How Herbivory Affects Grazing Tolerant and Sensitive Grasses in a Central Texas Grassland: Integrating Plant Response across Hierarchical Levels

The hypothesis that herbivore selectivity, rather than plant response to defoliation, is the overriding factor in determining community level responses to grazing was tested in a Texas grassland. We monitored defoliation intensity and subsequent regrowth and reproduction of herbaceous dominants Schizachyrium scoparium and Paspalum plicatulum at the individual tiller, population, and community levels of organization. While long-term observations indicate that Schizachyrium declines and Paspalum increases in response to herbivory, individual Schizachyrium tillers exhibited little response to any level of defoliation and were able to fully compensate for lost tissue on a seasonal basis (...)