Hazards like droughts and heatwaves increase tree mortality, through mechanisms that alter their carbon reserves.  In [1] we adapt the concept of ruin modelling, from the insurance industry, to devise a growth-ruin model for forests, as a response to climate hazards. This model allows to estimate the probability of « ruin », i.e. the loss of ability to maintain carbon reserves for trees, within one century and

We compare [1] two strategies of coping with hazards:

1. Pay in « cash »: trees stop growing and no longer build reserves
2. Pay in « credit »: trees go on growing but defer the effect of the hazard to the next year

We find that balancing ruin probability vs. high reserve depends on those strategies and the way hazards occur in time (duration and frequency). We determine thresholds of such parameters (coping strategies, hazard occurrence & intensity) that can trigger bifurcations of behavior, from low to high risk.

[1]Yiou, P. and Viovy, N.: Modelling forest ruin due to climate hazards, Earth Syst. Dynam., 12, 997–1013, https://doi.org/10.5194/esd-12-997-2021, 2021.