A scholar is investigating the impact of an invasive insect and the chemicals utilized to combat it on the wildlife inhabiting ancient hemlock forests. The hemlock woolly adelgid (HWA) has been causing significant damage to forests in southwestern Nova Scotia for nearly ten years. To control its spread, various entities, including Parks Canada, the province, local groups, and private landowners, have been employing insecticides like imidacloprid and dinotefuran. However, Mathilde Christjansen, a master’s student at Mount Allison University in Sackville, N.B., highlighted the lack of knowledge regarding the effects of woolly adelgid and the insecticides on other species.
Christjansen emphasized that imidacloprid, designed to impact insect nervous systems, may also affect other animals’ nervous systems. The researcher and her team are focusing on the eastern red-backed salamander as a bioindicator species to gain insights into the overall forest ecosystem. By studying these salamanders, which are sensitive to environmental conditions and pollutants, they aim to understand the broader implications of the current situation in hemlock forests.
In their study, scientists placed coverboards in forests last year to serve as salamander habitats. They monitored these coverboards regularly to count the salamanders living beneath them, conducting measurements and tagging them as part of the process. Additionally, behavioral tests were conducted on the salamanders, such as observing their reactions to predation stimuli and assessing their agility.
Julia Riley, an associate professor at Mount Allison University and a Canada Research Chair in integrative wildlife ecology, noted that salamanders are crucial indicators of forest health due to their responsiveness to environmental changes and their significant presence in forest ecosystems.
The research project, overseen by Christjansen and her team, also explores the impact of dying hemlock trees on salamanders. Chris Edge, a scientist with the Canadian Forest Service and a project supervisor, explained that the demise of hemlock trees disrupts the unique habitat conditions that are essential for various forest species, including salamanders.
The study, conducted in collaboration with multiple institutions, forms part of a broader investigation into forest health in Eastern Canada. Christjansen plans to continue her research until the following year, analyzing the data and footage collected during the summer fieldwork.
The study’s findings are expected to shed light on the intricate relationships between invasive species, insecticides, and forest ecosystems, providing valuable insights for conservation efforts in hemlock forests.