Do Functional Traits Relate Metabolic Scaling Theory to Observed Growth Rate?
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractTo model plant growth, ecologists have integrated metabolism into allometric equations, most notoriously known in the West Brown Enquist model, which is an extension of the all-inclusive Metabolic Scaling Theory (MST) (West et al. 1999). This formula takes form of the power function Ṁ = βMᶿ, where β is the allometric normalization constant, M is total biomass, θ is a scaling exponent, and Ṁ is the metabolic and thus growth rate of the organism. Kleiber's law assumes that M should scale to the ¾ power, and the WBE model supports this claim. To test this, we measured the growth rate of 64 trees on Mount Bigelow, Arizona and showed that Ṁ scales in proportion to M. While there are many external factors that influence plant growth, we focused on modeling two types of functional traits: leaf-based and hydraulic-based. Our results show that the theoretical Ṁ from both equations are significantly different than 1, and we conclude that the WBE model may not include all variables relating to plant growth.
Degree ProgramHonors College
Ecology and Evolutionary Biology