This case describes treatments implemented at three different sites, labeled Hart Lake, Prairie River, and Shoal Lake. All sites are on industry-owned land dedicated to commercial timber production. The silvicultural objective is to regenerate aspen-spruce mixed woods for multiple commercial entries. [We have decided to publish all three as the same case. Treatments are identical, only locations differ. Photos from all three sites are included. -ed.]
To regenerate conifer and aspen for multiple entries for commercial harvests.
Pre-treatment stand description and condition
Stand establishment and management history:
Aspen clearcut, planted with white spruce, and aspen allowed to resprout. No herbicides used.
Pre-treatment species composition:
Aspen, white spruce, balsam fir
Industrial land, for commercial timber production.
Manually release 3’ radius around all conifer seedlings with brush saws. 1100 trees per acre is the goal upon completion
What actually happened during the treatment
Migrant crews used brush cutters in summer of 2011 to remove all woody competition within 3 foot radius of each conifer on the site. A control area had been cordoned off and not cleared for comparison. Plots within control and treated sites were measured by Pike, Warren, Humenberger in 2011 after treatments were completed. Plots were finished in 2015.
Figure 1: White spruce release Hart Lake control plot
Figure 2: White spruce release Hart Lake treatment plot
Figure 3: White spruce release Shoal Lake control plot
Figure 4: White spruce release Shoal Lake treatment plot
Figure 5: White spruce release Prairie River control plot
Figure 6: White spruce release Prairie River control plot
Conifer trees within the treated plots were more vigorous than those in the untreated plots. Overall survival of planted spruce trees was high across the site (>75%). The prescription appears to be favorable to health of the conifers. We observed pockets of balsam fir, and occasional white pine trees that seeded in naturally.
Costs and economic considerations
Harvest was clearcut, pre-commercial treatment required approximately three days to complete on the 19-acre Shoal Lake site.
We established four 1/5 acre plots with rebar center posts in treated and adjacent control (untreated) areas to monitor the effects of the treatments over time. We collected baseline data for future study.
Summary / lessons learned / additional thoughts
The planted white spruce seedlings were vigorous; the overstory above them seemed to protect the seedlings from effects of early spring frost. The release was necessary and successful at invigorating the seedlings.