Establishment success of 25 rare wetland species introduced into restored habitats is best predicted by ecological distance to source habitats

Abstract

In response to ongoing local extinction of species and the current biodiversity crisis, the number of rein troduction programs aiming to establish new populations of rare species in the wild has increased, How ever, only a small proportion of these programs has been planned and monitored scientifically and comparative multi-species studies are missing in this context. Therefore, the relative importance of fac tors involved in reintroduction success is poorly known. In 2007, we assessed population growth since introduction as a measure of establishment success of 25 wetland species (rare or extinct in the wild nationwide) and a total of 50 populations in Switzerland that had been introduced at seven restored sites with apparently adequate environmental conditions between 1997 and 2005. We related establishment success to 32 life-history traits of these species obtained from the BiolFlor database, to initial number of introduced plants (propagule pressure with 1-130 individuals introduced per population), and to the ecological distance between source sites and restored sites based on vegetation records. Our results clearly showed the importance of close ecological similarity between source and introduction sites for successful establishment of wetland species into restored pond habitats. In contrast, neither life-history traits nor propagule pressure were related to establishment success in our study. Based on our results, we strongly recommend enforcing ecological studies prior to reintroduction to accurately assess the suitabil ity of restored sites, To unambiguously assess the key determinants of successful establishment, future reintroduction programs should be setup according to experimental designs.

A multi-level analysis to evaluate the extinction risk of and conservation strategy for the aquatic fern Marsilea quadrifolia L. in Europe

“…In recent years, several examples of M. quadrifolia reintroduction programmes have been described for European countries, for instance, in Poland (Schweitzer and Polakowski, 1994), in Spain within the Natural Park area of the Delta del Ebre (Estrelles et al, 2001;Bañares Baudet et al, 2004) and in Switzerland (Käsermann and Moser, 1999;Noël et al, 2011). Unfortunately, many of these reintroductions did not consider the integrated approach described in this work; in most cases, the intra-and interpopulation genetic diversity were not considered in the reintroduction plan.…”

Time‐lag in extinction dynamics in experimental populations: evidence for a genetic Allee effect?

“…; Noël et al . ) and classical biological control operations (Hall & Ehler ; Stiling ). However, these average rates hide a strong heterogeneity between introduction events, and it appears difficult to identify a minimum set of robust predictors that would be highly predictive of establishment and invasion success (Kolar & Lodge ; Facon et al .…”

The highs and lows of dispersal: how connectivity and initial population size jointly shape establishment dynamics in discrete landscapes

“…Providing reliable predictors of whether or not introduced individuals are able to persist in their novel environments is a crucial challenge for ecologists, with direct consequences for the management of invasive pests (Williamson and Fitter 1996), endangered species (Noël et al 2011) or biological control agents (Freckleton 2000). Theoretical population biology (Ebenhard 1991), as well as correlative data related to introductions in nature (Hayes and Barry 2008), point towards the number of introduced individuals being the main factor important for population persistence (Simberloff 2009).…”