The metabolic theory of ecology: prospects and challenges for plant biology

Summary The metabolic theory of ecology (MTE) as applied to the plant sciences aims to provide a general synthesis for the structure and functioning of plants from organelles to ecosystems. MTE builds from simple assumptions of individual metabolism to make predictions about phenomena across a wide range of scales, from individual plant structure and function to community dynamics and global nutrient cycles. The scope of its predictions include morphological allometry, biomass partitioning, vascular network design, and life history phenomena at the individual level; size‐frequency distributions, population growth rates, and energetic equivalence at the community level; and the flux, turnover and storage of nutrients at the ecosystem level. Here, we provide an overview of MTE, by considering its assumptions and predictions at these different levels of organization and explaining how the model integrates phenomena among all of these scales. We highlight the model’s many successes in predicting novel patterns and draw attention to areas in which gaps remain between observations and MTE’s assumptions and predictions. Considering the theory as a whole, we argue that MTE has made a significant contribution in furthering our understanding of those unifying aspects of the structure and function of plants, populations, communities, and ecosystems. Contents Summary 696 I. Introduction 697 II. Background and theoretical foundations: assumptions of WBE 698 III. Background and theoretical foundations: assumptions of MTE 699 IV. MTE at the individual plant level: metabolism, architecture and demography 699 V. Metabolism 700 VI. Morphology 701 VII. Biomass partitioning 701 VIII. Hydraulics 702 IX. Demography 702 X. MTE at population, community, and ecosystem scales 703 XI. Plant population density 703 XII. Plant population density within a site 704 XIII. Population growth rates 704 XIV. Ecosystem dynamics 705 XV. Discussion 706 Acknowledgements 708 References 708