Regenerating the Boreal Forest

Jun 11, 2020

Nestled in an area managed by Blue Ridge woods team in Alberta, there’s a science experiment that’s been taking root for almost two decades.

The Canadian Forest Service and the University of Alberta have been running the Judy Creek Mixedwood Experiment since 2002 to find the optimal combination of spruce competition control and aspen thinning to grow both these species. Planting trees takes more than simply sticking seedlings in the ground. The two-decade study is exploring the best ways to reforest a boreal forest, comparing the effects of manual tending, brushing, and, in some cases, herbicide. It’s a major study that parallels one also taking place in Ontario.

West Fraser provided the site for the experiment, as well as direct funding contributions. Our foresters are referring to the results in their own silviculture planning.

“This study gives us a much better understanding on how different types of competition affect spruce growth and the range of treatments that can be used,” says Shane Sadoway, the Woodlands Planning Superintendent at Blue Ridge Lumber.

This past fall, he and other members of the West Fraser woodlands team assisted with a tour of the area during the annual Forest Growth Organization of Western Canada meeting. The group looked at different planting sites that were treated differently, including various kinds of vegetation and hardwood controls, herbicide use, and other silviculture practices.

The goal of the research is to evaluate different approaches to reforesting spruce and spruce mixed wood forests, and if there are alternatives to herbicide use that produce similar results.

The controlled areas that were left untreated had the slowest growth of spruce, and the poorest survival of the planted spruce. The spruce grew the best where there was complete aspen and other vegetation control. But the spruce also grew well where some hardwood competition was still allowed. One of the alternative treatments included testing the growth of spruce where the aspen competition was thinned to (but not completely removed). The spruce grew a bit less, but it was protected from other, grassy competitors.

 “The different sites definitely stand out in the obvious difference in spruce growth. It’s pretty visual and abrupt, between the areas with no competition and those with heavy competition,” adds Sadoway. “
Often there are only small statistical differences in a research project, but because this study is over a long period of time, you can definitely see the difference.”

The results from this project are already being applied to reforestation efforts across Alberta. It shows that a range of treatments can be used to lead to a stronger, healthier reforested boreal forest, and provides information our foresters use to more successfully grow spruce to compete in a mixed forest.