¹ Margolis, Mac, “Attack of the Aliens: Migrating Species May Be the Biggest Threat to Plant and Animal Life on the Planet,” Newsweek, January 15, 2007Google Scholar.

² To determine that a species is “injurious,” USDA completes a review process including the following steps: petition or initiation of an evaluation; notice for information; proposed rule; economic analysis; and final rule. For a flow chart annotating this process, see http://www.fws.gov/contaminants/ANS/pdf_files/InjuriousWildlifeEvaluationProcessFlowChart.pdf.

³ A complete list can be found in the Federal Register at http://www.fws.gov/contaminants/ANS/pdf_files/50CF_16_10-05.pdf.

⁴ Noxious Weed Regulations, 7 C.F.R. 360.200 (2008). The Plant Protection Act became law in 2000 as part of the Agricultural Risk Protection Act.

⁵ Simberloff, Daniel, “Impacts of Introduced Species in the United States,” Consequences 2, no. 2 (1996)Google Scholar. See also Ruesink, J. L., Parker, I. M., Groom, M. J., and Kareiva, P. M., “Reducing the Risks of Nonindigenous Species Introductions: Guilty Unless Proven Innocent,” BioScience 45 (1995): 465–77CrossRefGoogle Scholar.

⁶ type="authors">Environmental Law Institute (ELI), Invasive Species Control: A Comprehensive Model State Law (Washington, DC: Environmental Law Institute, 2004)Environmental+Law+Institute+(ELI),+Invasive+Species+Control:+A+Comprehensive+Model+State+Law+(Washington,+DC:+Environmental+Law+Institute,+2004)>Google Scholar. See p. 7. In a study published in May 2007, ELI reviews statutes state-by-state and finds that no state has fully adopted the “clean list” approach, although the study praises Michigan, in particular, where the law “encourages action because it does not require listing by the agency as a prerequisite to control actions. Similarly, the automatic declaration of all pests and pest hosts as a public nuisance provides a solid base for both avoiding compensation for control actions and for requiring abatement.” Environmental Law Institute and the Nature Conservancy, “Strategies for Effective State Early Detection/Rapid Response Programs for Plant Pests and Pathogens,” published online May 2007. An electronic retrievable copy (PDF file) of this report may be obtained at no cost from the Environmental Law Institute Web site, http://www.eli.org; click on “ELI Publications,” then search for the “Strategies for Effective State Early Detection” report. Quotation at p. 50.

⁷ Environmental Law Institute, Invasive Species Control, 33. “A person owning private lands, waters or wetlands, or a person occupying private lands, waters or wetlands, or a person responsible for the maintenance of public lands shall control or eradicate all unpermitted introductions, populations or infestations of prohibited, restricted or regulated invasive species on the land.”

⁸ Filbey, Meg, Kennedy, Christina, Wilkinson, Jessica, and Balch, Jennifer, Halting the Invasion: State Tools for Invasive Species Management (ELI Project No. 020101, 003108) (Washington, DC: Environmental Law Institute, August 2002), 8. Available online at http://www2.eli.org/research/invasives/pdfs/d12-06.pdfGoogle Scholar.

⁹ The list of weeds “it is illegal to propagate, sell, or transport” in the Commonwealth of Pennsylvania can be found at http://www.agriculture.state.pa.us/agriculture/lib/agriculture/plantindustryfiles/NoxiousWeedControlList.pdf.

¹⁰ State of Pennsylvania, Department of Agriculture, “Noxious Weed Law Summary” (last modified January 18, 2007), http://www.agriculture.state.pa.us/agriculture/lib/agriculture/plantindustryfiles/NoxiousWeedLawSummary.pdfGoogle Scholar.

¹¹ Title 25, Chapter 10, Nebraska Administrative Code—Noxious Weed Regulations, http://www.agr.state.ne.us/regulate/bpi/actbb.htm.

¹² Ibid.

¹³ Press Release, Nebraska Department of Agriculture, August 7, 2007, http://www.agr.ne.gov/newsrel/august2007/phragmites.htm.

¹⁴ State of Pennsylvania, Rules and Regulations, Department of Agriculture, [7 PA. CODE CH. 110] “Noxious Weeds” [27 Pa.B. 1793]; available online at http://www.pabulletin.com/secure/data/vol27/27-15/549.html.

The belief that a non-native “generalist” or “weedy” species must “crowd out” native species adapted to particular environments, while a consequence of prevailing theory, has little empirical support. The difference between “generalist” and “specialist” species indicates poles of a spectrum; no one has shown that biologists would agree, if tested, where on the spectrum each of a random selection of species would lie. The empirical evidence does not generally show that “weedy” species crowd out “specialists”; that they do seems to be a consequence of definitions. (If species A crowds out species B, then A is to that extent “weedy.”) Suppose purple loosestrife is “r-selected” or “weedy.” Substantial evidence suggests that it does not crowd out but actually improves habitat for other species. (Loosestrife was initially introduced to support honeybee populations.) For studies that demonstrate the beneficial role of loosestrife in the natural environment, see, for example, Anderson, M. G., “Interactions between Lythrum Salicaria and Native Organisms: A Critical Review,” Environmental Management 19 (1995): 225–31CrossRefGoogle Scholar; and Treberg, M. A. and Husband, B. C., “Relationship between the Abundance of Lythrum salicaria (Purple Loosestrife) and Plant Species Richness along the Bar River, Canada,” Wetlands 19 (1999): 118–25CrossRefGoogle Scholar. Two researchers have concluded that ecologists “traced the history of purple loosestrife and its control in North America and found little scientific evidence consistent with the hypothesis that [it] has deleterious effects…. Loosestrife was initially assumed to be a problem without actually determining whether this was the case…. [T]here is currently no scientific justification for the control of loosestrife….” Hager, H. A. and McCoy, K. D., “The Implications of Accepting Untested Hypotheses: A Review of the Effects of Purple Loosestrife (Lythrum salicaria) in North America,” Biodiversity and Conservation 7 (1998): 1069–79CrossRefGoogle Scholar. For further confirmation, see Farnsworth, E. J. and Ellis, D. R., “Is Purple Loosestrife (Lythrum salicaria) an Invasive Threat to Freshwater Wetlands? Conflicting Evidence from Several Ecological Metrics,” Wetlands 21 (2001): 199–209CrossRefGoogle Scholar; Morrison, J. A., “Wetland Vegetation before and after Experimental Purple Loosestrife Removal,” Wetlands 22, no. 1 (2002): 159–69CrossRefGoogle Scholar; and Whitt, M. B., Prince, H. H., and Cox, R. R. Jr., “Avian Use of Purple Loosestrife Dominated Habitat Relative to Other Vegetation Types in a Lake Huron Wetland Complex,” The Wilson Bulletin 111 (1999): 105–14Google Scholar.

¹⁵ For discussion, see Paul, Ellen Frankel, Property Rights and Eminent Domain (New Brunswick, NJ: Transaction Books, 1987)Google Scholar, esp. chapter 2, “The Genesis and Development of Eminent Domain and Police Powers,” 71–184.

¹⁶ In the agricultural cases discussed here, it is assumed that a major agricultural industry in a state (e.g., apples or citrus) is affected with a “public interest,” not simply a private one. This assumption, which is reasonable, distinguishes these cases from Kelo v. City of New London, 545 U.S. 469 (2005), where it seems at least as plausible to suppose that only a private interest (that of certain developers) was served.

¹⁷ Resolutions, 2 Va. Fruit 159, 165 (1914) [18th VSHS (Jan. 1914)]. Sections 891 and 892 stipulate the proceeding to “determine the amount of damages” and the method by which apple growers will be taxed to pay that amount.

¹⁸ Buchanan, James M., “Politics, Property, and the Law: An Alternative Interpretation of Miller et al. v. Schoene,” Journal of Law and Economics 15 (1972): 438–52CrossRefGoogle Scholar; quotation at 447–48. According to Buchanan (ibid., 443), “what is relevant is the necessary place of compensation in the trading process between the two parties.” Buchanan follows Justice Stone in mistakenly believing that no scheme for compensation was enacted by the state.

¹⁹ Miller v. Schoene, 276 U.S. 272 (1928).

²⁰ Fischel, William A., “The Law and Economics of Cedar-Apple Rust: State Action and Just Compensation in Miller v. Schoene,” Review of Law and Economics 3, no. 2 (2007): 133–95CrossRefGoogle Scholar; quotation at 134.

²¹ Ibid., 173.

²² The state also paid for cutting the trees, stacking the wood, and cleaning the area. For details, see Bowman v. Virginia State Entomologist, 128 Va. 351 (November 18, 1920).

²³ Miller, 276 U.S. 272, 273. In Miller v. State Entomologist (146 Va. 175; 135 S.E. 813; 1926 Va.), the Virginia Supreme Court rejected several other reasons Dr. Casper Miller alleged as invalidating the law on constitutional grounds, among which were the vagueness or indefiniteness of one of its uses of the term “locality” and the possibility that it empowered citizens (the farmers who complained about his trees) to make law.

²⁴ Miller, 276 U.S. at 278.

²⁵ Id. at 279.

²⁶ Id. The Virginia Supreme Court had written, “The statute, so far as it relates to damages, is not clear, and we are to gather the intention of the legislature as best we can from a consideration of it as a whole.” Miller v. State Entomologist, 146 Va. 175, 192 (1926). The Virginia court construed compensation under the law to consist primarily in the state paying the costs of cutting, stacking the wood, and cleaning the area. “No doubt the legislature deemed such outlays as proper damages and expenses to be paid to the owner, if the circuit court deemed them proper” (id. at 193–94).

²⁷ Miller, 276 U.S. at 278.

²⁸ Freund, Ernst, The Police Power: Public Policy and Constitutional Rights (Chicago: University of Chicago Press, 1940), section 534, p. 565Google Scholar.

²⁹ Epstein, Richard A., Takings: Private Property and the Power of Eminent Domain (Cambridge, MA: Harvard University Press, 1985), 114Google Scholar.

³⁰ Fischel, “The Law and Economics of Cedar-Apple Rust,” 172. It is part of the brilliance of Fischel's analysis that he shows in terms of the details of the enactment of the law and its subsequent enforcement that the moral hazard problem defeated the otherwise constitutionally required payment.

³¹ The Virginia Cedar Rust Law, 1914 Va. Acts, p. 49 et seq., explicitly creates a fund paid for by taxes on apple growers to compensate the owners of especially valuable cedar trees. The relevant sections of the statute (sections 7 and 8) are reprinted in the Syllabus in Bowman v. Virginia State Entomologist, 128 Va. 351; 105 S.E. 141; 1920 Va.

³² The doctrine of average reciprocity of advantage was first stated by Justice Oliver Wendell Holmes in Pennsylvania Coal Co. v. Mahon, 260 U.S. 393, 415 (1922).

³³ Corneal v. State Plant Board, 95 So. 2d 1, 6–7 (Fla. 1957).

³⁴ Haire v. Florida Department of Agriculture and Consumer Services, 870 So. 2d 774, 782 (Fla. 2004).

³⁵ See Haire, 870 So. 2d 774 at 781, 783; and Miller, 276 U.S. at 279–80.

³⁶ Bowditch v. Boston, 101 U.S. 16, 18 (1880).

³⁷ See Haire, 870 So. 2d 774 at 785.

³⁸ Lucas required that “South Carolina … do more than proffer the legislature's declaration that the uses Lucas desires are inconsistent with the public interest, or the conclusory assertion that they violate a common-law maxim such as sic utere tuo ut alienum non laedas.” Lucas v. South Carolina Coastal Council, 505 U.S. 1003, 1031 (1992).

³⁹ Fischel, “The Law and Economics of Cedar-Apple Rust,” 146. Fischel cites Ellickson, Robert C., “Alternatives to Zoning: Covenants, Nuisance Rules, and Fines as Land Use Controls,” University of Chicago Law Review 40 (1973): 730CrossRefGoogle Scholar.

⁴⁰ For a collection of papers to this effect, see McKnight, B. N., ed., Biological Pollution: The Control and Impact of Invasive Exotic Species (Indianapolis: Indiana Academy of Sciences, 1993)Google Scholar.

⁴¹ Schmitz, Don C. and Simberloff, Daniel, “Biological Invasions: A Growing Threat,” Issues in Science and Technology Online, Summer 1997, http://findarticles.com/p/articles/mi_qa3622/is_199707/ai_n8780169Google Scholar.

⁴² Simberloff, Daniel, “The Biology of Invasions,” in Simberloff, Daniel, Schmitz, Don C., and Brown, Tom C., eds., Strangers in Paradise: Impact and Management of Non-Indigenous Species in Florida (Washington, DC, and Covelo, CA: Island Press, 1997), 3–17Google Scholar; quotation at 9.

⁴³ Simberloff, Daniel, Parker, Ingrid M., and Windle, Phyllis N., “Introduced Species, Policy, Management, and Future Research Needs,” Frontiers in Ecology and the Environment 3, no. 1 (February 2005): 12–20CrossRefGoogle Scholar; quotation at 14. See also Simberloff, Daniel, “Non-Native Species Do Threaten the Natural Environment,” Journal of Agricultural and Environmental Ethics 18 (2005): 595–607CrossRefGoogle Scholar.

⁴⁴ Simberloff, Daniel, Schmitz, D. C., and Brown, T. C., “Why Should We Care and What Should We Do?” in Simberloff, , Schmitz, , and Brown, , eds., Strangers in Paradise, 359–67Google Scholar; quotation at 364. According to Simberloff, “many scientists argue that every species should be considered a potential threat to biodiversity and sustainability if it were to be introduced…. That implies that every species proposed for deliberate introduction, whether or not it appears superficially to be innocuous, necessitates some formal risk assessment.” Simberloff, Daniel, “Nonindigenous Species—A Global Threat to Biodiversity and Stability,” in Raven, Peter H. and Williams, T., eds., Nature and Human Society: The Quest for a Sustainable World (Washington, DC: National Research Council, 1997), 329Google Scholar.

⁴⁵ The theory that species coevolve to form ecosystems—fragile communities of highly specialized interrelated organisms—produced the metaphors of conservation biology that analogized ecological communities to delicate machines. Paul Ehrlich analogized species to “rivets” holding up the wing on an airplane. See Ehrlich, Paul and Ehrlich, Anne, Extinction: Causes and Consequences of the Extinction of Species (New York: Random House, 1981)Google Scholar. Writing in the same a priori tradition, Simon Levin updated the metaphor to that of a computer. According to Levin, ecosystems constitute “complex adaptive systems assembled from sets of available components as one would assemble a new computer system.” Levin, Simon A., Fragile Dominion: Complexity and the Commons (Reading, MA: Perseus Books, 1999), 101Google Scholar.

⁴⁶ Ehrlich, Paul R. and Raven, Peter H., “Butterflies and Plants: A Study in Conservation,” Evolution 18 (1964): 586–608CrossRefGoogle Scholar; quotation at 605.

⁴⁷ Levin, Fragile Dominion, 104.

⁴⁸ This is the “niche assembly perspective” extensively examined in Hubbell, S. P., The Unified Neutral Theory of Biodiversity and Biogeography (Princeton, NJ: Princeton University Press, 2001)Google Scholar.

⁴⁹ Simberloff, Daniel and Von Holle, Betsy, “Positive Interactions of Nonindigenous Species: Invasional Meltdown?” Biological Invasions 1, no. 1 (1999): 21–32CrossRefGoogle Scholar.

⁵⁰ Ehrenfeld, David W., “Adulusian Bog Hounds,” Orion (Autumn 1999): 9–11Google Scholar.

⁵¹ Raven and Williams, eds., Nature and Human Society, 325.

⁵² Schmitz and Simberloff, “Biological Invasions.”

⁵³ For discussion, see, for example, Thompson, K., Hodgson, J. G., and Rich, T. C. G., “Native and Alien Invasive Plants: More of the Same?” Ecogeography 18 (1995): 390–402CrossRefGoogle Scholar; Goodwin, B. J., McAllister, A. J., and Fahrig, L., “Predicting Invasiveness of Plant Species Based on Biological Information,” Conservation Biology 13 (1999): 422–26CrossRefGoogle Scholar; and Williamson, M., Biological Invasions (London: Chapman and Hall, 1996)Google Scholar.

⁵⁴ In 1985, Dan Janzen, an empirical biologist, observed that species that do not share an evolutionary history may nevertheless fit together into normal ecosystems. Janzen, D. H., “On Ecological Fitting,” Oikos 45 (1985): 308–10CrossRefGoogle Scholar. For an example of a lush rainforest ecosystem composed entirely of introduced species, see Wilkinson, D. M., “The Parable of Green Mountain: Ascension Island, Ecosystem Construction, and Ecological Fitting,” Journal of Biogeography 31 (2004): 1–4CrossRefGoogle Scholar.

⁵⁵ This point is generally conceded. See, for example, Davis, M. A. and Thompson, K., “Invasion Terminology: Should Ecologists Define Their Terms Differently Than Others? No, Not If We Want to Be Any Help!” ESA Bulletin 82 (2001): 206Google Scholar: “In the United Kingdom, about equal numbers of native and alien plants are expanding their ranges, and an analysis of their traits shows that these two groups are effectively indistinguishable.”

⁵⁶ Sax, D. F., Stachowicz, J. J., Brown, J. H., et al. , “Ecological and Evolutionary Insights from Species Invasions,” Trends in Ecology and Evolution 22, no. 9 (July 2007): 465–71CrossRefGoogle ScholarPubMed; quotation at 468.

⁵⁷ For discussion, see Hobbs, Richard J., Arico, Salvatore, Aronson, James, et al. , “Novel Ecosystems: Theoretical and Management Aspects of the New Ecological World Order,” Global Ecology and Biogeography 15, no. 1 (2006)CrossRefGoogle Scholar.

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⁵⁹ For discussion, see Jax, Kurt, Jones, Clive G., and Pickett, Steward T. A., “The Self-Identity of Ecological Units,” Oikos 82 (1998): 253–64CrossRefGoogle Scholar. The concept of the natural world as flux and ecosystems as ephemeral became prominent in the 1990s, when disturbance rather than permanence became the leading metaphor. In reviewing these developments, environmental historian Donald Worster described the emerging view of nature as “a landscape of patches … a patchwork quilt of living things … responding to an unceasing barrage of perturbations. The stitches in that quilt never hold for long.” Worster, Donald, “The Ecology of Order and Chaos,” in Miller, Char and Rothman, Hal, eds., Out of the Woods: Essays in Environmental History (Pittsburgh, PA: University of Pittsburgh Press, 1997), 10Google Scholar. See also Worster, Donald, Nature's Economy (New York: Cambridge University Press, 1974, rev. ed. 1994)Google Scholar.

⁶⁰ Quoted in Marris, Emma, “Invasive Species: Shoot to Kill,” Nature 438 (November 17, 2005): 272–73CrossRefGoogle Scholar.

⁶¹ For essays seeking to bolster this assumption, see Weher, Evan and Keddy, Paul, eds., Ecological Assembly Rules: Perspectives, Advances, Retreats (Cambridge: Cambridge University Press, 1999)CrossRefGoogle Scholar.

⁶² MacArthur, R. H., “Species-Packing and Competitive Equilibrium for Many Species,” Theoretical Population Biology 1 (1970): 1–11CrossRefGoogle ScholarPubMed; MacArthur, R. H., Geographical Ecology: Patterns in the Distribution of Species (New York: Harper and Row, 1972)Google Scholar.

⁶³ Brown, James H. and Sax, Dov F., “Do Biological Invasions Decrease Biodiversity?” Conservation Magazine 8, no. 2 (April 2007)Google Scholar.

⁶⁴ Simberloff, “Biology of Invasions,” 3.

⁶⁵ John J. Stachowicz and David Tilman, “Species Invasions and the Relationships between Species Diversity, Community Saturation, and Ecosystem Functioning,” in Sax, Dov F., Stachowicz, John J., and Gaines, Steven D., eds., Species Invasions: Insights into Ecology, Evolution, and Biogeography (Sunderland, MA: Sinauer, 2005), 41–64Google Scholar; quotation at 41. These authors state (ibid., 55): “If lower resource levels lead to more intense competition, and thence to greater competitive ability, it seems plausible that a region with more species would be both harder to invade and more likely to produce successful invaders.” This a priori argument, which is representative of research in invasion biology, does not seem to match what is observed. According to Daniel Simberloff and Betsy Von Holle, the introduction of one exotic species often facilitates (rather than restricts) the introduction of others. “There is little evidence that interference among introduced species at levels currently observed significantly impedes further invasions, and synergistic interactions among invaders may well lead to accelerated impacts on native ecosystems—an invasional ‘meltdown’ process.” Simberloff and Von Holle, “Positive Interactions of Nonindigenous Species,” 21.

⁶⁶ Simberloff, “Biology of Invasions,” 3–4.

⁶⁷ The theory was developed initially in MacArthur, Robert and Wilson, E. O., The Theory of Island Biogeography (Princeton, NJ: Princeton University Press, 1967)Google Scholar. It subsequently met with severe criticism. See, for example, Stearns, S. C., “Evolution of Life-History Traits—Critique of Theory and a Review of Data,” Annual Review of Ecology and Systematics 8 (1977): 145–71CrossRefGoogle Scholar.

⁶⁸ For this definition, see Vellend, M., Harmon, L. J., Lockwood, J. L., Mayfield, M. M., Hughes, A. R., Wares, J. P., and Sax, D. F., “Effects of Exotic Species on Evolutionary Diversification,” Trends in Ecology and Evolution 22, no. 9 (2007): 481–88CrossRefGoogle ScholarPubMed; quotation at 481.

⁶⁹ McKinney, Michael L. and Lockwood, Julie L., “Biotic Homogenization: A Few Winners Replacing Many Losers in the Next Mass Extinction,” Trends in Ecology and Evolution 14, no. 11 (1999): 450–53CrossRefGoogle ScholarPubMed.

⁷⁰ “Thousands of species are doing quite well, thank you, in parts of the world where they did not evolve, a fact that alone provides the material for endless investigations. The editors and authors [of the book being reviewed] also note, summarizing earlier literature and contributing new information, that the general outcome of most invasions is to increase the overall pool of resident species.” Carlton, James T., “Species Invasions: Insights into Ecology, Evolution, and Biogeography,” BioScience 56, no. 8 (August 2006): 694–95CrossRefGoogle Scholar (reviewing Sax, Stachowicz, and Gaines, eds., Species Invasions).

⁷¹ For discussion, see Geerat J. Vermeij, “Invasion as Expectation: A Historical Fact of Life,” in Sax, Stachowicz, and Gaines, eds., Species Invasions, 315–39; esp. 326–31. Vermeij writes that “species play different roles in different places” (ibid., 329).

⁷² Ibid., 329.

⁷³ Simberloff and Von Holle, “Positive Interactions of Nonindigenous Species,” 22.

⁷⁴ Vellend et al., “Effects of Exotic Species,” 481.

⁷⁵ This is “Allopatric speciation: the creation of new species via genetic divergence in geographically separated populations.” Ibid.

⁷⁶ “[H]ybridization between individuals from genetically divergent native populations may result in introduced populations having more genetic variation than native populations of the same species.” Allendorf, Fred and Lunquist, Laura, “Introduction: Population Biology, Evolution, and Control of Invasive Species,” Conservation Biology 17, no. 1 (2003): 24–30CrossRefGoogle Scholar; quotation at 24–25.

⁷⁷ Lau, J. A., “Evolutionary Responses of Native Plants to Novel Community Members,” Evolution 60 (2006): 56–63CrossRefGoogle ScholarPubMed.

⁷⁸ Sax et al., “Ecological and Evolutionary Insights,” 466.

⁷⁹ Mooney, H. A. and Cleland, E. E., “The Evolutionary Impact of Invasive Species,” Proceedings of the National Academy of Sciences of the United States 98, no. 10 (2001): 5446CrossRefGoogle ScholarPubMed.

⁸⁰ Smith, S., Bell, G., and Bermingham, E., “Cross-Cordillera Exchange Mediated by the Panama Canal Increased the Species Richness of Local Freshwater Fish Assemblages,” Proceedings of the Royal Society of London, Series B, Biological Sciences 271, no. 1551 (2004): 1889–96CrossRefGoogle ScholarPubMed.

⁸¹ Sax et al., “Ecological and Evolutionary Insights,” 467.

⁸² Cohen, Andrew and Carlton, James, “Accelerating Invasion Rate in a Highly Invaded Estuary,” Science 279, no. 5350 (January 23, 1998): 555–58CrossRefGoogle Scholar.

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⁸⁴ Vermeij, “Invasion as Expectation,” 329.

⁸⁵ “Much of the evidence that introduced species cause extinction does not come from studies of introduced plants, but from those of introduced animals, generally predators, and plant diseases. Many of these studies involve animals on islands and, in particular, species of birds that have gone extinct following the introduction of a predatory species, such as the brown tree snake, Boiga irregularis, on Guam.” Myers, Judith H. and Bazely, Dawn, Ecology and Control of Introduced Plants (Cambridge: Cambridge University Press, 2003), 16CrossRefGoogle Scholar. The bird extinctions on Guam can hardly be said to have taken place in a “natural” area. The island was extensively bombed by the Allies during World War II. It was then extensively developed as a gargantuan shopping mall and recreation area for Japanese and other Asian consumers and tourists. For a study of the difficulty of finding a “natural area” on Guam, see Burdick, Alan, Out of Eden: An Odyssey of Ecological Invasion (New York: Farrar, Straus, and Giroux, 2005)Google Scholar.

⁸⁶ Brown and Sax, “Do Biological Invasions Decrease Biodiversity?”

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⁸⁹ Kilburn, Paul D., “Analysis of the Species-Area Relation,” Ecology 47, no. 5 (1966): 831–43CrossRefGoogle Scholar; quotation at 842.

⁹⁰ For a description of this letter, see the National Invasive Species Council, National Management Plan, October 2001, Meeting the Invasive Species Challenge, p. 13; available online at http://www.invasivespeciesinfo.gov/docs/council/mp.pdfGoogle Scholar. The text of the letter is available at http://aquat1.ifas.ufl.edu/schlet2.html.

⁹¹ Executive Order 13112, February 3, 1999, “Invasive Species,” Federal Register: February 8, 1999 (volume 64, number 25); available online at http://www.invasivespeciesinfo.gov/laws/execorder.shtml.

⁹² The management plan NISC published in 2001 states its view that “damage to natural areas is increasing in priority” relative to agriculture. National Invasive Species Council, National Management Plan, Meeting the Invasive Species Challenge, October 2001Google Scholar; quotation at p. 19. Of the roughly thirty-five invasive plants for which the Council has completed profiles, only about three are listed by USDA as noxious weeds in agriculture. For discussion and citation, see Pidot, Justin, “Note: The Applicability of Nuisance Law to Invasive Plants: Can Common Law Liability Inspire Government Action?” Virginia Environmental Law Journal 24 (2005): 183–230Google Scholar; see especially p. 195.

⁹³ National Invasive Species Council (NISC), Invasive Species Definition Clarification and Guidance, White Paper submitted by the Definitions Subcommittee of the Invasive Species Advisory Committee (ISAC); approved by ISAC, April 27, 2006. Published online at http://www.invasivespeciesinfo.gov/docs/council/isacdef.pdfGoogle Scholar. Quotation at p. 5.

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⁹⁸ National Invasive Species Council, National Management Plan, Meeting the Invasive Species Challenge, 10, 12.

⁹⁹ Simberloff, “Non-Native Species Do Threaten the Natural Environment,” 598–99.

¹⁰⁰ Soulé, Michael, “The Social Siege of Nature,” in Soulé, M. and Lease, G., eds., Reinventing Nature: Responses to Postmodern Deconstruction (Washington, DC: Island Press, 1995), 137–70Google Scholar; quotation at 143.

¹⁰¹ Haas, Peter M., “Introduction: Epistemic Communities and International Policy Coordination,” International Organisation 46, no. 1 (1992): 1–36CrossRefGoogle Scholar; quotation at 3.

¹⁰² Haas, Peter M., Saving the Mediterranean—The Politics of International Environmental Co-operation (New York: Columbia University Press, 1990)Google Scholar; Haas, Peter, “Banning Chlorofluorocarbons: Epistemic Community Efforts to Protect Stratospheric Ozone,” International Organizations 46, no. 1 (1992): 187–224CrossRefGoogle Scholar. See also Haas, Peter, “Obtaining International Environmental Protection Through Epistemic Consensus,” in Rowlands, Ian and Greene, Malory, eds., Global Environmental Change and International Relations (London: Macmillan, 1992)Google Scholar; and Haas, Peter, “Social Constructivism and the Evolution of Multilateral Governance,” in Hart, Jeffrey and Prakash, Aseem, eds., Globalization and Governance (London: Routledge, 1999)Google Scholar.

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¹⁰⁴ Simberloff, “Non-Native Species Do Harm the Natural Environment,” 597. For a principal paper supporting this consensus, see Wilcove, D. S., Rothstein, D., Dubow, J., Phillips, A., and Losos, E., “Quantifying Threats to Imperiled Species in the United States,” BioScience 48 (1988), 607–15CrossRefGoogle Scholar. For a critique of this paper, see Sagoff, Mark, “Do Non-Native Species Threaten the Natural Environment?” Journal of Agricultural and Environmental Ethics 18 (2005): 215–36CrossRefGoogle Scholar.

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¹⁰⁶ Schmitz and Simberloff, “Biological Invasions.”

¹⁰⁷ See note 90 above. Simberloff accurately describes those who disagree with the consensus within invasion biology as comprising primarily nonscientists and a few unreconstructed ecologists. Simberloff identifies “a number of authors from different cultural fields, who have joined with a few ecologists in a rearguard action to convince biologists and the lay public that the ecological threat from introduced species is overblown” (parenthetical citations omitted). Simberloff, Daniel, “Invasional Meltdown Six Years Later: Important Phenomenon, Unfortunate Metaphor, or Both?” Ecology Letters 9, no. 8 (August 2006): 912–19CrossRefGoogle Scholar; quotation at 915.

¹⁰⁸ Public agencies have attempted to make the monitoring and control (these are different things) of invasive species such as purple loosestrife and Eurasian water-milfoil conditions for obtaining licenses or permits. For an appreciation of the intricacies involved, see, for example, Rhinelander Paper Co. v. FERC, 405 F.3d 1 (D.C. Cir. 2005) (upholding a ruling by the Federal Energy Regulatory Commission that required the petitioner, the operator of a hydroelectric dam, as a condition of continuing its operating license, to develop and implement a plan to monitor purple loosestrife and Eurasian water-milfoil at the project site).

¹⁰⁹ McKnight, B. N., Biological Pollution: The Control and Impact of Invasive Exotic Species (Indianapolis: Indiana Academy of Science, 1993)Google Scholar.

¹¹⁰ Haas, “Epistemic Communities and International Policy Coordination,” 3.

¹¹¹ Mencken, H. L., Mencken Chrestomathy: His Own Selection of His Choicest Writing (New York: Vintage, 1982), 29Google Scholar.

¹¹² For an example of an attempt at applying the rule that makes property owners responsible for policing invasive species, see, for example, Moore, Richard, “Invasives Rule Would Allow DNR to Enter Private Property; Legislative Council Seeks Constitutional Justification,” Lakeland Times, November 21, 2008, http://www.lakelandtimes.com/main.asp?SectionID=9&SubSectionID=9&ArticleID=8720Google Scholar.

¹¹³ As a result, environmental law has by now largely ceased to exist as a separate form of jurisprudence. See Tarlock, A. Dan, “Is There a There There in Environmental Law?” Journal of Land Use and Environmental Law (Spring 2004): 214–52Google Scholar. Tarlock explains: “Environmental law, as now defined, is primarily a synthesis of pre–environmental era common law rules, principles from other areas of law, and post–environmental era statutes which are lightly influenced by the application of concepts derived from ecology and other areas of science, economics, and ethics” (ibid., 222).

¹¹⁴ Friends of the Earth, Inc. v. Laidlaw Environmental Services (TOC), Inc., 528 U.S. 167, 181 (2000).