PARENT SESSION
Oral Session #20: Invasions: Effects of invaders -- terrestrial systems. Presiding: R. Callaway.
Tuesday, August 7, 2001. 8:00 AM to 12:00 PM. Madison Ballroom C.
The impact of garlic mustard invasions on woodland salamander populations in New York.
Maerz, John1, Blossey, Bernd1, Nuzzo, Victoria2, 1 2
ABSTRACT- Introduced species are a major threat to wildlife including declining populations of amphibians. We used arrays of coverboards in invaded and non-invaded portions of several New York forests to study the impact of garlic mustard invasions on woodland salamander populations. Because garlic mustard displaces native understory plants and few invertebrates feed on garlic mustard, we hypothesize that garlic mustard negatively impacts salamander populations. Salamander diversity and abundance differed significantly among sites. At two of three sites, salamander abundance was lower in garlic mustard-invaded areas than adjacent non-invaded areas. Site has a major effect on both woodland salamander diversity and abundance; therefore, the impact of garlic mustard on woodland salamander populations might also depend on local conditions. The impact of garlic mustard invasions might depend the salamander species present and other local factors including topography, levels of deer herbivory on native understory plants, and the presence of other introduced organisms, such as predatory beetles, slugs, and earthworms. Our research introduces a new factor, introduced plant invasions, to the suite of factors that might contribute to amphibian population declines, and our early results suggest that understanding the impacts of an introduced species on native populations is complex and may vary among sites depending on local conditions.
KEY WORDS: salamander, garlic mustard, invasive species, amphibian population declines