On September 25th TLC Covenant Manager Torrey Archer and CRD Volunteer Coordinator Colleen Long led volunteers in tackling invasive species at the Atkins Covenant located near Thetis Lake.
Approximately 10 people worked on the site for about 4 hours, clearing away the invasive species known as St. John’s Wort (Hypericum calycinum). Unfortunately, this is not the medicinal type of St. John’s Wort (Hypericum perforatum), otherwise the work party could have turned into a “make your own medicine” party afterwards!
Nonetheless, the volunteers and staff had a very satisfying time ripping out the unwanted intruder. St. John’s Wort is a tricky plant to remove as it is much like English ivy and will re-sprout from any leftover rootlets. This often means literally sifting the soil to remove all rhizomes to reduce the chance of re-invasion. As the affected area is fairly large, our strategy is to remove the above-ground biomass and then cover it with a layer of unwaxed cardboard and other mulch to essentially smother the invasive species out. This technique is also part of “lasagna gardening”, a strategy aimed at reducing or eliminating the need to till soil by adding different components in layers the same way we add different ingredients to build a lasagna. This method is attractive as disturbing the soil often breaks the mycelial network found underground, which acts as a highway of nutrients and information. Research has shown that the greater the mycelial biomass, the greater the overall ecosystem health (http://link.springer.com/article/10.1007/s00374-002-0546-5 ).
After laying down the protective cardboard, we will then add a layer of top-soil and plant native species to avoid the possibility of other invasive species moving in on the freshly open space. This restoration approach will be guided by Kristen and James Miskelly from Saanich Native Plants, who are also involved with the Haliburton Biodiversity Project aimed at restoring the land for organic agricultural purposes. Haliburton Farm is no stranger to invasive species, and the persistent reed canary grass is present in one of the wetter areas of the site where volunteers have used the same approach we will take at the Atkins Covenant to smother out our undesirable guests!
The volunteers enjoyed the beautiful weather, the beautiful scenery, and the beautiful company of one another while getting a good workout. Garter snakes, orb-weaver spiders and many birds also joined them while they worked. At the end of the day the crew had made a sizable dent in the St. John’s Wort patch but they will have to return to finish the removal. If you’re interested in joining for the next removal work party, or the subsequent planting work party, please contact Torrey at covenants@conservancy.bc.ca to find out when, where and how you can be a part of ensuring the ecological health of the Atkins Covenant continues.
Atkins Road Covenant before invasive removal.
Volunteers working hard to removal the St. John’s Wort.
The Covenant after the volunteers completed the invasive species removal.