Potential Effects of an Invasive Nitrogen-Fixing Tree on a Hawaiian Stream Food Web.

dc.contributor.authorAtwood, Trisha B.
dc.contributor.authorWiegner, Tracy N.
dc.contributor.authorTurner, Jason P.
dc.contributor.authorMacKenzie, Richard A.
dc.date.accessioned2012-07-03T21:35:09Z
dc.date.available2012-07-03T21:35:09Z
dc.date.issued2010-07
dc.descriptionv. ill. 23 cm.
dc.descriptionQuarterly
dc.description.abstractFalcataria moluccana (albizia) is an exotic nitrogen (N)-fixing tree currently invading riparian forests in Hawai‘i, U.S.A. This study examined how this invasion is impacting stream ecosystems by using naturally occurring stable isotopes of carbon (C) and N to compare food web structure between a noninvaded and an albizia-invaded stream reach on the island of Hawai‘i. Isotopic signatures of particulate organic matter (POM), macroalgae, invertebrates, and fishes were collected and compared between the two stream reaches. Stable C isotopic signatures of organic matter sources (POM and macroalgae) and consumers (amphipods, caddisflies, crayfish, and fishes) from the invaded site were depleted in 13C compared with the noninvaded site. In contrast, all samples from the invaded site were enriched in 15N compared with the noninvaded site. Results from IsoSource and two-source mixing models suggested that albizia was a major contributor to diets of lower-level consumers within the invaded site, displacing POM and macroalgae as their major food sources. Albizia was also an indirect C and N source for higher-level consumers within the invaded site because albizia was the major dietary constituent of their prey. In addition, 15N enrichment of the macroalgae at the invaded site suggests that albizia may be an important N source to benthic primary producers and could be further altering the food web from bottom up. Our study provides some of the first evidence that invasive riparian N-fixing trees can potentially alter the structure of stream food webs.
dc.format.extent14 p.
dc.identifier.citationAtwood TB, Wiegner TN, Turner JP, MacKenzie RA. Potential Effects of an Invasive Nitrogen-Fixing Tree on a Hawaiian Stream Food Web. Pac Sci 64(3): 367-380.
dc.identifier.issn0030-8870
dc.identifier.urihttp://hdl.handle.net/10125/23112
dc.language.isoen-US
dc.publisherHonolulu, University of Hawaii Press
dc.relation.ispartofseriesvol. 64, no. 3
dc.subject.lcshNatural history--Periodicals.
dc.subject.lcshScience--Periodicals
dc.subject.lcshNatural history--Pacific Area--Periodicals.
dc.titlePotential Effects of an Invasive Nitrogen-Fixing Tree on a Hawaiian Stream Food Web.
dc.typeArticle
dc.type.dcmiText

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