A general model for mass–growth–density relations across tree-dominated communities

A general allometric scaling model predicts that plant body mass MT will scale as the −4/3 power of plant density N. Here, we show how this model predicts numerous other scaling attributes of plant populations and communities, including annual growth rate GT, standing leaf biomass ML, basal stem diameter D, and aboveand below-ground biomass, MSH and MR. These predictions are consistent with the ‘Law of Constant Yield’ (i.e. productivity is independent of plant density). Analysis of worldwide databases for woody plant-dominated communities spanning seven orders of magnitude in MT and five orders of magnitude in N provides strong support of all of the model’s predictions. Our model thus offers a theoretical basis for understanding and predicting the effects of crowding on plant size, growth and biomass partitioning across diverse ecological communities.