Plant growth and mortality under climatic extremes: An overview

• We review current understanding of plant responses to climate extremes.
• Various mechanisms underlying plant responses to climate extremes are summarized.
• We propose future research effort in extreme event research.

Ongoing climate change has caused extreme climatic events to happen more frequently, which can fundamentally threaten plant growth and survivorship. In this review paper, we found that extreme climatic events, such as heat waves, frost, drought and flooding, usually reduces plant production and induces mortality. The magnitude of impacts on production and mortality are exceedingly variable, which likely result from different severities of the climate extremes, sensitivities of various processes, vegetation types, and inherent regulatory mechanisms of plants and ecosystems. Climatologically severe events may not necessarily trigger plant responses. Different processes respond to the same extreme events differently. Such different responses also vary with species. Moreover, plants likely activate a variety of physiological and molecular mechanisms regulate their responses to extremes. Documenting those variable responses and identifying their causes are critical to advancing our understanding. Nevertheless, our research has to move beyond the documentation of phenomenon to reveal fundamental mechanisms underlying plant responses to climate extremes. Toward that goal, we need to define extreme climatic events under a plant perspective and evaluate different response patterns of various processes to climate extremes. In this review, we also propose to focus our future research on manipulative field experiments and coordinated networks of experiments at multiple sites over different regions to understand the real-world responses of plants and ecosystems.