Distinctiveness magnifies the impact of biological invaders in aquatic ecosystems

Abstract

There exist few empirical rules for the effects of introduced species, reflecting the context-dependent nature of biological invasions. A promising approach toward developing generalizations is to explore hypotheses that incorporate characteristics of both the invader and the recipient system. We present the first general test of the hypothesis that an invader's impact is determined by the system's evolutionary experience with similar species. Through a meta-analysis, we compared the taxonomic distinctiveness of high-and low-impact invaders in several aquatic systems. We find that high-impact invaders (i.e. those that displace native species) are more likely to belong to genera not already present in the system.

Exotic taxa less related to native species are more invasive

“…In addition, use of ultrametric supertrees provides a phylogenetic context to communities and more effectively estimates the true divergence of invaders from native communities than simply comparisons at the genus level. Our results, coupled with recent findings in several other systems (9,12,33,37), suggest that particular attention should be paid to newly introduced species for which there are no close relatives in the local biota.…”

“…[3][4][5][6][7][8]; however, identifying such attributes has proven challenging (7). Rather than considering traits of invaders and invaded communities in isolation, we support the view that the match between the invader and the invaded community is key to understanding invasiveness (9).…”

“…Only two studies, one on aquatic communities and the other on plant communities, have considered whether high-impact invaders differ in their relatedness to the native community from low-impact invaders. Both studies find that invaders with large impacts are more likely to come from genera not represented in the native fauna or flora than from genera with native representatives (9,33).…”

Benthic assemblages associated with native and non-native oysters are similar

“…Many previous studies examining the impacts of invasive ecosystem engineers, have examined the arrival of a novel functional group to the recipient community and identified positive as well as negative effects on diversity (Gribben et al, 2013;Lejart and Hily, 2011;Levin et al, 2006). Such invaders, which are taxonomically distinct and differ functionally from local species, are more likely to cause a greater impact on the recipient community (Ricciardi and Atkinson, 2004). It remains unclear whether such species, termed invasive on the basis of their impact on ecosystems lacking similar functional groups, have a strong, or any, impact on communities where functionally similar native species are also present.…”

Biological invasions, ecological resilience and adaptive governance

“…Even some invasions initially labeled as socially undesirable may be beneficial to some degree because they provide opportunity to gain a deeper understanding of complex system dynamics (e.g., Bertness and Cloverdale, 2013). Though scientific understanding and technological innovation has and will advance to further support a "detect and eradicate" approach for some invasive species (Simberloff, 2013), new conceptual frameworks for managing invasions are required to address the complexity of invasions (Ricciardi and Atkinson, 2004) especially given the rapid increase in ecological and socioeconomic uncertainties associated with global change.…”