The Science and Values of Restoration Ecology

It has been 22 years since William Jordan III and the University of Wisconsin Arboretum published the first issue of Restoration and Management Notes, 16 years since the founding of the Society for Ecological Restoration (SER), and 10 years since SER published the first issue of its flagship journal, Restoration Ecology. In this short time, restoration ecology has become a leader in North American conservation efforts. Believing it is important that the field has a strong scientific foundation (Bradshaw 1993), restoration ecologists have emphasized concepts such as ‘ecosystem health’ and ‘ecosystem integrity’ when articulating restoration goals and frequently have invoked ecological principles when describing and justifying their objectives (SER 2002). Although ecology plays a central and essential role in the implementation of restoration projects, we believe that defining restoration goals and objectives is fundamentally a value-based, not scientific, activity. Since its inception, SER has taken the lead in developing and articulating paradigms of restoration. SER’s most recent major publication, The SER Primer of Ecological Restoration (SER 2002), is developed around the notion that communities and ecosystems are ecological entities. In the Primer, the goal of restoration is stated to be ‘‘the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed.’’ The Primer describes a recovered ecosystem as one that ‘‘contains sufficient biotic and abiotic resources to continue its development without further assistance’’ and for which ‘‘potential threats to the health and integrity of the restored ecosystem have been eliminated.’’ An ecosystem is also considered restored when it ‘‘apparently functions normally for its ecological stage of development, and signs of dysfunction are absent.’’ The idea that communities and ecosystems possess traits such as health and integrity, that they exhibit an organic development, that their ‘‘health’’ can be injured or harmed and then can be restored through informed efforts of ecologists is reminiscent of earlier ecological claims of communities and ecosystems as integrated entities (Clements & Shelford 1939). Attributes such as ‘‘health’’ and ‘‘integrity’’ can be meaningfully applied to entities that have been directly shaped by evolution, such as individual organisms. Organisms normally have clearly defined boundaries and a myriad of homeostatic mechanisms that maintain those boundaries while the organism develops, matures, and reproduces. However, communities and ecosystems are not shaped as entities by evolution. Today, communities are no longer believed to be tightly organized systems (Slobodkin 2003). They are believed to lack coherence (Gould 2002) and clear boundaries (Stiling 1999). A community or ecosystem does not possess distinct boundaries nor does it have mechanisms that have evolved to regulate particular processes. Communities do not exhibit any kind of evolutionary imperative, such as reproduction, as do individual organisms. The terms ‘‘community’’ and ‘‘ecosystem’’ are useful in a practical sense for referring to species and processes occurring in a particular locale (O’Neill 2001), but this does not mean that there actually exists some integrated entity out there called an ecosystem that grows, lives, reproduces and dies, or can be injured or healed. If ecological communities and ecosystems lack any intrinsic evolutionary or ecological purpose, one cannot validly invoke any ecological (or evolutionary) rationale to establish particular restoration goals. As noted by Diamond, ‘‘this goal [of restoration ecology] is not itself a self-evident mandate. It is a choice based on values, and it is only one of many possible choices’’ (Diamond 1987). Restorationists have often tried to justify their goals by presenting them as fulfillling various ecological imperatives, e.g., restoring ecosystem health and restoring indigenous environments. However, characterizing communities and ecosystems as ‘‘healthy’’ or ‘‘damaged’’ is a value-based, not scientific, assessment (Lackey 2001). Architecture uses mathematics, physics, and engineering in its efforts to achieve a particular result of aesthetic and social value. In an analogous fashion, restorationists must use ecology, and often geology, soil science, and more to achieve results of social value. Often, their results are also of great beauty as well. Perhaps, ‘‘ecological architecture’’ might be a more apt characterization of the work of ecological restoration, because the term acknowledges the central roles played by both values and science. Ultimately, it is important that restorationists do their best to clearly distinguish between their science and their values in their discussions with the public and policy Department of Biology, Macalester College, Saint Paul, MN 55105, U.S.A. Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 11794, U.S.A. Address correspondence to Mark A. Davis, email davis@macalester.edu