Leaves in the lowest and highest winds: temperature, force and shape

Area of Science:

• Plant biology
• Ecology
• Biophysics

Background:

• Climatic extremes, not just averages, significantly impact organismal function and distribution.
• Lightweight, flexible structures like leaves are particularly sensitive to short-term environmental extremes.
• Understanding plant adaptations to climatic extremes is crucial for predicting species distribution and survival.

Purpose of the Study:

• To review the risks posed by two specific climatic extremes to plant leaves: rapid heating and high winds.
• To identify and discuss leaf structural and functional adaptations that mitigate these risks.
• To highlight the limited experimental research in this critical area.

Main Methods:

• Literature review of existing studies on plant leaf responses to environmental extremes.
• Analysis of physical principles governing heat transfer and aerodynamic forces on leaves.
• Synthesis of morphological and physiological traits conferring resilience.

Main Results:

• Leaves are vulnerable to rapid heating (below 0.5 m s(-1) airflow), with adaptations including reduced size, lobing, altered orientation, low infrared absorptivity, and heat storage.
• Leaves and clusters can curl into stable, low-drag shapes (cones, cylinders) to withstand high winds (≥20 m s(-1)).
• Leaf blade shape, petiole twisting, and low-speed instability facilitate this protective reconfiguration.

Conclusions:

• Plant leaves possess diverse adaptations to survive extreme climatic conditions, including heat stress and wind damage.
• These adaptations involve a combination of physical traits and dynamic responses.
• Further experimental research is needed to fully understand the efficacy and prevalence of these protective mechanisms.