The relative importance for plant invasiveness of trait means, and their plasticity and integration in a multivariate framework

Abstract

Summary• Functional traits, their plasticity and their integration in a phenotype have profound impacts on plant performance. We developed structural equation models (SEMs) to evaluate their relative contribution to promote invasiveness in plants along resource gradients.• We compared 20 invasive-native phylogenetically and ecologically related pairs. SEMs included one morphological (root-to-shoot ratio (R ⁄ S)) and one physiological (photosynthesis nitrogen-use efficiency (PNUE)) trait, their plasticities in response to nutrient and light variation, and phenotypic integration among 31 traits. Additionally, these components were related to two fitness estimators, biomass and survival.• The relative contributions of traits, plasticity and integration were similar in invasive and native species. Trait means were more important than plasticity and integration for fitness. Invasive species showed higher fitness than natives because: they had lower R ⁄ S and higher PNUE values across gradients; their higher PNUE plasticity positively influenced biomass and thus survival; and they offset more the cases where plasticity and integration had a negative direct effect on fitness.• Our results suggest that invasiveness is promoted by higher values in the fitness hierarchytrait means are more important than trait plasticity, and plasticity is similar to integrationrather than by a specific combination of the three components of the functional strategy.

Comparison of growth traits between abundant and uncommon forms of a non-native vine, Dolichandra unguis-cati (Bignoniaceae) in Australia

“…This study has shown that SP displayed superior values of traits known to be associated with successful invaders (Chun et al 2007; . Therefore it may be safe to assume that were the two forms to be introduced into novel environments at the same time, SP would likely be more successful in colonizing the habitats than LP (Gallagher et al 2015;Godoy et al 2012;Kolar and Lodge 2001;Pyšek and Richardson 2007;van Kleunen et al 2010). Thus, our results partly explain why SP seems to be abundant in Australia, although LP is postulated to also have a potential to become widespread if not carefully managed (see Taylor and Dhileepan 2012).…”

Characteristics of Successful Alien Plants

“…This has been demonstrated in Hawai'i, where distinct leaf traits allow some invasives to occupy novel, human-created biogeochemical niches not exploited by native species (Peñuelas et al 2010). Furthermore, this could also underlie the finding that invasive alien species in the Iberian Peninsula have higher photosynthetic nitrogenuse efficiencies than native species (Godoy et al 2012). Therefore, we predict that in regions that have recently undergone environmental change, there are stronger differences between successful aliens and natives.…”

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

“…Adaptive plasticity in colonizing populations may also provide a temporal buffer prior to directional and local selection (Ghalambor, Mc Kay, Carroll, & Reznick, 2007; Pigliucci, 2005). However, empirical evidence for the role of plasticity in invasive success is contradictory, with some meta‐analyses and reviews finding no difference in plasticity between invasive and noninvasive species (Godoy, Valladares, & Castro‐Díez, 2011; Godoy, Valladares, & Castro‐Díez, 2012; Palacio‐López & Gianoli, 2011), with others finding substantial differences (Daehler, 2003; Davidson, Jennions, & Nicotra, 2011). …”

“…As selective adaptation is often correlated with invasive success, higher plasticity levels could be detrimental in some conditions for long‐term invasive success. In a comparison of multiple sets of invasive and noninvasive congeneric species, invasive species grew larger and performed better than noninvasives, but they were similar in plasticity over a range of phenotypic traits (Godoy et al., 2012). In contrast, Centaurea melitensis plants from the non‐native range were higher in phenotypic plasticity for several traits than plants from the native range (Moroney, Rundel, & Sork, 2013).…”