Agroforesters needed in NZ? (Was: Re: [Scoop] Scientists Refute Government Spin-Campaign)
bsandle at southern.co.nz
Sun Feb 6 23:47:46 EST 2000
In bionet.agroforestry Patrick Dunford <no.sp at m.please> wrote:
: Behold, on Thu, 03 Feb 2000 17:28:59 GMT in
: nz.politics:<949598921.480664 at mnementh.southern.co.nz>, Brian Sandle
: (bsandle at southern.co.nz) didst uttereth:
:>*Maybe* the beech scheme could turn a profit? Read my recent article on
:>one of the German Scientist threads. It would have been unlikely to
:>turn a profit. Then the pest control would have been dropped, of course.
: Timberlands makes plenty off their other activities, why would they be
: money on beech?
:>*Maybe* enough profit to pay when the possibility has been the main
:>thrust of the `scientists' case for logging.
:>Let's not have the remaining lowland beech forest as a close to hand
:>laboratory for `sustainable' management to apply in countries which still
:>have a much larger proportion of theirs left.
: This is whitewash. Sustainable means self-maintaining. I suggest you read
: Moller's article in the Press.
Moller is very keen to protect the forest. Maybe he feels he has pushed
Timberlands back from improvent felling, so that the number of trees
felled would be reduced to one third. So now his intensity of argument
is reduced to one third. To recompense for the remaining third he has
been promised pest management. But how can the scheme be able to pay for
that? Moller, I presume is not an economist and is taking the promise on
Has he pushed Timberlands back from this figure?
Linkname: Timberlands West Coast, Beech Plan Overview - Sustainable
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The rate of improvement felling is restricted to a maximum of 10% of
surplus immature defective stems.
And defective from whose viewpoint?
A point which I asked around Christmas time I further go into, now.
It is only dying trees which are to be taken. Now the trees die often
because borer allows fungi in. So the dying trees are going to have lots
of borer. They will be of low value, not suitable for timber.
Linkname: Timberlands West Coast, Maruia Beech Plan - Forest
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A pinhole monitoring system will be implemented.
Beech trees are hosts to three species of Platypus pinhole borer (P.
apicalis, P. caviceps, P. gracilis). They attack recently felled logs
and branches, and both healthy and weakened living trees, causing
major defects in the timber (Wardle, 1984). Tunnels bored by Platypus
adults normally extend radially near the heartwood boundary and then
branch tangentially (Milligan, 1974). As well as damaging the timber,
Platypus is a vector for a fungal pathogen (Sporothrix sp.) that
creates cores of pathological wood within trees. Once infected with
the pathogen, trees of a merchantable size will suffer dieback or
death (McCracken, 1994). Adult male Platypus are probably attracted
to volatile substances which are released by stressed trees and the
females attracted by pheromones released from the hind gut of males
Several factors predispose beech trees to attack by Platypus spp.
These include the health and stress levels of the tree, proximity to
recently infested wind-fallen trees, the moisture content of the
wood, and the diameter of the tree (Kershaw, 1980). Litchwark (1978)
also demonstrated that the density of attack decreased progressively
up the stem and that trees with no attack at the base (<3m) were free
from attack further up the stem.
Management strategies have been adopted to reduce the incidence of
attack to trees surrounding harvesting sites (refer Section 4.4.2).
They include ripping or cutting logging slash into short lengths to
accelerate the drying process (making them unsuitable for attack),
and plunge-cutting tree stumps and treating them with urea to inhibit
yeast (Endomycopsis platypodis) growth.
The philosophy of the current approach to sustainable beech
management is that the harvesting of single or small groups of trees,
combined with good forest hygiene, should eliminate many of the
factors that are thought to predispose trees to attack. To test these
assumptions a survey method has been adopted (refer Operations Plan)
which is sufficiently sensitive to detect changes in Platypus damage
levels as low as 1% in the forest surrounding harvest sites (Hosking,
But what proportion of harvest is 1%? Look at this for rimu:
Linkname: Green Monitor Issue 9 June 1997
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generation. Rimu management forces one to take a very long-term view.
You become very conscious of the fact that today's actions will
affect the forest for centuries. It ensures caution and respect.
The new approach to sustainable management was developed by
Timberlands West Coast Limited in 1991 after a review of research and
management in New Zealand dating back as far as the 1930s. Early
logging trials within different forest types revealed situations
where harvesting was successful and others unsuccessful. The lessons
learned were that native trees are very sensitive to major
disturbance of the forest environment. Most historic logging
operations induced dieback of the residual forest through either
physical damage or harvesting too many trees.
Management today involves taking a few trees with very low impact
methods. Growth is naturally slow usually less than one cubic metre
of timber per hectare per year. A typical rimu tree in Westland
contains of 3 - 4 cubic metres of timber so on average only one tree
is removed from a hectare of forest every four years. Put another way
there are around 150 mature trees in any single hectare of lowland
rimu forest and if one is selected every four years the harvesting
rate is around 0.13%. By any standards this is a very low rate of
harvest and the measurable impact on the forest is scarcely
Note also there that the whole production rate of rimu appears to be
being taken. For beech no greater than 50% is being claimed, but does
that take into account loss to borer?
I have claimed beofre that this scheme is an experiment. I now claim
it appears that the measuring technique is not going to be able to give
results sensitive enough for requirements.
The experiment would prove nothing and should not go ahead.
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