Identifying Ecohydrological Early Warning Signals of Peatland Destabilization

Peatlands are globally important long-term sinks of carbon, however climate change-mediated drought is expected to threaten the integrity of their carbon sequestration function due to enhanced decomposition and moss moisture stress. Furthermore, the intensification of drought (or drainage) will also increase peat combustion loss during wildfire leading to peatland degradation and a potential ecosystem regime shift. Despite research developments on identifying ecohydrological early warning signals (EWS) of tipping points in other ecosystems (e.g., forests, grasslands), research on peatland EWS is lacking. There is an urgent need to identify EWS metrics to adequately represent the potential positive feedback between peatland carbon loss and climate change within Earth Systems Models. By establishing a suite of simple EWS metrics that can summarize an impending or ongoing regime shift, the uncertainty associated with climate change-mediated degradation can be reduced and the trajectory of the global peatland carbon stock more accurately projected.

In this poster presentation we aim to gain more insight into peatland ecosystem behaviour and the early warning signals that may be found in these systems. We present ideas on how to measure ecohydrological tipping points and explore simple metrics that may reveal when these tipping points have been exceeded and the implications this has for carbon storage and fluxes. Moreover, we review how alternate stable state and resilience theory can be applied to peatlands and we explore how ecohydrological modelling and water table time series analysis can be used to identify what environmental conditions herald a peatland regime shift.