Hamilton, Ontario, has amazing trails, forests, waterfalls and natural landscapes, but they are threatened by invasive species. Many people believe that planting new trees is the best way to grow the urban forest. However, taking care of existing healthy trees is actually one of the best ways to grow the urban forest; this includes managing invasive species.
According to the City of Hamilton’s Urban Forestry Strategy, Hamilton's urban area canopy coverage is currently estimated at approximately 17-20%. To help protect some of the existing trees in Hamilton, Green Venture staff has completed more than a dozen stewardship events at woodland sites in the Spring and Summer of 2024. Thanks to the Invasive Species Action Fund from the Invasive Species Centre, Green Venture received funds to collaborate with Hamilton Conservation Authority to tackle some invasive species at:
Felkers Falls: Friday, Jul 26, 2024
King and Nash : Tuesday, July 30 2024
Windermere Basin Park:Thursday, Aug 1, 2024
Coming up! Eramosa Karst : Tuesday, Aug 27, 2024
The Invasive Species Action Fund (ISAF) is a grant program designed to facilitate on-the-ground management and monitoring of invasive species in Ontario. The program is made possible thanks to the support of Ontario’s Ministry of Natural Resources (MNR).
The Role of the Hamilton Conservation Authority and Green Venture
In the fight against invasive species, the Hamilton Conservation Authority (HCA) and Green Venture play crucial roles. The HCA, responsible for managing many of Hamilton’s natural areas, leads efforts to control invasive species through a combination of manual removal, chemical treatments, and habitat restoration.
Green Venture, Hamilton’s leading environmental non-profit organization, complements the HCA’s work by engaging the community in sustainability initiatives. Green Venture organizes volunteer events, educates the public about the importance of invasive species removal, and worked this summer to restore native habitats in partnership with the HCA and other local groups.
What Are Native, Invasive, and Exotic Species?
- Native plants are those that occur naturally in an area.
- Invasive plants are not local and are spread by global trade, human and animal transport and escape from gardens. They tend to spread quickly and interfere with native plants, which reduces habitat for native wildlife.
- Exotic, non-invasive plants are non-native species that have been introduced from an area out of their natural distribution but do not generally cause environmental harm.
Why Is It Important to Remove Invasive Species?
The removal of invasive species is not just about protecting plants and animals; it’s about preserving the health of entire ecosystems. Invasive species can:
- Reduce Biodiversity: They often outcompete native species for resources, leading to a decline in native plants and animals.
- Disrupt Ecosystem Functions: Invasive species can alter water cycles, soil composition, and other essential ecosystem processes, leading to long-term environmental damage.
- Threaten Native Species: Many native species are adapted to specific conditions that are disrupted by invasive species, putting them at risk of extinction.
- Impact Human Activities: Invasive plants can clog waterways, reduce crop yields, and even increase the risk of wildfires.
By removing invasive species, we help to restore balance to ecosystems, protect native species, and maintain the natural beauty and ecological integrity.
Common Invasive Species at These Sites:
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Garlic Mustard (Alliaria petiolata)
- A biennial herb that can dominate the forest floor, outcompeting native plants by releasing chemicals into the soil that hinder their growth.
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European Buckthorn (Rhamnus cathartica)
- A shrub or small tree that forms dense thickets, shading out native plants and altering soil chemistry.
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Dog-Strangling Vine (Vincetoxicum rossicum)
- A perennial vine that twines around trees and other plants, preventing them from growing properly and displacing native species.
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Cow-Vetch (Vicia cracca)
- Crown vetch has rhizomes up to. 10 feet long which allows the plant to spread rapidly. The vegetative growth habit can rapidly cover and shade out native.
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Japanese Knotweed (Fallopia japonica)
- A highly aggressive plant that spreads rapidly and is difficult to control, leading to the displacement of native vegetation.
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Field Bindweed (Convolvulus arvensis)
- Extremely aggressive perennial with an extensive root system. This plant will latch onto other plants and entangle them in dense mats of stems with pinkish-white flowers that look similar to morning glories.
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Wild Parsnip (Pastinaca sativa)
- This plant can spread quickly in open woodland areas, and its sap can cause severe skin irritation.
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Common Burdock (Arctium minus)
- A biennial plant that forms large rosettes and can outcompete native ground flora, particularly in disturbed woodland edges.
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Perennial Sow Thistle (Sonchus arvensis)
- A perennial plant that spreads by seeds and rhizomes. Perennial sow-thistle is extremely competitive and will outcompete surrounding vegetation. Can be identified by the sap (latex) that exudes from the leaf when broken.
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MultiFlora Rose (Rosa Multiflora)
- A perennial shrub that aggressively grows on and climbs over surrounding plants, outcompeting native plants and shrubs. Dense thickets of this thorny shrub can emerge within a few years. Easily identified by its thorny stems similar to ornamental roses.
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Queen Annes Lace (Daucus carota)
- Also known as wild carrot, this biennial is commonly found along roadsides and in disturbed areas. It also poses a threat to newly restored/recovering areas due to its quick growth rate which helps it easily outcompete surrounding vegetation.
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Canada Thistle (Cirsium arvense)
- Plants rapidly spread through rhizomatous roots causing dense infestations. This plant can be found in most disturbed areas and will quickly out compete native species. This plant can easily be identified by its sharp and prolific spikes found along the leaves.
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Broadleaf Sweet Pea (Lathyrus latifolius)
- A perennial vining plant that spreads through seeds and rhizomes. Although not classified as a priority invasive, when left uncontrolled it becomes quite prolific engulfing any plant in its path.
How Can Volunteers Help?
Volunteers are the backbone of invasive species removal efforts. Whether you have experience in environmental work or are simply passionate about protecting Hamilton’s natural spaces, there are many ways you can get involved:
- Join a Volunteer Event: Both the HCA and Green Venture regularly organize invasive species removal events. These events often involve manual removal of invasive plants, planting native species, and monitoring restoration progress.
- Learn and Educate: Understanding which species are invasive and how to manage them is crucial. Green Venture offers resources and workshops to help you learn more about invasive species and how you can make a difference.
Spread the Word: Raising awareness about the importance of invasive species removal is essential. Share your experiences, educate others, and encourage more people to get involved in conservation efforts.
Conclusion
The fight against invasive species in Hamilton is an ongoing effort that requires the collective action of conservation authorities, non-profits, and dedicated volunteers. By removing invasive species and restoring native habitats, we can ensure that green spaces in Hamilton continue to thrive and provide vital ecological services to our community.
Whether you’re an experienced conservationist or someone looking to make a positive impact, your help is needed. Together, we can protect Hamilton’s natural heritage for future generations.
