Figure 2

Change in species richness between 1999 and 2010 was significantly related to the presence of Bromus tectorum in 1999 ( t = 2.2, p = 0.03). Each box denotes the first and third quartiles of the data with the median as a thick line near the center and whiskers extending to 1.5 interquartile distances. Observations beyond 1.5 interquartile distances from the median are shown as individual points. The gray horizontal line indicates zero change.