Manon Sabot

Ecosystems worldwide are facing unprecedented threats from climate change. On land, increases in the intensity, frequency, and duration of droughts and heatwaves could drive future mass forest die-back. Whilst alarming, this risk incurred by forests is challenging to assess. We lack a holistic theory of how plants respond to and recover from climatic stress, so regional to global (climate) model forecasts of tree responses are error-prone, and uncertainties in our ability to predict both the fate of different species in the landscape and the fate of whole ecosystems remain high. Fortunately, ecologists and plant ecophysiologists have spent the past decades setting up ecosystem observatories, roaming the field, and experimenting on plants in greenhouses, thus amassing a trove of empirical observations. In this talk, I will discuss how we are now exploiting this data to highlight behavioural patterns shared by different tree species, rule out hypotheses that appeared right for the wrong reasons, propose more coherent holistic theories, and identify areas in need of continued research. My examples will draw on observations recorded at a variety of scales, from the leaf to landscape level, and take you through different ecosystems on different continents. I will emphasise axes of change in water availability, atmospheric aridity, and CO2 concentration, laying out a pathway to improve our predictive capacity in novel climate spaces.