Ecosystems

, Volume 18, Issue 2, pp 186–201

Closely Related Tree Species Differentially Influence the Transfer of Carbon and Nitrogen from Leaf Litter Up the Aquatic Food Web

  • Zacchaeus G. Compson
  • Bruce A. Hungate
  • George W. Koch
  • Steve C. Hart
  • Jesse M. Maestas
  • Kenneth J. Adams
  • Thomas G. Whitham
  • Jane C. Marks
Article

DOI: 10.1007/s10021-014-9821-1

Cite this article as:
Compson, Z.G., Hungate, B.A., Koch, G.W. et al. Ecosystems (2015) 18: 186. doi:10.1007/s10021-014-9821-1

Abstract

Decomposing leaf litter in streams provides habitat and nutrition for aquatic insects. Despite large differences in the nutritional qualities of litter among different plant species, their effects on aquatic insects are often difficult to detect. We evaluated how leaf litter of two dominant riparian species (Populus fremontii and P. angustifolia) influenced carbon and nitrogen assimilation by aquatic insect communities, quantifying assimilation rates using stable isotope tracers (13C, 15N). We tested the hypothesis that element fluxes from litter of different plant species better define aquatic insect community structure than insect relative abundances, which often fail. We found that (1) functional communities (defined by fluxes of carbon and nitrogen from leaf litter to insects) were different between leaf litter species, whereas more traditional insect communities (defined by relativized taxa abundances) were not different between leaf litter species, (2) insects assimilated N, but not C, at a higher rate from P. angustifolia litter compared to P. fremontii, even though P. angustifolia decomposes more slowly, and (3) the C:N ratio of material assimilated by aquatic insects was lower for P. angustifolia compared to P. fremontii, indicating higher nutritional quality, despite similar initial litter C:N ratios. These findings provide new evidence for the effects of terrestrial plant species on aquatic ecosystems via their direct influence on the transfer of elements up the food web. We demonstrate how isotopically labeled leaf litter can be used to assess the functioning of insect communities, uncovering patterns undetected by traditional approaches and improving our understanding of the association between food web structure and element cycling.

Keywords

stable isotope tracers functional food webs trophic structure nutrient cycling decomposition cottonwood aquatic insect community 

Supplementary material

10021_2014_9821_MOESM1_ESM.docx (112 kb)
Supplementary material 1 (DOCX 109 kb)
10021_2014_9821_MOESM2_ESM.docx (83 kb)
Supplementary material 2 (DOCX 79 kb)

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Zacchaeus G. Compson
    • 1
    • 2
    • 3
  • Bruce A. Hungate
    • 1
    • 2
    • 3
  • George W. Koch
    • 1
    • 2
    • 3
  • Steve C. Hart
    • 4
  • Jesse M. Maestas
    • 1
    • 3
  • Kenneth J. Adams
    • 1
    • 3
  • Thomas G. Whitham
    • 1
    • 3
  • Jane C. Marks
    • 1
    • 2
    • 3
  1. 1.Merriam-Powell Center for Environmental ResearchNorthern Arizona UniversityFlagstaffUSA
  2. 2.Center for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffUSA
  3. 3.Department of Biological SciencesNorthern Arizona UniversityFlagstaffUSA
  4. 4.School of Natural SciencesUniversity of CaliforniaMercedUSA

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