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.

Density of Cape porcupines in a semi-arid environment and their impact on soil turnover and related ecosystem processes

“…Porcupines come closest of all the species in the Nieuwoudtville region to fulfilling these conditions. In other semi-arid regions, pocket gophers, kangaroo rats and prairie dogs impact on ecosystem function and heterogeneity through their burrowing and foraging activities (Huntly and Inouye, 1988;Ceballos et al, 1999;Schooley et al, 2000). Banner-tailed kangaroo rats (Dipodomys spectabilis) and plateau zokors (Myospalax fontanierii) have been classified as ecosystem engineers through the effects of their widespread soil disturbance (Schooley et al, 2000;Zhang et al, 2003).…”

Fungi and Algae Co-Occur in Snow: An Issue of Shared Habitat or Algal Facilitation of Heterotrophs?

“…Thus, any shifts in community-wide distributions should be detected locally (in all or most of the paired samples). Paired sample designs to interrogate community ecology are not new (Wellington, 1982;Schooley et al, 2000), but are often under-utilized in microbial community analyses (but see Taylor and Bruns, 1999;Hartmann et al, 2014). In this study, we addressed the following three questions: (1) do snow algae enrich the communities with specific fungi; (2) do snow algae shift fungal community composition; and, (3) will such shifts be consistent across larger geographic scales?…”

Interactive disturbance effects of two disparate ecosystem engineers in North American shortgrass steppe

“…On On mounds or nests proper, Adj directly adjacent to mounds or nests proper, 3 m 3 m from mounds or nests proper. DiVerent letters above bars denote signiWcant diVerences within a sampling position at the P · 0.05 level because some ant species associate with disturbed soil mounds and others with the matrix (Schooley et al 2000). Kangaroo rat-driven shifts in ant species composition could subsequently alter the characteristics of ant-induced disturbances that manifest at relatively small scales.…”