Species-area relationships and trend line for all major, exhaustive bee inventory studies conducted in the United States in natural or semi-natural habitats.

(a) The black trend line delineates expectations for how the number of species will increase with increasing area size based on the (log-transformed) species-area relationship. Studies above the trend line (grey points) recorded more bee species than expected for the area of the site; those below the line (black points) recorded fewer bee species than might be expected on average for that size area. Pinnacles National Park is circled in red. (b) Barplot of the difference in the number of bee species observed in each study relative to the number of bee species predicted by the trend line plotted in panel (a). Pinnacles National Park is outlined in red. Study details are listed in Table 4.