FIG. 4.
Comparison of theoretical lognormal models with observed data from four Arizona soils. Fifteen model communities were constructed by using three different values for Rmax (10, 11, and 12) and five different values for ST (2,000, 4,000, 6,000, 8,000, and 10,000 species). Data from 12 of the models are shown in the figure. The solid square and diamond represent observed data from Sunset Crater and Cosnino interspace soils, respectively. The semifilled square and diamond represent observed data from Sunset Crater and Cosnino rhizosphere soils, respectively. The plotted symbols for the Arizona communities would be positioned artificially high (by 5 to 20%) if the surveys contained PCR artifacts.