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Oikos 000: 001–006, 2013 doi: 10.1111/j.1600-0706.2013.01228.x © 2013 The Authors. Oikos © 2013 Nordic Society Oikos Subject Editor: Dries Bonte. Accepted 15 October 2013 A call for an end to calls for the end of invasion biology Daniel Simberloff and Jean R. S. Vitule D. Simberloff ([email protected]), Dept of Ecology and Evolutionary Biology, Univ. of Tennessee, Knoxville, TN 37996, USA. – J. R. S. Vitule, Laboratório de Ecologia e Conservação, Depto de Engenharia Ambiental, Setor de Tecnologia, Univ. Federal do Paraná, 81531, 980, Curitiba, Paraná, Brazil. Calls for the end of invasion biology are misguided. There is no evidence that modern invasion biology has progressed slowly in its short life. Although some aspects of biological invasions fit comfortably in the framework of ecological succession, many others do not. Some native species, particularly in the wake of various anthropogenic impacts, behave like invasive non-native species, but the probability and degree of harmful impact are greater for non-native than for native species. Neither native nor non-native species suffer lack of attention and research by virtue of the fact that invasion biology focuses on the latter. Basing management solely on current observed impact is highly risky because impacts may be subtle but nonetheless important, and impacts often change, as they are contingent on the physical or biotic environment. The known harmful impacts of many non-native species suggest that recent introductions warrant attention even if impacts are not evident. Neither is the focus of modern invasion biology on non-native species motivated by xenophobia. Rather, it reflects the recognition of their likelihood of harmful impact. A related call for the end of traditional restoration ecology shares many features with calls to terminate invasion biology, not least because management of invasive non-native species is a key component of restoration ecology. Such species are a dominant element in generating the ‘novel ecosystems’ that are said to render traditional restoration ecology obsolete. The argument that both invasion management and traditional restoration are largely futile endeavors is contradicted by substantial and growing successes in both fields. What is it about invasion biology? No one calls for an end to conservation biology or marine biology or aquatic ecology or physiological ecology, but now Valéry et al. (2013), following Davis (2009), call for an end to invasion biology, at least as we currently know it. Surely it is unusual for two authors (Davis 2009, Lefeuvre 2013 [a coauthor in Valéry et al.]) to write monographs on a subject while simultaneously calling for its immediate demise. However, a science wanes and disappears not because of such calls, but rather as researchers, particularly young ones not committed to a particular perspective, cease to find the old field exciting and progressive and find some other research paradigm more fruitful (Kuhn 1962, Lakatos 1970). In ecology, something of this sort occurred with the decline of phytosociology by the 1960s in favor of a more general plant ecology (Ewald 2003). By contrast, invasion biology is vibrant and growing, with entire journals devoted to the subject (e.g. Biological Invasions, NeoBiota, Aquatic Invasions, BioInvasions Records), numerous invasion articles in prominent ecology journals (e.g. Ecology, Diversity and Distributions, Ecology Letters, Molecular Ecology, Ecological Applications, Oikos) and conservation journals (e.g. Biological Conservation, Conservation Biology, Conservation Letters), a rising tide of invasion biology books (Simberloff 2004), an increasing number of regular international conferences (e.g. NeoBiota, EMAPi, Biolief, the international conferences on aquatic nuisance species, the ICBI conferences in China), and sessions every year at several annual society meetings. Is invasion biology proceeding too slowly? As do Valéry et al. (2013), Davis et al. (2005) and Davis (2009) lament what they see as the slow progress of invasion biology, which they attribute to the failure of invasion biologists to fold their discipline into the much older and, in their view, highly productive field of succession ecology. However, they present no evidence that modern invasion biology has progressed slowly in its short (ca 25 years – cf. Simberloff 2011b) existence, and the burgeoning plethora of papers, books and conferences cited above belies the claim. The very fact that Davis (2009) and Lefeuvre (2013) wrote entire monographs about modern invasion biology, with calls for its termination relegated to small sections, suggests that the field remains interesting and progressive. Davis (2009) even admitted that his call for its end was surely quixotic. In fact, Davis’s call led to a response by Lövei et al. (2012) that in turn inspired a new network (MDBI – Megadiverse Region BioInvasion Network) composed mostly of scientists from developing nations who aim to EV-1 protect the biodiversity of megadiverse regions from threats by invasive non-native species through collaboration on research and management strategies. If abolishing invasion biology by merging it with succession ecology would allow scientists to progress more rapidly in understanding and managing invasions, this abolition will arise not by pronouncements but by workers in the field recognizing the opportunities and progressively working under the new paradigm rather than the old one, as Kuhn (1962) and Lakatos (1970) describe for scientific progress in general. be studied if invasions were solely considered from the perspective of plant succession. The massive invasion of the yellow crazy ant Anoplolepis gracilipes on Christmas Island (O’Dowd et al. 2003, Abbott 2004), facilitated by a nonnative scale insect, is a good example. Traditional successional models would also not accommodate many of the aquatic invasions that are a leading feature of modern invasion biology (Gherardi 2007, Francis 2011). And some aquatic invasions have major impacts on adjacent terrestrial ecosystems, as has the introduction of mysid shrimp to Flathead Lake, USA (Spencer et al. 1991, Ellis et al. 2011). Are invasions just a part of ecological succession? Why not incorporate native species in invasion biology? Davis (2009) seeks to end invasion biology mainly because he feels the processes of plant succession subsume those of plant invasion, so the latter should be studied in the framework of the former rather than as part of a separate discipline. This is not a new argument. For instance, Egler (1942) suggested that the processes that led certain introduced plants in the Hawaiian Islands to spread widely and others to remain restricted or to die out were basically the same as those that drove certain native plant species to replace other native plant species during ordinary secondary succession and that the same sort of research would be needed to elucidate both phenomena. Unlike Davis (2009) and Davis et al. (2011), however, Egler (1947) recognized that the rapid impact of particular introduced plants, such as red mangrove Rhizophora mangle and Chilean mesquite Prosopis chilensis, was likely to surpass that of any native species. Davis (2009) and Davis et al. (2011) tend to downplay the impact of non-native species and incorporate them into the larger body of impacts of any kinds of species, native or non-native. However, as will be discussed in the next section, both the likelihood of substantial impact and the magnitude of impact are far greater for non-native species. In any event, the argument to incorporate invasion biology in succession ecology was directed at plants only (Davis et al. 2005), not at animals or microorganisms. As Elton (1927) pointed out in one of the earliest books on animal ecology, animal ecologists should understand plant succession because of its influence on animal population abundance and dynamics, but he also suggested that plant ecologists should study animals, not least because sometimes animal populations control plant succession. For instance, Egler (1947) pointed to introduced grazing livestock as “paramount” in the disintegration of the “conventional” concept of succession back to a climax. Research in invasion biology has provided a wealth of evidence not only on the specifics of Elton’s assertion (e.g. the influence of introduced reindeer: Leader-Williams 1988, goats: Cronk 1989, and rabbits: Copson and Whinam 1998, on plant succession) but also on how impacts of nonnative animal species are greatly influenced by introduced non-native plant species (Lewandowski 1982) or vice versa (Aplet 1990, Woodward et al. 1990). Certainly the progress of some invasions fits comfortably in traditional models of plant community succession, but other invasion phenomena are very different from successional processes (Egler 1947, Simberloff 2010). For example, many instances of “invasional meltdown” (Simberloff 2006) would scarcely EV-2 Similarly to Davis (2009) and Davis et al. (2011), Valéry et al. (2013) object to the focus of invasion biology on nonnative species, claiming that it has “restricted the relevance of the field both from theoretical and practical viewpoints.” A close examination of Valéry et al. (2013) shows that their title is an example of literary hyperbole, exploiting the prominence achieved by Davis’s earlier call. Valéry et al. (2013) do not really demand that scientists stop studying invasions. Rather, their gripe is that some native species act, in certain circumstances, in similar ways to some nonnative species that become invasive. This is true (see references in Simberloff et al. 2012). Valéry’s own doctoral dissertation on the rapidly spreading European intertidal grass Elymus athericus is an excellent example (Valéry 2006). It is also true that the number of such situations is a small fraction of the tally of those involving non-native species. For instance, in the United States, non-native plant species are 40 times more likely than native plant species to behave in ways that would be termed invasive (Simberloff et al. 2012). In those instances where native plant species have become troublesome and begun to replace native plants, this has almost always been in response to some major anthropogenic change in the environment, such as fire suppression or grazing of livestock (Simberloff et al. 2012). Furthermore, Paolucci et al. (2013) have shown that nonnative predators and herbivores inflict greater damage on prey and host populations, respectively, than do native predators and herbivores; likewise, Salo et al. (2007) found that, among terrestrial vertebrates, non-native predators are more dangerous than native predators to prey populations. The reason for these striking results has not been proven, but Aldo Leopold (1939) probably guessed it correctly – native species have coevolved with one another for eons, while introduction of a non-native species lacking the opportunity for coadaptation is likely to disrupt parts of the native ecosystem. Does science or society suffer because the relatively few native species that become problematic are not generally considered under the rubric ‘invasive species’? They are certainly still studied; this is why Simberloff (2011a) and Valéry et al. (2013) could easily cite a few. The nature of the particular damage caused by any non-native or native species and the reason some species are problematic and others are not are difficult questions that can be answered only by sustained study of the particular case at hand. We doubt that this is not being done simply because some problematic species is native. The junipers that Valéry et al. (2013) point to, following Leopold (1924, 1944), Simberloff et al. (2012) and many others, have been the subject of extensive research, both as to the cause of their spread and means of controlling it. To the extent that rapid expansions of native species shed light on invasions by non-native ones, this information is widely available in the ecological and management literature and is cited by invasion biologists. Is invasion biology xenophobic? Davis (2009) and Davis et al. (2011) level a darker charge against invasion biology’s focus on non-native species. They hint that it reflects or at least encourages xenophobia – consider, for instance, the title of Davis et al. (2011): “Don’t judge species on their origins.” This is an accusation long raised against invasion biology by writers in other fields, particularly the social sciences – e.g. philosophy (Sagoff 1999), history (Pauly 1996), art history (Helmreich 1997), anthropology (Tsing 1995), sociology (Larson 2011), geography (Warren 2011), women’s studies (Subramaniam 2001), garden architecture (Wolschke-Bulmahn 1997) – but occasionally by ecologists (Brown 1989). It has entered the popular media (Raffles 2011). In the United States, some critics of non-native species a century ago doubtless were motivated by the same nativist animus that swept American politics during this period, but there is little evidence that such motivations have been present during the rise of modern invasion biology (Coates 2006). Similar statements in Europe in the first half of the 20th century were at least partly motivated by xenophobia (Simberloff 2003). However, even during the prehistory of invasion biology, much of the early motivation for concern about non-native species and regulations governing them was demonstrable, highly visible ecological damage, such as that wrought by introduced predators and plant pathogens (Simberloff 2003). Does it make sense to focus on impacts, not origins? The notion of critics of invasion biology that management should focus on impacts rather than origins (Davis et al. 2011) is short-sighted on several grounds (cf. Simberloff 2013, Simberloff et al. 2013). First, invasion biology is a very young field, as noted above (cf. Pyšek and Hulme 2009), and very few non-native species have been studied in sufficient detail in their native and non-native ranges for us to have a good sense of what their impacts really are. Second, recent research shows that many introduced species (e.g. those that modify soil chemistry) have consequences for entire ecosystems that are initially subtle but ultimately as severe as those of the predatory animals and overgrowing plants that have attracted the most attention (Ehrenfeld 2011). Third, many non-native species persist innocuously in restricted areas and numbers for an extended period before suddenly exploding across the landscape (Crooks 2005). The reasons for these lag times are sometimes apparent and other times mysterious, but the fact of their existence is not in doubt. These lags contribute to what Essl et al. (2011) have termed an “invasion debt” of impacts that will occur in the future from invasions that have already occurred. Finally, the phenomenon of invasional meltdown, previously discussed, demonstrates that a currently harmless invader can cause major damage in the future if particular other species are introduced. Invasional meltdown and lag effects show that invasion impact may change drastically. It is contingent on presence or absence of other species and on changes in physical conditions that may be very slight but may greatly affect the extent and impact of an invasion (the “invasion cliff” phenomenon described by Davis 2009). Our limited knowledge of many invasion impacts, their contingency, and the demonstrably greater likelihood and size of non-native impact over native impact (Salo et al. 2007, Simberloff et al. 2012, Paolucci et al. 2013) imply that deciding on whether to attempt to control a non-native species based on its current perceived impact and not on its non-native origin is a highly risky strategy. Is it futile to fight invasions? Davis et al. (2011) also suggest that invasion biologists are overly focused on a futile fight to control many invasions for which substantial impacts are not evident, thereby wasting resources that could be better spent in the service of conservation. Thomas (2013) echoes this concern, seeing such programs as a “waste of effort” powered by an “irrational dislike of invading species.” These ideas are echoed by science writers (Marris 2010, Vince 2011). This argument is at least partly based on the faulty view that all invasions are targeted for action, when in fact managers and policymakers are forced by chronic lack of funding to focus almost exclusively on a few invaders with highly visible impacts, often associated with threats to agriculture or public health. This problem has long been lamented by invasive species managers and is the aegis for the broad effort among invasion biologists to produce risk assessment tools for management triage (Skinner et al. 2000, Stohlgren and Schnase 2006). For recent invaders that have not spread widely, the cost of action is often relatively low and, in light of the uncertainty about future impacts described above, it would be wise to attempt to eradicate or to contain them (Simberloff et al. 2013). Shackelford et al. (2013), who suggest that they are seeking a middle ground in the controversy over what to do about invasions, agree with this view. It is often feasible to minimize the impact of more widely distributed, longestablished invaders, and even sometimes to eradicate them, but they have been embedded so long in a native community that eliminating them or even reducing their populations might negatively affect native species (Shackelford et al. 2013, Simberloff et al. 2013). Each case should be judged on its own merits. However, it is important to recognize that there have been many successful management projects, even of widespread invaders, and the array of possible tools is expanding rapidly owing to research and increasing recognition of the importance of such projects (Simberloff 2009, 2014). A related call for the end of traditional restoration ecology It is not coincidental that, just as Davis (2009) and Valéry et al. (2013) are calling for an end to invasion biology, at EV-3 least as we currently know it, several restoration ecologists are calling for the end of restoration ecology as we know it (Hobbs et al. 2006, 2009, 2013, Seastedt et al. 2008, Hobbs 2013) as part of a “new world order” (Hobbs et al. 2006). A large component of restoration ecology has been the control or removal of non-native species (Jordan and Lubick 2011). The critics contend that the earth is increasingly dominated by ‘novel ecosystems’, generated by an influx of non-native species and shifting ranges of native species in response to various anthropogenic forces, including climate change. Therefore, according to this line of reasoning, it is futile in many instances to try to remove non-native species in an attempt to restore past conditions, and instead we should focus on promoting and molding novel ecosystems to provide desired ecosystem services. The key role of non-native species in novel ecosystems, and the overlapping authorship of manifestos against invasion biology on the one hand and heralds of the primacy of novel ecosystems on the other (Richard Hobbs, Ariel Lugo, Mark Gardener, Timothy Seastedt, Katharine Suding) suggest that these two arguments are closely linked. For instance, Standish et al. (2013) transfer the argument of Davis et al. (2011) that we should concentrate on impacts of species, not their origins, to the matter of what species to target in ecological restoration. As with some criticisms of invasion biology, a close examination reveals that many advocates of a new restoration ecology (Standish et al. 2013) are not actually calling for eliminating traditional restoration ecology. Rather, they seek to broaden the field, so that the focus is not exclusively on attempting to restore ecosystems to a semblance of some historical reference ecosystem, or, as the field has evolved more recently in recognition of the fact of ongoing changes of various degrees, some historical ecosystem trajectory (Clewell and Aronson 2013). Standish et al. (2013), for example, emphasize that they do not favor abandoning attempts to manage exotics, so long as the focus is on their impacts rather than their non-nativeness – exactly an agenda of Davis et al. (2011). Other proponents of abandoning traditional restoration ecology in favor of a new field focusing on understanding and molding novel ecosystems are not as conciliatory. For instance, Marris (2013), a noted skeptic of the importance of invasion impacts (cf. Marris 2009), believes the “pristine” environments that restoration ecologists have sought to recreate, such as oldgrowth forests, never existed in the first place, while Hobbs (2013) sees advocates of traditional restoration ecology as psychologically trapped in a sequence of states analogous to those characterizing grieving for deceased loved ones. Discussion Calls to end invasion biology are based primarily on the view that the field has not advanced quickly enough by virtue of not incorporating itself into succession ecology and its focus on non-native species, but the explosion of invasion research and literature belies that assertion. Some invasions do fit comfortably into the succession framework, but many others do not. Neither is it the case that similar phenomena to those manifested in invasions, when they EV-4 arise in native species, fail to be studied because they are excluded from the mainstream of invasion biology. The recent calls for the end of invasion biology come amidst a long history of charges that the entire enterprise of studying and managing invasions is a manifestation of displaced xenophobia. These arguments usually arise from outside biology, and they consist of a social construction of the science and fail to account for the evident focus of invasion biologists on impacts. There is no evidence that modern invasion biology is infected by xenophobia. In fact, the focus of the field on non-native species is precisely because they are far more likely than native species to produce harmful ecological impacts. A focus solely on current observed impacts, ignoring whether a species is native or not, would risk delaying important measures that could limit or, in some cases, eliminate invasion impacts. Traditional ecological restoration has also been targeted for termination, in favor of ‘novel ecosystems’ consisting of introduced species and native species whose ranges have shifted owing primarily to climate change. The dominant motivation is a slight expansion of the argument that fighting invasive species is largely futile – including in this case both invasive species and climate change. As with calls to give up on invasive species and learn to appreciate what we have (Marris 2011, Thomas 2013), the argument to give up on traditional restoration also sees a silver lining – in this case, the possibility that novel ecosystems can be molded to yield ecosystem services for humankind. Yet there has been progress in ecological restoration, and there are success stories (Rey Benayas et al. 2009, Moreno-Mateos et al. 2012), while the science of molding novel ecosystems so that they reliably yield a range of ecosystems services is in its earliest infancy. Finally, calls to end invasion biology, such as those by Davis (2009) and Valéry et al. (2013), can influence policies and management. They can provide carte blanche to policymakers (who often lack the time, training, or inclination to read and analyze the details of an abstract argument or to recognize academic hyperbole) to think and act in terms of the short-term profit that introductions can bring or the short-term costs that managing them would impose, rather than potential long-term consequences, like losses of species and ecosystems that will be remarkable and significant for future generations (cf. Rodewald 2012). Similarly, arguments that traditional restoration ecology is inappropriate for today’s challenges, as advanced by Hobbs et al. (2006, 2009, 2013), Seastedt et al. (2008), and Hobbs (2013), risk jeopardizing large-scale, restoration efforts supported by governments in mega-diverse nations and elsewhere (J. Aronson pers. comm. 2013). The public can easily be led to believe that a major scientific controversy exists when a few credentialed critics repeatedly say that it does, thus delaying important actions (Oreskes and Conway 2010). The experience in the United States with critics of Darwinian evolution and the notion of anthropogenic climate change come to mind. Leaders of major conservation organizations recently deplored the threat that the barrage of criticisms of invasion biology outlined above pose to numerous sound management programs for invaders worldwide (Lambertini et al. 2011). It would be a pity if effective programs for managing invasive species and restoring ecosystems damaged by them were hindered by a barrage of charges that do not stand up to scrutiny. References Abbott, K. L. 2004. Alien ant invasion on Christmas Island, Indian Ocean: the role of ant-scale mutualisms in the dynamics of supercolonies of the yellow crazy ant, Anoplolepis gracilipes. – PhD thesis, Biological Sciences, Monash Univ., Melbourne, Australia. Aplet, G. H. 1990. Alteration of earthworm community biomass by the alien Myrica faya in Hawaii. – Oecologia 82: 411–416. Brown, J. H. 1989. Patterns, modes and extents of invasions by vertebrates. – In: Drake, J. A. et al. (eds), Biological invasions: a global perspective, pp. 85–109. Clewell, A. and Aronson, J. 2013. Ecological restoration, 2nd ed. – Island Press. Coates, P. A. 2006. American perceptions of immigrant and invasive species: strangers on the land. – Univ. of California Press. Copson, G. and Whinam, J. 1998. Response of vegetation on subantarctic Macquarie Island to reduced rabbit grazing. – Aust. J. Bot. 46: 15–24. Cronk, Q. C. B. 1989. The past and present vegetation of St. Helena. – J. Biogeogr. 16: 47–64. Crooks, J. A. 2005. Lag times and exotic species: the ecology and management of biological invasions in slow-motion. – Écoscience 12: 316–329. Davis, M. A. 2009. Invasion biology. – Oxford Univ. Press. Davis, M. A. et al. 2005. Vegetation change: a reunifing concept in plant ecology. – Persp. Plant Ecol. Evol. Syst. 7: 69–76. Davis, M. A. et al. 2011. Don’t judge species on their origins. – Nature 474: 153–154. Egler, F. E. 1942. Indigene versus alien in the development of arid Hawaiian vegetation. – Ecology 23: 14–23. Egler, F. E. 1947. Arid southeast Oahu vegetation, Hawaii. – Ecol. Monogr. 17: 383–435. Ehrenfeld, J. G. 2011. Ecosystem consequences of biological invasions. – Annu. Rev. Ecol. Evol. Syst. 41: 59–80. Ellis, B. K. et al. 2011. Long-term effects of a trophic cascade in a large lake ecosystem. – Proc. Natl Acad. Sci. USA 108: 1070–1075. Elton, C. S. 1927. Animal ecology. – Macmillan. Essl, F. et al. 2011. Socioeconomic legacy yields an invasion debt. – Proc. Natl Acad. Sci. USA 108: 203–207. Ewald, J. 2003. A critique for phytosociology. – J. Veg. Sci. 14: 291–296. Francis, R. A. (ed.) 2011. A handbook of global invasive freshwater species. – Earthscan. Gherardi, F. (ed.) 2007. Biological invaders in inland waters: profiles, distribution and threats. – Springer. Helmreich, A. L. 1997. Re-presenting nature: ideology, art and science in William Robinson’s ‘Wild garden.’ – In: Wolschke-Bulmahn, J. (ed.), Nature and ideology. Natural garden design in the twentieth century. Dumbarton Oaks, pp. 81–111. Hobbs, R. J. 2013. Grieving for the past and hoping for the future: balancing polarizing perspectives in conservation and restoration. – Restor. Ecol. 21: 145–148. Hobbs, R. J. et al. 2006. Novel ecosystems: theoretical and management aspects of the new ecological world order. – Global Ecol. Biogeogr. 15: 1–7. Hobbs, R. J. et al. 2009. Novel ecosystems: implications for conservation and restoration. – Trends Ecol. Evol. 24: 599–605. Hobbs, R. J. et al. (eds) 2013. Novel ecosystems: intervening in the new ecological world order. – Wiley. Jordan, W. R. III, and Lubick, G. M. 2011. Making nature whole. A history of ecological restoration. – Island Press. Kuhn, T. S. 1962. The structure of scientific revolutions. – Univ. of Chicago Press. Lakatos, I. 1970. Falsification and the methodology of scientific research programmes – In: Lakatos, I. and Musgrave, A. (eds), Criticism and the growth of knowledge. – Cambridge Univ. Press, pp. 91–196. Lambertini, M. et al. 2011. Invasives: a major conservation threat. – Science 333: 404–405. Larson, B. M. H. 2011. Metaphors for environmental sustainability. – Yale Univ. Press. Leader-Williams, N. 1988. Reindeer on South Georgia: the ecology of an introduced population. – Cambridge Univ. Press. Lefeuvre, J.-C. 2013. Les invasions biologiques. Un danger pour la biodiversité. – Buchet Chastel. Leopold, A. 1924. Grass, brush, timber, and fire in southern Arizona. – J. For. 22: 1–10. Leopold, A. 1939. A biotic view of the land. – J. For. 37: 727–730. Leopold, A. 1944. Review of ‘‘Fighting the mesquite and cedar invasion on Texas ranges,’’ by H. M. Bell and E. J. Dyksterhuis (Soil Conserv. 9: 111–114. 1943). – J. For. 42: 63. Lewandowski, K. 1982. The role of early developmental stages in the dynamics of Dreissena polymorpha (Pall.) (Bivalvia) populations in lakes. II. Settling of larvae and the dynamics of numbers of settled individuals. – Ekol. Polska 30: 223–286. Lövei, G. L. et al. 2012. Megadiverse developing countries face huge risks from invasives. – Trends Ecol. Evol. 27: 2–3. Marris, E. 2009. The end of the invasion? – Nature 459: 327–328. Marris, E. 2010. The new normal. – Conserv. Mag. 11: 13–17. Marris, E. 2011. Rambunctious garden: saving nature, in a post-wild World. – Bloomsbury. Marris, E. 2013. Coming of age in a trash forest. – In: Hobbs, R. J. et al. (eds), Novel ecosystems: intervening in the new ecological World order. – Wiley, pp. 245–246. Moreno-Mateos, D. et al. 2012. Structural and functional loss in restored wetland ecosystems. – PLoS Biol. 10:e1001247 O’Dowd, D. J. et al. 2003. Invasional meltdown on an oceanic island. – Ecol. Lett. 6: 812–817. Oreskes, N. and Conway, E. M. 2010. Merchants of doubt. – Bloomsbury. Paolucci, E. M. et al. 2013. Origin matters: alien consumers inflict greater damage on prey populations than do native consumers. – Divers. Distrib. 19: 988–995. Pauly, P. J. 1996. The beauty and menace of the Japanese cherry trees. – Isis 87: 51–73. Pyšek, P. and Hulme, P. 2009. Invasion biology is a discipline that’s too young to die. – Nature 460: 324–324. Raffles, H. 2011. Mother nature’s melting pot. – New York Times, April 3, p. WK12. Rey Benayas, J. M. et al. 2009. Enhancement of biodiversity and ecosystem services by ecological restoration: a meta-analysis. – Science 325: 1121–1124. Rodewald, A. D. 2012. Spreading messages about invasives. – Divers. Distrib. 18: 97–99. Sagoff, M. 1999. What’s wrong with exotic species? – Rep. Inst. Philos. Public Policy 19: 16–23. Salo, P. et al. 2007. Alien predators are more dangerous than native predators to prey populations. – Proc. R. Soc. B 274: 1237–1243. Seastedt, T. R. et al. 2008. Management of novel ecosystems: are novel approaches required? – Front. Ecol. Environ. 6: 547–553. EV-5 Shackelford, N. et al. 2013. Finding a middle-ground: the native/ non-native debate. – Biol. Conserv. 158: 55–62. Simberloff, D. 2003. Confronting introduced species: a form of xenophobia? – Biol. Invas. 5: 179–192. Simberloff, D. 2004. A rising tide of species and literature: a review of some recent books on biological invasions. – BioScience 54: 247–254. Simberloff, D. 2006. Invasional meltdown six years later – important phenomenon, unfortunate metaphor, or both? – Ecol. Lett. 9: 912–919. Simberloff, D. 2009. We can eliminate invasions or live with them! – High-tech and low-tech success stories. – Biol. Invas. 11: 149–157. Simberloff, D. 2010. Invasions of plant communities – more of the same, or something very different? – Am. Midl. Nat. 163: 219–232. Simberloff, D. 2011a. “Native invaders.” – In: Simberloff, D. and Rejmánek, M. (eds), Encyclopedia of biological invasions. – Univ. of California Press, pp. 472–475. Simberloff, D. 2011b. Charles Elton – neither founder nor siren, but prophet. – In: Richardson, D. M. (ed.), Fifty years of invasion ecology. – Wiley, pp. 11–24. Simberloff, D. 2013. A world in peril? The case for containment. – In: Dobson, A. et al. (eds), Biosecurity: the sociopolitics of invasive species and infectious diseases. – Earthscan, pp. 29–43. Simberloff, D. 2014. Biological invasions: what’s worth fighting and what can be won? – Ecol. Engin., in press. Simberloff, D. et al. 2012. The natives are restless, but not often and mostly when disturbed. – Ecology 93: 598–607. Simberloff, D. et al. 2013. Impacts of biological invasions – what’s what and the way forward. – Trends Ecol. Evol. 28: 58–66. Skinner, K. et al. 2000. Using noxious weed lists to prioritize targets for developing weed management strategies. – Weed Sci. 48: 640–644. Spencer, C. N. et al. 1991. Shrimp stocking, salmon collapse, and eagle displacement. – BioScience 41: 14–21. EV-6 Standish, R. J. et al. 2013. Concerns about novel ecosystems. – In: Hobbs, R. J. et al. (eds), Novel ecosystems: intervening in the new ecological World order. – Wiley, pp. 296–309. Stohlgren, T. J. and Schnase, J. L. 2006. Risk analysis for biological hazards: what we need to know about invasive species. – Risk Anal. 26: 163–173. Subramaniam, B. 2001. The aliens have landed! Reflections on the rhetoric of biological invasions. – Meridians Feminism Race Transnationalism 2: 26–40. Thomas, C. D. 2013. The Anthropocene could raise biological diversity. – Nature 502: 7. Tsing, A. L. 1995. Empowering nature, or: some gleanings in bee culture. – In: Yanagisako, S. and Delaney, C. (eds), Naturalizing power. Essays in feminist cultural analysis. – Routledge, pp. 113–143. Valéry, L. 2006. Approche systémique de l’impact d’une espèce invasive. Le cas d’une espèce indigène dans un milieu en voie d’eutrophisation. – PhD thesis, Mus. Natl d’Hist. Nat., Paris. Valéry, L. et al. 2013. Another call for the end of invasion biology. – Oikos 122: 1143–1146. Vince, G. 2011. Embracing invasives. – Science 331: 1383–1384. Warren, C. 2011. Nativeness and nationhood: what species “belong” in post-devolution Scotland? – In: Rotherham, I. D. and Lambert, R. A. (eds), Invasive and introduced plants and animals. Human perceptions, attitudes and approaches to management. – Earthscan, pp. 67–79. Wolschke-Bulmahn, J. 1997. The nationalization of nature and the naturalization of the German nation: ‘teutonic’ trends in early twentieth-century landscape design. – In: Wolschke-Bulmahn, J. (ed.), Nature and ideology. Natural garden design in the twentieth century – Dumbarton Oaks, pp. 187–219. Woodward, S. A. et al. 1990. Use of the exotic tree Myrica faya by native and exotic birds in Hawai’i Volcanoes National Park. – Pac. Sci. 44: 88–93.