Grant: Discovery Grants Program - Individual

Our lab uses field experiments to examine the role of belowground biotic interactions in controlling the distribution and diversity of plant species along environmental gradients. We have two main model systems: the invasion of native grassland by woody plants, and the invasion of grassland by non-native grasses. One focus is the seasonality of productivity. Data based on leaf phenology suggests that climate warming will have large effects on productivity. 80-90% of productivity in temperate vegetation, however, is belowground. Thus the reliability of using leaf data to predict whole-system phenology is unknown. We predict that the correlation between root and shoot phenology increases significantly with decreasing productivity, and will test this at large spatial scales (southern vs northern Saskatchewan) using one species, aspen, and along a compact arctic alpine gradient with high turnover of growth forms. Another focus is the impact of aboveground herbivory on belowground productivity and carbon sequestration. We will examine the impact of aboveground herbivores and seed predators on the species composition, diversity and belowground function of grasslands in field experiments arrayed across southern Saskatchewan. Lastly, we will continue to explore the extent to which contrasting species influence ecosystem processes. This has implications for soil fertility and carbon storage, and is relevant because management (forestry, ranching, restoration) and climate change are driving strong changes in species composition.