title: Influence of small-scale disturbances by kangaroo rats on Chihuahuan Desert ants.
abstract: Banner-tailed kangaroo rats (Dipodomys spectabilis) are prominent ecosystem engineers that build large mounds that influence the spatial structuring of fungi, plants, and some ground-dwelling animals. Ants are diverse and functionally important components of arid ecosystems; some species are also ecosystem engineers. We investigated the effects of patch disturbances created by D. spectabilis mounds on ant assemblages in a Chihuahuan Desert grassland in southern New Mexico by using pitfall traps in a paired design (mound vs. matrix). Although the disturbances did not alter species richness or harbor unique ant communities relative to the matrix, they did alter species composition; the abundances of 6 of 26 species were affected. The disturbances might also act to disrupt spatial patterning of ants caused by other environmental gradients. In contrast to previous investigations of larger-scale disturbances, we detected no effects of the disturbances on ants at the functional-group level. Whether ant communities respond to disturbance at a functional-group or within-functional-group level may depend on the size and intensity of the disturbance. Useful functional-group schemes also may be scale-dependent, however, or species may respond idiosyncratically. Interactions between disturbance-generating mammals and ants may produce a nested spatial structure of patches.
authors.affiliation: Department of Biology, Colorado State University, Fort Collins, CO 80523, USA e-mail: schooley@lamar.colostate.edu Tel.: +1-970-4910952, Fax: +1-970-4910649, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Schooley
authors.affiliation: Department of Biology, Colorado State University, Fort Collins, CO 80523 USA, USA.
authors.forename: B T
authors.initials: BT
authors.lastname: Bestelmeyer
authors.affiliation: Department of Biology, Colorado State University, Fort Collins, CO 80523 USA, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Kelly
keywords: Disturbances; Formicidae; Heteromyidae; Key words Ecosystem engineers; Spatial scale