Intraspecific variation among clones of a naïve rare grass affects competition with a nonnative, invasive forb

Abstract

Intraspecific variation can have a major impact on plant community composition yet there is little information available on the extent that such variation by an already established species affects interspecific interactions of an invading species. The current research examined the competitiveness of clones of a globally rare but locally common native grass, Calamagrostis porteri ssp. insperata to invasion by Alliaria petiolata, a non-native invasive species. A greenhouse experiment was conducted twice over consecutive years in which 15 clones from three populations of Calamagrostis were paired with rosettes of Alliaria in pots containing native forest soil previously uninvaded by Alliaria. Both species showed a negative response to the presence of the other species, although Alliaria more so than Calamagrostis. Moreover, the effect of Calamagrostis depended upon population, and, to a lesser extent, the individual clone paired with Alliaria. Competitive effects were stronger in the first experiment compared with when the experiment was repeated in the second year. The influence of Calamagrostis clones on the outcome of the experiment varied among populations and among clones, but also between years. Clones from one of the three populations were more influential than clones from the other two populations. Only one of 15 clones, both from the same population, was influential in both experiments. This research supports a growing literature indicating that intraspecific variability among clones of a dominant species can affect interspecific interactions and that such variability in a native species can affect performance of an invading species.

Phylogenetic diversity reveals hidden patterns related to population source and species pools during restoration

“…The different effects of population sources on phylogenetic diversity of species in the species pools were inconsistent with the observation based upon taxonomic richness, where differences only occurred between species pools restored with local ecotypes (Gibson et al . ).…”

Effects of diversity on community assembly in newly formed pond communities

“…, Gibson et al. ). In addition, several studies suggest that genetic identity, and not richness per se, is responsible for explaining both intra‐ and interspecific dynamics (Birch , Pimentel , Vellend et al.…”

“…We predicted that in the ''high'' clonal diversity treatments, there would be an increased likelihood that one or more introduced genotypes would exhibit high fitness in the pool in which it was stocked, resulting in rapid population establishment and reduced invasion by competing species (De Meester et al 2002, Leibold et al 2004, Urban et al 2008, Urban and De Meester 2009. Multiple studies have shown that genotypic diversity can impact population-, community-, and ecosystem-level processes (Hughes et al 2008, Ellers et al 2011, Crawford and Rudgers 2012, 2013, Forsman et al 2012, Gibson et al 2014). In addition, several studies suggest that genetic identity, and not richness per se, is responsible for explaining both intra-and interspecific dynamics (Birch 1960, Pimentel 1968, Vellend et al 2010, Gibson et al 2014Holmes et al 2016).…”

“…Multiple studies have shown that genotypic diversity can impact population-, community-, and ecosystem-level processes (Hughes et al 2008, Ellers et al 2011, Crawford and Rudgers 2012, 2013, Forsman et al 2012, Gibson et al 2014). In addition, several studies suggest that genetic identity, and not richness per se, is responsible for explaining both intra-and interspecific dynamics (Birch 1960, Pimentel 1968, Vellend et al 2010, Gibson et al 2014Holmes et al 2016). For example, Fridley et al (2007) demonstrated that genetic identity of interspecific neighbors influenced patterns of plant growth and fertility in populations of tussock grass (Koeleria macrantha) and sedge (Carex caryophyllea).…”

Functional response of subordinate species to intraspecific trait variability within dominant species

“…The ITV of the subordinate species that we observed could: (a) be as proposed above a phenotypic plastic response to the inner filter environment created by different dominant species population sources (Hulshof & Swenson, ; Messier, McGill, & Lechowicz, ; Siefert et al, ), (b) reflect heritable variation in their genetic composition in response to the environment of different population sources or (c) be a response to the legacy of the post‐agricultural soils of our experiment irrespective of dominant species population source in which the subordinate species were growing (Jung, Violle, Mondy, Hoffmann, & Muller, ; Lajoie & Vellend, ; Pywell et al, ; Siefert et al, ). Intraspecific variation within and among populations of a dominant species can affect the competitive environment (Bennett, Riibak, Tamme, Lewis, & Pärtel, ), and competitive interactions with and ultimately success of subordinates during establishment (Gibson et al, ; Gibson, Dewey, Goossens, & Dodd, ). A previous study by Gustafson et al () in this same experiment showed that intraspecific variation of the dominant species can cause intraspecific genetic variation among the subordinate species Chamaecrista fasciculata .…”