PARENT SESSION
Poster Session #67: Conservation Ecology.
Friday, August 9. Presentation from 8:00 AM to 9:30 AM. Exhibit Hall B & C, TCC
66
Blackland prairie restoration in central Texas.
MITTELHAUSER, JENNIFER*,1, BARNES, PAUL1, BARNES, TOM2, 1 Southwest Texas State University, San Marcos, Texas2 University of Kentucky-Lexington, Lexington, Kentucky
ABSTRACT- Blackland Prairie of Texas, which once covered over 48 million ha in the east-central part of the state, has been reduced to less than 21,000 ha in modern times, and this type of tallgrass prairie has been given a high priority for preservation and restoration. Reestablishment of Blackland Prairie is often difficult as a result of competition from exotic C4 grasses. In a randomized block field experiment (n=3) conducted near San Marcos, TX, we tested the effectiveness of four levels of a post-emergent herbicide, imazapic, on weed control and establishment and growth of four native C4 grasses. After one year of study, herbicide treatment did not affect initial native grass seedling density, but had a marginally significant effect (p=0.085) on combined end-of-season native grass biomass. In particular, plots treated with 4324 g/ha of imazapic showed greater total native grass biomass than controls (p=0.068), but no treatment differences (p>0.3) were found between controls and plots treated with higher levels of imazapic (8649 g/ha and 12,972 g/ha). Herbicide effects on biomass, however, varied with species (species x treatment, p=0.002), such that the greatest increases were found for Andropogon gerardii and Bouteloua curtipendula. In general, these results suggest that low levels of imazapic may enhance establishment and growth of native grasses in this habitat by reducing weed competition, but higher levels may have direct, inhibitory effects on these species.
KEY WORDS: Blackland, prairie, restoration, imazapic