Fig. 2.

Effect sizes of herbivory (a–c and h) and fertilization (d and e) and their interaction (f, g, and i) on producer species richness (a–g) and producer community evenness (h and i). Effect sizes are significantly related to producer community evenness (a, d, and g), ecosystem productivity (b), experiment duration (c and e), fertilization effects on producer biomass (f), producer community richness (h), and experiment size (i). Symbols represent freshwater (gray circles), marine (triangles), and terrestrial (black squares) systems. Horizontal lines indicate neutral effects, and thick lines indicate significant regressions from bivariate metaanalysis (see Table 1 for statistical results). rel., relative; Exp., Experiment; Fert., Fertilization; ln, natural log.