title: An allometry-based approach for understanding forest structure, predicting tree-size distribution and assessing the degree of disturbance.
abstract: Tree-size distribution is one of the most investigated subjects in plant population biology. The forestry literature reports that tree-size distribution trajectories vary across different stands and/or species, whereas the metabolic scaling theory suggests that the tree number scales universally as -2 power of diameter. Here, we propose a simple functional scaling model in which these two opposing results are reconciled. Basic principles related to crown shape, energy optimization and the finite-size scaling approach were used to define a set of relationships based on a single parameter that allows us to predict the slope of the tree-size distributions in a steady-state condition. We tested the model predictions on four temperate mountain forests. Plots (4 ha each, fully mapped) were selected with different degrees of human disturbance (semi-natural stands versus formerly managed). Results showed that the size distribution range successfully fitted by the model is related to the degree of forest disturbance: in semi-natural forests the range is wide, whereas in formerly managed forests, the agreement with the model is confined to a very restricted range. We argue that simple allometric relationships, at an individual level, shape the structure of the whole forest community.
authors.affiliation: Dipartimento Territorio e Sistemi Agro-Forestali, University of Padova, 35020 Legnaro, Italy. tommaso.anfodillo@unipd.it
authors.forename: Tommaso
authors.initials: T
authors.lastname: Anfodillo
authors.forename: Marco
authors.initials: M
authors.lastname: Carrer
authors.forename: Filippo
authors.initials: F
authors.lastname: Simini
authors.forename: Ionel
authors.initials: I
authors.lastname: Popa
authors.forename: Jayanth R
authors.initials: JR
authors.lastname: Banavar
authors.forename: Amos
authors.initials: A
authors.lastname: Maritan
mesh_terms: D001699:Biometry; D058448:Biota; D003710:Demography; D016468:Forestry; D007558:Italy; D008954:Models, Biological; D012383:Romania; D014197:Trees / Q000254:growth & development*