Grant: Discovery Grants Program - Individual

Communities and ecosystems are increasingly being impacted by global change but much of our understanding of these impacts in terrestrial ecosystems is based on aboveground organisms. In contrast, although soils are highly diverse and support many key ecosystem functions such as carbon cycling, we have a limited understanding of global change impacts belowground and in particular how impacts vary across spatial and temporal scales. My research focuses on addressing this gap in our knowledge using a combination of field observations, experiments, modelling, and data synthesis. I use earthworms as a model group in my research because they act as ecosystem engineers with the potential for large impacts on other organisms and because many species have invaded new regions. My students and I will investigate the following key questions: 1) How are soil invertebrates distributed across multiple spatial scales and how will this be altered by global change? We will examine effects of global change on earthworm biodiversity over time, and on distributions of non-native earthworm species. We will also investigate the relative importance of climate, habitat, and human activity in determining northern distributions of non-native earthworms and use this information to model potential future distributions. 2) How does global change directly and indirectly impact species interactions and community composition in the soil? We will test how changes in plant communities (e.g., shrub expansion) due to climate warming affect soil invertebrate communities and litter decomposition in northern ecosystems. 3) How do changes in species distributions and communities impact ecosystem functioning? We will examine how shifts in soil macrofauna communities occurring as a result of global change affect ecosystem functions such as microbial respiration. Five undergraduate students, three graduate students, and one postdoctoral fellow will be trained during the course of this grant. In addition, a citizen science project will provide the public with the opportunity to directly participate in this research. Publications from this research will provide key insights into how global change affects soil communities and ecosystem functioning, as well as how biodiversity and invasion theories apply to belowground systems.