Migratory instabilities have been observed across North America due to climate change. The planet is heating up and species are moving further north to survive. This expansion of the territory is not without effect on the rest of the ecosystem.
Alyson Roussel – Local Journalism Initiative – APF – West
Changes in behavior
Heat waves, changing precipitation, freezing and thawing cause some species to move in search of food and temperatures more suitable for their metabolism.
In response to climate change, several phenomena are occurring, says the environmental science professor at theUniversity of Alberta, Glynnis Hood. Some species extend their territory and move further north, while some others, co-dependent, are content with a reduced territory. As the professor explains, “in ecology, everything is connected”.
Therefore, while moving in colder terrain may be relatively easy for animals, it is not necessarily easy for plants, says another expert, Quinn Barber, fire science analyst at the Canadian Forest Service. According to him, if the situation is worrying for the fauna, it is even more so for the flora.
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Flora, the main factor
“While a moose can easily move 5 km each year, the same cannot be said of a plant,” says Barber.
Animals move north, he explains, because the plants they feed on are also affected by the changing temperatures. In the Canadian plains, it is easier to see an impact on flora. “In the Rockies, if a plant is exposed to too much heat, it can go up in elevation,” says Barber. In the plains, these fragile plants will disappear without human intervention ”.
The effects of these displacements
In Alberta, we have noticed in recent years that the migratory trends of birds have shifted. “They often come too early when there is still frost or at the right time, but the season for some invertebrates they feed on is already over,” says Glynnis Hood.
For these bird species, a different location on a map does not always have a negative effect. In 2016, a study conducted by Finnish researchers from Finnish Museum of Natural History, published in the scientific journal Global Change Biology, explained that between 1970 and 1989, then 2000 and 2012, 128 species of birds had changed their trajectories towards the northeast of Finland. They had thus increased the density of their flights 37 km further north.
Beavers synonyms of danger
On a larger scale, beaver populations in North America and the Arctic are expanding their ranges and they are doing so quickly, adds Glynnis Hood. Beavers are radically changing habitats by creating dams and bodies of water. Arctic streams then become wetlands. According to her, they also affect permafrost and shrub growth.
A complex dilemma
Researchers like Glynnis Hood or analysts like Quinn Barber cannot accurately determine the long-term effects of these migrations on flora and fauna. For example, beavers can have a negative as well as a positive impact with the creation of new habitats. According to Hood, researchers are just beginning to predict the effects of beaver actions on permafrost, but they are unaware of their effects on biodiversity.
“The fact that beavers can increase biodiversity in the North doesn’t mean it’s necessarily bad,” she says.
Research is already being undertaken in Western Canada on the adaptation of certain plant areas, in particular trees and shrubs, to different climates. In British Columbia, for example, the experience Assisted Migration Adaptation Trial is in progress. The province plants approximately 240 million seeds each year to support the movement of these species north. Ms. Hood reminds us that research is essential to understanding migration phenomena. “Without knowing what we are facing, she says, it is difficult to say what will happen.”