Oecologia

, Volume 158, Issue 2, pp 259–272

Utilization of invasive tamarisk by salt marsh consumers

Authors

    • Integrative Oceanography DepartmentScripps Institution of Oceanography
    • San Francisco Bay National Estuarine Research ReserveSFSU-Romberg Tiburon Center
  • Lisa A. Levin
    • Integrative Oceanography DepartmentScripps Institution of Oceanography
  • Drew Talley
    • San Francisco Bay National Estuarine Research ReserveSFSU-Romberg Tiburon Center
  • Jeffrey A. Crooks
    • Tijuana River National Estuarine Research Reserve
Plant-Animal Interactions - Original Paper

DOI: 10.1007/s00442-008-1144-5

Cite this article as:
Whitcraft, C.R., Levin, L.A., Talley, D. et al. Oecologia (2008) 158: 259. doi:10.1007/s00442-008-1144-5

Abstract

Plant invasions of coastal wetlands are rapidly changing the structure and function of these systems globally. Alteration of litter dynamics represents one of the fundamental impacts of an invasive plant on salt marsh ecosystems. Tamarisk species (Tamarix spp.), which extensively invade terrestrial and riparian habitats, have been demonstrated to enter food webs in these ecosystems. However, the trophic impacts of the relatively new invasion of tamarisk into marine ecosystem have not been assessed. We evaluated the trophic consequences of invasion by tamarisk for detrital food chains in the Tijuana River National Estuarine Research Reserve salt marsh using litter dynamics techniques and stable isotope enrichment experiments. The observations of a short residence time for tamarisk combined with relatively low C:N values indicate that tamarisk is a relatively available and labile food source. With an isotopic (15N) enrichment of tamarisk, we demonstrated that numerous macroinvertebrate taxonomic and trophic groups, both within and on the sediment, utilized 15N derived from labeled tamarisk detritus. Infaunal invertebrate species that took up no or limited 15N from labeled tamarisk (A. californica, enchytraeid oligochaetes, coleoptera larvae) occurred in lower abundance in the tamarisk-invaded environment. In contrast, species that utilized significant 15N from the labeled tamarisk, such as psychodid insects, an exotic amphipod, and an oniscid isopod, either did not change or occurred in higher abundance. Our research supports the hypothesis that invasive species can alter the trophic structure of an environment through addition of detritus and can also potentially impact higher trophic levels by shifting dominance within the invertebrate community to species not widely consumed.

Keywords

Isotope enrichmentSalt cedarExotic speciesTrophicTamarix

Supplementary material

442_2008_1144_MOESM1_ESM.doc (280 kb)
Electronic supplementary material (DOC 279 kb)
442_2008_1144_MOESM2_ESM.doc (224 kb)
Appendices in Electronic supplementary material (DOC 224 kb)

Copyright information

© Springer-Verlag 2008