Metabolic theory predicts whole-ecosystem properties.

Area of Science:

• Ecology
• Ecosystem Science
• Metabolic Theory

Background:

• Understanding organism impacts on ecosystem material cycles is crucial for predicting climate change, land use, and biodiversity shifts.
• Existing approaches often focus on either organism-level metabolism (bottom-up) or ecosystem-level processes (top-down).

Purpose of the Study:

• To present a unified theory integrating metabolic and systems approaches to explain how individual organism metabolism affects ecosystem material and energy flows.
• To predict variations in carbon residence time, total system throughflow (TST), and recycling based on organism body size, temperature, and trophic structure.

Main Methods:

• Developed a theory integrating organismal metabolism with ecosystem dynamics.
• Evaluated theoretical predictions against numerical ecosystem models and empirical data from diverse real-world ecosystems.

Main Results:

• The theory accurately predicts that ecosystem residence times increase linearly with the ratio of ecosystem biomass to primary productivity (B/P).
• Residence times vary significantly across ecosystems (weeks to centuries) but follow a universal relationship.
• Total system throughflow (TST) is primarily driven by primary productivity, while recycling is influenced by microbial-to-animal energy transfer.

Conclusions:

• The integrated theory provides a robust framework for quantifying energy, carbon, and material fluxes and storage in all ecosystem types.
• It offers a powerful tool for understanding the roles of organisms and environments in ecosystem processes from local to global scales.