Limits to post-fire vegetation recovery under climate change

Abstract

Record-breaking fire seasons in many regions across the globe raise important ques-tions about plant community responses to shifting fire regimes (i.e., changing fire fre-quency, severity and seasonality). Here, we examine the impacts of climate-drivenshifts in fire regimes on vegetation communities, and likely responses to fire coincid-ing with severe drought, heatwaves and/or insect outbreaks. We present scenario-based conceptual models on how overlapping disturbance events and shifting fireregimes interact differently to limit post-fire resprouting and recruitment capacity.We demonstrate that, although many communities will remain resilient to changingfire regimes in the short-term, longer-term changes to vegetation structure, demogra-phy and species composition are likely, with a range of subsequent effects on ecosys-tem function. Resprouting species are likely to be most resilient to changing fireregimes. However, even these species are susceptible if exposed to repeated short-interval fire in combination with other stressors. Post-fire recruitment is highly vul-nerable to increased fire frequency, particularly as climatic limitations on propaguleavailability intensify. Prediction of community responses to fire under climate changewill be greatly improved by addressing knowledge gaps on how overlapping distur-bances and climate change-induced shifts in fire regime affect post-fire resprouting,recruitment, growth rates, and species-level adaptation capacity.