March 13, 2013
Invasive Russian Plant Imperils Canada’s Native Ecosystems
April Flowers for redOrbit.com - Your Universe Online
The so-called dog-strangling vine (Vincetoxicum rossicum) is an exotic plant originating from the Ukraine and southeastern Russia, and it is becoming increasingly invasive in southern Ontario, Canada. It grows successfully in a variety of environments, including both disturbed and undisturbed areas, in open fields, forest edges and understories, parks, road edges and railway embankments. The aggressively invasive plant forms large, dense strands that climb over other indigenous plants, effectively competing for light.A new study from the Invasive Species Research Institute at Algoma University explores the effects of the V. rossicum invasion. The results of the study were published in the open access, peer-reviewed journal“¯NeoBiota.
The ecological impact of a possible V. rossicum invasion goes beyond simply displacing local plant species as well as endangered populations of local soil organisms and pollinator species. Researchers are also concerned with the dog-strangling vine's potential ability to invade region´s alvar environments. Alvars are "naturally open habitats with either a thin covering of soil or no soil over a base of limestone or dolostone." Alvars are a particularly rare type of habitat that support a number of important of rare plant and animal species.
Another concern is that V. rossicum might also be allelopathic, meaning that its roots release chemicals into the surrounding soil that are toxic to other types of plant life.
Temperature, light and moisture levels are key environmental cues for flowering plants. The reproductive cycle of the dog-strangling vine is particularly affected by temperature, with reproduction taking longer in cooler growing conditions. A significant delay in budding, flowering and the formation of seedpods is produced with a slight reduction in the current growing temperature conditions of the dog-strangling vine, limiting its capacity to spread into northern climates simply because it may not be able to complete its lifecycle.
To test this possibility, Laura Sanderson and Pedro Antunes grew“¯V. rossicum under temperature conditions simulating those found in northern and southern Ontario. They also forced V. rossicumto to compete with“¯Solidago canadensis, a plant that is highly abundant across Ontario.
The authors found that "in spite of a delay in growth under cooler conditions,“¯V. rossicum produced just as many seeds as it did under temperature regimes typical of its current distribution range. In competition with S. canadensis, they found reductions in fitness and total biomass of V. rossicum, however, the total biomass reductions were greater for the competing native species, regardless of climatic temperature regime.”
"Phenotypic plasticity may enable“¯V. rossicum to spread into northern Ontario", conclude the authors. Phenotypic plasticity refers to the ability of an organism to modify its physical characteristics in response to environmental changes.