Assisted migration (AM), an ecosystem engineering technology, is receiving increasing attention and significant support as a means to save biodiversity in a changing climate. Few substantive, or not obviously deficient, reasons have been offered for why pursuing this conservation goal via these means might be good. Some proponents of AM, including those who identify themselves as “pragmatists,” even suggest there is little need for such argument. We survey the principal reasons offered for AM, as well as reasons offered for not offering reasons. As exemplified by the case for translocating whitebark pine, which may at first seem especially strong, we note the incongruence of framing the goal of AM in terms of “saving biodiversity,” neglect of some crucial moral questions, marginalization of normative and scientific context when AM is cast as the lesser of two evils in a “crisis,” doubtful validity and, in any case, marginal importance of arguments that AM projects ought to be undertaken, inconsistent use of scientific facts, and omission of science that counters sanguine assessments. All told—even in cases such as whitebark pine for which AM may seem most defensible—there is little reason to think that AM projects are good as means to “save biodiversity,” or good as means to other goals that have accreted into arguments for these projects.
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Hällfors et al. (2014) discuss the surfeit of names for assisted migration, none of which were mentioned by Peters and Darling (1985). The pleas of some to standardize terminology—by attaching specific names to specific kinds of projects that differ in goals or conditions imposed—have so far been ignored. Nothing substantive is at stake in our choice of the name "assisted migration."
Halfway to ecosystem services are "ecosystem functions" or functional properties of an ecosystem that some ecosystem engineers want to engineer into some ecosystems that lack them. Among those who advocate translocating organisms to bolster certain properties are Lunt et al. (2013). We remark on the normative relevance of these properties in our later discussion of AM for whitebark pine.
See Schwartz et al. (2012, p. 733, Table 1) for another tabulation of project types involving moving organisms to some selected locale.
The “Missing and Hazy Moral and Scientific Context” section takes up the exceptions.
The worry that stakeholders with morally objectionable goals may prevail is not abstract. This, precisely, has happened in the UN-affiliated Intergovernmental Panel on Biodiversity and Ecosystem Services (IPBES). With destructive corporations included as "stakeholders", the IPBES have adopted a framework that essentially places its imprimatur on those corporations' destructive behavior (Maier and Feest 2015). See also Maier (2016) on including stakeholders.
The term "socioeconomic data" may also refer to factors other than actual desires and cultural norms, which are normatively relevant—for example, human safety.
That economic value reflects not just willingness but ability to pay entails that it disproportionately represents the actual desires of the rich.
For example, I am justified in my moral unconcern about the risk of my stepping on sidewalk cracks as I stroll downtown.
The phrase "ethical challenges" comes from the title of Schwartz et al. (2012), discussed just below in the main text.
For example, torture by even the best methods does not make its practice good.
The ubiquitous phrase "ecosystem integrity" is used in multifarious ways, often as an approximate synonym for "ecosystem health." These two phrases jointly embody a concept that formerly was referred to as "the balance of nature."
With his suggestion that the value of species is essentially intertwined with its particular relationships, Sandler (2010, 2012, 2013) is one of the few who not only avoids but also rejects the assumption that the goodness of a thing entails a duty to promote its continued existence: For him a species' continued existence is not good absent these relationships.
While the need to research and thoroughly understand diseases transmitted by translocated organisms is often acknowledged, Dodd (2005, p. 268) highlights other, seldom acknowledged investigative requirements regarding: the causes for decline (some of which may be masked by the most obvious ones); the habitat, demographic, and biophysical factors that constrain every stage of the organism's life history; and the organism's population genetics alongside (for many animals) its social structure. Pedlar et al. (2011, p. 766) suggest how formidable is the investigative task for trees when they state, "the existence of established provenance trials, seed transfer guidelines, seed procurement systems, and plantation establishment protocols makes AM considerably more feasible for most commercial tree species than for most species of conservation concern."
A translocated organism's invasiveness can manifest only after decades (Simberloff 2013, pp. 92–96).
It is important to note that our complaint about the naïve pretensions of AM as a significant means of "saving biodiversity" is different in kind as well as in scope from the commonly voiced complaint that devoting too many resources to AM might undercut other kinds of worthwhile conservation efforts. The latter complaint is about misjudging the allocation of resources. In contrast, our complaint calls into question that it is even possible for AM to accomplish what it is supposed to—even if all conservation resources worldwide were dedicated to them.
Palmer and Larson (2014, p. 647) are an exception in allowing that whitebark pine is subject to a "multiplicity of threats", some of which may be considered independently of climate change.
Mention of these other means should not be interpreted as advocacy.
Jared Farmer (2013, Part Two, Eucalypts: The Taxonomy of Belonging) vividly recounts this tale.
Many of these refuges—Dawes Arboretum in Newark, OH, Hoyt Arboretum in Portland, OR, Tilden Regional Park's Regional Park Botanic Garden in Berkeley, CA, and the United States National Arboretum in Washington, DC—are far removed from the tree's "native" montane haunts or any habitat that even remotely resembles them. The websites for these facilities document their various specimens.
The verdict on this possibility is not decided by the failure of a massive campaign in the early and mid-20th century to eradicate WPBR throughout the United States by eradicating native and introduced species of Ribes (Maloy 1997). This campaign, impossibly large in scope, was also waged in ignorance of more recently uncovered (McDonald et al. 2006; Zambino et al. 2006) host capabilities of Pedicularis and Castilleja spp. It also led to a successful genetics program to develop rust-resistant western pine (Pinus monticola) (Maloy 1997).
See, for example, Simberloff (2013, p. 66).
One might hope that this discussion would fill the lacuna left in Larson and Palmer (2013, pp. 17–18) where these authors also tout the potential for translocations to bolster ecosystem services, but offer no substantive reason to support this claim.
See Maier (2012, pp. 173–174) for more discussion of the indifference of services to particular service-providers.
Eucalyptus pauciflora has even earned the imprimatur of the Royal Horticultural Society, with its Award of Garden Merit for one subspecies.
It is worth observing that the proposition of "conserving" or bolstering ecosystem properties that benefit people differs substantially and substantively from "conserving biodiversity"—particularly, the number and identity of species in ecosystems (Maier 2012; Maris 2014; Schröter et al. 2014). This observation has led to an enormous research program that has spent decades attempting to show that biodiversity per se is the basis of some functional properties (Tilman et al. 2014). Serious questions about the validity of this research remain. But even if doubts about the research were allayed, the normative relevance of these "functions" would remain in doubt.
Maier (2012, §6.9) details how the related claim that biodiversity more generally has option value (in the economic sense) unravels.
This is essentially the credo of novel ecosystem engineering, which we touch on just below in the main text. The credo admits many rationales, including many that have little or nothing to do with any commonsense notion of "conserving nature," for engineering re-arrangements of ecosystems.
Maier (2016) more fully discusses the single-premise version of the novel ecosystem licensing argument and its variants.
Hale et al. (2013, p. 68) present an " 'Argument from Reparation,' which, suggests that our obligations to assist in adaptation stem from a moral obligation to right prior wrongs." These obligations, they say, "rest on a prior failure to justify one’s actions." However they, like Palmer and Larson, neglect to discuss a number of critical elements, which a credible reparation argument must include. The most basic are: what, exactly the "prior wrongs" consist of, what or whom (if any particular things) is wronged, and what reasons we have to consider some particular "assisted adaptation" measure to constitute the morally required reparation actions. At one point, Hale et al. hint that nature is the thing that has been wronged by suggesting that restituting actions be taken "on behalf of nature." But this helps little, absent some plausible account of what it means to wrong nature and how, exactly, adaptive interventions have moral significance as acts of restitution.
For a raft of other ways in which an organism's introduction may trigger prediction-defying effects, see Simberloff (2013, pp. 85–96).
While these animals are all predators and Clark's Nutcracker is not, the general principle remains. Predation is but one of multiple means of placing pressure on the populations of other creatures—as illustrated by the barred owl's displacement of spotted owl populations in the U.S. Pacific northwest.
Recall Dodd and Seigel's (1991) report of less than a 20 % "success" rate for amphibian relocations.
Maritime pine (P. pinaster) and Douglas fir (Pseudotsuga menziessii) growing in close proximity to infected Monterey pines appear unaffected by the previously unknown oomycete (Durán et al. 2008, p. 726).
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Maier, D., Simberloff, D. Assisted Migration in Normative and Scientific Context. J Agric Environ Ethics 29, 857–882 (2016). https://doi.org/10.1007/s10806-016-9628-5
- Assisted migration
- Ecosystem engineering
- Whitebark pine