Fig. 2.

Nearest neighbor distance, d_k, as a function of diameter size class, D_k; multiple censuses are presented plotted for the forests on Barro Colorado Island (A) and the San Emilio (B). Data are binned at 1-cm increments. 95% confidence intervals for the mean of each size class, k, were calculated, but when sample sizes were large (smaller trees), they were often smaller than the plotted symbol. For each census of each forest ordinary least squares (OLS) regression fits to the data are not statistically different from the predicted value of 1.0, revealing a regular allometric packing rule for how trees fill space to use all available resources.