ENVIRONMENTAL CONSEQUENCES in rocky mountain coniferous ...

INTRODUCTION
Lodgepole pine (Pinus contorta) may well be our most promising species for
increased fiber production and short rotations on many areas. It occurs on millions
of acres in the Rockies, much of it grows on relatively gentle terrain, and its dual
serotinous and nonserotinous cone characteristics provide a mixture of regeneration
opportuni ties available for but few species (Lotan 1975a, lW5b). Clearcutting is
the most viable si lvicul tural method of regenerating lodgepole pine (Tackle 1954;
Lotan 1975b) but large amounts of residue left after logging leave the areas un-
sightly, create fire hazards, are obstacles for forest management activities, and are
a waste of a wood resource. Lodgepole residues consist primarily of branches, cull
logs, and treetops above the merchantable limit. There 1 ies the problem--what do
you do with all the residue and how does the disposition affect the total resource?
In 1971, the U.S. Forest Service Intermountain Forest & Range Experiment
Station, Intermountain Region, and U. S. Plywood Champion Paper Company (now Champion
1nternational)l started a cooperative study aimed at assessing the effects of differ-
ent util i zation and residue disposal methods on esthetics (Benson l974), fiber yields
(Gardner and Hann 1972), nutrient cycling and subsurface water chemistry (Hart and
DeByle 1975), soil stability (Packer and Williams l98O), and seedling establishment
and development (Lotan and Perry 1977). This paper is a followup to the latter; it
reports the regeneration es tab1 ishment and development the first 5 years after
residues treatment.
METHODS
Area
This study was conducted in overmature lodgepole pine stands on the Bridger-
Teton National Forest in northwest Wyoming. This area is a gently rolling plateau
at an elevation of about 2 850 m (about 9,300 feet). It falls within Reed's (1969)
Picea engelmanni i/Vacciniu~rl sco arium habi tat type. The climate is severe, wi th
the mean July minimum about *F). Precipitation is evenly distributed
throughout the year, averaging about 75 cm (30 inches) annually (Baker 1944). The
area has been heavily glaciated, and the soils are shallow, brown podzols (Reed
1969).
Four timbered blocks were selected for clearcutti ng in overmature lodgepol e
pine. Two blgcks were logged to conventional utilization standards and two were
lagged to near-complete util i zati~n (trees were skidded intact, and down and broken
material was brought to the landing and chipped). Slash was tractor niled and burned
on two separate quarters of each conyentionally logged unit; it was broadcast burned
on the other two quarters, Two separate quarters of each near-complete utilization
unit was left as it was foll~wing logging (there was about 11 000 kg per ha (5 tons
per acre) of wood fragments left on the soil surface); the other two quarters were
covered with 10 to 13 cm (4 to 5 inches) of wood chips roughly equivalent in weight
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endorsement of or approyql by the U.S. Department of Agriculture of any product or
service to the exclusion of others which may be suitable.