by Alissa Brown
We’ve all heard the accusatory statistics blaming humans for changing the face of earth’s natural systems: we are appropriating non-renewable resources for our use, changing the composition of the atmosphere, and damaging life-support systems. However, we are also implementing habitat restoration efforts to repair the damage we caused. But ecological restoration is still in its infancy, and we don’t always know how to successfully restore a degraded site. Pulling weeds and planting native plants, alone, is not usually the solution. Fortunately, restoration ecology is emerging as one of the most important fields of the 21st century, and many brilliant minds are working to answer the question: How do we return an injured system to its natural condition?
Successful restoration is not guaranteed, given the complexities of ecosystems, past land use, and ongoing degradation. Restoration practitioners are faced with a multitude of critical decisions about how to implement their projects. Given that about 30% of restoration projects fail, and another 35% do not achieve complete recovery, these decisions can make or break a restoration project. One would assume that the restoration process to transform a degraded area into what it looked like before it incurred damage is straightforward. Unfortunately, the process is anything but clear-cut, and successful restoration is far from inevitable, even after implementing large-scale efforts that may cost millions of dollars.
Practitioners charged with implementing ecological restoration often do not have formal academic training. Formal training is regrettably scarce in this discipline. With its roots in land management and stewardship, the ecological restoration field has only recently become a branch of scientific research, with academics designing and testing different approaches to restore degraded land to its natural condition. As a science, restoration ecology has come a long way since its beginnings in the 1930s, when the dust bowlsspurred concern about the condition of U.S. managed lands. Scientists at the University of Wisconsin, including Aldo Leopold, the father of land management, began testing different restoration techniques on experimental plots at the school’s arboretum. The Society for Ecological Restoration was founded in 1987, and their scientific journal, Restoration Ecology, followed in 1993.
We have learned much about best practices in restoration since the mid-20th century; yet, many new ideas have yet to be implemented on a large scale because they run the risk of failure or are simply not yet known by practitioners. Even so, we have learned a thing or two about how to reduce the risk of a failed restoration project. It is essential to understand certain components of a project site, including:
With these answers, restoration ecologists can design a viable, site-specific restoration project adaptable to environmental and human-induced change.
Here are some examples of how ecological consulting firms, regulators, Federal, state and local agencies, universities, and not-for profit stakeholders have applied innovative restoration approaches to tidal wetlands, urban, and coastal landscapes.
Tidal Wetland Restoration
The construction of Los Angeles County’s Marina del Rey in the 1960s severely impacted the hydrology of the native marshes in the area. The construction destroyed more than 900 acres of wetlands and created a straight, hardened channel (Ballona Creek) that provides little wildlife or aquatic value. The Ballona Wetlands Restoration Project aims to increase tidal and freshwater flow through the wetlands and enhance native plant and animal communities. The California State Coastal Conservancy has received several restoration alternatives from land planners and engineers, each requiring different degrees of effort and funding. The most dramatic alternative involves completely reshaping the Ballona Creek, creating more natural, sinuous curves that allow tidal fluctuation to reach more area within the wetland. Additionally, a joint effort between Great Ecology, the Santa Monica Bay Restoration Foundation, and the Center for Santa Monica Bay Studies (Loyola Marymount University) modeled future sea-level rise impacts to the Ballona Wetlands. As a result of the modeling study, we now know how future sea levels might affect the wetlands, enabling restoration designers to select the most appropriate alternative for the site.
Restoration alternative for the Ballona Wetlands which reshapes Ballona Creek allowing for more natural tidal fluctuations within the wetland. Image courtesy of the Coastal Conservancy.
Restoration in Urban Landscapes
Restoring natural areas within an urban framework poses a unique challenge to practitioners. In human-dominated landscapes, natural areas may be: (1) limited in size, with development abutting one or more sides, (2) subject to ongoing pollution (e.g., air and stormwater runoff), (3) susceptible to continual invasive plant introduction, or (4) threatened by further development. Restoration efforts for urban landscapes often incorporate the human element to their advantage. Urban restoration design includes public access points, hiking trails, and educational elements to entice community involvement and understanding of the ecosystem. For example, one of Great Ecology’s award-winning projects, the Brooklyn Bridge Park converted old industrial piers into a restored, native coastal habitat in New York City. In addition, it provides a green space for city residents to visit, where they can experience and learn about freshwater wetlands, tidal wetlands, and tidal pools.
Construction of the restoration plan may involve engineered structures and natural wetlands to filter and clean the urban runoff before it reaches open water sources. Volunteer programs encourage the community to remove invasive plants and/or plant native plants.
Historically, shoreline erosion control included structural hardening of the shore with rocks and cement; however, more recent restoration projects have incorporated living shorelines. Living shorelines include native marsh plants, seagrass beds, human-made organic fiber mats, or oyster beds, all of which stabilize eroding shorelines. For example, oyster beds not only function to filter water and provide much-needed habitat for nursery fish and other aquatic organisms but also serve to stifle high-energy waves, thereby reducing shoreline erosion.
Notoriously difficult to restore, seagrass beds have been the focus of restoration efforts in marine systems due to their role in providing nursery habitat and food for sea turtles and other important aquatic organisms. Some creative techniques have emerged from this challenge. Biologists are testing the use of so-called passive fertilization approaches to encourage seagrass growth: they install stakes on which sea birds can perch, where they fertilize the seagrass with their feces.
Rigs-to-reefs programs use decommissioned petroleum structures as artificial reefs. The U.S. Bureau of Ocean Energy Management requires these retired platforms to be disposed; however, one alternative is to allow them to remain in the marine environment and attract a variety of marine organisms, such as corals, anemones, and fish. Resource managers use these structures for fishery management, but they also benefit other marine organisms, recreational divers, the fishery industry, and local communities. Watch these artificial reefs in action.
So what’s next?
Resource managers and ecological restoration scientists are continuously developing new ideas and concepts to speed ecosystem recovery. With emerging technological advances, increasing interest in ecological restoration, and advancements of environmental policies, the science of ecological restoration will continue to solve complex ecological challenges with novel design tools, techniques, and approaches. If we unlock the formula for successful restoration, restoration projects can approach 100% success rates, saving money, communities, and ecosystems. Ahead of us are a plethora of possibilities to restore our native ecosystems and natural resources, reversing some of the damage caused by rapid human development.
Hobbs, R.J., Harris, J.A. Restoration Ecology: Repairing the Earth’s Ecosystems in the New Millennium.
Jones, Holly P., Schmitz, Oswald J. Rapid Recovery of Damaged Ecosystems.
Noss, Reed F., Paul Beier, Wallace Covington, Edward Grumbine, David B. Lindenmayer, Joh W. Prather, Fioa Schmiegelow, Thomas D. Sisk, and Diane J. Vosick. “Recommendations for Integrating Restoration Ecology and Conservation Biology in Ponderosa Pine Forests of the Southwestern United States.” Restoration Ecology (2006).
Ormerod, S. J. (2003), Restoration in applied ecology: editor’s introduction. Journal of Applied Ecology, 40: 44–50. doi: 10.1046/j.1365-2664.2003.00799