[Terrapreta] ancient forests: under-rated carbon sinks

[dyarrow at nycap.rr.com]

----- Original Message ----- 
From: Michael Bailes 
Sent: Tuesday, March 06, 2007 7:19 PM
Subject: Re: [Terrapreta] Some clarifying answers

On the Old forests thing, there is some new research that is casting 
doubt on the role of older forests in carbon sequestration.  It would 
be good if they are right.  See:
http://news.mongabay.com/2006/1204-forests.html

On the decomposition thing do we know what is going on re soil zoology 
vis-a-vis CO2?
Are the fungi and "wee beasties" storing or exhaling CO2?
Does anyone know? 

Michaelangelica

Fast growing young forests are good carbon offsets, because the bulk 
of the carbon which they take in as CO2, stays perched in the trees 
above and swollen into the roots systems below many hectares of land.  
When forests get older, they are no longer net carbon sinks, because 
they have decomposition of the plant material which puts CO2 back into 
the atmosphere.  A forest can sequester lots of carbon for a good 
twenty years.  Terra Preta soil has carbon which stays almost 
permanently, certainly with half-life of many thousands of years.

--------------------------------------------------------
my common sense says:

having conducted ancient forest surveys in the northeast US, and 
examined old growth forests up close and personal, and having at least 
skimmed the literature defining and quantifying ancient forest 
processes, and having sat through discussions by the experts-in-the-
forest that are twisting trails throuh minutiae, i think many of the 
assumptions about ancient forests are wrong -- or at least deceptively 
simplistic, and definitely no more than preliminary guesses at what 
are complex communities and processes.  and i have very limited faith 
in the assumptions and judgments of professional forestry, since 
virtually all those experts are hired guns for an industrial forestry 
that sees trees as commodities for harvest, and will argue against any 
statement that challenges their views and values that forests should 
be cut down for timber and pulp.

one caution is that old growth forests are a complex diversity.  here 
in the northeast US, there are many different types of old growth, 
from 100-year-old pitch pine growing on rock and sand, to 700-year-old 
black tupelo growing in swamps, to 1000-year-old white cedars growing 
on cliffs and talus in the niagara river gorge.

a second caution: old growth forests are rare.  in the eastern US, 
less than one quarter of one percent -- and a significant proportion 
of that are "secondary old growth" -- cut once in the first wave of 
settlement, then abandoned to regenerate into ancient trees and 
supported communities.  and the ancient forests that are left were 
generally left because they grow in extreme and inaccessible 
environments: steep slopes, cliffs, bare rock, mountaintops, 
swamps....  it is difficult to make firm assumptions and 
generalizations based on such a limited sample size of freakish 
forests.

most eastern forests were cleared and burned to make potash and 
charcoal; creating new farmland was often a secondary goal -- the 
immediate need was cash.  logs and limbs were piled and burned in open 
air to make potash to sell as a fundamental industrial chemical.  logs 
and limbs piled and covered with dirt were smoldered to create 
charcoal to sell to industrial furnances such as iron smelters.  once 
cleared, the thick, humus-rich topsoil rapidly eroded downslope to 
accummulate in ravines, valleys, swamps, lake bottoms, and other 
landscape hollows.  this wholesale soil destruction and erosion was 
accelerated by the common practice of plowing up and down slopes.  and 
such plowing opened the soil to accelerate the oxidation of humus, 
outgassing immense amounts of carbon.

i have hiked through ancient forests, and bounced on their deep, 
spongy layers of duff, humus, moss, mycelium, algae, lichen, and all 
else.  i've seen deep ravines lined with talus and boulders nearly 
hidden under thick deposits of humus.  and those carbon-rich humus 
deposits were still growing thicker year-by-year, and distributed by 
wind and water beyond forest boundaries to other enviroments.  my 
favorite example of this richness of soil is palmaghatt kill ravine in 
minnewaska state park in the NY hudson valley:
www.championtrees.org\oldgrowth\surveys\MinnewaskaSP20413.htm

i agree that new trees exhibit rapid growth, and thus quickly 
sequester large amounts of carbon -- that's their job -- to reshape 
soil, shade the land, replenish surface moisture, and regenerate 
habitat to support slower growing trees of a mature forest -- and all 
the complex communities that live in and under the shelter of trees.  
those rapid growth rates are not sustainable over a long term in most 
environments, and must inevitably slow down as trees get larger, more 
crowded, and divert energy into flowering, fruit and seeds.

but an ancient forest isn't just trees, but an ecosystem community.  
slower tree growth is matched by broadening diversity, density and 
complexity of all the other living organisms supported by the ancient 
tree habitat.  studies of microbes and larger life forms on soils show 
that ancient forests are much more alive than even humus-enriched 
farmland.  and in a temperate climate, those organisms enjoy a longer 
growing season because forest soils stay warmer in winter.  in fact, 
complex symbiotic relationships are created where trees deliberately 
feed other life forms -- a significant percent of the carbon converted 
to carbohydrates by trees is then deliberately secreted by roots to 
feed bacteria, fungi and vast populations of larger life forms in the 
soil.  and the more carbon stored in soil, the thicker, richer and 
more diverse are soil microbial populations.  or consider that the 
pollen of certain trees actually act as microbial stimulants.

another variable are assumptions about maximum tree height and 
volume.  for example, today in the east, it is rare to find white pine 
that reach 150 feet tall except in unusual sanctuaries.  yet, in the 
early days of european colonization, white pine over 200 feet tall -- 
even over 250 feet -- were not unusual.  a large amount of biomass is 
accumulated in those added 50 to 100 feet of top growth.  or consider 
that george washington himself measured a sycamore on the ohio river 
with a 60 foot circumference.  and who has measured the additional 
biomass in root systems and their symbiotic extensions?

i find the notion that that old growth forests are poor carbon sinks 
to based on faulty reasoning and short-sighted assumptions.  and i 
haven't the time to read, digest, dissect, and critique all the 
studies -- i'm too fiercely busy trying to preserve, publicize and 
protect what is left of our ancient forests.  and a dozen other 
similar battles.

aside from this quibbling and scribbling over the minutiae of data, 
the flat fact is trees as forests are the lungs of the earth.  these 
complex, tree-based communities allow the biosphere to breathe in its 
poly-cyclic synchronies.  for thousands of millennia they have 
performed multiple functions to regulate the circulation, balance and 
quality of water, oxygen, carbon, and other factors that create and 
sustain the atmosphere, climate and weather.  carbon sequestration is 
only one of many reasons to regenerate and preserve these 
silvicultural communities -- a tough challenge considering the tiny 
amount of them still surviving.

since the late 70s, i've supported and facilitated establishing 
organic, permaculture and other earth-sensible farming systems.  and 
while i support ongoing efforts to restore true full spectrum 
fertility to our farm soils, and thus our foods, i consider 
restoration of full spectrum minerals and stable organic carbon in our 
forests to be a much more crucial task to restore stability and 
temperateness to our earth's atmospheric thermal engine.  this is the 
greater challenge, since we can easily make money selling fertilizer 
to farmers, but it is rare to meet any forester who thinks deeply 
about restoring the integrity and quality of our forest soils.

enough for now.  remember: the law of good land is the way of the 
forest.  if yer not forest, yer against us.

David Yarrow
"If yer not forest, yer against us."
Turtle EyeLand Sanctuary
44 Gilligan Road, East Greenbush, NY 12061
518-330-2587
dyarrow at nycap.rr.com
www.championtrees.org
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