Invasive species denialism revisited: response to Sagoff

Using the IUCN Environmental Impact Classification for Alien Taxa to inform decision-making

The Environmental Impact Classification for Alien Taxa (EICAT) is an important tool for biological invasion policy and management and has been adopted as an International Union for Conservation of Nature (IUCN) standard to measure the severity of environmental impacts caused by organisms living outside their native ranges. EICAT has already been incorporated into some national and local decision-making procedures, making it a particularly relevant resource for addressing the impact of non-native species. Recently, some of the underlying conceptual principles of EICAT, particularly those related to the use of the precautionary approach, have been challenged. Although still relatively new, guidelines for the application and interpretation of EICAT will be periodically revisited by the IUCN community, based on scientific evidence, to improve the process. Some of the criticisms recently raised are based on subjectively selected assumptions that cannot be generalized and may harm global efforts to manage biological invasions. EICAT adopts a precautionary principle by considering a species' impact history elsewhere because some taxa have traits that can make them inherently more harmful. Furthermore, non-native species are often important drivers of biodiversity loss even in the presence of other pressures. Ignoring the precautionary principle when tackling the impacts of non-native species has led to devastating consequences for human well-being, biodiversity, and ecosystems, as well as poor management outcomes, and thus to significant economic costs. EICAT is a relevant tool because it supports prioritization and management of non-native species and meeting and monitoring progress toward the Kunming-Montreal Global Biodiversity Framework (GBF) Target 6.

Logical fallacies persist in invasion biology and blaming the messengers will not improve accountability in this field: a response to Frank et al

We analyze the "Logical fallacies and reasonable debates in invasion biology: a response to Guiaşu and Tindale" article by Frank et al., and also discuss this work in the context of recent intense debates in invasion biology, and reactions by leading invasion biologists to critics of aspects of their field. While we acknowledge the attempt by Frank et al., at least in the second half of their paper, to take into account more diverse points of view about non-native species and their complex roles in ecosystems, we also find the accusations of misrepresenting invasion biology, for instance by "cherry-picking" and "constructing 'straw people'", directed at the Guiaşu and Tindale study to be unwarranted. Despite the sometimes harsh responses by leading invasion biologists to critics of their field, we believe that persistent and fundamental problems remain in invasion biology, and we discuss some of these problems in this article. Failing to recognize these problems, and simply dismissing or minimizing legitimate criticisms, will not advance the cause, or enhance the general appeal, of invasion biology and will prevent meaningful progress in understanding the multiple contributions non-native species can bring to various ecosystems worldwide. We recommend taking a more open-minded and pragmatic approach towards non-native species and the novel ecosystems they are an integral part of.

Defining invasive species and demonstrating impacts of biological invasions: a scientometric analysis of studies on invasive alien plants in Brazil over the past 20 years

Despite biological invasions being widely recognised as an important driver of environmental change, lack of consensus regarding the definition of invasive alien species (IAS) and vagueness around the demonstration of their impacts limits knowledge and research in this field. In this study, a scientometric approach was used to analyse academic documents published between 2002 and 2021 in three databases with reference to invasive alien plants in Brazil. Despite the growing body of scientific literature in the area, only 10% of the publications provided some definition of invasive species. Of the 398 publications analysed, 23.6% found some type of damage caused by the invader and, of these, only 5% addressed economic or social damage. Only 17% of the publications proposed a method for controlling and/or mitigating biological invasions. The absence of clear terminology and the lack of focus on impacts limits understanding of IAS of plants in Brazil. Based on the present findings, future studies on IAS of plants should move towards a consensus on the definition of biological invasion, as well as understand the impact caused by these species. In addition, it is recommended that further scientometric studies should guide future efforts to support objective measures for management and decision-making.

From anti-science to environmental nihilism: the Fata Morgana of invasive species denialism

Invasive species denialism (ISD) is a controversial and hitherto underexplored topic, particularly with regard to its potential impacts on stakeholder engagement in support of invasive species management and policy. We examined how ISD is framed within the Great Lakes invasive species community, as well as the impacts of excluding and including those perceived as denialists in engagement efforts. We interviewed key informants in the region to gain an understanding of their framings of ISD, as well as focus groups allowing participants to discuss the impacts of exclusion and inclusion of stakeholders during the engagement process. ISD discussions were organised into three framings: 1) invasive species denialism; 2) invasive species cynicism; 3) invasive species nihilism. Participants raised concerns about outright exclusion of stakeholders and offered recommendations for mitigation of the impacts of inclusion of proponents of ISD in during stakeholder engagement. Our results have shown that a better understanding of the different framings of ISD is crucial to improve communication with stakeholders and to better inform responses and mitigation efforts. The newly defined framings of invasive species cynicism and invasive species nihilism demonstrate that more targeted responses to specific forms of ISD are needed to improve stakeholder engagement outcomes.

The Sixth Mass Extinction: fact, fiction or speculation?

There have been five Mass Extinction events in the history of Earth's biodiversity, all caused by dramatic but natural phenomena. It has been claimed that the Sixth Mass Extinction may be underway, this time caused entirely by humans. Although considerable evidence indicates that there is a biodiversity crisis of increasing extinctions and plummeting abundances, some do not accept that this amounts to a Sixth Mass Extinction. Often, they use the IUCN Red List to support their stance, arguing that the rate of species loss does not differ from the background rate. However, the Red List is heavily biased: almost all birds and mammals but only a minute fraction of invertebrates have been evaluated against conservation criteria. Incorporating estimates of the true number of invertebrate extinctions leads to the conclusion that the rate vastly exceeds the background rate and that we may indeed be witnessing the start of the Sixth Mass Extinction. As an example, we focus on molluscs, the second largest phylum in numbers of known species, and, extrapolating boldly, estimate that, since around AD 1500, possibly as many as 7.5-13% (150,000-260,000) of all ~2 million known species have already gone extinct, orders of magnitude greater than the 882 (0.04%) on the Red List. We review differences in extinction rates according to realms: marine species face significant threats but, although previous mass extinctions were largely defined by marine invertebrates, there is no evidence that the marine biota has reached the same crisis as the non-marine biota. Island species have suffered far greater rates than continental ones. Plants face similar conservation biases as do invertebrates, although there are hints they may have suffered lower extinction rates. There are also those who do not deny an extinction crisis but accept it as a new trajectory of evolution, because humans are part of the natural world; some even embrace it, with a desire to manipulate it for human benefit. We take issue with these stances. Humans are the only species able to manipulate the Earth on a grand scale, and they have allowed the current crisis to happen. Despite multiple conservation initiatives at various levels, most are not species oriented (certain charismatic vertebrates excepted) and specific actions to protect every living species individually are simply unfeasible because of the tyranny of numbers. As systematic biologists, we encourage the nurturing of the innate human appreciation of biodiversity, but we reaffirm the message that the biodiversity that makes our world so fascinating, beautiful and functional is vanishing unnoticed at an unprecedented rate. In the face of a mounting crisis, scientists must adopt the practices of preventive archaeology, and collect and document as many species as possible before they disappear. All this depends on reviving the venerable study of natural history and taxonomy. Denying the crisis, simply accepting it and doing nothing, or even embracing it for the ostensible benefit of humanity, are not appropriate options and pave the way for the Earth to continue on its sad trajectory towards a Sixth Mass Extinction.

Invasion costs, impacts, and human agency: response to Sagoff 2020

Article impact statement: In an era of profound biodiversity crisis, invasion costs, invader impacts, and human agency should not be dismissed.

Fact and value in invasion biology

Some invasion biologists contend their science has reached a consensus on 4 facts: cost estimates of the effects of nonindigenous species provided in papers by Pimentel et al. are credible; invasive species generally, not just predators, pose significant extinction threats; characteristic biological differences distinguish novel from native species, ecosystems, communities, and processes; and ontological dualism, which distinguishes between natural and anthropogenic processes and influences, plays a useful role in biological inquiry. I contend there is no convincing empirical evidence for any of these propositions. Leading invasion biologists cite their agreement about these propositions as evidence for them and impugn the motives of critics who believe consensus should be based on evidence not the other way around.

On allegations of invasive species denialism

Science denialism retards evidenced-based policy and practice and should be challenged. It has been a particular concern for mitigating global environmental issues, such as anthropogenic climate change. But allegations of science denialism must also be well founded and evidential or they risk eroding public trust in science and scientists. Recently, 77 published works by scholars, scientists, and science writers were identified as containing invasive species denialism (ISD; i.e., rejection of well-supported facts about invasive species, particularly the global scientific consensus about their negative impacts). We reevaluated 75 of these works but could find no examples of refutation of scientific facts and only 5 articles with text perhaps consistent with one of the 5 characteristics of science denialism. We found, therefore, that allegations of ISD were misplaced. These accusations of science denialism may have arisen because invasion biology defines its subjects-invasive species-based on multiple subjective and normative judgments. Thus, more than other applied sciences its consensus is one of shared values as much as agreed knowledge. Criticisms of invasion biology have largely targeted those subjective and normative judgments and their global imposition, not the knowledge on which the discipline is based. Regrettably, a few invasion biologists have misinterpreted the critique of their values-based consensus as a denial of their science when it is not. To make invasion biology a more robust and widely accepted science and to avoid unnecessary misunderstandings and conflicts, invasion biologists could be more accepting of perspectives originating from other disciplines and more open to values-based critique from scholars and scientists outside their field. This recommendation applies to all conservation sciences, especially those addressing global challenges, because these sciences must serve and be relevant to communities with an extraordinary diversity of cultures and values.

Invasive species denialism: Sorting out facts, beliefs, and definitions

In the last decades, thousands of investigations confirmed the detrimental effects of species translocated by man outside of their native ranges (nonindigenous species, or NIS). However, results concluding that many NIS have null, neutral, or positive impacts on the biota and on human interests are as common in the scientific literature as those that point at baneful impacts. Recently, several scholars confronted the stand that origin per se is not a reliable indicator of negative effects, suggesting that such conclusions are the expression of scientific denialism, often led by spurious purposes, and that their numbers are increasing. When assessed in the context of the growing interest in introduced species, the proportion of academic publications claiming that NIS pose no threats to the environment and to social and economic interests is extremely low, and has not increased since 1990. The widely prevailing notion that many NIS are effectively or potentially harmful does not conflict with the fact that most have mixed (negative, neutral, and positive) impacts. When based on solid grounds, reports of positive or neutral impacts should not be labeled as manipulative or misleading unless proven otherwise, even if they may hamper interest in- and funding of research and control bioinvasion programs.