Welcome! Log In Create A New Profile Recent Posts
Fern on the Four Mile Trail, Yosemite National Park

The Moon is Waning Crescent (12% of Full)


Advanced

Beetle Dead Trees, What Good are They?

All posts are those of the individual authors and the owner of this site does not endorse them. Content should be considered opinion and not fact until verified independently.

avatar Beetle Dead Trees, What Good are They?
January 05, 2010 04:11PM
Got this link from another list, very interesting stuff, well reasoned, and referenced:
About 50 minutes of youtube video links included in the blog:

http://wuerthner.blogspot.com/2009/06/tesimony-mountain-pine-beetles.html

Excerpt:

BEETLE KILL DOES NOT NECESSARILY LEAD TO GREATER FIRE SEVERITY OR SPREAD.
A common misconception is that dead trees will increase fire hazard. For instance, one study on beetles and wildfire occurrence that span the last 2500 years, found little correlation between wildfire and beetle events (Berg and Anderson 2006).

Another study (Lynch 2006) in Yellowstone on recently beetle killed lodgepole pine found that susceptibility to wildfire was not necessarily increased, though an earlier beetle event did appear to increase fire occurrence (the reasons are not due to dead trees, however, as I will explain below). Similar findings were reported for subalpine forests elsewhere in the Rockies (Bebi et al. 2003, Schoennagel et al. 2004, Biger et al 2005).

After a beetle event, there appears to be significant variability in fire susceptibility of forests that varies over time—assuming you have the prerequisite drought, wind, and low humidity that drives all large fire. Flammability is increased immediately after a tree is killed by beetles in what is known as the “red needle phase.” However, after the passage of one or two winters and the needles and small branches fall from the tree, the flammability goes way down. Thus if there is no ignition in those first few years (which as we noted earlier is very unlikely), the fire risk is significantly reduced.

It is only after the passage of several decades that susceptibility to fire increases, but not as much due to fuels, but as a result of rapid growth of small trees and shrubs that occurs after the forest canopy is opened by beetles. These small trees provide a ladder for flames to reach up into the forest canopy.

Nevertheless, even this period passes as the forest canopy once again closes, reducing forest fire susceptibility for many decades, even hundreds of years. (See Romme et al. 2006)



The cure for a fallacious argument is a better argument, not the suppression of ideas.
-- Carl Sagan
Sorry, only registered users may post in this forum.

Click here to login