Description:

Measuring the unpredictable: climate change impacts on infectious tree disease 

Climate change is predicted to shift the distribution and severity of infectious diseases around the globe. Particularly for infectious diseases that are reshaping the foundations of ecosystems, improving our understanding of climate change impacts is critical for society and the environment. Combining insights from a long-term study of over 8,000 trees with a multi-year assessment of drought impacts on infectious tree disease, I will present recent findings on the complex relationship between climate change and white pine blister rust.  White pine blister rust (Cronartium ribicola, Fisch) is one of the most deleterious invasive tree pathogens in North America. Over the past 100 years, its rapid spread has caused many white pine hosts to decline, including whitebark pine, an IUCN endangered species. This talk will focus on spread dynamics near the latitudinal range edge, where blister rust infections are expected to decline under climate change. Using a robust modelling approach that enables greater causal inference, I will show that climate change has nonlinearly shifted blister rust prevalence, which threatens high elevation pine hosts. These results also underscore the importance of interacting, stochastic events that cause unexpected outcomes as climate change shifts infectious diseases.