PARENT SESSION
Poster Session # 9: Herbivory.

Tuesday, August 5 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.

Grasshopper herbivory of Solidago speciosa varies with distance from Juniperus virginiana in tallgrass prairie.

Sheik, Cody^*,1, Oliver, Taylor¹, Wallace, Linda¹, ¹ University of Oklahoma, Norman, OK

ABSTRACT- Earlier work has shown that Solidago speciosa is a favored forage for grasshoppers in a tallgrass prairie landscape in central Oklahoma. This work also indicated that plants closer to Juniperus virginana trees may be more heavily grazed than those farther away. We examined possible reasons behind this including an examination of abiotic factors, plant community structure and physiological responses of S. speciosa to herbivory. We found that soil temperature and light increased significantly with distance from the tree, but that air temperature and relative humidity were unaffected. Significant community differences were found at the canopy edge, but not where the majority of herbivory was occurring. We also found no photosynthetic differences between grazed and ungrazed S. speciosa. However, a significant negative relationship existed between grazing intensity and distance from trees. Grazing intensity was greater on shorter plants, but no relationship between distance and height was found. We hypothesize that trees may represent a safe haven from avian predation, making forage plants closer to trees more at risk for grasshopper herbivory.

Key words: Oklahoma, grasshoppers, tallgrass prairie, tree encroachment