Colorado Plateau Native Plant Program Field Trial Study

In the southwest US, monsoon precipitation increases sharply along a northwest to southeast gradient. Pleuraphis jamesii or galleta grass, is an important C4 grass species that spans across this large range in precipitation pattern. In this study we are assessing the ability of galleta grass to adapt to changes in the seasonality of rainfall (termed “plasticity”). In the fall of 2014, we transplanted four populations of galleta grass to a common garden field trial at the Canyonlands Research Center and allowed them to establish for one year. In 2016, we began applying three precipitation seasonality treatments to the populations: spring only, monsoon only and spring and monsoon. We are examining the phenological, ecophysiological and morphological responses to assess plasticity.