Invasive Species Pull
In June 2022, Human Nature Projects (HNP) Ontario partnered with Toronto Nature Stewards (TNS) to pull out two invasive plants, dog-strangling vines and garlic mustards from the Middle Mill Area. By volunteering at this event, our team of 60+ volunteers helped to save numerous habitats, the surrounding wildlife, and our native plants!
What Are Invasive Species?
Invasive species are non-native organisms that are introduced to new environments. Because of this, they have no natural predators to limit their spread. As a result, these species cause harm to the environment, the economy as well as human, animal, and plant health. Invasive species tend to threaten native plants (that are important to our ecosystems) by competiting with their resources and territories and therefore, lead to biodiversity loss. Furthermore, invasive species impact our daily lives by threatening our health, culture and connection with the environment. To elaborate, they impact human health by exposing us to new diseases and by being vessels for other diseases.
Garlic mustards were brought as a source of food and medicine to Ontario in the 1800s, but quickly spread out of control of cultivators. They are considered invasive species because they release chemicals such as cyanide that alter the chemistry of the surrounging soil which then impacts and hinders the growth of other species. Garlic mustards are known to produce glucosinolates, a class of chemicals toxic to animals and humans. Futhermore, livestock that consumes garlic mustards produces milk that is tainted with a garlic flavour.
HISTORY OF GARLIC MUSTARDS:
- 1800: First introduced to North America from Europe as an edible herb.
- 1879: First record of garlic mustards in Ontario.
- 1891 - 1898: Garlic mustards found in Kingston and Ottawa.
- 1900: Garlic Mustard continued to propagate until it has become an invasive herb today.
Dog-strangling vines are perennial plants (ie: live for more than 2 years) that have vines that can grow up to 2 meters long by wrapping onto or "strangling" nearby trees and plants. They often grow in sunny areas but can also be found under light shade. Introduced as an ornamental plant for the early settlers, dog-strangling vines release allelopathic chemicals that block sunlight for smaller plants. Therefore, dense clusters of these invasive plants create a negative change in the habitat for wildlife. Dog-strangling vines also endanger native insects such as monarch butterflies because these butterflies mistake the dog-strangling vine for milkweed and lay their eggs on it, only for them to starve.
HISTORY OF DOG-STRANGLING VINES:
- THE MID-1800s: First introduced to North America from Eastern Europe.
- 1897: First record of the dog-strangling vine in the United States.
- THE 1900s: Dog-Strangling vines spread to southern Ontario.
- PRESENT: Dog-strangling vine continues to expand its range and spreads to even more southern parts of Quebec.