PARENT SESSION
Oral Session #14: Invasive species: Effects.
Presiding: S. DeSimone
Monday, August 5. 1:00 PM to 3:45 PM. Greenlee Meeting Room, TCC.

The effect of Lehmann lovegrass (Eragrostis lehmanniana) in the semiarid ecosystems of the Southwestern United States: faunalpedoturbation as an ecosystem indicator.

Kulas, Christina^*,1, ¹ Michigan State University, East Lansing, Michigan

ABSTRACT- Lehmann lovegrass(Eragrostis lehmanniana) a grass from South Africa, has become naturalized in the southwestern United States. The objective of this study is to compare amounts and types of faunalpedoturbation in semi-arid grasslands to determine if the invasion of Lehmann lovegrass is affecting animal activity and the ecosystem processes those animals maintain. Faunalpedoturbation is soil disturbance by animals. It contributes to the spatiotemporal heterogeneity of the landscape as well as provides evidence of animal activity. Data were collected during each of five months from 18 sites, nine dominated by native grasses and nine with varying degrees of Lehmann lovegrass presence, on the semi-arid grasslands of the Santa Rita Experimental Range (SRER) in southeastern Arizona and the Jornada Basin in southern New Mexico. Area, volume, diversity and types of soil disturbances were statistically treated for all sites. The area of soil disturbed was significantly less on sites dominated by Lehmann lovegrass during all months sampled, at the SRER study area. Rodent activity and ejecta were also significantly less on the SRER Lehmann lovegrass sites. Results from the Jornada basin were variable. The degree to which Lehmann lovegrass affects faunalpedoturbation appears to be related to the history of the site, specifically the establishment time and dominance of the grass as well as the intensity of grazing.

KEY WORDS: Lehmann lovegrass, Invasive species, faunalpedoturbation, soil disturbance