Global climate change and the evolutionary ecology of ecosystem functioning

Area of Science:

• Ecology
• Climate Change Biology
• Evolutionary Ecology

Background:

• Global climate change causes environmental warming, a stressor impacting organismal physiology and ecosystem carbon cycling.
• Current theoretical frameworks for predicting warming effects on ecosystem carbon balance via organismal physiology are underdeveloped.
• Ecosystem science needs to integrate evolutionary ecology principles to understand how environmental stress on organisms affects ecosystem carbon dynamics.

Purpose of the Study:

• To develop a theoretical framework linking organismal physiology shifts to ecosystem carbon cycling under environmental warming.
• To illustrate how animal metabolic responses to thermal stress influence elemental demand and carbon allocation.
• To demonstrate the disproportionate impact of animals on ecosystem carbon balance, particularly under climate change.

Main Methods:

• Utilized selected case studies to explore the relationship between thermal stress, animal physiology, and carbon cycling.
• Developed a theoretical model to predict shifts in animal elemental demand and resource selection.
• Analyzed how changes in animal resource use alter carbon partitioning among atmospheric, biotic, and soil pools.

Main Results:

• Environmental warming increases animal metabolic rates, prompting phenotypically plastic shifts in elemental demand.
• Animals shift resource selection from nitrogen-rich proteins to carbon-rich carbohydrates to meet elevated energy demands.
• This shift in resource selection alters the partitioning of carbon between atmospheric and ecosystem pools.

Conclusions:

• Animal physiological responses to thermal stress, driven by climate warming, significantly mediate ecosystem carbon cycling.
• Despite low biomass, animals can exert a disproportionately large influence on carbon dynamics in stressed ecosystems.
• Integrating evolutionary ecology offers a robust framework for predicting climate change impacts on ecosystem carbon balance.