Gregory+Niguidula+-+Literature+Review+-+First+Draft

Invasion ecology and many of its guiding principles were first put forward by Charles Elton in his 1958 book //The Ecology of Invasions by Animals and Plants//. The book was actually written for a general audience, rather than just fellow scientists(Ricciardi and MacIsaac). The concept of species invasions was not introduced in this text, but the idea that but the idea that these invasions were not anomalies but indicative of a larger, human-created problem. It has been noted that the book made heavy use of war metaphors. Some have speculated that his framing of the invasions stems from his experiences during World War II, both as a scientist tasked by the British government with controlling rat and rabbit populations and as a British citizen living in fear of Nazi invasion. In any case, the book is also credited with creating a divide between invasion ecology and the rest of the scientific community that has persisted to the present day. Later works by Elton would solidify this divide by distinguishing between species dispersal and species invasions, a distinction that has been criticized, but remains widely accepted (Davis, Thompson, and Grime). Though Elton’s book was published in 1958, invasion ecology did not “take off” as a field until 1991, a year that saw the number of invasion ecology publications skyrocket. Since then the number of publications has continued to increase (Ricciardi and MacIsaac). In fact, some said that the field was becoming glutted with theories, ideas, and issues (Davis 1) Another notable problem that has plagued the field is the lack of clear consensus on what constitutes an invasive species. The lack of definition is problematic, especially when one has to distinguish between native species, alien species, and the many other classifications. There have been several attempts to remediate this. In 2000, Davis and Thompson crafted a species classification scheme based on three factors: dispersal distance, uniqueness, and impact in the new environment. Each category is dichotomous; dispersal distance is long or short, uniqueness is novel or common to the region colonized, and impact can be small or great. This leads to eight possible classifications, but the authors argued that a species can only be considered invasive if uniqueness is novel and the impact is great, otherwise the species is harmless (Davis and Thompson). In 2004, Colautti and MacIsaac similarly attempted to clarify the field’s terminology, but instead of giving new definitions to terms already in common use such as invasive, alien, exotic, etc. they created a conceptual framework that allows for the subclassifcation of nonindigenous species into one of six stages (labelled 0 to 5).Each stage represents a different part of the invasion timeline. Stage 0 is when the potential invader resides in a donor region; Stage 1 is when the species is being carried to a new environment by a transportation vector of some kind; Stage 2 is when the species has been introduced, Stage 3 is when the species has become established; Stage 4 is divided into two, species reach 4a when they have become widespread (but not dominant) and 4b when they have become dominant (but not widespread); finally, a species reaches stage 5 when it has become both widespread and dominant in the new environment (Colautti and MacIsaac). By establishing a new system of terminology instead of trying to redefine old terms, the authors hoped that the integration of their system into future literature would be easier than that proposed by Davis and Thompson. However, neither system has been widely adopted. Mark Davis in a later text concluded that while it is problematic for the field to be without standardized definitions, it may not be worth the effort (Davis). He and his colleagues, however, have not stopped trying to change how invasion ecologists operate Unfortunately, lack of standardized language is only the first among many criticisms levelled at the field. Another ongoing debate pertains to the true danger that invasive species present. While it is generally agreed that certain species have been responsible for significant damage to ecosystems they have been introduced to, there is contention over whether such cases are exceptional or the norm and whether the fear of these things have been overblown. Those that subscribe to the first set of ideals have been called overly cautious, those that subscribe to the second have been called xenophobic, and both have been criticized for lack of evidence (Simberloff). The debate is exemplified in a series of letters published in //Trends in Ecology and Evolution// and papers published other journals. In 2011, Davis and eighteen of his colleagues published a critique of the field of invasion ecology that advocated for assessing the value of a species not based on whether it is native or invasive to an area, but on its potential for damage to the ecosystem, the economy, and human lives and even provided examples of species detrimental in their native habitats (Davis et al.). In 2013, a review article published by Daniel Simberloff and several others dismissed the idea of beneficial non-native species, arguing that harmful and beneficial were purely subjective terms and that often perceived benefits actually had hidden costs. They also argued that it was the duty of scientists to inform the public about the negative impacts of invasive species (Simberloff). In response, scientists from the ZiF Working Group on Ecological Novelty wrote a letter criticizing these assertions, positing that there simply is not enough information available for invasion ecologists to reliably fulfill the advisory roles on these matters (Larson and Kueffer). This prompted Simberloff and his colleagues to write their own letter defending their position, submitting for consideration the idea that refusing to act because there is high uncertainty is more dangerous than taking an action that may or may not be correct (Simberloff, Maris, and Martin). Both letters also addressed the issue of military terminology within invasive ecology literature. The ZiF working group disapproved of invasive species being compared to moving armies in the Simberloff review saying that such language prompts people to action despite the high uncertainty. Brenden Larson addressed the issue more completely in an earlier paper, which criticized the phenomenon for creating a militaristic framework that is not adequate for the issue of invasive species. Larson concluded that militaristic terminology should be dispensed with because the ultimate effects were inaccurate perceptions of invasive species, societal misunderstandings, charges of xenophobia, and thought patterns that are counterproductive to conservation (Larson). This is not a recent development, however. The use of military metaphors began with Elton’s book, the first chapter of which opens with the following sentences: Nowadays we live in a very explosive world, and while we may not know where or when the next outburst will be, we might hope to find ways of stopping it or at any rate damping down its force. It is not just nuclear bombs and wars that threaten us, though these rank very high on the list at the moment: there are other sorts of explosions, and this book is about ecological explosions. (Elton 15) This is likely a result of both Elton’s experiences during World War II and the fact that the text was written for the layman to read. Overall, the field appears to be developing more nuanced positions on invasive species. Despite the disagreements with Davis’ team, Simberloff and his colleagues also dismiss the idea that native species are inherently “good” and invasive species are inherently “bad.” In an interview for Scientific American, Davis detailed how he eventually to hold that view. Initially, he, like the majority of his colleagues, was vehemently against the existence of invasive species until, in 1994, he read an article that described attempts to recreate ecosystems of the past as futile. This eventually led to him reformulating his viewpoint to tolerate introduced species that had no harmful effects on the environment (Borrell). Still, not all scientists are quite convinced of this. Most recently, Tassin and Kull published an article explaining that such an attitude only contributes to the creation of //desired natures//, which are the idealized versions of nature that society holds within its collective conscience. This is problematic because societal preferences are not necessarily ecologically beneficial (Tassin and Kull). It seems that this way of thinking is gradually taking hold. In the future, it will be interesting to see how it translates to the general public and policymakers’ decisions.

Borrell, Brendan. “A Friend to Aliens.” //Scientific American// 304.2 (2011): 74–77. //www.nature.com//. Web. 9 Nov. 2014. Colautti, Robert I., and Hugh J. MacIsaac. “A Neutral Terminology to Define ‘invasive’ Species.” //Diversity and Distributions// 10.2 (2004): 135–141. //Wiley Online Library//. Web. 8 Sept. 2014. Davis, Mark A. et al. “Don’t Judge Species on Their Origins.” //Nature// 474.7350 (2011): 153–154. //www.nature.com//. Web. 15 Oct. 2014. ---. //Invasion Biology//. OUP Oxford, 2009. Web. 12 Nov. 2014. Davis, Mark A., and Ken Thompson. “Eight Ways to Be a Colonizer; Two Ways to Be an Invader: A Proposed Nomenclature Scheme for Invasion Ecology.” //Bulletin of the Ecological Society of America// (2000): 226–230. Print. Davis, Mark A., Ken Thompson, and J. Philip Grime. “Charles S. Elton and the Dissociation of Invasion Ecology from the Rest of Ecology.” //Diversity and Distributions// 7 (2001): 97–102. Print. Elton, Charles S. //The Ecology of Invasions by Animals and Plants//. Great Britain: Methuen & Co Ltd, 1958. Print. Larson, Brendon M. H. “The War of the Roses: Demilitarizing Invasion Biology.” //Frontiers in Ecology and the Environment// 3.9 (2005): 495. //CrossRef//. Web. 19 Nov. 2014. Larson, Brendon M. H., and Christoph Kueffer. “Managing Invasive Species amidst High Uncertainty and Novelty.” //Trends in Ecology & Evolution// 28.5 (2013): 255–256. //ScienceDirect//. Web. 15 Oct. 2014. Ricciardi, Anthony, and Hugh J. MacIsaac. “In Retrospect: The Book That Began Invasion Ecology.” //Nature// 452.7183 (2008): 34–34. //www.nature.com//. Web. 15 Oct. 2014. Simberloff, Daniel. “Biological Invasions: What’s Worth Fighting and What Can Be Won?” //Ecological Engineering// 65 (2014): 112–121. //ScienceDirect//. Web. 6 Sept. 2014. Simberloff, Daniel, Virginie Maris, and Jean-Louis Martin. “Inaction ≠ Caution: Response to Larson, Kueffer, and the ZiF Working Group on Ecological Novelty.” //Trends in Ecology & Evolution// 28.5 (2013): 257. //ScienceDirect//. Web. 15 Oct. 2014. Tassin, Jacques, and Christian A. Kull. “Facing the Broader Dimensions of Biological Invasions.” //Land Use Policy// 42 (2015): 165–169. //ScienceDirect//. Web. 7 Sept. 2014.