ENVIRONMENTAL CONSEQUENCES in rocky mountain coniferous ...

hold throughout a series of habitat types featuring a wide range of intermediate
temperature and moisture conditions. However, we would expect that extreme sites
(i .e., very cold, wet, dry, or a combination thereof) induce different behavior. If
the threshold values of temperature, moisture or other conditions for the various
microor anisms are exceeded, the microorganisms may either become dormant or die
(fig. 4 9 . For example, the Teton experimental site (location and description provided
elsewhere in Harvey and others 11980al this proceedings) apparently is too cold
or too dry most of the time to support decay organisms. As a result, periodic fuel
accumulations and wildfire function as the principal carbon recycling agent on this
site, and all types of organic matter, especially soil wood, tend to be in short
supply. Although our data indicate that intense ectomycorrhizal activity is supported
by accumulations of humus or decayed wood, these accumulations rarely occur on the
Teton site.
THRESHOLD VALUES
WARM I 1 I
DRY WET
MOISTURE
Figure 4.--Some proposed theoret{cai: factors Zimiting the actk~i-kies of
soiZ microorganisms and *he predictabiZity of changes in their activities
over a temperature-moistm gradient.
The Teton site provides an excellent example of how forest management practices
could: 1) limit fuel accumulations to levels that would minimize the occurrence of
extremely hot fires; 2) lop and scatter residues to get them in contact with the
ground for increasing decay and decreasing fire hazard; and 3) protect the integrity
of the organic accumulations that have occurred by limiting the disturbance of u per
soil layers. In these ways we might eventually be able to achieve a higher leve of
site productivity than would occur through natural processes.
!