Predicting plant invaders in the Mediterranean through a weed risk assessment system

Abstract

Risk assessment schemes have been developed to identify potential invasive species, prevent their spread and reduce their damaging effects. One of the most promising tools for detecting plant invaders is the weed risk assessment (WRA) scheme developed for Australia. Our study explores whether the Australian WRA can satisfactorily predict the invasion status of alien plants in the Mediterranean Basin by screening 100 invasive and 97 casual species in Spain. Furthermore, we analysed whether the factors taken into account in the WRA are linked to invasion likelihood (i.e., invasion status) or to impacts. The outcome was that 94% of the invasive species were rejected, 50% of the casual species were rejected and 29% of them required further evaluation. The accuracy for casuals is lower than in other studies that have tested non-invasive (i.e., casuals or non-escaped) alien species. We postulate that low accuracy for casual species could result from: (1) an incorrect ''a priori'' expert classification of the species status, (2) a high weight of the WRA scores given to potential impacts, and (3) casual species being prone to becoming invasive when reaching a minimum residence time threshold. Therefore, the WRA could be working as a precaution early-warning system to identify casual species with potential to become invasive.

Assessing Stakeholder Perspectives on Invasive Plants to Inform Risk Analysis

“…These actions are influenced by stakeholders' values and opinions of acceptable risk and the costs and benefits of implementation (National Research Council 2009). Researchers have developed many risk-assessment models to screen nonnative plants for invasiveness (Daehler et al 2004;Gassó et al 2010;Gordon and Gantz 2008;Pheloung et al 1999;Reichard and Hamilton 1997;Widrlechner et al 2004). None of these models is perfect; they are subject both to false positive and false negative errors.…”

Global approaches to addressing biofuel‐related invasive species risks and incorporation into U.S. laws and policies

“…Due to growing concern about the potential for introduction and spread of invasive species as a result of biofuel feedstock production, a number of recent studies have used the Australian WRA (adapted to the United States or Europe, with or without refinements) to evaluate the invasive potential of biofuel feedstock species (Daehler and Carino 2000, Barney and DiTomaso 2008, Crosti et al 2008, Gordon et al 2008b, Nishida et al 2008, Buddenhagen et al 2009, 2011b, Gasso´et al 2010, McClay et al 2010; also see footnote 4). In all, 64 species identified by researchers to be under consideration as biofuel feedstock crops have been evaluated at least once using the Australian WRA framework, but very few have been analyzed with the other tools to date; therefore, this synthesis focuses on evaluations using the Australian WRA.…”

“…Researchers are using WRA tools extensively to evaluate candidate biofuel feedstock species (Daehler and Carino 2000, Barney and DiTomaso 2008, Crosti et al 2008, Gordon et al 2008b, Nishida et al 2008, Buddenhagen et al 2009, 2011b, Gasso´et al 2010, McClay et al 2010; see also Weed risk assessments for Florida database, available online).…”

A review of risk prioritisation schemes of pathogens, pests and weeds: principles and practices

“…Weeds in Australia (Pheloung 1995) Weeds in Australia (Cunningham et al 2004), Australia and New Zealand (Pheloung et al 1999), Hawaii (Daehler et al 2004;Buddenhagen et al 2009), Florida (Gordon et al 2008b), Chicago (Jefferson et al 2004), Spain (Gassó et al 2010;Andreu and Vilà 2010), Italy (Crosti et al 2010), Czech Republic (Křivánek and Pyšek 2006), Japan (Nishida et al 2009;Kato et al 2006), and Tanzania (Dawson et al 2009). Also applied to fish in the UK (Copp et al 2005;Copp et al 2009;Tricarico et al 2010).…”

“…Results are validated by comparing some of them against known hazards (Smallwood and Salmon 1992;Weber and Gut 2004;Gassó et al 2010;Mataragas et al 2008), by subjecting them to expert evaluations (Daehler et al 2004;Pheloung et al 1999) or by comparing against results of other models ( words the resource requirements for evaluation are not excessive. In the reviewed studies, when mentioned, it took 1 or 2 days to find the required information and evaluate a species.…”