Simplified inference about dominance in forest stands

▶ Dominance curves are useful for understanding forest dynamics. ▶ However, dominance curves cannot always be constructed from available data. ▶ A simplified approach allows testing dominance hypotheses when data are limiting. ▶ An example shows that an old-growth kauri stand had reverse dominance. In a series of papers, Binkley and coauthors suggested dominance curves as a framework for understanding growth dominance and resource use efficiency in forest stands. Constructing a dominance curve requires three major supporting components: an appropriate allometric equation for biomass, sufficient data to characterize the size distribution of trees in the stand, and data on growth from a sufficient number of trees to characterize the relationship between tree size and growth across the entire size distribution. These components are not always available. Here, I propose a simplified approach to inference that can be used to diagnoze positive, neutral, and reverse dominance when the conditions for constructing a full dominance curve cannot be met. I illustrate the approach with published data from an old-growth kauri ( Agathis australis) stand, which shows clear evidence of reverse dominance.