Restoration ecology: the challenge of social values and expectations

© The Ecological Society of America www.frontiersinecology.org The Society for Ecological Restoration’s Science & Policy Working Group define ecological restoration as the process of assisting the recovery of damaged, degraded, or destroyed ecosystems (SER 2002). While ecological restoration involves restoring ecosystems at specific project sites, restoration ecology is the science on which the practice is based, and should ideally provide clear concepts, models, methodologies, and tools to support it. Restoration ecology is still an emerging science, with its roots in practical restoration projects around the world. Research generally focuses on improving the conceptual, technical, and socioeconomic bases for conducting effective ecological restoration. In recent years, there has been a move away from siteand situation-specific studies of particular restoration projects to a broader consideration of the conceptual basis for restoration ecology and the publication of synthetic treatments of the subject (Hobbs and Norton 1996; Whisenant 1999; Hobbs and Harris 2001; Perrow and Davy 2002; Temperton et al. in press). To restore an ecosystem, we need to understand how it worked before it was modified or degraded, and then use this understanding to reassemble it and reinstate essential processes. There is an increasing recognition that ecosystem dynamics can be complex, non-linear, and often unpredictable. The importance of broadscale processes and interactions between adjoining ecosystems adds further complexity, since impacts in one place may be the result of events or management decisions elsewhere. This makes it difficult to correctly diagnose the problems leading to ecosystem degradation or preventing recovery, and to initiate effective corrective or restorative management. The type of intervention required in restoration depends heavily on the type and extent of damage to the ecosystem. In some cases, relatively small changes in the management or manipulation of the species composition are required, as in the removal of harmful invasive species or the replacement of missing species. In other cases, a substantial alteration of the physical and/or chemical environment may be needed to restore ecosystem or landscape processes such as hydrology and nutrient dynamics. In still others, the scale of the restoration treatments required can be massive – for example, the restoration of the Florida Everglades involves extensive restoration activities over much of southern Florida (SFWMD 1996). The more degraded an ecosystem is, and the more fundamentally the basic ecosystem processes have been altered, the more difficult and expensive restoration will be. Similarly, the difficulty and expense of restoration depends on the goals we set. It is relatively easy to achieve successful restoration when the goal is to restore some degree of function and/or some of the species. However, it is very difficult to achieve complete restoration of the ecosystem back to its original state (Lockwood and Pimm 1999). It is often hard to determine what the ecosystem structure and composition was in any particular place, since there are seldom accurate historical records. This is sometimes done using reference ecosystems, or relatively undisturbed areas nearby that are similar to the original state of the area to be restored. However, the objective of restoration is often to return the system to some previous state, often one that existed prior to human influence, such as pre-Columbian North America. We will probably never know enough about what past ecosystems were like to reset the clock and return to some notional “prehuman” state. In many situations, this is probably impossible because of ongoing broad changes in the global environment (Vitousek et al. 1997). Deciding on restoration goals involves a set of values, including the ethical and philosophical bases for our actions, concepts of “good” restoration, its aims, humanity’s place in nature, and the influence of indigenous peoples on the environment. Setting realistic restoration goals is essential to the planning process. Yet, these goals are often determined by preconceptions or misconceptions that place more value on particular ecosystem states or on how the ecosystem was, or might have been, at some particular time. These preconceptions may limit or bias the discussion of restoration possibilities, and therefore prevent the development of more effective and efficient strategies. Thus, while restoration ecology is making important strides in developing a sound conceptual basis and improved understanding and techniques, it faces an important challenge in tackling the societal expectation of ambitious restoration goals. A mix of scientific uncertainty, value-laden decisions, and unrealistic expectations can lead to costly and demoralizing failures. A clear exposition of what is possible in particular cases, and at what cost, is required. In most cases, there will be a range of options that vary in expected outcome and relative cost, and there needs to be a clear FORUM FORUM FORUM