Grant: Discovery Grants Program - Individual

The long-term vision of my research program is to advance our understanding of the mechanisms underlying plant diversity with a focus on plant responses to environmental stress and apply this to improve ecological restoration in Canada and internationally. Much of my work has focused on plant water relations and I will extend this to address how adaptations to moisture stress interact with other stressors, starting with acidic and saline soils. My approach considers both adaptation and plasticity, assessing plant responses through growth, morphological, and physiological traits linked to detailed environmental measurements in field and greenhouse experiments. Evolution of stress tolerance in the Ericaceae: The ability to tolerate water limitation may pre-adapt an organism to other stressors, possibly enabling transitions into new environments over evolutionary time. I will determine the mechanisms underlying ecological shifts from water-limited to other harsh environments in the Ericaceae (heath) family through comparative phylogenetic studies using plant trait and habitat data collected from habitats that differ in water availability and soil chemistry. Do water-use traits enable acid tolerance? Water-use traits may enable acid tolerance due to shared responses between osmotic and ionic stress, but we know surprisingly little about how plants directly respond to acids. Given that soil acidity naturally limits nutrient availability, it can be difficult to tease these apart in nature. My lab will test this in bog shrubs. Bogs are peat-forming wetlands that are highly acidic and many species possess traits adaptive under water deficits even though water is seemingly unlimited. We will test whether drought tolerance is adaptive in acid soils using greenhouse experiments, field studies along pH gradients, and in a long-term nutrient addition experiment that has been ongoing at the Mer Bleue Bog (Ottawa, ON) for the past 20 years. Variation in water availability, acidity, and salinity in Atlantic heathlands: Altered precipitation patterns and sea-level rise from climate change are exposing many coastal areas to new and increasing water and salt stress. Atlantic heathlands - Ericaceae-dominated, nutrient-poor shrublands - provide a unique system to address these issues: in Nova Scotia there are wetlands (bogs) and drylands (rock barrens) with coastal and inland counterparts, creating natural variation in soil moisture, pH, and salinity. I will establish a new long-term field experiment to decrease water availability and increase salinity in coastal and inland bogs and rock barrens. Rainfall will be reduced using permanent rainout shelters and marine salts will be added during the growing season. Responses and mechanisms will be determined by annual monitoring of species abundance, traits, and growth. I intend to maintain this experiment for the duration of my career to capture long-term responses that may not appear for several years.