Theoretical and experimental approach of scale relations and fractality of vegetation on a seasonally flooded area in the Amazon Forest

Abstract

The relationship between plant physiology and metabolism, as well as energy flows mediated by vegetation, is poorly understood today. According to the West, Brown and Enquist (WBE) theory, some plant parameters, such branch diameters, are expected to obey power law distributions. In this work, we tried to approach the relations of scale and fractality in two seasonally flooded areas of the Amazon Forest. Specifically, the aim was to answer if there is a relationship of power law type (free of scale) for the distribution of the diameters of the trunks in the study areas, if there is a similar relationship with respect to the distribution of the branch diameters in some species in these same areas, and there is still a similarity with the distribution of the trunks, in such a way that we can say that the tree ‘imitates’ the forest in which it is contained. We also present a way to measure the fractality in the studied trees based on the relationships between the branch diameters of the subsequent generations (β) coefficient of variation. It was observed that some exponents differ from those predicted by the WBE theory and that the trunk distributions are of the power law-type, but with expressive variations of R². For the branches, the results indicate that the parameters really follow power laws, but with variations in R² between the studied species. It has also been shown that at least one species is more self-similar (fractal) than others. Finally, there was a brief discussion about what is the role of this pattern in the adaptation and evolution of plants.

Keywords:
Allometry; Power-law; WBE model