Jack of all trades, master of some? On the role of phenotypic plasticity in plant invasions

Abstract

Invasion biologists often suggest that phenotypic plasticity plays an important role in successful plant invasions. Assuming that plasticity enhances ecological niche breadth and therefore confers a fitness advantage, recent studies have posed two main hypotheses: (1) invasive species are more plastic than non-invasive or native ones; (2) populations in the introduced range of an invasive species have evolved greater plasticity than populations in the native range. These two hypotheses largely reflect the disparate interests of ecologists and evolutionary biologists. Because these sciences are typically interested in different temporal and spatial scales, we describe what is required to assess phenotypic plasticity at different levels. We explore the inevitable tradeoffs of experiments conducted at the genotype vs. species level, outline components of experimental design required to identify plasticity at different levels, and review some examples from the recent literature. Moreover, we suggest that a successful invader may benefit from plasticity as either (1) a Jack-of-all-trades, better able to maintain fitness in unfavourable environments; (2) a Master-of-some, better able to increase fitness in favourable environments; or (3) a Jack-and-master that combines some level of both abilities. This new framework can be applied when testing both ecological or evolutionary oriented hypotheses, and therefore promises to bridge the gap between the two perspectives.

Latitudinal and longitudinal clines of phenotypic plasticity in the invasive herb Solidago canadensis in China

“…High phenotypic plasticity has frequently been invoked to be a mechanism that promotes a species' invasiveness (Baker 1965;Richards et al 2006). Meta-analyses have not revealed consistent patterns in this regard (Davidson et al 2011), but this could be because most studies have compared invasive species to native instead of to non-invasive alien species (van Kleunen et al 2010).…”

“…Compared to narrowly distributed species, widespread ones are expected to be characterized by a higher level of phenotypic plasticity because of larger variation in environmental conditions that they experience (Bradshaw 1965;Pintor et al 2015). High phenotypic plasticity is also likely to contribute to the spread of invasive alien plants (Baker 1965;Richards et al 2006;MolinaMontenegro et al 2013;Keser et al 2014; but see Davidson et al 2011). Rapid adaptive evolution along environmental gradients is also commonly observed in invasive plants (Maron et al 2004;Colautti et al 2009;Moran and Alexander 2014;Oduor et al 2016).…”

Adaptive phenotypic plasticity contributes to divergence between lake and river populations of an East African cichlid fish

“…In particular, adaptive phenotypic plasticity—the generation of a phenotype that is better suited for a novel environment (Ghalambor, McKay, Carroll, & Reznick, 2007)—can promote the expansion of populations into new niches (Yeh & Price, 2004; Richards, Bossdorf, Muth, Gurevitch, & Pigliucci, 2006; Thibert‐Plante & Hendry, 2011). This is because adaptive phenotypic plasticity can temporarily protect genetic diversity from the direct impact of natural selection, thereby saving time for beneficial mutations to arise and to spread within a population, which may eventually result in genetic differentiation (Schlichting, 2004).…”

Traits correlate with invasive success more than plasticity: A comparison of three Centaurea congeners

“…Phenotypic plasticity is thought to broaden the ecological niches of species and thus play an important role in biological invasions (Daehler, 2003; Richards, Bossdorf, Muth, Gurevitch, & Pigliucci, 2006; Zenni, Lamy, Lamarque, & Porté, 2014). This may be particularly important in disturbed environments where environmental variation is frequent (Daehler, 2003).…”