When grazing occurs, the old tissue that photosynthesizes at a lower rate than the potentially attainable is removed. From Toft et al. 1987 . Figure 2 .
Open symbols correspond to defoliated plants and close symbols to non-defoliated plants.
The X axis represents time after defoliation. From Detling and Painter 1983 . Agropyron spicatum and A. desertorum plants grown in the field. From Caldwell et al. 1981 . From Detling and Painter 1983 .