ACTUALLY,
The Spraying of Aspen IS happening in Edson, Alberta. It started a few years back as a measure to increase the speed that conifers can get to before having to compete with the VERY FAST Growing Poplar / Aspen. Manual thinning works the same, but takes big labour costs to get guys in with brush saws to do it.
Poplar will come back naturally after being clear cut, as thick as 75,000 seedlings an acre! They out compete the pine, spruce, etc. It takes many years before the natural forest succession sees the confirs finally dominate (30 + years!!!).
However, the value of board feet vs Pulp (What Aspen is used for by APAC and Diashawa) drives the helicopter spraying of Roundup on the cut blocks.
Drewski