mainly been wiped out.
In the Ureweras, for example, the layer now consists mainly of stinging nettle, one of our very few "nasties", and hook-sedge (Uncinia).
In Westland, the subalpine rata trees that used to turn the hills scarlet in a good flowering season are now mainly grey ghosts.
Erosion scars many hills, in some, moving rocks now make the slopes impossible to traverse.
Parts of the north face of Mt Wilberg, in South Westland, are an example. But then, these are places where amateurs never go.
I believe there are millions of possums in that area alone.
The most dangerous situation for our native forests consists of possums browsing the canopy while goats below even ringbark the trunks of the trees. That situation is not uncommon in Northland. I believe the present situation here arose because DOC does not have the funds or personnel to monitor the bush. It required an outsider to blow the whistle in this case.
New Zealand is unique in the world in the character of its vegetation, and it has to take unusual steps to control it.
Control by hunting, etc, works only near the bush edges. It might succeed, perhaps, if the local iwi took slashers and cross-gridded the Mangamuka Ranges, etc, with walking tracks, but meanwhile the pigs, which don't do as much damage anyway, are strictly pedestrian. Biological controls could affect domestic animals.
1080 is the only effective means presently available to save the bush.
John G Rawson
(Forester)
Whangarei
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