RESTORATION ECOLOGY AND THE ECOSYSTEM PERSPECTIVE

The ecosystem perspective provides a framework within which most other aspects of the ecology of restoration can be incorporated. By conside ring the ecosystem functions of a restoration project, the restoration ist is forced to consider the placement of the project in the landscap e-its boundaries, its connections or lack thereof to adjoining ecosyst ems, and its receipts and losses of materials and energy from its phys ical surroundings. These characteristics may set limits on the kind(s) of biotic communities that can be created on the site. The ecosystem perspective also gives restorationists conceptual tools for structurin g and evaluating restorations. These include the mass balance approach to nutrient, pollutant, and energy budgets; subsidy/stress effects of inputs; food web architecture; feedback among ecosystem components; e fficiency of nutrient transfers, primary productivity and decompositio n as system-determining rates; and disturbance regimes. However, there are many uncertainties concerning these concepts, their relation to e ach other, and their relationships to population-and community-level p henomena. The nature of restoration projects provides a unique opportu nity for research on these problems; the large spatial scale of restor ations and the freedom to manipulate species, soil, water, and even th e landscape could allow ecosystem-level experiments to be conducted th at could not be performed otherwise.