 |
Boreal mixedwood forests are rich in diversity, with a mix of tree and plant species. However, these complex forests are also challenging to manage.
 |
| OFRI Research Technician Lindsey Freeman measures how well young aspen are growing and whether they have stem or crown deformities for an aspen quality study in northeastern Ontario. Young aspen forests often have many uniform stems growing closely together from a single root system. |
For example, it can be difficult to control aspen enough to allow high-value conifers to get a good start. The traditional approach—clearcut harvest followed by planting conifers and spraying—does a good job of reducing the density of young aspen suckers but weakens their growth and lowers their quality.
According to OFRI research scientist Rongzhou Man, his recent studies in jack pine-aspen and spruce-aspen mixedwoods in northeastern Ontario show that applying a herbicide before harvest is an effective solution. This approach reduces the density of aspen regeneration, but surviving aspen are expected to be of marketable quality.
Although Man’s results are from young stands, he contends that preharvest spray offers an alternative approach to mixedwood management that shows promise both silviculturally and ecologically.
For more information about this research, contact Rongzhou Man. E-mail OFRI to request copies of these publications:
- Effects of pre- and post-harvest spray with glyphosate and partial cutting on growth and quality of aspen regeneration in a boreal mixedwood forest
- Early effects of pre- and post-harvest herbicide application and partial cutting in regenerating aspen–jack pine mixtures in northeastern Ontario
For information about related research and publications, visit Man's profile on OFRI's People page.
Did you know...? Facts about trembling aspen
 |
| Trembling aspen grow in groups of genetically identical trees that stem from a single root system. Each group is known as a clone, and some have been around for 80,000 years! New research is helping forest managers ensure that regenerating aspen stems are of high quality. Aspen is useful for many products, including sauna seats, as its splinter-free wood provides a safe base. Photo by MNR's Stan Vasiliauskas. |
- Aspen has the widest range of any tree species in North America.
- They are usually easy to pick out in the boreal forest because:
- They tend to grow in groups known as clones, with trees from a single clone similar in appearance.
- When the wind blows, their leaves tremble like thousands of waving hands.
- In the fall, the leaves of all the trees in each clone turn a beautiful golden yellow at about the same time, creating a spectacular display of colour that contrasts beautifully with the dark green of conifers.
- Aspen trees are the James Dean of the boreal forest: They live for speed (grow relatively fast) and die young.
- The hundreds or thousands of trees that make up an aspen clone can stem from a single root network that can be thousands of years old. The famous Pando aspen clone in Utah has been producing aspen trees for 80,000 years!
- If you cut all the aspen trees in a forest, they will quickly resprout from the clonal root system. This ability to sucker makes aspen easy to regenerate but difficult to control; foresters viewed it as a weed for many decades.
- However, that began to change in the late 1970s, when oriented strandboard was invented. This popular plywood alternative is made of thin strips of aspen or similar wood that is arranged in layers and bonded with waterproof adhesives.
- Since aspen loves light, it tends to take over after a forest burns or is harvested. That’s why OFRI researchers have been working hard to determine how to change harvesting practices in the boreal forest ensure the right mix of trees species grows back.
- Aspen wood is not as flammable as that of many other tree species, making it useful for making matches.
- Aspen wood doesn’t splinter, making it a comfortable choice for sauna seats and backrests.
- Aspen is also used to make chopsticks, with one company in Georgia sending millions of them to China every year!
- Shredded aspen, known as wood wool, is used as packing material and stuffing. It’s also useful for animal bedding because unlike other some others species (such as pine), it does not contain phenols that can make animals sick.
- Aspen trees contain salicylates, chemicals related to aspirin, so First Nations people have used it to treat many ailments, from burns to swollen joints.
- Young aspen provide food (bark, buds, twigs) for many forest animals, such as moose, black bear, deer, beaver, porcupine, elk, ruffed grouse, and rodents.
Related information
