Abstract
Limited data from terrestrial ecosystems suggest that invasive species can affect energy flow and nutrient cycling in invaded systems. This is likely also true for aquatic ecosystems, yet little information is available on food web effects of invasive macrophytes. This study examined the effects of dominant invasive Eurasian watermilfoil on lake trophic structure and energy flow. Stable isotopes of carbon and nitrogen were used to compare trophic structure in invaded and uninvaded lakes and macrophyte stands. Contribution of native and invasive macrophytes, their epiphyton and detritus to the upper trophic level of lacustrine food webs was partitioned using mixing models. Carbon isotope values of macroinvertebrate consumers were similar to macrophyte-associated production in stands from which they were collected. However, contribution of Eurasian watermilfoil and its epiphyton to higher trophic level was negligible, and littoral fish derived most of their energy from sources associated with native macrophytes, despite their lower abundance. This means that littoral fish may depend on the remaining patches of native macrophytes in lakes invaded by non-native plants. Considering previous findings, these results show that the assessment of ecosystem-level processes is needed to understand the entire range of impacts of invasive species.
Original language | English (US) |
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Pages (from-to) | 23-34 |
Number of pages | 12 |
Journal | Hydrobiologia |
Volume | 721 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2014 |
Bibliographical note
Funding Information:Acknowledgments We are grateful to Dan Dugan, Matthew Spickard and Krisan Webb for invaluable help in the field, Jean Aycock for dietary analysis, and Bonnie Earleywine for amphipod identification. We dedicate this work to the memory of Matthew Spickard. We thank the Department of Wildlife and Fisheries, Mississippi State University for financial support. Gary Ervin, John Madsen and Todd Tietjen provided feedback during earlier stages of this study. This work has been improved by the comments of several anonymous reviewers and John Havel.
Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
Keywords
- Food web
- Macrophyte
- Non-native species
- Stable isotopes