effects of alternative conifer release treatments on a soil seed bank in a boreal spruce plantation
abstract
evaluates the effects of 5 alternative conifer release treatments : cutting with brushsaws and a mechanical cleaning machine, applying herbicides (release triclopyr and vision glyphosate) by helicopter, and, untreated control on environmental components in a young spruce plantation. documents the effects of clearcutting. study site: fallingsnow ecosystem project near thunder bay, ontario. this soil seed bank study was carried out as part of the fallingsnow ecosystem
project, located near thunder bay, ontario. the project is an operational scale,
integrated, multi-disciplinary study that was established in 1993. it evaluates the effects
o f 5 alternative conifer release treatments (cutting with brushsaws and a mechanical
cleaning machine; applying herbicides (release [a.e. triclopyr] and vision ® [a.e.
glyphosate]) by helicopter and untreated control) on environmental components in a
young spruce plantation. in addition, the project documents the effects of clear cutting
on the environmental components by comparing post-harvest changes with changes in
adjacent unharvested forests. this study compares the treatment effects on the soil seed
bank.
samples o f the soil seed bank were collected in 1996 and green house grown
during the winter of 1997. the resulting germinants were identified and quantified by
species and treatment. thirty-four species were identified, two of which were tree
species: white birch (betula papyrifera marsh.) and trembling aspen (populus
tremuloides michx ). species richness, abundance and evenness indices clearly show
that there was a treatment effect on the seed bank. analysis further shows a significant
difference in richness (number of species) between treatments. species abundance
curves were completed and are typical for the northern hemisphere. orthogonal
comparisons also show significant differences in species abundance between the forest
and the cutover, the brushsaw treatment compared to the silvana selective treatment,
and the treated cutover (brushsaw, silvana selective, release®, vision® in comparison to
the untreated cutover and the forest combined. these seed bank germination differences
resulting from applied silvicultural treatments could play a role in future forest
management practices that strive to emulate forest fire effects.
collections
- retrospective theses [1604]