%0 Research article
%T Effectiveness of delayed brush cutting and herbicide treatments for vegetation control in a seven-year-old jack pine plantation in northwestern Ontario, Canada
%A Mallik, Azim U.
%A Bell, F. Wayne
%A Gong, Yanli
%D 2002
%J Silva Fennica
%V 36
%N 2
%R doi:10.14214/sf.541
%U https://silvafennica.fi/article/541
%X 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.