Computer simulations support a core prediction of a contentious plant model

Area of Science:

• Plant biology
• Theoretical ecology
• Mathematical modeling

Background:

• The West, Brown, Enquist (WBE) theory is a prominent plant model predicting botanical scaling relationships.
• A key assumption of the WBE model is that natural selection favors hierarchal networks for efficient nutrient distribution, leading to highly efficient organisms.
• Few studies have empirically tested the fundamental assumptions underlying the WBE plant model.

Purpose of the Study:

• To evaluate the core assumptions of the West, Brown, Enquist (WBE) plant model.
• To simulate plant competition to determine if an idealized WBE plant model outcompetes other plant types.
• To investigate the impact of deviations from WBE scaling parameters on plant competition outcomes.

Main Methods:

• A computer simulation model was employed to test WBE theory predictions.
• Simulations involved competitive interactions between an idealized WBE plant, a generic angiosperm (GA), and GA-like WBE variants.
• Seven WBE variants were created, each differing from the GA in a single scaling parameter.

Main Results:

• The idealized WBE plant consistently outcompeted all other simulated plants in light-shade and open-field conditions.
• Modifications to a single WBE scaling parameter led to either the demise of the WBE plant or coexistence with the GA plant.
• Simulation results indicate that even minor deviations from WBE scaling relationships significantly impact competitive success.

Conclusions:

• The simulation results provide strong support for a central assumption of the WBE plant model.
• The findings suggest that the strict adherence to WBE scaling parameters may explain why such an "idealized" plant has not evolved in nature.
• This study highlights the sensitivity of plant competitive dynamics to specific scaling relationships predicted by the WBE theory.