BayCEER Workshop 2024

Investigating novel disturbance interactions among 33 tree species with simulated late-frost and drought events

The frequency and duration of early spring and summer-time drought events is expected to increase significantly in Central Europe during the coming decades. At the same time, the risk of late-spring frost events (up to mid-May) remains. The resulting novel disturbance regime will likely have a profound impact on the future of Central European forests The greatest practical challenge facing European forestry today is deciding which tree species to plant now to ensure future forests are productive, resilient, and supporting of biodiversity, even in the face of the most severe climate change scenarios. This will prove especially difficult in Central Europe, where the depauperating effects of the Plio-Pleistocene transition and subsequent glaciations have resulted in a much smaller species pool compared to the temperate zone in North America or Southeast Asia. Within the scope of a controlled ecological experiment, we test the responses of juveniles of 33 native and non-native tree species to simulated late frost and drought events. We utilize a gradient approach, exposing trees to different combinations of frost and drought to determine both species-specific stress and mortality thresholds. Stress was quantified through leaf chlorophyll content, elementary analysis (C and N), and extraction of total phenolic content (antioxidants). Using these responses, we investigate disturbance interactions in 2244 juvenile tree individuals.