Serpentine grasslands serve as refuges for native grassland plant species. Exotic invasive plants increasingly displace even serpentine natives. Fire is a common tool used by managers to control exotic vegetation. Controlled experimental burns were conducted to evaluate the impacts of early summer burning on plant community species richness and the abundance of Leptosiphon ambiguus, Bromus hordeaceus, Lessingia micradenia var. glabrata, Plantago erecta and grasses in two kinds of patches: those with a high abundance of L. ambiguus and little B. hordeaceus, and those with a moderate abundance of both L. ambiguus and B. hordeaceus. This two-year study, conducted in Santa Clara County, California, used a Randomized Block Repeated Measure design (n = 10) with the treatments (burned, not burned) applied after the first year's data were collected. From a management perspective there were three main benefits and one drawback of burning. Increases in species richness in both types of patches and the increase in L. ambiguus and reduction of B. hordeaceus in the B. hordeaceus-invaded patches were beneficial outcomes. The reduction of L. micradenia in L. ambiguus-rich patches was a drawback. Additionally, the study revealed that there was an increase in P. erecta abundance with higher burn temperatures in L. ambiguus-rich quadrats; in B. hordeaceus-invaded quadrats, there was a decrease in P. erecta abundance with higher burn temperatures. Burning also decreased the abundance of all annual grasses combined. Overall, prescribed burning at the grazed study site appeared to be beneficial
