Evolutionary trends and the scaling of plant growth and biomass
Plants (here defined as photosynthetic eukaryotes to include the polyphyletic and ancient algal lineages and the monophyletic Viridiplantae) comprise over ninety percent of all of the visible biomass and reflect the greatest diversity in physiology, morphology, and ecology. It is reasonable, therefore, to say that any “synthetic and predictive science” for “scaling in ecology” must be consistent with the empirically observable scaling phenomena of plants, both living and extinct.
Among the most robust of these scaling phenomena are the relationship between annual growth and body mass and the relationship between annual growth and the light-gathering capacity of the individual. These two scaling relationships, which span 18 orders of magnitude, are reviewed and shown to give rise to verifiable predictions, e.g., annual growth rates should scale isometrically with tissue DNA content. These predictions will be discussed in a broader context including evolutionary trends before and after the advent of secondary growth.