Biological invasions – the widening debate: a response to Charles Warren

Conceptual Clarity, Scientific Rigour and ‘The Stories We Are’: Engaging with Two Challenges to the Objectivity of Invasion Biology

“…This engagement, I think, should be actively pursued and sustained, so that invasion biologists and their critics can learn to understand one another better, and to appreciate one another ' s work better. In this process, the critics of invasion biology may discover that their bright proposals for alternative approaches or methodologies have in fact long been known and practised in invasion biology (as Richardson et al (2008) recently reminded us); whereas invasion biologists may discover that they also live with some of the questions and uncertainties that their critics write about.…”

Metaphors in Invasion Biology: Implications for Risk Assessment and Management of Non-Native Species

“…to discriminate between native and non-native species is not without reason, as non-native species are more likely to become a pest (Paolucci, MacIsaac, & Ricciardi, 2013), due to factors such as high dispersal ability and broad tolerance ranges, absence of natural enemies and the unpredictable nature of their population development and spread (Richardson, Pysek, Simberloff, Rejmanek, & Mader, 2008). therefore, to a certain extent, it seems reasonable to develop targeted risk assessment tools and policies.…”

Subjectivity and flexibility in invasion terminology: too much of a good thing?

“…For example, the term impact from question #7 (Set B) is not clearly associated with any specific ecological or evolutionary processes (Williamson 2001), and thus includes both methodological subjectivity and the values held by society as a whole (Lodge et al 2006). We suggest that this is a crucial motivation for excluding any connotation of impact in any criteria for a biological definition of invasive (see Richardson et al 2000Richardson et al , 2008Daehler 2001;Rejmánek et al 2002; but see Thompson 2000, 2001 for counterarguments). When we argue for greater objectivity in invasion biology, we are (i) advocating a reduction in motivational subjectivity in scientific research, without dismissing its importance for public education as a whole, and (ii) implicitly allowing for methodological subjectivity-a limited form of flexibility in definition.…”

“…Scientists occasionally attempt to clarify terminology in their discipline and this is particularly true for invasion biology, where definitions of invasive, naturalized or alien have been debated frequently (e.g. Davis and Thompson 2000;Richardson et al 2000Richardson et al , 2008Daehler 2001;Rejmánek et al 2002;Colautti and MacIsaac 2004;Pyšek et al 2004;Colautti 2005;Warren 2007;Valéry et al in press). But attempts to clarify or unify ecological terminology have been criticized recently, mainly over concerns about the inevitability of subjectivity in scientific research, the impossibility of a formalized scientific method or lexicon, and the importance of flexible terminology for communicating scientific issues (e.g.…”

“…This explains why impact has been included as a criterion for invasive species in public policy issues (e.g. Executive Order 13112 on Invasive Species, February 3, 1999), despite objections by many ecologists (see Richardson et al 2000Richardson et al , 2008Daehler 2001;Rejmánek et al 2002).…”