Do thick leaves avoid thermal damage in critically low wind speeds?
Article first published online: 1 FEB 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 194, Issue 2, pages 477–487, April 2012
How to Cite
Leigh, A., Sevanto, S., Ball, M. C., Close, J. D., Ellsworth, D. S., Knight, C. A., Nicotra, A. B. and Vogel, S. (2012), Do thick leaves avoid thermal damage in critically low wind speeds?. New Phytologist, 194: 477–487. doi: 10.1111/j.1469-8137.2012.04058.x
- Issue published online: 19 MAR 2012
- Article first published online: 1 FEB 2012
- Received: 11 November 2011, Accepted: 23 December 2011
- desert plants;
- heat stress;
- leaf temperature;
- leaf thickness;
- thermal damage;
- time constant;
- wind speed
- •Transient lulls in air movement are rarely measured, but can cause leaf temperature to rise rapidly to critical levels. The high heat capacity of thick leaves can damp this rapid change in temperature. However, little is known about the extent to which increased leaf thickness can reduce thermal damage, or how thick leaves would need to be to have biological significance. We evaluated quantitatively the contribution of small increases in leaf thickness to the reduction in thermal damage during critically low wind speeds under desert conditions.
- •We employed a numerical model to investigate the effect of thickness relative to transpiration, absorptance and leaf size on damage avoidance. We used measured traits and thermotolerance thresholds of real leaves to calculate the leaf temperature response to naturally occurring variable low wind speed.
- •Our results demonstrated that an increase in thickness of only fractions of a millimetre can prevent excursions to damaging high temperatures. This damping effect of increased thickness was greatest when other means of reducing leaf temperature (transpiration, reflectance or reduced size) were lacking.
- •For perennial desert flora, we propose that increased leaf thickness is important in decreasing the incidence of extreme heat stress and, in some species, in enhancing long-term survival.