There is an alien invader on Canada's most southern island, and it has conservationists sounding the alarm.
Conservation staff at Point Pelee National Park first discovered the alien during a survey of Middle Island.
Tammy Dobbie, a member of the staff, was looking for the Wild Hyacinth, a rare flower whose Canadian range is limited to just a few islands in Lake Erie. What she found would have "rippling effects throughout the scientific community," said Parks Canada.
On the west side of the island, Dobbie found a small cluster of plants she did not recognize. She was puzzled. She considered herself familiar with the entire inventory of plant species growing there.
She searched for an answer back at the office but got nowhere until she received a call from botanist Jack Kamstra. He too had visited Middle Island and was able to identify the plant as a Japanese Chaff-flower.
How did it get to an 18.5-hectare island in the middle of Lake Erie?
(Photo of the Japanese Chaff-flower courtesy of Parks Canada)
The Japanese Chaff-flower, known by its scientific name as Achyranthes japonica, is native to East Asia but first appeared in North America in 1981.
Within 15 years of its discovery in Kentucky, the invasive flora had spread over 500 km along the Ohio River Valley from West Virginia to Illinois, covering riverbanks and choking out native plants.
Kamstra and Dobbie can only speculate the seeds were dispersed to Middle Island by migratory birds, and there is some evidence to suggest the culprits are double-crested cormorants.
Not only is the Japanese Chaff-flower invasive, it is hardy. It thrives in a variety of soil conditions in six different ecological zones, so it has the potential to threaten native species elsewhere in Canada.
The Canadian Food Inspection Agency is conducting a full risk assessment so it can determine its threat and develop a strategy to contain it.
Control and eradication efforts are already underway at Point Pelee National Park. Within a year of Dobbie's discovery, the plant has reproduced and increased in number to more than ten thousand plants on Middle Island. Park staff concentrated on pulling the plants out by hand this year and plan to promote the persistence of native plant communities in the park.
Meanwhile, the Wild Hyacinth is a federally-listed species at risk and endangered species that only exist on the Lake Erie Islands. Conservationists fear the Japanese Chaff-flower will only further threaten the flower.
