Letter | Published:

Drought alters the structure and functioning of complex food webs

Nature Climate Change volume 3, pages 223227 (2013) | Download Citation

Abstract

Climate change is expected to make many regions of the world much drier over coming decades1,2. More intense drought would transform rivers 3 with potentially severe but largely unknown consequences at higher (multispecies) levels of organization4. Here we show experimentally how the intensification of drought may alter the underlying structure and functioning (biomass flux dynamics) of freshwater food webs—networks of species and their interactions5. Drought triggered substantial losses of species and links, especially among predators, leading to the partial collapse of the food webs. Total resource–consumer biomass flux was also strongly suppressed by disturbance, yet several network-level properties (such as connectance and interaction diversity) were conserved, driven by consumer resource fidelity and a substantial reconfiguration of fluxes within the webs as production shifted down the size spectrum from large to small species. Our research demonstrates that drier climates could have far-reaching impacts on the functioning of freshwater ecosystems.

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Acknowledgements

The Freshwater Biological Association (FBA) and the Centre for Ecology and Hydrology generously supported this research. We would like to thank R. Harris and P. Armitage for their significant contribution to the project. R. Death and J. Montoya provided helpful comments that improved the manuscript. The project was supported by a FBA/Natural Environmental Research Council (NERC) postdoctoral fellowship to MEL and NERC grants NER/B/S/2002/00215 and NE/J02256X/1.

Author information

Affiliations

  1. School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK

    • Mark E. Ledger
    • , François K. Edwards
    •  & Alexander M. Milner
  2. School of Geography/water@leeds, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK

    • Lee E. Brown
  3. Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, OX10 8BB, UK

    • François K. Edwards
  4. Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska 99775, USA

    • Alexander M. Milner
  5. School of Biological and Chemical Sciences, Queen Mary, University of London, London, E1 4NS, UK

    • Guy Woodward

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Contributions

M.E.L. was responsible for funding application, research design and planning, data collection and analysis, L.E.B. prepared and analysed food webs, F.K.E. collected and analysed data, A.M.M. applied for funds and planned the experiment, G.W. applied for funds and planned food web research. All authors discussed the results and wrote the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Mark E. Ledger.

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DOI

https://doi.org/10.1038/nclimate1684

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