Individual study: Threshold effects of variable retention harvesting on understory plant communities in the boreal mixedwood forest
Craig A. & Macdonald S.E. (2009) Threshold effects of variable retention harvesting on understory plant communities in the boreal mixedwood forest. Forest Ecology and Management, 258, 2619-2627
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Use clearcutting to increase understory diversity
A replicated, randomized, controlled study in 1998-2006 in boreal mixed wood forest in Alberta Canada (Craig & Macdonald 2009) found that clearcutting and high thinning intensity increased the cover of understory vegetation, particularly of grasses. The average percentage cover of all species under the canopy was 67% in clearcut and high thinning intensity plots (0-10% retention) and 55% in the three low thinning intensities and uncut plots (20-100% retention). The average percentage cover of grasses was 14% in clearcut and high thinning intensity plots and 4% in the three low thinning intensities and uncut plots. Species richness was unaffected by retention level. In winter 1998-1999, six 10 ha compartments within each of three blocks (∼2 km2) were randomly assigned to six harvesting treatments: clearcutting (0% retention), 10% retention, 20% retention, 50% retention, 75% retention and uncut (100% retention). Sampling was conducted in summer 2006 in twenty 1×1 m plots in each of the 18 compartments.