TOWARDS A CONCEPTUAL-FRAMEWORK FOR RESTORATION ECOLOGY

Heightening human impacts on the Earth result in widespread losses of production and conservation values and make large-scale ecosystem rest oration increasingly urgent. Tackling this problem requires the develo pment of general guiding principles for restoration so that we can mov e away from the ad hoc, site- and situation-specific approach that now prevails. A continuum of restoration efforts can be recognized, rangi ng from restoration of localized highly degraded sites to restoration of entire landscapes for production and/or conservation reasons. We em phasize the importance of developing restoration methodologies that ar e applicable at the landscape scale. Key processes in restoration incl ude identifying and dealing with the processes leading to degradation in the first place, determining realistic goals and measures of succes s, developing methods for implementing the goals and incorporating the m into land-management and planning strategies, and monitoring the res toration and assessing its success. Few of these procedures are curren tly incorporated in many restoration projects. The concept that many e cosystems are likely to exist in alternative stable states, depending on their history, is relevant to the setting of restoration goals. A r ange of measures, such as those being developed to measure ecosystem h ealth, could be used to develop ''scorecards'' for restoration efforts . Generalizable guidelines for restoration on individual sites could b e based on the concepts of designed disturbance, controlled colonizati on, and controlled species performance. Fewer explicit guidelines are available at the landscape scale, beyond nonquantitative generalities about size and connectivity. Development of these guidelines is an imp ortant priority so that urgent large-scale restoration can be planned and implemented effectively.