Disturbances are fundamental ecological processes that structure the biodiversity, biogeochemistry, and services within ecosystems.

However, novel disturbance regimes are perturbing ecosystems to such an extent that they are undergoing a variety of transformations with uncertain long-term implications. To illustrate the impact of changing disturbance regimes on ecosystems over multiple decades, Adam Pellegrini will present findings from meta-analyses, field surveys, and model simulations. He will focus on forests on the edge, namely the existence of sites that span ecotones between forest and savanna.

Using a global dataset and field sampling, his team found fire-driven soil organic carbon losses were larger on a relative basis in more arid and seasonal environments, correlated with declines in tree biomass inputs, and exceeded absolute losses of plant biomass carbon in semi-arid sites. Dynamic Global Vegetation Models predicted a pattern opposite to field data, suggesting an underestimate of the vulnerability of drier ecosystems to fire. He will then present data and a new ecosystem model from one of the longest running fire experiments that illustrates the vulnerability of forests to fire and disease and how intermediate burning can lead to the most resilient system when multiple disturbances co-occur. In summary, the consideration of forests on the edge provides numerous insights into how vulnerability to fire may increase with drying climates, the mechanisms controlling losses of soil organic matter, and how disease-fire interacts may change biome stability.

Registration

This seminar will be taking place online via Zoom and in person at the Oxford Martin School. Please register at: https://www.tropicalforests.ox.ac.uk/event/octf-adam-pellegrini/

The seminar is organised by the Oxford Centre for Tropical Forests