PARENT SESSION
Oral Session # 73: Invasive Species VI: Terrestrial.
Presiding: S DeWalt
Thursday, August 7. 8:00 AM to 11:30 AM, SITCC Meeting Room 204.
Nonnative species in forest food webs and their impacts on woodland salamander populations.
Maerz, John*,1, Blossey, Bernd1, Nuzzo, Victoria2, Liebherr, Jame3, 1 Ecology and Management of Invasive Plants Prorgram, Ithaca, NY, USA2 Natural Areas Consultants, Richford, NY, USA3 Department of Entomology, Ithaca, NY, USA
ABSTRACT- Using coverboard monitoring plots, we examined the prevalence of nonnative species in forests, and their impacts on woodland salamander populations at 10 sites in the northeastern United States. Numerous nonnative invertebrates were found at all sites, and many were important prey for woodland salamanders. Nonnative earthworms were particularly important at all sites, as they influenced the abundance of several other nonnative species and had a large effect on woodland salamander populations. Nonnative earthworms were important prey for adult salamanders; however, high earthworm densities resulted in rapid loss of leaf litter. Decreased leaf litter levels were associated with reduced abundance of small arthropods, including some nonnative arthropods, and reduced abundance of salamanders that depend on small arthropods as prey. For two nonnative plant species studied, garlic mustard (Alliaria petiolata) and Japanese barberry (Berberis thunbergii), plant invasions were strongly associated with heavy impacts from earthworm invasions. We could not detect any additional effects of plant invasions on salamander abundance independent of earthworm impacts. Our research shows that multiple nonnative species from a range of taxonomic and trophic groups are well established in forest food webs and impacting a key native generalist predator. Further, this study illustrates that invasions often occur in the context of other invasions, which must be considered if we are to accurately assess the impact of a particular invasive species.
Key words: salamander, earthworms, invasive species, forest food webs