Ecosystem Restoration: Fact or Fancy?
Ecological restoration is generally accepted as the reestablishment of natural ecological processes that produce certain dynamic ecosystem properties of structure, function, and processes. But restore to what? The most frequently used conceptual model for the restoration process is the shift of conditions from some current (degraded) dynamic state to some past dynamic state, generally that presumed to have occurred prior to European settlement. The authors find an alternative conceptual model more helpful, that of the self-renewal – rehabilitation – restoration continuum. In this model, the state of the forest ecosystem can range from "natural" to "degraded" and can be affected by reversible or irreversible changes. As the forest moves from a natural to a degraded state, the ability of a manager to prevent irreversible changes decreases, and the cost of intervention increases non-linearly. The need for restoration presumes a loss of ecosystem function, for example, by clearing of the forest and conversion to agriculture. A continuum model avoids the problem of precisely specifying an endpoint for restoration, and offers a context for landowners with management objectives other than preservation to contribute to ecosystem restoration.
Restoration of the myriad communities of bottomland hardwoods and the diverse communities of longleaf pine is the subject of intense interest in the Southern United States. The authors examine some common myths about restoration of these forest ecosystems from the perspective of a continuum model. The potential for restoration of bottomland hardwood ecosystems to the Lower Mississippi River Valley has barely been tapped. If current funding levels are maintained, close to 200,000 ha could be restored over the next decade. The bulk of this will be on private land enrolled in the Wetlands Reserve Program, a Federal incentive program. In contrast to forested wetlands, the major blocks of remaining longleaf pine ecosystems are on public lands, and restoration activities are planned or underway on many of these lands across the South. Private landowners, however, can be voluntary partners in conserving these ecosystems in a mixed ownership mosaic. Much research is in progress to sharpen understanding of the economic as well as the ecological values of longleaf pine and bottomland hardwood ecosystems.