Survival of Planted Stock: Survival varied by species. White spruce survival was especially good at 98%, but high survival was expected. In similar trials Blandin Paper reports >70% survival over 7 years. Dense bracken fern and thick aspen regeneration had reduced the vigor of the planted spruce, but nearly all survived. Hopefully, they will recover quickly with this release. Also the white pine survival of 56% was acceptable, especially without bud-capping or any form of protection. Many of the white pines grew above the bracken, but they are not stout. The white cedar was attempted because the adjacent stand had some natural cedar regeneration in thickets of balsam fir along the highway right-of-way. The planting stock was healthy, but no cedars could be found in the fall of 2009 after frost. Deer and snowshoe hares did not significantly browse the white spruce and white pine. The cedar plantings seem to have been removed because no dead trees were ever located. I don’t know what did this.
Species
|
Starting density
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Planting density
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2014 density
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Percent survival
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White spruce
|
0 TPA
|
167 TPA
|
163 TPA
|
98%
|
White pine
|
0 TPA
|
41 TPA
|
23 TPA
|
56%
|
White cedar
|
0 TPA
|
41 TPA
|
2 TPA
|
5%
|
Regeneration: The 2012 regeneration plot data were lost. However the plan was to manipulate the regeneration anyway with the brush saw work. Silviculturally it didn’t matter how much regeneration there was, as long as 800-100 selected trees could be released and spaced across the stand. The planted white spruce and white pine are evenly distributed across the site because they were planted that way and because survival was good. There was impressive establishment of northern red oak across the site, estimated to be about 50 TPA. Before the harvest, there were over 12,000 balsam fir and red maple seedlings <1” dbh. Very little of that advance regeneration responded favorably to the clear cut. Most recruitment of advance regeneration of fir and maple was in size classes >1” dbh.
Effect of Treatment on Ground Layer: Species richness of the site was assessed at 11 different scales using a nested plot system (see Field Form for Species-area Curves in Supplemental Docs). The stand was sampled in 2007 prior to treatment, and in 2008 and 2014. There was very little effect of clear cutting this MHn44 stand on species richness. Based upon other case-studies, this is typical of harvesting on frozen ground followed by natural regeneration or planting without site prep. In general, species richness increased slightly from as a result of the treatment Refer to Species-area Plots, 2007, 2008, 2014 in photographs section.
The treatment also did not result in significant invasion of the site by introduced or invasive species. There were no introduced or invasive species on the plot in 2007. In 2014 a dandelion (introduced) was picked up on the 7th plot (64m2), and the invasive Canada thistle was encountered on the 9th plot (256m2). Both occurrences were single individuals, not expected to survive canopy closure. This stand is very close to large populations of introduced and invasive species along Hwy 169 and Smith Creek Trail.
There was a surprising amount of species turnover between the 2007 and 2014 samplings (refer to Species-area Comparison Report in Supplemental Docs). Thirteen plants were lost from the plot, and 22 species were gained. The difference in mean synecological coordinates between the lost group and the gained group suggests that there were significant changes in site. The plants invading the site have synecological coordinates that would suggest the stand is warmer, drier, more nutrient rich, and slightly darker. Warmer and drier are consistent with the idea that more sunlight is hitting the ground, increasing soil temperatures and thus transpiration and direct evaporation. Increased nutrient levels are consistent with the idea than slash decomposing for 7 years as added nutrients to the forest floor. That a site could be shadier after a clear cut makes little sense. However, the treatment caused dense growth of waist-high bracken fern and it is possible that the groundlayer really is shadier. Alternatively, it was very hard to find plants in the bracken and it is possible that some of the species “lost” were just missed, especially on the larger plots.