Agroforesters needed in NZ? (Was: Re: [Scoop] Scientists Refute Government Spin-Campaign)

Brian Sandle 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:

: snip

:>*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 
: losing
: 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 
trust.
 
Has he pushed Timberlands back from this figure?
**************
   Linkname: Timberlands West Coast, Beech Plan Overview - Sustainable
          Yield Regulation
        URL:
          http://www.timberlands.co.nz/forest/sustforestry/mgtplans/bcho
          verview/Part_2/Section_5/sub_2.html
   Last Mod: Mon, 05 Oct 1998 22:45:51 GMT
       size: 421 lines
 
   
   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
          Management
        URL:
          http://www.timberlands.co.nz/forest/sustforestry/mgtplans/bchm
          aruia/section_4/sub_8-9.html
   Last Mod: Mon, 05 Oct 1998 22:33:35 GMT
       size: 249 lines
 
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
   (Ytsma, 1988).
   
   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,
   1996).
*******************
But what proportion of harvest is 1%? Look at this for rimu:
*******************
 
   Linkname: Green Monitor Issue 9 June 1997
        URL:
          http://www.timberlands.co.nz/publications/greenmonitor/issue_0
          9.html
   Last Mod: Tue, 22 Sep 1998 22:02:57 GMT
       size: 247 lines
 
   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
   discernible.
***************
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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