Belowground advantages in construction cost facilitate a cryptic plant invasion

Abstract

Energetic costs of tissue construction were compared in two subspecies of Phragmites australis, the common reed – namely the primary native and introduced lineages in North America. Caplan et al. report that the introduced lineage has lower construction costs than the native under all environmental conditions assessed, driven mainly by its lower cost rhizomes. These results highlight the fact that belowground energetics, which are seldom investigated, can influence the performance advantages that drive many plant invasions. The authors also demonstrate that tissue construction costs in organs not typically assessed can shift with global change, suggesting that they may have increasingly important implications into the future.

Complementary responses of morphology and physiology enhance the stand‐scale production of a model invasive species under elevated CO2 and nitrogen

“…We found contrasting results between morphological traits and leaf‐level physiological traits in response to interacting global change factors. As expected, P. australis displayed strong trait responses to both eCO 2 and N in our field experiment, some of which have been observed previously in containerized settings (Caplan et al., ; Eller et al., ; Mozdzer et al., 2012). However, because this study was based on mature clones grown in a field setting, it provides a more realistic assessment of the magnitude of morphological and physiological responses to these interacting global change factors.…”

“…Furthermore, many studies typically identify one or a few functional traits that are highly responsive to global change factors and speculate how changes in those traits may facilitate invasion without empirically evaluating longer‐term or larger‐scale effects (e.g. Caplan, Wheaton, & Mozdzer, ; Sullivan, Wildova, Goldberg, & Vogel, ). Moreover, short‐term, containerized studies only modestly predict field‐scale responses (Poorter et al., ).…”

“…As a C 3 facultative halophyte, it invades freshwater, brackish and saline wetlands, but its distribution is thought to be limited by high salinity (Chambers, Osgood, Bart, & Montalto, ; Mozdzer, Brisson, & Hazelton, ). Because it has responded strongly to eCO 2 and N in containerized experimental conditions (Caplan et al., ; Eller, Lambertini, Nguyen, & Brix, ; Mozdzer & Megonigal ) and is among the most well‐studied organisms globally (Meyerson et al., ), it is an appropriate species for investigating C 3 plant responses to the interactive effects of eCO 2 and N on plant functional traits.…”

Fine‐root traits are linked to species dynamics in a successional plant community

“…For the root traits examined here, natives typically exhibited a broader range of trait values than exotics, perhaps constraining the potential for changes in traits with successional position seen within the exotics. While the invasion of exotic species is often considered to be derived from unique or extreme trait values (Tecco et al 2010, van Kleunen et al 2010, Caplan et al 2014, Lee et al 2017, the successful exotic species in the BSS appear to utilize a subset of the same root trait space occupied by native species rather than any ecologically novel part of that trait space. However, while this study and others identify categorical differences in functional traits between native and exotic plant species, it is important to note that there is substantial variation within each group (Dawson et al 2012a, Flores-Moreno et al 2013); many native species express acquisitive traits and many exotic species express conservative traits, with broad ranges for each.…”

Root and leaf traits reflect distinct resource acquisition strategies in tropical lianas and trees

“…Collectively, these findings suggest that lianas create fine roots with limited structural integrity, which as a result are likely to turn over more quickly relative to the roots of trees (Eissenstat and Yanai 1997;Reich and Hall 2013). Rapid turnover may allow liana roots to explore the soil volume efficiently and may be less costly to the plant via low C construction costs, especially under elevated atmospheric CO 2 conditions (Caplan et al 2014). …”