By Marla J. Stelk, Policy Analyst, ASWM
Ecological restoration is certainly a hot topic these days. The Association of State Wetland Managers (ASWM) has been working on finding solutions for wetland restoration challenges through two different U.S. EPA Wetland Program Development Grants for the last three and a half years and our work has generated a significant amount of interest all across the county and into Canada. Among many of our findings, one of the biggest hurdles we have identified is that, as the world becomes more and more complex, so too does the practice of ecological restoration. For example, rapid climate change creates a whole new layer of complexity as it requires practitioners to consider potential future climate scenarios that may or may not support the current or historical ecosystem type, and therefore habitat, for a particular site or region. Invasive species are spreading rapidly and radically reducing biodiversity, while in some areas they are providing important ecosystem functions. With increasing development and population growth, practitioners and managers have to consider trade-offs for the environment, society and the economy in every decision they make.
The topic of “novel ecosystems” among restoration practitioners and academics has generated substantial debate about what ecological restoration is and what the goals for restoration should be. Perring, et al (2014) view novel ecosystems as “offering opportunities for conservation and restoration in the coming years and a pragmatic recognition that it may not always be possible, or desirable, to overcome adverse consequences of environmental degradation to reinstate historical systems.” This concept, however, should not preclude efforts to restore certain ecosystems to a previously existing undisturbed state – there are certainly some areas – generally more rural – where this is still a possibility. And some would argue that by setting the bar higher, even if the historical pre-disturbance condition is never attained, the performance outcomes will at least reach the best attainable condition. However, in urban landscapes, the possibility of attaining any sort of natural historical state (i.e., pre-colonialization) is essentially nil. But does this mean that we should not even try?
Many would argue that the practice of urban stream restoration is not possible, too risky or too expensive. In contrast, Dr. Ann Riley’s newest book, Restoring Neighborhood Streams: Planning, Design, and Construction” (2016) provides an honest, proficient and hopeful evaluation of the practice of urban stream restoration. Ecological restoration in urban environments, whether of a wetland or a neighborhood stream, presents a unique set of challenges for those willing to take on such a project. As such, the objectives, design, implementation and assessment methods are by necessity different from ecological restoration projects sited in more rural environments. Dr. Riley, Executive Director of the Waterways Restoration Institute, doesn’t shy away from reporting project failures – as a professional in the field of riparian restoration for more than thirty years, she has seen her fair share of mistakes and misguided assumptions. However, she highlights these past mistakes in order to share the critical lessons learned over many decades of experimentation so that the reader can benefit from the knowledge and experience that she and her colleagues have gained.
Due to the conflicting opinions of what restoration is or what it should be, Dr. Riley spends an entire chapter on clarifying the different perspectives on restoration. She concludes that the various disciplines and perspectives of ecological restoration can complement rather than conflict with each other. She emphasizes, however, that ecological restoration should not be confused with beautification efforts (i.e., projects that prioritize aesthetics over condition or function, and that do not contribute to dynamic natural processes) or it is simply an exercise in “decorating a corpse.” Yet she does recognize that restoration means different things to different professionals based on their field of work and varying project goals. Figure 1 illustrates Riley’s perspective on restoration definitions as rungs on a ladder representing different levels of restoration: historical restoration, ecological restoration, functional restoration, and enhancement of controlled channels. The highest rung on the ladder, historical restoration, represents the highest level of ecological recovery attainable – although in many places due to alternations of streams and watersheds it is not attainable. The lowest rung on the ladder, enhancement of controlled channels, represents highly engineered projects that primarily provide aesthetic improvements.
In her book, Dr. Riley offers several urban stream and river case studies that are organized around the following questions:
- Did the project result in a geomorphically and biologically functioning stream?
- Could the project substitute for an engineered channel to provide a solution to flooding and excessive erosion?
- Were the identified benefits of the project achieved at a reasonable cost?
- How were the land uses in conflict with achieving a functioning ecosystem system resolved?
She gauges a restoration project’s “success” according to seven criteria:
- Creates an Ecologically Dynamic Environment
- Improves Ecological Conditions
- Increases Resiliency
- Does No Harm
- Pre and Post Ecological Assessments are Conducted
- Creates Learning about Restoration Planning, Design, and Construction for the Future
- Creates Community Benefits
Riley’s book is as much of a history lesson as it is a practical guide for best practices in the field of urban stream restoration. The many case studies described in the book provide the reader not only with theory but with real world examples of what has worked well and what has not – and more importantly why. She provides a strong argument that urban stream restoration is not only possible, but that it provides multiple important ecological, social and economic benefits to communities, particularly those that have been historically underserved. Her findings mirror those that we heard during a webinar hosted by ASWM for its Improving Wetland Restoration Success webinar series on Wetland Restoration in Urban and Highly Disturbed Landscapes. The recording of the webinar is available on ASWM’s website for free by clicking here. But For Peat’s Sake, I think anyone with an interest in the field of ecological restoration, whether an academic, biologist, ecologist, hydrologist, engineer, landscape architect, regulator, policy maker, community activist or otherwise will benefit from reading Dr. Riley’s book and embracing her wisdom.
 Perring et al. Ecological Processes 2014, 3:8