Extinction and Extirpation Conditions in Coalescent and Ecotonal Metacommunities

TL;DR

This paper analytically explores the conditions under which communities merge, coexist, or face extinction in ecotonal zones, providing critical thresholds and inequalities for community dynamics and species invasion.

Contribution

It introduces a novel analytical framework for understanding extinction, coexistence, and invasion conditions in coalescent and ecotonal metacommunities.

Findings

Derived critical mixing strength for extinction.

Established inequality for full coexistence.

Identified conditions for species invasion and extirpation.

Abstract

Here we present extinction, extirpation and coexistence conditions where / when two communities combine. We consider one specific model where two communities coalesce, and another model where the communities coexist side by side, blending in a transitionary zone called the ecotone. Specifically, (1) we analytically calculate the shifts in abundances as a function of mixing strength. (2) Obtain a critical value for the mixing strength leading to extinction. (3) Derive an inequality condition for full coexistent mixing. (4) find how the individual communities penetrate into one other as a function of mixing strength. (5) derive the conditions for one species to cross the ecotone and invade an neighboring community and (6) conditions for a native species to get extirpated. Lastly, (7) we spatially investigate the species richness within the ecotone and derive a condition that determines whether the ecotone will have higher or lower richness compared to its surrounding habitats.