A researcher is investigating the impact of an invasive insect and the chemicals used to combat it on the wildlife in ancient hemlock forests. 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 such as Parks Canada, the province, local groups, and private landowners have employed insecticides like imidacloprid and dinotefuran.
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 insecticides on other species. She expressed concerns about the potential impact of imidacloprid on various animals beyond insects, citing its presence in the brains of fish and tadpoles.
Rather than conducting individual studies on all species across hemlock forests, Christjansen and her team are focusing on the eastern red-backed salamander as a bioindicator species. These salamanders are sensitive to environmental changes and pollutants, making them ideal for assessing ecosystem health.
The study involves placing coverboards in forests to create salamander habitats. Scientists then monitor these areas to record salamander populations, conduct behavioral tests, and assess their overall well-being. The research aims to determine how salamanders in treated and untreated forests are faring, providing insights into broader ecosystem impacts.
Chris Edge, a scientist with the Canadian Forest Service, emphasized the importance of hemlocks in creating unique habitats for wildlife. The study also considers how dying hemlocks may affect salamanders, whose sensitive skin and moisture requirements make them susceptible to changes in forest conditions.
The project, a collaborative effort involving multiple institutions, including Mount Allison University, the Canadian Forest Service, and others, forms part of a larger study on forest health in Eastern Canada. Christjansen plans to continue her research until next year, analyzing data collected during the summer to further understand the implications of HWA and insecticides on forest ecosystems.