Cariboo
Forest
Region
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Group Selection Systems for High Elevation Forests
in the Cariboo Forest Region
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|
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Extension Note EN09
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Introduction
Mountain caribou spend much of the year in high elevation forests and feed
almost exclusively on arboreal lichens during the winter, mainly Alectoria
sarmentosa and Bryoria spp. Lichen dispersal, establishment
and growth are slow, and an estimated one or two hundred years are required
before a new clearcut will supply arboreal lichen comparable to old growth
stands. Forest companies have prepared development plans identifying timber
values in these areas, and alternative silvicultural systems which sustain
lichen for caribou need to be explored.
Group selection was chosen as a practical silvicultural system to test
under these circumstances, to examine the effectiveness of extracting timber
while maintaining lichen growth and availability. The study is located
at Blackbear and Grain Creeks in the Quesnel Highland of the Horsefly Forest
District. The project is being conducted by the Forest Sciences Section
of the BC Ministry of Forests, Cariboo Forest Region, with the cooperation
of the Horsefly Forest District and Weldwood of Canada Ltd., Williams Lake
Division. It has been primarily designed to develop a viable silvicultural
system that will provide a basis for economical timber harvesting and also
maintain suitable caribou habitat.
Objectives
The group selection system project's objectives specifically address the
following:
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The viability of group selection on ESSF sites to maintain caribou habitat
and old growth characteristics in managed forests
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Blowdown risk and the incidence of forest health problems in group selection
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The effectiveness of different natural and artificial regeneration treatments
within a group selection system
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The effects on soils, snow accumulation and melt, and wildlife diversity
(especially small mammal and bird populations)
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Providing Extension opportunities, in the form of a demonstration site,
research reports, and high elevation management guidelines for operational
foresters
Harvesting
Four blocks, averaging 40 ha each, were harvested in August 1992 and December
1992 / January 1993 using three treatments of different opening sizes:
.03 ha, 0.13 ha and 1.0 ha. The target volume removal for each treatment
was 30%, including skid trails but exclusive of roads and landings.
Silviculture
The project is testing a total of 64 natural and artificial regeneration
treatments for the three opening sizes. Natural regeneration treatments
include natural and hand seeding of two species, Engelmann spruce and subalpine
fir, on a scarified patch and an untreated section. Artificial regeneration
treatments include planting lodgepole pine, Engelmann spruce and subalpine
fir on five planting treatments in the summer of 1993 and 1994. The planting
location treatments include untreated, a scarified patch and three microsite
locations: naturally raised sites, rotten wood, and microsites protected
from snow creep. These microsites are intended to improve the seedlings'
environment by warming the soil and protecting from snow creep.
Lichen Monitoring
Arboreal lichens are being carefully measured around each of the different
opening sizes to compare growth and abundance with the undisturbed forest.
For measuring growth rates, lichen is collected, transported to the regional
lab, stabilized and weighed at a standard relative humidity, and placed
in specially designed enclosures which are hung on tree branches. The process
is repeated annually to measure growth.
Land Management Handbook Field Guide Insert #7 (refer to Extension Note
#8) has been produced for operational use to estimate lichen abundance
in stands. It will assist field staff in standardizing the description
of lichen abundance which is necessary for deciding on suitable silvicultural
systems in high elevation stands.
Other Aspects
The project's multi-disciplinary approach includes linking soil characteristics
with seedling growth, estimating post-harvest site disturbance, and observing
mycorrhizal presence in plots. Root form and foliar nutrient analysis will
be conducted on seedlings slated for destructive sampling.
Snow hydrology studies will include snowcourse measurements, tipping
bucket snow lysimeters in the harvested openings and undisturbed forest,
and measures of snow creep.
Small mammals are being monitored for diversity and population density
using Longworth live-capture traps. Bird species response is also being
monitored using census points and spot mapping of territories.
The project has been designed to integrate as many aspects of forest
biology and management as possible for practical application of the research
results.
Contact
For more information, please contact Michaela
Waterhouse, Research Associate Silviculture Systems, at 250-398-4405.
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