[Terrapreta] Sustainable Forest Management

[lou gold]

Hi Ron,

I think that the key paragraphs for China are:

Trees and rising temperatures are not a good combination. Large-scale
die-offs from drought, fire, and disease outbreaks loom large in current
ecological models of climate change and have the capacity to turn a carbon
sink into a carbon source almost instantaneously. Direct carbon emissions
from forest fires in Korea in 2000, for example, negated one to three
percent of the global forest carbon uptake.(2) A greater forest area coupled
with an increased risk of disaster is surely tempting fate.

Recent computer simulations carried out by Jing Ming Chen's research group
at the University of Toronto underscore the risk. Although China's forests
sequestered an estimated 13 percent of the total CO2 absorbed by the world's
forests during the 1990s, their model suggests a rather different picture a
hundred years from now.(3) Under some conditions brought about by plausible
changes in the climate and atmospheric makeup, the forests could even become
net carbon emitters. So if we are counting on those forests to take carbon
out of the system, we could be in trouble.

Quite frankly, I am not qualified to evaluate the above. But I don't see
anything to suggest that the forests are not healthy NOW. I do believe that
you've seen a lot of healthy trees. If I understand the argument correctly,
it is that rising temperatures and drought stress MAY quickly and
dramatically turn what looks good now into something catastrophic later in
the century. As I said, I dunno. I provided this article  not some much in
agreement with the model but to answer the question of how forests might
become net-emitters. But, how do you see char-amending the soil as the thing
that would alter the outcome? Would char-amended soil retain more water and
counter the effects of warming, or what? And what be the effect of "plowing"
the forest floor? It's disturbance that releases what had been sequestered
in the soil.

I also wanted to point out that the tropics are both the potentially
positive exception (because forests generate clouds and moisture) and the
place where deforestation and fire are a huge threat that could turn half of
Amazonia into savanna quickly and be a 'tipping-point' in the global system.
It's scary!

But, bottom-line, I mostly wanted to underscore the complexities of
understanding exactly how temperate forests will play into the global
warming picture. When you see the current drought stress and fires in the
American West, it's both sad and scary. My most precious forest in Oregon
burned massively and twice in the last 10 years. And the young returning
forest will be even more susceptible because the fuel loading will be closer
to the ground and fire will not be able to under-burn as it often did with
old-growth in the past. And here's the great irony -- the char amended
post-fire soils do support fast regrowth which means more fuel for the next
fire. So we might be entering a positive feedback where char is part of the
process rather than a countervailing force. I don't know this as a fact. I
want it not to be true. I'm afraid that it might be.

OK, that's my best shot at responding to your good questioning.

lou




On 9/20/07, rongretlarson at comcast.net <rongretlarson at comcast.net> wrote:
>
> Jon, Lou, etal
>
>    1.  This being written from China - which is prominent in the article
> cited by Lou.
>
>    2.  I haven't seen enough of China to be an expert - but I have seen a
> lot of trees - and the countryside looks quite healthy (and bustling).
>
>    3.  The article fails to mention anything about managing forests with a
> heavy use of biochar production and the plowing back of a lot of biochar
> into the forests. I believe the article's analysis of albedo effect without
> considering char production and sequestration is too outdated to mean
> anything.
>
> Ron
>
>
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