Integrating ecological responses to environmental variation across levels of biological organization

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Understanding and anticipating ecological responses to environmental change is a central yet daunting challenge for ecologists. Major information gaps that limit our predictive ability include 1) the role of environmental variability (e.g., the magnitude, frequency, and timing of environmental fluctuations), 2) the impacts of multiple stressors experienced either simultaneously or asynchronously, and 3) the ways in which the sum of individual species' responses to environmental forcing translate to shifts in biodiversity and ecosystem function. My goal is to better understand ecological responses to climate change and other forms of environmental variation by bridging the gap between mechanistic ecophysiological studies and outcomes at the level of communities and ecosystems. At the organismal level, my students and I will test predictions regarding the costs and benefits of prior stress exposure by manipulating the frequency and magnitude of environmental variation. We will assess the importance of multiple stressors, including temperature, desiccation, and ocean acidification, on environmental tolerance limits, and how shifts in one driver may increase or decrease vulnerability to another. From these single species studies, we will scale up to test theory on how plant-herbivore interactions are influenced by complex changes in the environment. Specifically, we will test the prediction that shifts in one factor (temperature) can lead to runaway algal production or over-consumption, but that the tipping point in this relationship will shift depending on a second factor (ocean acidification). We will also scale up from repeat-stress laboratory work by experimentally imposing environmental stress events in the field. In so doing, we will study the ecological implications of events like the 2021 western heat dome, which had extensive detrimental effects on habitat-forming species, to better understand the ripple effects of these events at scales that range from short term recovery to longer term community vulnerability to subsequent thermal extremes. Finally, we will examine broad scale patterns of change that will be driven by the increasing frequency of extreme events. For example, we will test the hypothesis that non-indigenous marine species are more warm-adapted and have broader thermal niches than native marine species in British Columbia. Further, we will experimentally explore the consequences of species replacements as further warming favours exotic species like Pacific oysters over native species like blue mussels, a community shift which may have important consequences for water filtration, local diversity, and ecological resilience. The results of these inter-related projects will improve our ability to anticipate when "ecological surprises" might actually be expected, and allow us to better understand the role of key species in mediating changes in community structure and ecosystem function in a rapidly changing world.