Fig. 1.

Summary of the meta-analysis of fruit-set effect sizes of pollen-supplementation experiments conducted on 241 species in different biodiversity zones of the world. The biodiversity map was modified from ref. 18 (available upon request). Species richness is likely underestimated to a greater degree in areas of higher species richness (i.e., tropical regions), and these regions are the same areas where the fewest pollen supplementation studies have been conducted. We predict that further data will strengthen the patterns observed in this study.