🚀 go-pugleaf

In article <38109@mindlink.bc.ca>,
Steve Vestergaard <Steve_Vestergaard@mindlink.bc.ca> wrote:

>Brazil:
>- soil is depleted of nutrients as jungle quickly reincorporates debris
>- extreme biodiversity.  An acre may contain a species not seen anywhere else
>in the world
_____________
Sorry:  Big issue in Brazil is land conversion.  When forests are cut down
the idea is to make them into farms, not more forests.  I gather that
the Brazillian government has ceased pushing city dwellers into the bust
to farm since the torrential rains and poor productivity of upland forests
make the process uneconomical or sustainable.  Coastal Brazillian forests
are being cleared at *tremendous* rates, however.

Biodiversity is more complex than species count.  Sure forests in Brazil
can have thousands of species per acre, however the mix is similar over
millions of acres.  In BC we have many less species per acre (alpha
diversity) but many different species groups across the landscape (beta
diversity).   Our forests are almost wihtout exception in some process of
recovery from disturbance (some are long processes) which leads to a
mosaic of recovery states within each forest type (temporal diversity). 
Many ecologists are now arguing that the "nose and beak" measure of
biodiversity often glamourizing tropical forests is far from an accurate
assessment of the issue.

>BC
>- soil rich with humous created by worms and bugs in decaying debris
>- low biodiversity, but contains a far greater biomass than any other forest
>in the world.  The decaying logs and snags actually tie up more co2 then the
>trees which grow around them.  Many species can not exist without this
>debris, which is removed during logging.
_____________
Coastal forests often accumulate so much acid humus that trees barely
grow!  Some interior forests are accumulating woody debris too, due to the
suppression of naturally frequent forest fires, which is changing the
basic nature of the region.  Normally these forests would have little or
no organic material due to the frequent fires, so any particular fire
wouldn't be very hot.  Now when they do occur they kill trees that
normally survived.

As to the carbon accumulation, studies have shown that intensive cropping
of coastal BC forests would actually remove more CO2 than the logging
produced due to disturbance.  Old Growth forests are often so old that
they are decaying faster than they are growing so in many cases the CO2
sink is draining anyway.  This debris isn't removed during logging, it is
tossed up a bit and the input of new, undecayed material stops, allowing
decay to accelerate somewhat.  So called "wasteful" logging has been
demonstrated to resolve this issue.

>Covering the ground with seedlings isn't the same as rebuilding the original
>forest.  Forest practices have a long way to go, and few biologists (as
>opposed to foresters) will agree that large clearcuts are sustainable.
_____________
Most biologists aren't trained in the dynamics of forest ecology.  I for
one will stand by the rational scientific basis for forest ecology.  Any
biologists willing to bite?

>You
>can't drive roads and clearcuts through an ecosystem without damaging the
>whole.
____________
Really?  What scale do you define ecosystem on?  Have you heard of the
Gaia Hypothesis?  Some people believe all processes are related on a
global scale.  I'd ask an ecologist before I make this statement.

>In the case of the Clayoquot, you are correct.  No logging at all should
>occur there.  This is the last example of this particular ecosystem (lots of
>moisture, no fire, unchanged since last ice age).  It must be included in the
>12%.
____________
Um, there is a whole bunch of Costal Western Hemlock Biogeoclimatic Zone
in intact Old Growth state and a bunch of that is preserved, including two
large scale watersheds in clayoquot, for example.  Windthrow and insect
problems have taken out areas of wet, coastal forest in addition to fire,
and streams like Caramanah creek churn up the beds now and again making
habitat for shade intolerant trees like Sitka Spruce, which would have no
home without it.

>Most environmentalists feel that they've already bent over backwards in
>compromise.  Most of the province (almost 90%) is up for grabs.  After
>liquidating most of Canada's old growth, the companies refuse to save what is
>left.
_____________
Well, only 50% of the province has operable forest on it, for instance. 
Given that 80% of that remains in age classes over 150 years, I'd say that
you are dead wrong.  Most of the forests in BC remain Old Growth and will
rewmin so for a hellava long time.
-- 
....Robert Froese

                                                .....taganov@unixg.ubc.ca