Abstract

Understanding food web responses to global warming, and their consequences for conservation and management, requires knowledge on how responses vary both among and within species. Warming can reduce both species richness and biomass production. However, warming responses observed at different levels of biological organization may seem contradictory. For example, higher temperatures commonly lead to faster individual body growth but can decrease biomass production of fishes. Here we show that the key to resolve this contradiction is intraspecific variation, because (i) community dynamics emerge from interactions among individuals, and (ii) ecological interactions, physiological processes and warming effects often vary over life history. By combining insights from temperature-dependent dynamic models of simple food webs, observations over large temperature gradients and findings from short-term mesocosm and multi-decadal whole-ecosystem warming experiments, we resolve mechanisms by which warming waters can affect food webs via individual-level responses and review their empirical support. We identify a need for warming experiments on food webs manipulating population size structures to test these mechanisms. We stress that within-species variation in both body size, temperature responses and ecological interactions are key for accurate predictions and appropriate conservation efforts for fish production and food web function under a warming climate.

Keywords

body growth; population size structure; trait variation; predator–prey; fish production; climate change

Published in

Philosophical transactions of the Royal Society of London. Series B, Biological sciences
2020, Volume: 375, number: 1814, article number: 20190449

SLU Authors

• Gårdmark, Anna

  • Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
    

• Huss, Magnus

  • Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
    

Associated SLU-program

Coastal and sea areas
Lakes and watercourses


Sustainable Development Goals

Conserve and sustainably use the oceans, seas and marine resources for sustainable development
Take urgent action to combat climate change and its impacts


UKÄ Subject classification

Fish and Aquacultural Science
Ecology


Publication identifier

DOI: https://doi.org/10.1098/rstb.2019.0449

Permanent link to this page (URI)

https://res.slu.se/id/publ/109061