Community rescue in experimental metacommunities

Abstract

The conditions that allow biodiversity to recover following severe environmental degradation are poorly understood. We studied community rescue, the recovery of a viable community through the evolutionary rescue of many populations within an evolving community, in metacommunities of soil microbes adapting to a herbicide. The metacommunities occupied a landscape of crossed spatial gradients of the herbicide (Dalapon) and a resource (glucose), whereas their constituent communities were either isolated or connected by dispersal. The spread of adapted communities across the landscape and the persistence of communities when that landscape was degraded were strongly promoted by dispersal, and the capacity to adapt to lethal stress was also related to community size and initial diversity. After abrupt and lethal stress, community rescue was most frequent in communities that had previously experienced sublethal levels of stress and had been connected by dispersal. Community rescue occurred through the evolutionary rescue of both initially common taxa, which remained common, and of initially rare taxa, which grew to dominate the evolved community. Community rescue may allow productivity and biodiversity to recover from severe environmental degradation.

Where less may be more: how the rare biosphere pulls ecosystems strings

“…Similarly, for mammals the presence of a single predator can impact the behavior and physiology of a herd of prey. Another example of rare microbes influencing abundant microbes stems from the work of Low-Décarie et al (2015), who showed that rare microbes rescued whole communities from lethal stress, possibly via horizontal gene transfer. Horizontal transfer of genetic material can also be found in animals and plants (Panaud, 2016), but occurs more frequently between microbes and probably has a larger role in microbial communities.…”

Functional Rarity: The Ecology of Outliers

“…It has also been described as a "strategy" for a species to expand its niche width via a release of intraspecific competition or the exploitation of alternative resources [33]. In addition, both microbial experiments and theoretical studies emphasized the positive role of rare phenotypes in the rescue of ecological communities in face of severe environmental stresses [34,35]. However this principle has not been tested over large scales where functional rarity needs to be well defined and assessed.…”

Eco‐evolutionary dynamics in fragmented landscapes

“…This could be achieved by comparing experiments and models with and without dispersal. At present, most eco‐evo studies did not tested for the effect of dispersal (Yoshida et al ) or relied on assisted dispersal movements (Bell and Gonzalez , Low‐Décarie et al ). We suggest that a more comprehensive approach would allow active movements of individuals among populations in order to test for the effect of non‐random dispersal on eco‐evo interactions in realistic and complex fragmented systems (Fig.…”