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11:09
Relating Stomatal Conductance to Leaf Functional Traits
Published on: October 12, 2015
An evolutionary attractor model for sapwood cross section in relation to leaf area
Mark Westoby1, William K Cornwell, Daniel S Falster
1Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia. mark.westoby@mq.edu.au
Journal of Theoretical Biology
|July 6, 2012
Summary
Plants adjust sapwood area per leaf area (SA:LA) to balance water transport costs and photosynthetic revenue. Optimal root surface area per leaf area (RA:LA) is independent of environmental factors, but plant height may increase in favorable conditions.
Area of Science:
- Plant physiology
- Ecology
- Evolutionary biology
Background:
- Sapwood cross-sectional area per unit leaf area (SA:LA) is a key plant trait influencing water transport and photosynthesis.
- Plants must balance the costs and benefits of resource allocation for survival and growth.
Purpose of the Study:
- To develop theoretical models for SA:LA and root surface area per leaf area (RA:LA) based on maximizing net revenue.
- To predict how environmental factors and plant height influence optimal SA:LA and RA:LA.
Main Methods:
- Theoretical modeling of plant hydraulic and photosynthetic economics.
- Analysis of trait coordination under varying environmental conditions (soil water potential, VPD, CO2) and plant heights.
Main Results:
- SA:LA is predicted to increase in environments that reduce photosynthetic revenue, such as low water potential, high VPD, and low CO2.
- Optimal SA:LA may decrease with increasing VPD in tall plants due to high sapwood costs.
- Optimal RA:LA is unaffected by VPD, CO2, or plant height, but plant height may increase under improved water relations.
Conclusions:
- Plant trait adjustments, including SA:LA and RA:LA, are crucial for optimizing resource acquisition and competitive advantage.
- Environmental factors significantly influence the optimal allocation of resources to water transport structures.
- Evolutionary pressures favoring height can lead to substantial increases in plant stature under favorable conditions.
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