Extreme Heat as the New Normal: A Methodological Roadmap Incorporating Behavior, Physiology, and Species...

Area of Science:

• Ecology
• Evolutionary Biology
• Climate Science

Background:

• Extreme weather events, particularly extreme heat, are increasing in frequency and intensity due to climate change.
• Extreme heat significantly impacts organismal biology, including physiology, behavior, geographic ranges, and extinction risk.
• Current research on extreme heat's biological impacts is limited by non-standardized definitions and a lack of user-friendly workflows for biologists.

Purpose of the Study:

• To provide a standardized methodological roadmap and reproducible code for integrating extreme heat into ecological and evolutionary studies.
• To demonstrate the utility of extreme heat metrics in species distribution models (SDMs) and biophysical simulations.
• To highlight the critical role of extreme heat dynamics in population dynamics and conservation efforts.

Main Methods:

• Developed standardized computational approaches for defining and quantifying extreme heat events.
• Fitted species distribution models (SDMs) for California quail (Callipepla californica) incorporating an extreme heat metric.
• Conducted biophysical simulations to assess thermal stress exposure in sleepy lizards (Tiliqua rugosa).
• Accounted for temporal autocorrelation in temperature profiles within population simulation models.

Main Results:

• Species distribution models (SDMs) with extreme heat metrics showed improved predictions of habitat suitability, especially at range edges.
• Biophysical simulations revealed significant variation in thermal stress exposure across different macro- and microclimates for sleepy lizards.
• Population simulation models demonstrated that clustered heat extremes, often missed by average temperatures, can elevate the risk of population collapse.

Conclusions:

• Integrating extreme heat dynamics into ecological and evolutionary studies is essential for understanding climate change impacts.
• Standardized methods and reproducible workflows are crucial for advancing research on extreme heat and organismal biology.
• Accurate predictions of ecological impacts and effective conservation strategies require the explicit consideration of extreme heat events in a warming world.