Allelopathy as a mechanism for the invasion of Typha angustifolia

Abstract

The direct competitive effects of exotic plants on natives are among the leading causes of plant extinctions worldwide. Allelopathy, one type of direct plant competition, has received relatively little research, particularly in aquatic and wetland systems, even though allelopathy can be a potent mechanism through which plant communities are structured. Typha angustifolia (narrow-leaved cattail) is an invasive exotic plant in North America that often forms monocultures in disturbed wetlands and is more invasive than native members of its genus. We tested whether T. angustifolia was allelopathic and whether it produced different biochemicals than a native congener by growing it with the native bulrush Bolboschoenus fluviatilis (river bulrush) in soil with and without activated carbon and by qualitatively and quantitatively comparing soluble phenolics produced in the roots of T. angustifolia and the native Typha latifolia (broad-leaved cattail). T. angustifolia had a strong allelopathic effect on B. fluviatilis, reducing the longest leaf length and root, shoot, and total biomass of B. fluviatilis. When the allelopathy of T. angustifolia was ameliorated by activated carbon, however, longest leaf length, ramet number, root biomass, shoot biomass, and total biomass of T. angustifolia were greatly reduced due to resource competition with B. fluviatilis. Furthermore, T. angustifolia produced different, but not more, soluble phenolics than T. latifolia suggesting that the identity of the phenolics is different between the two species rather than the concentrations. The allelopathic effects of T. angustifolia on a North American native wetland plant and its production of root biochemicals that appear to differ from those produced by a native congener are consistent with the possibility that T. angustifolia may use a novel allelochemical in its invasion of North American wetlands.

The relative importance of immediate allelopathy and allelopathic legacy in invasive plant species

“…The most likely explanation is that allelochemicals released by the invasive species were degraded by the soil microbial community (Barto & Cipollini 2009;Kaur et al, 2009;Zackrisson & Nilsson 1992), and thus could not affect native species in the long term. Our finding fits into a growing body of evidence which shows that invasive species release allelochemicals that immediately affect their competitors (Abhilasha et al, 2008;Gomez-Aparicio & Canham 2008;Jarchow & Cook 2009;Murrell et al, 2011;Newingham & Callaway 2006;Ridenour & Callaway 2001). Due to the high number of invasive species studied, we can conclude that immediate allelopathy of invasive species generally decreases the competitive ability of natives.…”

Allelopathy of a native grassland community as a potential mechanism of resistance against invasion by introduced plants

“…While allelopathic effects of introduced invasive species on native resident species have received much attention (e.g. Hierro and Callaway 2003;Orr et al 2005;He et al 2009;Jarchow and Cook 2009;Del Fabbro et al 2014), the reverse the allelopathic effect of a native community on introduced species has been largely neglected (Cummings et al 2012;Hou et al 2012).…”

“…Therefore, it has been suggested that many highly invasive introduced plant species can dominate plant communities because they produce allelopathic compounds that are novel to the native resident plants (Callaway and Ridenour 2004). Because of this novelty, and a lack of co-evolutionary history with the introduced invasive species (Verhoeven et al 2009;Saul et al 2013), the native species may be strongly affected by the allelopathic chemicals (Callaway and Vivanco 2007;Jarchow and Cook 2009;Gruntman et al 2014). Indeed, there are many studies showing that the competitive ability of invasive introduced plants is partly mediated by allelopathy (Ens et al 2009;Murrell et al 2011;Bauer et al 2012;Svensson et al 2013;Del Fabbro et al 2014), and thus might contribute to invasiveness.…”

Allelopathic Effects of <i>Argemone mexicana</i> to Growth of Native Plant Species

“…Allelopathic effect of some invasive species is stronger on other species in introduced ranges than in native ranges because in new habitat species may not be as adapted to specific allelochemicals of invaders as species do in the native range [10]. Most of invasive plant species has competitive and defensive characteristics which accounts to allelopathic impact [3] [10] [14]. Allelochemicals also affect native species through different pathways that includes interruption of plants nutrients uptake, change in membrane permeability [15], interference in cell division and elongation in roots and shoots [16]- [18], interference in chlorophyll formation [19], protein synthesis inhibition [15] [20] and change or inactivate the activity and functions of certain hormones and enzymes [15] [21].…”