With the line between human and natural environments becoming increasingly blurred, how do we ethically design with ecological systems? One session at the Society for Ecological Restoration's conference in Madison, Wisconsin, examined the ethics of ecological restoration and human interventions in nature.

Ben Minteer, Global Institute of Sustainability, Arizona State University, described the tension between two seemingly opposed views on human agency in nature – preservationism and pragmatism. Preservationists have long advocated wild, "pristine" landscapes as holding moral value. Therefore, human intervention in nature should be minimized, except to return landscapes to some kind of historical baseline. In recent years, this philosophy has come under fire as being impractical and simplistic. After all, historical baselines can be arbitrary and difficult to establish, and many landscapes have been altered to a point that they have no natural analog.

Minteer described how new, anthropocentric approaches to nature call for an abandonment of idealized notions of pristine wilderness. According this view – pragmatism – human intervention should aim to enhance ecosystem services instead of attempting to restore to a certain point in history. But he also cautioned that this approach, where humans have complete control over nature, could promote reckless interventionism. Instead, Minteer advocated a middle ground between preservationism and pragmatism – a "pragmatic preservationism." In this view, humans' interventions in nature are equally weighted with an ethical responsibility toward the land.

Eric Higgs, University of Victoria, also advocated a middle ground for ecological restoration, worrying about what he viewed as the risk of reckless intervention. Higgs described a spectrum of restoration challenges, from pristine landscapes (historically continuous ecosystems) to radically altered landscapes (novel ecosystems). He defined ecosystems that fall between these extremes as "hybrid." According to Higgs, a responsible attitude toward restoration involves restoring hybrid ecosystems to historical baselines whenever possible, while still recognizing that many ecosystems may be altered beyond a threshold where this is possible. Ecological restoration then uses history more as a guide than as a template. Like Minteer, Higgs stressed the need for ethical responsibility when dealing with any notions of new, historically-unprecedented natures.

Higgs was followed by Alexander Felson, ASLA, Yale University. Felson, who is both a landscape architect and an ecologist, spoke to the challenges and opportunities facing restoration ecologists dealing with urban ecological systems. Felson emphasized the need for ecologists to expand beyond their field, bridging theory and practice. This involves considering difficult questions regarding how we define nature and what we want out of nature. For instance, is an ecosystem restored to a historical baseline always doing as much good as one designed purely for ecosystem services? He described the need for ecologists to engage in designed experiments within urban ecological systems in order to generate data (the image above is an example of Felson's work in this area). By integrating experimental research with design projects, we may begin to answer questions about the role of designed ecosystems in sustainable urban design.

Joy Zedler, University of Wisconsin – Madison, concluded the session by exploring how restoration might work in the face of an uncertain future, considering the challenges of climate change, extreme weather events, new hydrological conditions, nutrient loading, and invasive species. Zedler acknowledged that many attempts to restore to a historical precedent, or "turning back the clock," fall short. Furthermore, this notion of total restoration is becoming even more impractical as we lose pristine reference ecosystems and the ability to quantify ecosystem services.

Still, Zedler stressed that historical precedence should remain the primary guiding influence for ecological restoration, but should not be used as an absolute template. Instead, restoration targets should be flexible and dynamic, and all restoration projects should be treated as experiments to generate new data. By taking an improvisational approach, continually testing alternative restoration methods and evaluating their effectiveness, we can embrace uncertainty and learn while restoring.

This guest post is by Ben Wellington, Master's of Landscape architecture graduate, Louisiana State University and ASLA 2012 summer intern.

Image credit: A constructed eco-system. Bio-retention garden system in Bridgeport, CT / Urban Omnibus