Present addresses: Department River Ecology, Helmholtz Centre for Environmental Research GmbH – UFZ, Brückstr. 3a, D-39114 Magdeburg, Germany.
Human lakeshore development alters the structure and trophic basis of littoral food webs
Article first published online: 18 MAY 2011
© 2011 The Authors. Journal of Applied Ecology © 2011 British Ecological Society
Journal of Applied Ecology
Volume 48, Issue 4, pages 916–925, August 2011
How to Cite
Brauns, M., Gücker, B., Wagner, C., Garcia, X.-F., Walz, N. and Pusch, M. T. (2011), Human lakeshore development alters the structure and trophic basis of littoral food webs. Journal of Applied Ecology, 48: 916–925. doi: 10.1111/j.1365-2664.2011.02007.x
- Issue published online: 1 JUL 2011
- Article first published online: 18 MAY 2011
- Received 23 November 2010; accepted 15 April 2011 Handling Editor: Shelley Arnott
- aquatic-terrestrial coupling;
- coarse woody debris;
- habitat loss;
- retaining walls;
- riparian clearcutting;
1. Shoreline development and the associated loss of littoral habitats represent a pervasive alteration of the ecological integrity of lakes and have been identified as major drivers for the loss of littoral biodiversity world-wide. Little is known about the effects of shoreline development on the structure of, and energy transfer in, littoral food webs, even though this information is urgently needed for management and mitigation measures.
2. We measured macroinvertebrate biomass and analysed potential food resources using stable isotopes (δ13C, δ15N) and mixing models to compare the complexity and the trophic base of littoral food webs between undeveloped and developed shorelines in three North German lowland lakes.
3. The lower diversity of littoral habitats found at developed shorelines was associated with lower diversity of food resources and consumers. Consequently, the number of trophic links in food webs at developed shorelines was up to one order of magnitude lower as compared with undeveloped shorelines.
4. Mixing model analysis showed that consumer biomass at undeveloped shorelines was mainly derived from fine particulate organic matter (FPOM) and coarse particulate organic matter of terrestrial origin (CPOM). The contribution of CPOM to consumer biomass was twofold lower at developed shorelines, and consumer biomass was mainly derived from FPOM and suspended particulate organic matter.
5.Synthesis and application. Shoreline development impacts the flow of organic matter within littoral food webs primarily through the reduction in littoral habitat diversity. These effects are exacerbated by clearcutting of the riparian vegetation, which disrupts cross-boundary couplings between the riparian and the littoral zone. Lakeshore conservation should focus on preserving the structural integrity of the littoral zone, while restoration of coarse woody debris, reed and root habitats can be a cost-efficient measure to improve degraded lakeshores. The local effects of shoreline development demonstrated in this study might lead to whole-lake effects, but future studies are needed to derive thresholds at which shoreline development has consequences for the structure and functioning of the entire ecosystem.