Michel Soucy, Martin Béland. (2020). A crop tree release variant of precommercial thinning using a backpack mounted chain saw. Silva Fennica vol. 54 no. 3 article id 10205. https://doi.org/10.14214/sf.10205

Keywords: thinning; hardwood; spacing; time study; brushsaw; motor-manual; work performance

Highlights: Backpack mounted chain saws offer an opportunity to effectively cut larger stems in precommercial thinning treatments compared to conventional circular blade brushsaws; Productivity in performing precommercial crop tree release (PCTR) in a hardwood stand using a backpack mounted chain saw varied between 0.22 to 0.47 ha h^–1.

Abstract | Full text in HTML | Full text in PDF | Author Info

Although crop tree release (CTR) in hardwood stands is an accepted variant of precommercial thinning (PCT), the lack of an affordable and feasible method hinders its adoption. CTR implies selecting between 150 and 500 trees ha^–1 when trees are between 7 and 12 m high and cutting only stems competing with the target crop trees. We performed a field trial of a CTR variant of PCT in a 27.8 ha hardwood stand using a backpack mounted chain saw. A detailed time study was performed to document the trial over 13 days. Compared to conventional PCT performed earlier in the life of a stand, precommercial crop tree release required cutting larger stems, which showed to be feasible and productive using a backpack mounted chain saw. Productivity varied between 0.22 to 0.47 ha h^–1 during the trial, Although productivity could vary with stand characteristics and worker, this proof of concept trial demonstrates some of the potential uses that this new saw configuration offers and sets the basis for an eventual larger scale deployment of this treatment.

Soucy, Université de Moncton, 165 boulevard Hébert, Edmundston, N.-B. Canada, E3V 2S8, (506) 737-5248 https://orcid.org/0000-0003-0531-5549 E-mail: michel.soucy@umoncton.ca
Béland, Université de Moncton, 165 boulevard Hébert, Edmundston, N.-B. Canada, E3V 2S8, (506) 737-5248 https://orcid.org/0000-0001-8591-671X E-mail: martin.beland@umoncton.ca

article id 541, category Research article

Azim U. Mallik, F. Wayne Bell, Yanli Gong. (2002). Effectiveness of delayed brush cutting and herbicide treatments for vegetation control in a seven-year-old jack pine plantation in northwestern Ontario, Canada. Silva Fennica vol. 36 no. 2 article id 541. https://doi.org/10.14214/sf.541

Keywords: species richness; Pinus banksiana; species diversity; conifer release treatments; glyphosate; brushsaw; competition index

Abstract | View details | Full text in PDF | Author Info

Efficacy of three conifer release treatments, i) single application of glyphosate (Vision™) herbicide, ii) multiple application of glyphosate herbicide, and iii) motor-manual brush cutting for controlling competing plants, particularly trembling aspen (Populus tremuloides), pin cherry (Prunus pensylvanica), green alder (Alnus viridis spp. crispa), and beaked hazel (Corylus cornuta spp. cornuta), was studied in a seven-year-old jack pine (Pinus banksiana) plantation in northwestern Ontario, Canada. The single and multiple glyphosate applications were equally effective in controlling trembling aspen and pin cherry, causing over 90% stem mortality. The brushsaw treatment caused an initial decrease followed by an increase in stem density of these two species. A high degree of stem thinning by natural mortality in the untreated control plots was observed in trembling aspen (23–46%) and pin cherry (41–69%) over four years. As with trembling aspen and pin cherry, stem density of green alder and beaked hazel initially decreased and then increased following the brushsaw treatment, mainly due to resprouting. Stem mortality in green alder and beaked hazel was 45% and 97%, respectively, two years after the operational glyphosate treatment. Competition index (CI) was low (mean CI = 52, ranging from 18 to 115) in all the plots including the untreated control. There was a significant increase in basal diameter of jack pine in the brushsaw and herbicide-treated plots compared to the control three years after the treatments. Jack pine seedlings in the brushsaw and glyphosate treated plots were taller compared to that of control but differences were not significant. Lower species richness and diversity were recorded in the herbicide-treated plots compared to the brushsaw and control plots in the third growing season following treatment.

Mallik, Department of Biology, Lakehead University, Thunder Bay, Ontario, Canada P7B 5E1 E-mail: azim.mallik@lakeheadu.ca
Bell, Ontario Forest Research Institute, Ontario Ministry of Natural Resources, Sault Ste. Marie, Ontario, Canada P6A 2E5 E-mail: fwb@nn.ca
Gong, Department of Biology, Lakehead University, Thunder Bay, Ontario, Canada P7B 5E1 E-mail: yg@nn.ca

Click this link to register to Silva Fennica.

If you are a registered user, log in to save your selected articles for later access.

Contents alert

Your selected articles

Follow @SilvaFennica