As a kid, I remember riding my bicycle along the Galloping Goose trail in Victoria and seeing Scotch broom plants densely packed along the sides of the trail. Their brilliant yellow flowers caught my eye as their aromatic scent filled the hot summer air. To me their blooming marked the beginning of summer, and the end of another school year. Naturally, their presence was a reassuring sight as I went on my merry way. Even though they were all around me, I was ignorant to the existence of invasive species. Over time, I began to understand how humans have a massive impact on the natural spaces around us and that invasive species are just one example of our impact. Nowadays, when I see those yellow flowers, I have the urge to grab my pruners!
Before joining the Mayne Island Conservancy as an Ecosystems Technician, I spent the previous five summers working as a kayak tour guide, based in Telegraph Cove. People came from all over the world to observe orca whales in the wild and to kayak along the unique coastline. During my time on the water, I learned how imbalances in ecosystems can lead to negative environmental effects. For example, the near-extinction of the sea otter on the B.C. coast led to an overabundance of their main prey – sea urchins. Urchins feed on bull-kelp, so an increase in urchins leads to a decrease in kelp. Eventually, this leads to the formation of “urchin barrens” – areas completely devoid of kelp. This loss of kelp leads to the loss of important fish and invertebrate habitat. The kelp forests serve as a nursery for young fish, like salmon, which orcas depend on. Therefore, when one piece of an interconnected ecosystem is removed, the effects can be far reaching. Similar effects can occur in terrestrial ecosystems.
During my time on Mayne Island, I’ve had the chance to learn more about invasive species and their impact the island’s ecosystem. Whether by accident or by design, a variety of non-native species have been introduced here. Scotch broom is a notable example of this, having been introduced to Vancouver Island by settlers in the 1850’s. Originally, broom was valued as an ornamental flower that reminded settlers of their Scottish homeland. Over time, it ran rampant across the region. Unfortunately, this type of story is all too common in North America.
The Invasive Story
If the conditions are right, introduced species like Scotch broom can out-compete native species, leading to a reduction in biodiversity and ecosystem services that native species provide. If the ecological and economic effects become severe, a species can transition from simply being considered “non-native” to “invasive.” Although the term may seem vague, anyone who has seen a blackberry bush completely overtake a roadside will understand the meaning of “invasive plant.”
One way to help rehabilitate areas affected by invasive species is to assess the state of the ecosystem, make a restoration plan, and follow the plan to completion. Eventually, natural processes will take over the restoration work for us, but a helping hand is often needed. The Mayne Island Conservancy has written habitat restoration plans for all of the public parks on Mayne Island, which they deliver in collaboration with the different park managers. For example, each year Scotch broom is removed from Henderson Park in places where it was preventing forest regeneration following logging in 2005. At Mt. Parke, Bennett Bay, and St. John Point, shade tolerant species like daphne and English holly are removed throughout the entire park to prevent their establishment. At Bennett Bay and St. John Point, slow but steady progress is being made to return fields of introduced grass to diverse native vegetation.
The Action of Restoration
Restoration projects play a key role in improving the health of Mayne’s ecosystems. So far, I’ve been lucky enough to organize habitat restoration work parties in various parks, including St. John Point Regional Park, Henderson Community Park, and Bennett Bay (part of Gulf Islands National Park). These events have been a wonderful way for me to connect with Mayne Islanders, and to familiarize myself with the ongoing restoration projects on the island. I’ve seen how deer fencing plays a key role, by giving young plants a safe place to develop away from the grazing pressure of fallow and black-tail deer. It’s amazing that many areas now forested with young trees were once dry clear-cuts, full of species like Scotch broom and Himalayan blackberry. Thanks to the efforts of hardworking volunteers and staff, these beautiful natural spaces are on the road to recovery.
One project I find particularly exciting is the Conservancy’s wetland restoration taking place at Hedgerow Farm. A weir was installed, re-flooding a portion of hayfield that was formerly a wetland. The changes at the site occurred rapidly following the installation of the weir and deer fencing. Wetland plants such as sedges and rushes have expanded to fill areas once dominated by exotic grasses. Bird species such as red-winged black birds, barn swallows, and violet-green swallows are feasting on the dragonflies and other insects thriving in the shallow waters, where pacific chorus frog have also greatly increased. Great blue herons now hunt in the shallows on spindly legs, and the distinctive breeding call of the Wilson’s snipe can now be heard. The vast majority of wetlands and wet forests on Mayne were cleared and drained for agriculture in the late 1800’s and early 1900’s, making a restored ecosystem like the one at Hedgerow even more precious.
Putting Theory into Practice
While studying at Camosun College, I had the opportunity to work on a restoration project of my own. Two classmates and I began the work of restoring a small park in Langford called Katie’s Pond. We did this work as part of the final project for our Environmental Technology diploma. Working on my own project on weekends while simultaneously working for the Conservancy during the week kept me busy, and it provided me with valuable field experience. Both positions complemented each other and allowed me to apply my learning. The college project culminated in a restoration work party, which was only possible with the help of volunteers from our class and the community. We removed Scotch broom and Himalayan blackberry, and our plan for the fall is to plant native trees and shrubs, all purchased from the Conservancy’s native plant nursery!
Consider joining our mailing list and coming out to one of our restoration events, where muffins and tea will be provided! If you’d like to find ways to conserve Mayne’s natural areas and wetlands, consider booking a visit from our biologist, Rob Underhill, free of charge. He will explore your property with you and suggest restoration options that will help improve the ecosystems on Mayne Island.