Consumer-Resource Model for species coexistence

by Deepak Gupta (Technische Universität Berlin)

Monday 27 Apr 2026, 15:30 → 17:30 Europe/Stockholm

Albano 3: 6228 - Mega (22 seats) (Albano Building 3)

Species in an ecological community with similar characteristics often compete with each other for available nutrients/resources. The Competition Exclusion Principle (CEP) predicts that the fittest species outcompetes the others to survive. MacArthur’s consumer-resource model successfully explains the validity of this competitive exclusion principle, i.e., the number of coexisting species competing for available resources is bounded by the number of resources themselves. On the contrary, we still observe rich biodiversity, where several species coexist in nearby regions. So far, several explanations via different modeling techniques have been proposed to understand this rich biodiversity, but a definite answer in this direction is still not available. In this talk, I will introduce an effective resource competition model for species coexistence that is obtained by performing spatial coarse-graining. With this new model, I will show how many species can coexist and violate CEP. Our analytical calculations and numerical simulations correctly predict the empirical species abundance distribution (SAD) of the plankton community data. In the second part of my talk, I will discuss our recent results discussing how biodiversity is influenced by the presence of environmental fluctuations. By applying the dynamical mean field theory (DMFT), I will show the effective mean field equations for species competing for resources. These mean field equations correctly predict the empirical SAD and many other features.

G. Hardin, The competitive exclusion principle, Science 131, 1292 (1960). 

P. Chesson, Macarthur’s consumer-resource model, Theor. Popul. Biol. 37, 26 (1990).

G. E. Hutchinson, The paradox of the plankton, Am. Nat. 95, 137 (1961).

A. Posfai, T. Taillefumier, and N. S. Wingreen, Metabolic Trade-Offs Promote Diversity in a Model Ecosystem, Phys. Rev. Lett. 118, 028103 (2017). 

S. Roy and J. Chattopadhyay, The stability of ecosystems: A brief overview of the paradox of enrichment, J. Biosci. 32, 421 (2007).

 D. Gupta, S. Garlaschi, S. Suweis, S. Azaele, and A. Maritan, Effective Resource-Competition Model for Species Coexistence, Phys. Rev. Lett. 127, 208101 (2021).

D. Zanchetta, D. Gupta, S. Moschin, S. Suweis, A. Maritan, and S. Azaele, Emergence of ecological structure and species rarity from fluctuating metabolic strategies. PRX Life, 3, 033016 (2025).

zoom : https://stockholmuniversity.zoom.us/j/622224375