Integrating architectural analysis and metabolic scaling theory

Metabolic scaling theory (MST) predicts the scaling of core aspects of organismal functioning, including metabolic rate, with body size across broad domains of life. The West, Brown and Enquist (WBE) model hypothesizes that branched networks evolved to minimize resistance to fluid flow, while maximizing metabolic exchange surface area. In plants, these criteria predict a space-filling, self-similar branching architecture with 3/4-scaling of metabolic rate with network size. In this talk I show that tree images from Terrestrial Laser Scanning (TLS): i) adhere to 3/4-power scaling, but ii) do not always fill space in the sense defined by WBE. Instead, I propose a mechanism for space-filling based on architectural analysis of tree networks. In particular, I hypothesize that space-filling emerges at intermediate scales in tree networks, as geometric ratios of subtrees, rather than ratios of internodes.