Conceptual progress towards predicting quantitative ecosystem benefits of ecological restorations

Satisfying the needs of mitigation for losses of habitat and biological resources demands further development of ecological theory to improve quantitative predictions of benefits of ecological restoration projects. Several limitations now exist in scaling compensatory restoration to match losses of ecosystem services. Scaling of restoration projects has historically been done by area of habitat, assuming that function follows. One recent development in compensatory mitigation uses a currency of secondary production, which has the important merit of specifying one measurable, functional goal against which to judge success. Future development of the fundamental basis for restoration ecology might profitably include: (1) identifying and quantifying important ecosystem services to serve as alternative goals of restoration; (2) discriminating among size classes in a population in estimating their contributions to ecosystem services; (3) re-evaluating the practice of restoring the populations of only a few representative or dominant species to replace a diversity of species losses; (4) contrasting the success of habitat restorations versus population enhancements; (5) incorporating more landscape- scale considerations into ecosystem-based restoration designs; (6) injecting more formal uncertainty analyses into scaling restoration projects; (7) enhancing the basic science of population, community, and ecosystem ecology to improve the capacity of the discipline to predict impacts of interventions; (8) integrating empirical and theoretical developments in food web dynamics to resolve contradictions in our models of how population changes propagate across trophic levels; and (9) incorporating the concept that populations, communities or ecosystems targeted for restoration may now be in alterna- tive states and that restoration targets have been biased by shifting historical baselines. Forging part- nerships between the practitioners of ecological restoration and basic ecologists holds a dual promise for testing ecological theory and for improving the effectiveness of environmental restoration.