Variation between individuals fosters regional species coexistence. (7th August 2018)

• Record Type: Journal Article
• Authors: Uriarte, María; Menge, Duncan
• Editors: Angert, Amy
• Is Part Of: Ecology letters. Volume 21:Number 10(2018)
• Page Start: 1496
• Page End: 1504
• Publication Date: 2018-08-07
• Subjects: Beverton–Holt model -- competition -- habitat specialisation -- interpatch dispersal -- intraspecific variability -- Jensen's inequality -- plasticity -- spatial coexistence -- spatial structure; Ecology -- Periodicals; 577
• DOI: 10.1111/ele.13130
• Languages: English
• ISSNs: 1461-023X

Abstract

Abstract: Although individual‐level variation (IV) is ubiquitous in nature, it is not clear how it influences species coexistence. Theory predicts that IV will hinder coexistence but empirical studies have shown that it can facilitate, inhibit, or have a neutral effect. We use a theoretical model to explore the consequences of IV on local and regional species coexistence in the context of spatial environmental structure. Our results show that individual variation can have a positive effect on species coexistence and that this effect will critically depend on the spatial structure of such variation. IV facilitates coexistence when a negative, concave‐up relationship between individuals' competitive response and population growth rates propagates to a disproportionate advantage for the inferior competitor, provided that each species specialises in a habitat. While greater variation in the preferred habitat generally fosters coexistence, the opposite is true for non‐preferred habitats. Our results reconcile theory with empirical findings.