permaculture

[Toby Hemenway <hemenway@jeffnet.org>]

on 4/29/02 7:57 PM, Heide Hermary at heidehermary@pacificcoast.net wrote:

> I am not sure you are totally right about fire being introduced into
> landscapes by humans.

I didn't say that humans are the only source of fire; 'course not! But there
have been many studies  showing that fire frequency increased dramatically
once humans arrived.  Journal of Forestry 80:647-651, 1982,  shows that fire
frequency in the American Rockies increased 4- to10-fold  once Native
Americans showed up; other research shows that the American prairie
increased enormously in extent after people arrived and burned it more
often. Oregon's Willamette valley and most of California were both burned
frequently and extensively by humans for millennia, reducing tree cover and
promoting sclerophyllous shrubs or grassland, as pollen records show.
Fire-adapted landscapes (not species, but whole landscapes and ecosystems)
were greatly increased in area after humans arrived.
 
"Huge forest fires" in the US Northwest (my home too) were quite rare until
whites instituted fire suppression, allowing fuel loads to build up. Fire
scar patterns show that until the late 19th C. most (though not all)
lightning-caused fires were cooler understory burns that left big trees
intact. I've seen several lightning strikes that have not caused fires in
the well-managed, low fuel forest near me, while the same storms caused
large fires in nearby Forest Service and BLM (fire suppressed) land.

I realize I have to be careful not to overstate my case; human burning
doesn't always create deserts, as Mark points out. New England was burned
just as often as California but stayed wet. My point was more that history
suggests that, since we've always done it, maybe it's ethically tolerable
for us to consider modifying landscapes on a large scale, but this time to
increase water availability, fire-resistant species, and perhaps the whole
response of the land to fire.

Though they aren't quiet as simple a tool as a fire stick, Mark is right:
rotational grazing plus keyline and other water catchment systems could get
us a long way toward a naturally fire-suppressant landscape.



Toby