Growth, death, and resource competition in sessile organisms

Abstract

Population-level scaling in ecological systems arises from individual growth and death with competitive constraints. We build on a minimal dynamical model of metabolic growth where the tension between individual growth and mortality determines population size distribution. We then separately include resource competition based on shared capture area. By varying rates of growth, death, and competitive attrition, we connect regular and random spatial patterns across sessile organisms from forests to ants, termites, and fairy circles. Then, we consider transient temporal dynamics in the context of asymmetric competition, such as canopy shading or large colony dominance, whose effects primarily weaken the smaller of two competitors. When such competition couples slow timescales of growth to fast competitive death, it generates population shocks and demographic oscillations similar to those observed in forest data. Our minimal quantitative theory unifies spatiotemporal patterns across sessile organisms through local competition mediated by the laws of metabolic growth, which in turn, are the result of long-term evolutionary dynamics.

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Integrating theory and experiments to link local mechanisms and ecosystem-level consequences of vegetation patterns in drylands

“…Segregated patterns are very common in drylands and are expected to emerge exclusively due to ecological interference or competition (Pringle and Tarnita, 2017). Aggregated patterns, which are the focus of this study, are ecologically more intriguing because they might result from a richer set of mechanisms (van de Rietkerk and van de Koppel, 2008;Lee et al, 2021) and their ecological implications strongly depend on them (Fig. 2c, d).…”

Worldwide Scaling of Waste Generation in Urban Systems

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