Meta‐analysis suggests biotic resistance in freshwater environments is driven by consumption rather than competition

Abstract

Native communities are thought to mediate the establishment and performance of invasive species through competitive and consumptive interactions, a concept referred to as ''biotic resistance.'' We investigated the generality of this concept across ecosystems. Despite the conspicuousness of freshwater invasions, investigations of biotic resistance have focused mostly on terrestrial and, more recently, marine coastal communities. We collected in-situ studies that tested the impacts of native freshwater communities on invading primary producers and consumers. Meta-analysis demonstrated that evidence of competitive biotic resistance in freshwater habitats was not as strong as that in marine and terrestrial ecosystems. In freshwater ecosystems consumptive resistance was significantly stronger than competitive resistance and consumptive resistance appeared to be as strong in freshwater as in marine and terrestrial systems. The limited number of studies considering freshwater biotic resistance hindered our ability to understand the importance of factors including latitude, experimental duration, and method. However, the strength of biotic resistance varied among freshwater habitats; specifically, biotic resistance was strongest in lentic environments. Our analysis identifies mechanisms underlying biotic resistance in freshwater ecosystems that warrant further investigation given the potential ongoing and future impacts of invasive species in these systems.

Vive la résistance: reviving resistance for 21st century conservation

“…Identifying the determinants of resistance in the face of a persistent disturbance is particularly valuable for conservation management [26]. For instance, invasion ecology has provided many ideas about the ability of biotic communities to 'resist' ongoing species invasion [26,27]. For example, biotic communities with diverse functional groups have been shown to be more resistant to the spread of invasive species [28].…”

The vulnerability of species to range expansions by predators can be predicted using historical species associations and body size

“…The strong effect of negative species associations and the importance of total length, given gape limitation, suggest that the impacts which we demonstrate are more likely to be driven by consumption than competition. Similarly, recent meta-analysis examining a broad suite of taxa suggests that consumption is more important than competition in determining biotic resistance to aquatic invasions [48].…”

An overview of recent research in marine biological invasions

“…Biotic interactions may promote or impede the establishment and spread of NIS in recipient environments via mechanisms such as competition, exploitation, facilitation, and mutualism (e.g., Simberloff and Von Holle 1999; Freestone et al 2013; Alofs and Jackson 2014). This collection explores the effects of facilitation, kleptoparasitism, scavenging, herbivory, predation, and competition on invasion success of marine NIS.…”