Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model.

Area of Science:

• Ecology
• Ecological Modeling
• Macroecology

Background:

• Anthropogenic activities drive global ecosystem degradation, threatening essential ecosystem services.
• Accurate understanding of ecosystem degradation is crucial for effective mitigation and conservation strategies.
• Mechanistic predictive models, grounded in ecological principles, are vital tools for assessing ecosystem health.

Purpose of the Study:

• To introduce the first global, mechanistic General Ecosystem Model (GEM) applicable to both terrestrial and marine environments.
• To simulate ecosystem structure and function across all organismal body masses and global scales.
• To demonstrate the capability of GEM to predict emergent ecological properties.

Main Methods:

• Developed a mechanistic General Ecosystem Model (GEM) incorporating fundamental ecological principles.
• Derived functional forms and parameter values from extensive theoretical and empirical ecological literature.
• Simulated the dynamics of organisms across a 14-order-of-magnitude body mass range globally.

Main Results:

• GEM successfully simulated emergent properties at individual, community, ecosystem, and macroecological levels.
• Simulated properties, including growth rates, biomass turnover, trophic pyramids, and global trophic structure, align with existing data and theory.
• Model predictions emerged organically from organismal biology and interactions, without imposed constraints.

Conclusions:

• Sufficient ecological knowledge exists to construct realistic, global, mechanistic ecosystem models.
• GEM provides a powerful framework for predicting diverse ecosystem properties and their responses to anthropogenic pressures.
• This modeling approach is essential for advancing ecological understanding and informing environmental management.