Canadian Aspen Forests and Parklands This ecoregion is characterized by a vegetation of quaking aspen with balsam poplar. It is the most extensive boreal-grassland transition in the world and is the northernmost breeding area for many warbler species and hosts extenesive waterfowl breeding habitat. As mapped in 2001 and amended in 2017, there are four … More Canadian Aspen Forests and Parklands, Part 1