Natural disturbances like fire and grazing impact plant communities differently depending on the frequency and scale of these disturbances. In tallgrass prairies, frequent burning reduces both spatial and temporal diversity, while grazing by bison decreases spatial diversity but increases temporal diversity. The rate of community change slows down with more frequent fires, but grazing does not affect this rate. The interaction between fire and grazing on diversity changes depending on the scale of measurement, with grazing increasing spatial diversity in some cases but decreasing it in others. Overall, fire homogenizes plant communities at all scales, while grazing has varying effects depending on the frequency and intensity of burns.