Alder buckthorn, an invasive species to eliminate

ISubmitted by the Association forestière du sud du Québec (AFSQ)

nterested in working to help the environment and protect our forests? We invite you to join the fight against the Alder Buckthorn. Originally introduced to Quebec as an ornamental plant, Alder Buckthorn has become an invasive plant with a devastating effect on our forests. It has adapted so well to Quebec that today it can grow in all types of environment and it prevents natural vegetation, plants and trees, from growing in several places. It is found in large quantities in the Eastern Townships and, to a lesser extent, in the surrounding regions of Estrie, and is gradually spreading.

Why is it such a problem?

Buckthorn is a much better competitor than native plants at all levels. It grows very quickly, up to one metre in height per year. Its leaves are present on the branches longer than any other plant, which promotes its growth and slows that of others. It can reproduce by its very abundant fruits, but also by its roots. Its seeds can survive in the soil for several years. Cutting it promotes the growth of new stems. Finally, it is able to live in the most diverse environments. completely eliminated buckthorn.

An impermeable geotextile can be used to help limit new stems, but run-of-the mill landscaping fabric will not be robust enough to slow the growth of buckthorn.

In forest environments :

In the forest, uprooting is not a feasible strategy and few other options are available. We can try to live with it, but a high density of buckthorn can cause little or no regeneration of the trees, a loss of diversity of native plants and shrubs and a loss of habitat for wildlife. However, if the density is not too high, it is possible. We can then continue our forestry activities. The important thing is not to favor buckthorn by cutting it or loosening it too much.

If you want to reduce the amount of buckthorn in the forest, you have to kill it. The only technique with proven efficacy in scientific studies is the use of herbicides, such as glyphosate. Fall is a good time to apply this herbicide, as native plants are dormant while buckthorn is still active. Note, however, that the treatment is not absolutely effective. It will take several applications to allow trees to regenerate and despite this, buckthorn may remain present.

Before using herbicides in the forest or carrying out forestry work in the presence of buckthorn, we advise you to always contact a forest adviser.

It is very important to limit the pressure of invasive species on our forests. This is why buckthorn must be removed wherever it is possible to do so, such as residential areas. We need everyone’s collaboration for this action. Let’s go outside alone, as a family, or at a distance with our neighbors and get the buckthorn! While it is important to maintain social distancing measures, this time of confinement represents a great opportunity to help our environement.

More information is available in French on the AFSQ website at www.afsq.org/information-foret/ nos-arbres/ennemis-des-arbres/nerprun-bourdaine/ or in English at https://treecanada.ca/resources/trees-of-canada/glossy-buckthorn-rhamnus-frangula/