Influence of Founder Population Size, Propagule Stages, and Life History on the Survival of Reintroduced Plant Populations

The reintroduction of rare and endangered species is now widely practiced as a conservation tool to reestablish species within their historic range (Guerrant and Kaye 2007; Seddon et al. 2007; Menges 2008). The fundamental goal of a plant reintroduction is to create a self-sustaining population with evolutionary potential that can resist ecological perturbations (Maunder 1992; Guerrant 1996a). Reintroduction practitioners face many challenges and complex choices, many of which have been formulated into generic guidelines for reintroducing a species (Akeroyd and Wyse-Jackson 1995; Falk et al. 1996; Kaye 2008). After choosing reintroduction sites based on biological, logistical, and historical attributes (Fiedler and Laven 1996; Maschinski et al. [chap. 7], this volume), reintroduction practitioners must decide how many individuals to introduce, which propagule stage to introduce, and what follow-up management treatments and aftercare are necessary to ensure that a population survives and reaches critical demographic benchmarks, including sexual reproduction and recruitment of the next generation (Pavlik 1996; Menges 2008). To complicate matters, reintroduction practitioners must balance tradeoffs between the availability of propagules, which are often limited with rare and endangered plants, and population dynamic theory, which predicts that the initial size and composition of the founding population are important determinants in the survival of reintroduced populations (Guerrant 1996a; Kirchner et al. 2006; Maschinski 2006; Armstrong and Seddon 2007). Consequently, a major question in the field of reintroduction biology is whether the persistence of a reintroduced population is affected by the size of the founding population and by the developmental stage of the propagules (Guerrant 1996a; Maschinski 2006; Armstrong and Seddon 2007).