Individual variation and interactions explain food web responses to global warming

Area of Science:

• Ecology
• Climate Change Biology
• Fisheries Science

Background:

• Global warming affects species richness and biomass production.
• Warming can cause contradictory responses, like faster individual growth but lower fish biomass.
• Intraspecific variation is key to understanding these complex food web dynamics.

Purpose of the Study:

• To resolve contradictions in warming responses across biological levels.
• To elucidate mechanisms of warming effects on food webs via individual responses.
• To highlight the importance of intraspecific variation for conservation and management.

Main Methods:

• Utilized temperature-dependent dynamic models of simple food webs.
• Analyzed observations across extensive temperature gradients.
• Integrated findings from mesocosm and whole-ecosystem warming experiments.

Main Results:

• Resolved contradictions by emphasizing intraspecific variation in individual responses.
• Demonstrated how individual-level responses, influenced by life history, shape food web dynamics.
• Identified mechanisms linking warming waters to food web alterations through individual fish.

Conclusions:

• Intraspecific variation in body size, temperature response, and ecological interactions is critical for accurate predictions.
• Conservation and management strategies for fish production and food web function require considering within-species variability.
• Further research with manipulated population size structures in warming experiments is needed.