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Article
Invasive Litter, Not an Invasive Insectivore, Determines Invertebrate Communities in Hawaiian Forests
USDA National Wildlife Research Center - Staff Publications
  • Nathania C. Tuttle, Department of Wildland Resources and the Ecology Center, Utah State University, Logan, UT 84322-5230, USA
  • Karen H. Beard, Department of Wildland Resources and the Ecology Center, Utah State University, Logan, UT 84322-5230, USA
  • William C. Pitt, USDA/APHIS/WS/National Wildlife Research Center, Hilo Field Station, Hilo, HI 96721, USA
Date of this Version
1-1-2009
Comments
Published in Biol Invasions (2009) 11:845–855.
Abstract
In Hawaii, invasive plants have the ability to alter litter-based food chains because they often have litter traits that differ from native species. Additionally, abundant invasive predators, especially those representing new trophic levels, can reduce prey. The relative importance of these two processes on the litter invertebrate community in Hawaii is important, because they could affect the large number of endemic and endangered invertebrates. We determined the relative importance of litter resources, represented by leaf litter of two trees, an invasive nitrogen-fixer, Falcataria moluccana, and a native tree, Metrosideros polymorpha, and predation of an invasive terrestrial frog, Eleutherodactylus coqui, on leaf litter invertebrate abundance and composition. Principle component analysis revealed that F. moluccana litter creates an invertebrate community that greatly differs from that found in M. polymorpha litter. We found that F. moluccana increased the abundance of non-native fragmenters (Amphipoda and Isopoda) by 400% and non-native predaceous ants (Hymenoptera: Formicidae) by 200%. E. coqui had less effect on the litter invertebrate community; it reduced microbivores by 40% in F. moluccana and non-native ants by 30% across litter types. E. coqui stomach contents were similar in abundance and composition in both litter treatments, despite dramatic differences in the invertebrate community. Additionally, our results suggest that invertebrate community differences between litter types did not cascade to influence E. coqui growth or survivorship. In conclusion, it appears that an invasive nitrogen-fixing tree species has a greater influence on litter invertebrate community abundance and composition than the invasive predator, E. coqui.
Citation Information
Nathania C. Tuttle, Karen H. Beard and William C. Pitt. "Invasive Litter, Not an Invasive Insectivore, Determines Invertebrate Communities in Hawaiian Forests" (2009)
Available at: http://works.bepress.com/karenh_beard/192/