Principles for Ecological Land Reuse

Restoration—the return of a degraded ecosystem to a close approximation of its remaining natural potential—is experiencing a groundswell of support across the United States, and is a key component of many land reuse projects. Many ongoing or completed restoration projects now offer valuable lessons for future projects. To help build on these lessons and promote effective ecological land reuse, EPA assembled this list of principles proven critical to the success of a wide range of restoration and reuse projects:

Focus on feasibility. Particularly in the planning stage, it is critical to focus on whether the proposed reuse is feasible, taking into account scientific, financial, social, and other considerations. Remember that solid community support for a project is needed to ensure its long-term viability.

Preserve and protect existing resources. Existing, relatively intact ecosystems are the keystone for conserving biodiversity - they provide the biota and other natural materials needed for the recovery of impaired systems. Restoration does not replace the need to protect ecological resources in the first place. Rather, it is a complementary activity that, when combined with protection and preservation, can help achieve overall improvements in a greater percentage of degraded soils. Even with sites for which a different land use is planned, the first objective should be to prevent further land degradation.

Restore ecological integrity. Ecological integrity refers to the condition of an ecosystem; particularly the structure, composition, and natural processes of its biotic communities and physical environment. An ecosystem with integrity is a resilient and self-sustaining natural system able to accommodate stress and change. Its key ecosystem processes, such as nutrient cycles, succession, groundwater levels and flow patterns, and the dynamics of sediment erosion and deposition, are functioning properly within the natural range of variability. Biologically, its plant and animal communities are good examples of the native communities and diversity found in the region. Structurally, physical features such as soil morphology are dynamically stable. Ecological land reuse strives for the greatest progress toward ecological integrity achievable within the current limits of the area by using designs that favor the natural processes and communities that have sustained native ecosystems through time.

Restore natural structure. Harmful alteration of a site’s physical characteristics may break down its natural structure. Loss of soil structure may lead to habitat degradation, erosion, changes in plant species composition, and other problems. Land reuse should address soil health and structure. Restoring the original site morphology and other physical attributes can leads to success in the overall site cleanup goals, such as improving water quality and reinvigorating native biota.

Restore natural function. Structure and function are closely linked in an ecosystem. Reestablishing the appropriate natural structure can bring back beneficial functions. For example, restoring a site’s natural soil structure is critical for reestablishing its hydrological regime and nutrient fluxes. In order to maximize the societal and ecological benefits of the restoration project, it is essential to identify what functions should be present, and make missing or impaired functions priorities in the restoration. Verifying reestablishment of land functions is a good measure of reuse success.

Work within the watershed and broader landscape context. Ecological reuse requires a design based on the entire watershed or the broader landscape, not just the part that may be the most degraded. Activities throughout the landscape or watershed can have an adverse effect on the specific area that is being restored. A localized project may not be able to change what goes on in the broader area, but it can be designed to better accommodate environmental effects. Beyond a watershed, for example, the broader landscape context also influences restoration through factors such as interactions with terrestrial habitats in adjacent watersheds and landscapes, or the deposition of airborne pollutants from other regions.

Understand the natural potential of the site or area. Establishing ecological reuse goals for a degraded site requires knowledge of the historical range of conditions that existed there prior to degradation, and predictions of what future conditions might be. In some cases, the extent and magnitude of changes in the area may constrain the ecological potential of the site. Accordingly, reuse planning should take into account any irreversible changes in the area that may affect the system being restored and focus on restoring its remaining natural potential.

Develop clear, achievable, and measurable goals. Well-defined goals provide focus and increase project efficiency. Goals direct implementation and provide the standards for measuring success. Simple conceptual models are a useful starting point to define the problems, identify the type of solutions needed, and develop a strategy and goals. Restoration teams should evaluate various alternatives to assess those which can best accomplish project goals. The chosen goals should be achievable both ecologically and socioeconomically, given the natural potential of the area, the available resources, and the extent of community support for the project. Also, all parties affected by the land reuse should understand each project goal clearly to avoid misunderstandings later.

Use a reference site. Reference sites are areas that are comparable in structure and function to the proposed restoration site before it was degraded. Reference sites may be used as models for reuse and as a yardstick for measuring the project’s progress. While it is possible to use historic information on sites that have been altered or destroyed, historic conditions may be unknown and it may be most useful to identify an existing, relatively healthy, similar site as a guide for your project. Remember, however, that each project will present a unique set of circumstances, and no two ecosystems are truly identical. Therefore, each project should be tailored to the given situation and differences between the reference site and the area being restored should be taken into account.

Anticipate future changes. Although it is impossible to precisely plan for the future, many foreseeable ecological and societal changes can and should be factored into reuse designs. In addition to potential impacts from changes in land use, natural changes such as plant community succession can also influence restoration and reuse. For instance, long-term, post-project monitoring should take successional processes such as forest regrowth into account when evaluating the outcome of the project.

Involve the skills and insights of a multi-disciplinary team. A reuse project can be a complex undertaking that integrates a wide range of disciplines including ecology, soil science, hydrology, geomorphology, engineering, planning, communications, and social science. It is important that, to the extent that resources allow, the planning and implementation of a project involve people with experience in the disciplines needed for the particular project. With more complex projects, effective leadership will also be needed to bring the various disciplines, viewpoints, and styles together as a functional team.

Design for self-sustainability. Perhaps the best way to ensure the long-term viability of a reused site is to minimize the need for continuous maintenance. High maintenance approaches not only add costs to the restoration project, but also make its long-term success dependent upon human and financial resources that may not always be available. In addition to limiting the need for maintenance, designing for self-sustainability also involves favoring ecological integrity, as an ecosystem in good condition is more likely to have the ability to adapt to changes.

Use passive restoration, when appropriate. Before actively altering a site for reuse, determine whether passive restoration (i.e., simply reducing or eliminating the sources of land degradation and allowing recovery time) will be enough to allow the site to naturally regenerate. Often, there are reasons for restoring a site as quickly as possible, but sometimes immediate results are not critical. While passive restoration relies on natural processes, it is still necessary to analyze the site’s recovery needs and determine whether time and natural processes can meet them. It is also important to monitor and control invasive species.

Restore native species, and avoid non-native species. Natural areas throughout the country are experiencing significant problems with invasive, non-native (invasive, exotic) species. Many invasive species outcompete natives because they are expert colonizers of disturbed areas and lack natural controls. The temporary disturbance present during restoration projects invites colonization by invasive species which, once established, can undermine reuse efforts and lead to further spread of these harmful species. Invasive, non-native species should not be used in a restoration project, and special attention should be given to avoid the unintentional introduction of invasive species at the reused site when it is most vulnerable to invasion. In some cases, removal of non-native species may be the primary goal of the restoration project.

Use natural fixes and bioengineering techniques, where possible. Bioengineering is a construction method which combines live plants with dead plants or inorganic materials to produce living, functioning systems that prevent erosion, control sediment and other pollutants, and provide habitat. Bioengineering techniques can often be successful for erosion control, water treatment, and restoring soil structure and function.

Monitor and adapt where changes are necessary. Every combination of soil characteristics, sources of stress, and restoration techniques is unique. For this reason, even a well-planned reuse may not proceed exactly as envisioned. Adapting a project to at least some change or new information should be considered normal. Monitoring before and during the project is crucial for finding out whether goals are being achieved. If they are not, mid-course adjustments should be made. Post-project monitoring will help determine whether additional actions or adjustments are needed and can provide useful information for future restoration efforts. This process of monitoring and adjustment is known as adaptive management. Monitoring plans should be feasible in terms of costs and technology, and should always provide information relevant to meeting the project goals.