ENVIRONMENTAL CONSEQUENCES in rocky mountain coniferous ...

METHODS
Barger (1980) describes the various aspects of the sites and treatments used in
this study. The basic silvicultural prescriptions included group selection, shelter-
wood and clearcutting. At one site partial cuttings removing both the overstory and
the understory were used. On all sites we used an uncut portion of the stand as a
control ,
Residue and seedbed preparation treatments were superimposed on the cutting
units. Intensive util ization standards and conventional util ization standards left
differing amounts of di fferent-s ized residues on the sites. Both treatments were
broadcast burned at one site (fig. 1A). At two other sites residues were left
unburned (fig. 10). One treatment on all areas studied had a1 1 residues and advanced
regeneration removed to 1 inch in diameter, leaving only low understory vegetation
(fig. 1~). At one site residues were chipped and spread back on the site (fig. ID).
The four study sites represented a variety of habitat and timber types, with climatic
conditions varying from warmldry to coldlwet and elevations as high as 9,500 feet
(2 900 m).
Following are brief descriptions of each site:
Coram Ex~erimental Forest is near West Glacier, Mont. Habitat types
are varibus phases of the Abies lasiocarpa ~lintonia uniflora type (~fister
and others 1977) on elevat~ons d
from 4, 0 f-m-0 ft
(1 585 m). ~11. treatment areas had an east facing aspect on 40-60 percent
slopes.
Lubrecht Experimental Forest is on the Blackfoot River approximately 35
miles northeast of Missoula, Mont. The habitat type is basically
Pseudotsuga menziesii/Vaccinium caes itosuy on gently rolling terrain at
4,000 ft (1 20 0 m) elevqtion wit Ti- west to northwest aspects.
Solo-Hemlock area is in extreme eastern Washington near Priest Lake,
Idaho. Habitat type is Tsu a hetero h lla pachistima rn rsinities at an
elevation of 4,000 ft (1 -Lent 2
areas h
a a nort aspect
with 10-20 percent slopes. The stand was virgin timber 300-400 years old.
Wyoming Site is in the Union Pass area of the Bridger-Teton National
Forest, 40 miles southwest of Dubois, Wyo. Habitat type is - Abies lasiocarpa/
Vaccinium sco arium. The stand is lodgepole pine at elevations ranging
- O h 0 m) to 9,500 ft (2 900 m), with an east facing aspect
on slopes from 0-20 percent.
Our objectives were to monitor the operational factors to determine their
response to the selected harvesting and residue treatments, We chose to evaluate the
microsites at or near the ground surface and not attempt to monitor conditions
within the forest canopy. Many of the specific microsites monitored were selected
because of other studies on regeneration, microbiology, entomology, etc. We also
chose to base our measurements on data that would allow us to evaluate the energy
budget components described by Geiger (1 950). Interrelationships between various
energy flow components can be represented by the following balance equation (Gates
1968; Lowry 1958), called the energy budget equation: