I would like to say that the issue with respect to Beech Forests, NZ,  can
be summarized as follows:

(1)     The ancient Beech Forests of the West coast consist of remnants.
They are low elevation forests and not many remain in a native state.

(2)     Ecologists have determined these forests to be rare. Many endangered
and sensitive species live in these remnant forests (Dept. of Conservation,
Landcare, etc.).

(3)     The public and ecologists are agreed that they must be protected
from destruction. The vast majority of public submissions (9-10 thousand)
support protection and no logging. The minority of public submissions do not
support logging. 

(4)     Ecologists have assessed Timberlands forest plans and have
determined that over time the large trees would dissappear (Chris Perley
disagrees). 

(5)     Timberlands indicates in a least one publication that they cannot be
certain that the ecologically sustainable forest practices will in fact
result in the conservation of species and habitat. This is confirmed in the
responses section published to the statements by the Department of
Conservation. 

(6)     The science of ecology is not much different than any other science,
especially where there is uncertainty and where there is certainty. Truth is
a path, not an artifact. The inferences that may be drawn about the impacts
of a human disturbance at the scale that Timberlands proposes are much more
frequent than the majority of natural disturbances that would create several
gaps per hectare each 10 to 15 years in an ancient forest of South American
beech. 

(7)     If Timberlands case is to be made cogent then the least desireable
inference that they could have made in response to the Dept. of
Conservation, and the public, is that they are uncertain about the causes of
the declines in sensitive species in their proposal. Where the DoC indicates
that the issue of quality of habitat as an antecedent condition influencing
sensitive species is *paramount*, Timberlands indicates that it is predation
by introduced species that 'may' be operating. Timberlands does not agree
with habitat being of *paramount* importance (cognitive dissonnance)

(8)     The dilemna is not  an ethical dilemna at all, but represents a
failure on the part of Timberlands to assess the environmental impacts
adequately in advance. In law we call this the 'failure to warn theory of
cause' which occurs in toxic tort law (convictions) when the manufacturer of
a product fails to warn the purchaser of any inherent defect in the product
that it sells which harms the user. 

(9)     Timberlands has indicated that it is not certain about any of the
inferences as to causality in the decline of species in the beech forest. 

A true ethical dilemna would involve a 'trade off' in the sense that had
Timberlands and the DoC concluded an assessment of impacts with a high level
of certainty that (a) logging of the beech forest (at any rate of
sustainable extraction) would compromise conservation of endangered
indigenous, and the (b) a decision had to made based on priorities (first
principles) about whether to log or not to log. 

When you have a high level of certainty and there is consensus in the
scientific community reagarding the impacts of logging, then the ethical
dilemna arises as to what is more important:

(a)     human welfare (jobs, houses, newspaper)

(b)     the welfare of the endangered species and their habitat.

However based on the lack of certainty in the assessment that Timberlands
has provided there is no ethical dilemna here. There is no consensus between
Timberlands and DoC. Even Timberlands admits it is uncertain, and that the
best it can do is make plans which are intentionally sustainable. 

>CP:  The gaps are not that big.  You cannot notice them.   I repeat -
>perhaps you would read it this time - there are no coups with clean edges
>etc.  The disturbance is on the same scale as a natural one or two tree
>event - sometimes with other smaller trees associated.  That is not to say
>there are not natural gaps far larger than that - but Timberlands let the
>catastrophic events do their own thing.  The Southern Alps "gap" I worked in
>above were counted in the hundreds of hectares.

What do you mean by 'cannot notice them? If the gaps are large enough to
result in an increase in light, water and nutrients in soil solution, then
the gaps must be noticeable.

Your comment that this artificial form of gap dynamics is at the same scale
of frequency as in nature is patently false. Trees that are merchantable
just don't die that frequently. In fact patches of forest will continue to
be undisturbed unless there is large windstorm, a wildfire, or an avalanche,
for instance. We have forests on the west coast that are 8000 years old.
They have never seen wildfires, and therefore the primary natural
disturbance is infrequent windthrow which may occur at time intervals of
over one thousand years, or frequently as twenty years. 

Your gap dynamic theories are misleading as well. For instance 

Canopy Breakup.

"Olivers model concludes with 'old-growth'.... It starts when crown
expansion no longer compensates for mortality in the canopy and
opportunities are thus provided for suppressed individuals of the first
cohort to enter the canopy." 

"The initial values of the attributes which follow the U-shaped curve depend
on the inheritance from the preceeding stand: generally they are lower if
the preceeding stand was destroyed before it achieved old-growth...."

"...secondary regeneration (in an old a closed canopy old growth forest)
establishment was mainly restricted to fallen logs, and tip-up mounds, the
proportion of birch was much lower and growth was slower." (Siren 1955). 

Timberlands model of sustainable management would prevent the forest from
reaching this old growth closed canopy state where the trees would not
expand into the gaps after a gap is created by group extraction. This means
that - like you have indicated - that new regeneration would be created
*after* the canopy was opened up. The existing established seedlings would
be replaced by new trees that germinated on the disturbed soils around the
fallen tree. Therefore in an undisturbe old growth forest the regeneration
has established before the disturbance. In the frequentist dynamics of 10-15
disturbances the floristics would shift to pioneer light demanding species
(remember the seeds from the new regen would get into the gaps created by
earlier man made gaps). This is why I proposed  a rotation and entry of
250-400 years. That why you can be certain that logging is not creating a
different floristics (eg see Chris Maser and Michel Soule's writings, in
particular The Redesigned Forest). 

One other point. The site indices for managed stand of commercially valuable
trees are often much greater than are site indices for old growth forests.
The site indices indicate the potential of the young managed forest for
growth and yield (minus contraints, biotic factors, etc.)

If you look at the normal J shaped curve that represents density versus age,
then it should be intuitive that the older trees reduce density
dramatically. The compensatory function though in a stand is that some
species of trees are shade tolerant. If you have only one species of tree in
the stand there is no compensatory density function filled by more shade
tolerant trees. So in fact what happens with human induced change and
disturbances that are as frequent as Timberlands modelling indicates and
(probably has not been introduced into the model) is this compensatory
function of shade intolerance. 

As the stands become harvested the gaps will have lots of irregular edges
(eg you say that 'you cannot see the gaps') which means that the increased
light will benefit less the truly shade intolerant species that are
associated with large gaps (catastrophic windthrow, wildfires, etc.). The
shade intolerant species will usurp the less intolerant species (eg hemlock
versus birch), and this will have a tremendous impact on the remaining large
trees because of the vigor of the dense understory (I have seen 20 or more
thousand saplings established per hectare in selection forests). The
remaining older and larger trees will not have the same competitive ability
to obtain nutrients as they did. So the artificial gaps that are created in
each hectare will have a cummulative impact through root competition that
will result in greater stress during the dry periods. In fact the younger
trees which are more shade tolerant will have a tremendouse competive
ability due to the fact that they have more carbohydrate to put into growth
of xylem (ht/grith) since many species do not begin to flower (make cones
and seeds) until the reach an age of 50 years. 

Timberlands model of forestry therefore to 'emulate' the natural
disturbances would have to have long intervals between entries, and many of
the older trees would have to harvested to 'emulate' natural windthrow. This
is why 10-15 years is too frequent. You cannot simply take only the
intermediate sized trees, but on the other hand taking the dominants would
upset the natural disturbance pattern associated with gap dynamics. 

Science does not like uncertainty, unfortunately, and neither do humans like
uncertainty when it comes to insurance policies, etc. 

john foster


"When an idea is new, it is seen as crazy. This is followed by a period in
which it is viewed as dangerous. After this, there is a period of
uncertainty. In the end, you can't find anyone who disagreed with it in the
first place".  

Stephen J. Gould



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%