ARS | Publication request: Effects of saltcedar invasion and biological control on small mammals

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 26, 2009
Publication Date: N/A

Technical Abstract: Effects of invasive saltcedars (Tamarix spp.) on bird populations and communities have received considerable interest, but impacts on other vertebrate taxa have received less attention. Moreover, only one published study examined effects on vertebrates of biological control efforts directed at saltcedar, and that focused on birds. I discuss an 8-year data set from two saltcedar-invaded sites in western Nevada and one site in eastern California that allows paired comparisons of small mammal abundances and species composition in saltcedar-invaded versus native riparian vegetation. Saltcedar dominated riparian systems tended to harbor fewer individuals of rodent species often associated with native riparian habitats, such as voles and harvest mice, and instead had a greater representation of arid desert-adapted taxa, such as heteromyid rodent species. Only one rarely-captured species, the montane vole (Microtus montanus), has been found exclusively in native riparian habitats and never in saltcedar; there are no counterexamples of species trapped exclusively in saltcedar. Biological control by the saltcedar leaf beetle (Diorhabda elongata) has apparently had little effect on small mammals. To date, comparisons of trapping data before and after beetle introduction have revealed only minor differences that are likely explained by annual variation in abundance.