The Effects of Plant–Soil Feedbacks on Invasive Plants: Mechanisms and Potential Management Options

Th ere are countless examples of management projects that have attempted to decrease or eradicate invasive species at a site, only to have them rapidly recolonize within a few years. While this is often attributed to reinvasion through propagules remaining at the site, or high propagule pressure from the surrounding landscape (Leung et al., 2004; Lockwood et al., 2005), this also may be due to invasive species changing site conditions to favor conspecifi cs over native species. Many studies have documented that invasive plants can impact numerous soil properties and processes (Leffl er and Ryel, Chapter 4, this volume; Ehrenfeld, 2010), and that invader impacts on soil can infl uence competitive dynamics between plant species, often favoring the invaders (Callaway and Aschehoug, 2000; Reinhardt and Callaway, 2006; Batten et al., 2008; Kulmatiski et al., 2008; reviewed in Eviner et al., 2010). Some of the eff ects of invasive species on soils can persist after the invader has been removed, making the system more susceptible to reinvasion (reviewed in Eviner and Hawkes, 2008; Kulmatiski and Beard, 2011). In these cases, restoration eff orts must be focused not only on removing invasive species, but also counteracting their eff ects on soil characteristics and processes (Heneghan et al., 2008; Harris, 2009; Eviner et al., 2010). In this chapter, we explore the mechanisms driving plant–soil feedbacks in invaded systems, and potential management tools to alter these feedbacks to be more benefi cial to natives over invasive species.