Plants can change their traits or behavior depending on the conditions they are exposed to, a phenomenon known as plasticity. Plasticity helps plants cope with heterogeneous or changing environments, and can determine the outcome of competitive interactions and ultimately the structure and diversity of plant communities. For example, plants often respond to herbivore attacks by accumulating defense chemicals, which alters their competitive abilities. However, very little is known about how competition with other plants may induce plastic responses and what induced plastic responses mean for competitive ability. Furthermore, evidence suggests that competitor identity matters in how intensely things compete: plants that are more similar to one another likely require the same resources and compete severely for them. This greenhouse-based project will test whether plants native to the Colorado Plateau and commonly used in restoration efforts in the region: 1) exhibit plastic responses when grown with similar or dissimilar species, and 2) test whether those resulting plastic responses impact competitive ability. Results will be analyzed within the framework of plant community dynamics theory and applied to restoration efforts in the region.