Date of Award
Open Access Master's Thesis
Master of Science in Forest Ecology and Management (MS)
Administrative Home Department
College of Forest Resources and Environmental Science
Tara L. Bal
Committee Member 1
Valoree S. Gagnon
Committee Member 2
Rebecca G. Ong
To delve into further understanding of the relationships between introduced earthworms, forest ecosystems, and the human systems they impact, two approaches were taken. In the first approach, we seek to explore ways we can shift the discourse within and regarding the field of invasion ecology by re-framing how we approach discussion, management, and education regarding introduced species. Language issues surrounding introduced species through the example of earthworms in North America are described and potential solutions are provided, including a repositioned perspective that may facilitate better relationships with the natural world. The goal is to shift the language to be more conscientious and respectful while also promoting inclusivity and diversity of perspectives that will lead to advancements in the field. A theme running through this narrative is approaching the field of invasion ecology through two-eyed seeing, which is an illustrative way to describe equitable utilization of the unique strengths of Western and Traditional Ecological Knowledge systems to create inclusive, holistic, integrative, multi-perspective and multi-disciplinary solutions to ecological issues.
The second approach described here is a pilot study looking into the possible changes that earthworm activity incurs in sugar maple sap. The introduction of earthworms has led to significant ecological impacts in northern hardwood forests, especially on sugar maples, as declines in sugar maple health have been correlated with introduced earthworm activity. Sugar maple sap was collected during the spring of 2023, along with soil sampling, and earthworm population data to explore potential impacts of introduced earthworms on overall sap sugar content using linear regression models. The results highlight a complex, dynamic network of impacts that begin with earthworm activity that induce changes within the soil that subsequently cause shifts in soil biogeochemistry, impacting the overall health of the sugar maples, and leading to the long-term impairment of impacted sugar maples to produce quality sap. Most notably, the presence of anecic earthworms at sites with long-established earthworm communities is negatively correlated with overall sugar content in sap (R² = 0.52, p = 0.038). These findings have important relevance especially to the maple syrup and maple sugar industries.
Overall, this thesis highlights the importance of understanding the relationships introduced organisms are building in their new environments. By taking the time to learn from these organisms, we can create more effective management practices and policies.
Lane-Clark, Shelby Nicole, "IMPACTS OF INTRODUCED EARTHWORMS ON SUGAR MAPLE SAP CHEMISTRY AND THE DISCOURSE OF INVASION ECOLOGY", Open Access Master's Thesis, Michigan Technological University, 2023.