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. 2024 Jun;105(6):e4314.
doi: 10.1002/ecy.4314. Epub 2024 May 6.

Environmental warming increases the importance of high-turnover energy channels in stream food webs

James R Junker  1 , Wyatt F Cross  1 , James M Hood  2   3 , Jonathan P Benstead  4 , Alexander D Huryn  4 , Daniel Nelson  5 , Jón S Ólafsson  6 , Gísli M Gíslason  7
Affiliations

Environmental warming increases the importance of high-turnover energy channels in stream food webs

James R Junker et al. Ecology. 2024 Jun.

Abstract

Warming temperatures are altering communities and trophic networks across Earth's ecosystems. While the overall influence of warming on food webs is often context-dependent, increasing temperatures are predicted to change communities in two fundamental ways: (1) by reducing average body size and (2) by increasing individual metabolic rates. These warming-induced changes have the potential to influence the distribution of food web fluxes, food web stability, and the relative importance of deterministic and stochastic ecological processes shaping community assembly. Here, we quantified patterns and the relative distribution of organic matter fluxes through stream food webs spanning a broad natural temperature gradient (5-27°C). We then related these patterns to species and community trait distributions of mean body size and population biomass turnover (P:B) within and across streams. We predicted that (1) communities in warmer streams would exhibit smaller body size and higher P:B and (2) organic matter fluxes within warmer communities would increasingly skew toward smaller, higher P:B populations. Across the temperature gradient, warmer communities were characterized by smaller body size (~9% per °C) and higher P:B (~7% faster turnover per °C) populations on average. Additionally, organic matter fluxes within warmer streams were increasingly skewed toward higher P:B populations, demonstrating that warming can restructure organic matter fluxes in both an absolute and relative sense. With warming, the relative distribution of organic matter fluxes was decreasingly likely to arise through the random sorting of species, suggesting stronger selection for traits driving high turnover with increasing temperature. Our study suggests that a warming world will favor energy fluxes through "smaller and faster" populations, and that these changes may be more predictable than previously thought.

Keywords: climate change; energy flux; environmental filtering; food webs; species traits; temperature.

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References

REFERENCES

    1. Adams, G. L., D. E. Pichler, E. J. Cox, E. J. O'Gorman, A. Seeney, G. Woodward, and D. C. Reuman. 2013. “Diatoms Can be an Important Exception to Temperature–Size Rules at Species and Community Levels of Organization.” Global Change Biology 19: 3540–3552.
    1. Altermatt, F. 2010. “Climatic Warming Increases Voltinism in European Butterflies and Moths.” Proceedings of the Royal Society B: Biological Sciences 277: 1281–1287.
    1. Andersen, T., P. S. Cranston, and J. H. Epler. 2013. Chironomidae of the Holarctic Region: Keys and Diagnoses, Part 1. Lund: Media Tryck.
    1. Angilletta, M. J., Jr., T. D. Steury, and M. W. Sears. 2004. “Temperature, Growth Rate, and Body Size in Ectotherms: Fitting Pieces of a Life‐History Puzzle.” Integrative and Comparative Biology 44: 498–509.
    1. Árnason, B., P. Theodorsson, S. Björnsson, and K. Saemundsson. 1969. “Hengill, a High Temperature Thermal Area in Iceland.” Bulletin Volcanologique 33: 245–259.