Warming-Induced Growth Inhibition Weakens the Resilience of Low-Latitude Tidal Marshes to Sea-Level Rise

Abstract

Sea-level rise (SLR) is expected to suppress the growth of tidal marshes due to prolonged inundation, but this can be compensated by increasing surface elevation with SLR. Warming-induced growth regulation could make it more complicated. We applied a spatially explicit individual-based model (IBM) with dynamic parameterization to predict the range expansion ofSpartina alternifloraby 2100 over a low-latitude wetland, under one low-emission scenario (Shared Socioeconomic Pathway 1 [SSP1]: 0.28 m SLR and 0.55 °C warming) and one high-emission scenario (SSP5: 1.01 m and 3.55 °C). The results showed that (a) the simulations of an IBM with life-history-mediated biophysical feedbacks (IBM1) better tracked the actual range expansion ofS. alternifloraover 2014 to 2017 (90.1% accuracy) than that without the feedbacks (IBM0) (83.0%); (b) under SSP1, most marshes were predicted to survive SLR by 2100 in both IBM0and IBM1, while, under SSP5, the marshes were predicted to disappear much more in IBM0(93.2% drowned) than IBM1(31.9%); and (c) warming-induced growth inhibition ofS. alternifloraleads to exacerbated disappearance and even collapse of the marshes under SSP5 in IBM1. This study highlights the importance of life-history-mediated biophysical and physiological feedbacks in regulating the response of tidal marshes to climate change. Warming-induced growth inhibition weakens low-latitude tidal marsh resilience to SLR.