ASSESSMENT OF RESTORED RWERINE HABITAT USING RCHARC1

ABSTRACT: The Riverine Community Habitat Assessment and Restoration Concept (RCHARC) was developed to integrate habitat enhancement into the stream restoration process. RCHARC assumes that aquatic habitat quality is closely related to hydraulic diversity based upon a “comparison standard” reach approach to stream restoration. A Beta test was performed by applying the RCHARC process to Rapid Creek in Rapid City, South Dakota. Standard and restored stream reaches were selected and data were collected. A comparison of field data and velocity-depth distributions indicated that the restored stream closely replicated the standard reach. The RCHARC methodology has the potential to assess habitat quality for planned comparison reaches and indicate the level of success resulting from restoration.     

FORUM: Restoration of Stream Habitats in the Western United States: Restoration as Reexpression of Habitat Capacity

/ Ecological restoration is increasingly invoked as a tool for the maintenance and regeneration of biodiversity. Yet the conceptual foundations and assumptions underlying many restoration management activities are frequently unclear or unstated. Unforeseen, undesirable consequences of restoration activities may emerge as a result. A general conceptual framework for restoration is needed to better accommodate dynamic habitat systems and evolving biota in restoration strategies. A preliminary framework for stream habitat restoration emphasizing stream habitat-biota development is proposed. As developing systems, streams and stream biota exhibit temporal behaviors that change with stream environments. Underlying the dynamic development of streams is potential capacity. Streams express this capacity as an array of habitats over time and across the landscape. Human land uses in the western United States have rapidly altered aquatic habitats and the processes that shape habitat. As a result, the diversity of native fishes and their habitats has been suppressed. Restoration is fundamentally about allowing stream systems to reexpress their capacities. Several steps are provided to guide stream restoration activities. Key tasks include: identification of the historic patterns of habitat development; identification of developmental constraints; relief of those constraints; classification of sensitive, critical, or refuge habitats; protection of the developmental diversity that remains; and monitoring of biotic responses to habitat development. KEY WORDS: Stream habitat; Stream biota; System capacity; System development; Restoration; Classification     

Creating False Images: Stream Restoration in an Urban Setting

Stream restoration has become a multibillion dollar business with mixed results as to its efficacy. This case study utilizes pre‐ and post‐monitoring data from restoration projects on an urban stream to assess how well stream conditions, publicly stated project goals, and project implementation align. Our research confirms previous studies showing little communication among academic researchers and restoration practitioners as well as provides further evidence that restoration efforts tend to focus on small‐scale, specific sites without considering broader land use patterns. This study advances our understanding of restoration by documenting that although improving ecological conditions is a stated goal for restoration projects, the implemented measures are not always focused on those issues that are the most ecologically salient. What these projects have accomplished is to protect the built environment and promote positive public perception. We argue that these disconnects among publicized goals for restoration, the implemented features, and actual stream conditions may create a false image of what an ecologically stable stream looks like and therefore perpetuate a false sense of optimism about the feasibility of restoring urban streams.     

Assessing the Restoration Success of River Widenings: A Landscape Approach

During the last 200 years, many rivers in industrialized countries have been modified by canalization. In the last two decades, the philosophy of river management has changed considerably, and restoration of ecological integrity has become an important management goal. One appealing restoration approach is to create “river widenings” that permit braiding within a limited area. This study presents a new and efficient framework for rapidly assessing such widening projects and offers a novel method to comparing restored sites with near-natural stretches (stencil technique). The proposed framework evaluates spatial patterns of riparian habitat types using landscape metrics as indicators. Three case studies from river restoration (river widening) in Switzerland are presented for demonstration purposes.The method compares restored sites with prerestoration conditions and near-natural conditions, which are assumed to represent the worst and best case states of a river system. To take into account the limited spatial extent of the restored sites, the so-called “stencil technique” was developed, where the landscape metrics of the near-natural reference sites are calculated for both the entire study area and smaller sections (clips). The clips are created by using a stencil that has the exact shape and size of the restored area (random window-sampling technique). Subsequently, the calculated metrics for the restored sites are compared to the range of values calculated for the near-natural data subset. Our studies show that the proposed method is easy to apply andprovides a valid way to assess the restoration success of river widenings. We found that river widenings offer real opportunities for establishing riparian habitats. However, they promote mainly pioneer successional stages and the habitat mosaic of the restored section is more complex than at the near-natural reference sites.     

Ecological restoration as a strategy for conserving biological diversity

Though the restoration of disturbed ecosystems has so far played a relatively modest role in the effort to conserve biological diversity, there are reasons to suspect that its role will increase and that its contribution to the maintenance of diversity will ultimately prove crucial as techniques are further refined and as pristine areas for preservation become scarcer and more expensive.It is now possible to restore a number of North American communities with some confidence. However, it should be noted that many current efforts to return degraded lands to productive use, like attempts to reclaim land disturbed by mining, try only for rehabilitation to a socially acceptable condition and fall considerably short of actually restoring a native ecological community.Possible uses for restoration in the conservation of biodiversity include not only the creation of habitat on derelict sites, but also techniques for enlarging and redesigning existing reserves. Restoration may even make it possible to move reserves entirely in response to long-term events, such as changes in climate. Restoration in the form of reintroduction of single species to preexisting or restored habitat is also a critical link in programs to conserve species ex situ in the expectation of eventually returning them to the wild. And restoration provides opportunities to increase diversity through activities as diverse as management of utility corridors, transportation rights-of-way, and parks.     

Calculating resource restoration for an oil discharge in Lake Barre,Louisiana, USA

Under the United States Oil Pollution Act of 1990, natural resource trustees are charged with assessing natural resource impacts due to an oil spill and determining the type and amount of natural resource restoration that will compensate the public for the impacts. Habitat equivalency analysis is a technique through which the impacts due to the spill and the benefits of restoration are quantified; both are quantified as habitat resources and associated ecological services. The goal of the analysis is to determine the amount of restoration such that the services lost are offset by services provided by restoration. In this paper, we first describe the habitat equivalency analysis framework. We then present an oil spill case from coastal Louisiana, USA, where the framework was applied to quantify resource impacts and determine the scale of restoration. In the Louisiana case, the trustees assessed impacts for oiled salt marsh and direct mortality to finfish, shellfish, and birds. The restoration project required planting salt-marsh vegetation in dredge material that was deposited on a barrier island. Using the habitat equivalency analysis framework, it was determined that 7.5 ha of the dredge platform should be planted as salt marsh. The planted hectares will benefit another 15.9 ha through vegetative spreading resulting in a total of 23.4 ha that will be enhanced or restored as compensation for the natural resource impacts.     

Characterizing a Major Urban Stream Restoration Project: Nine Mile Run (Pittsburgh,Pennsylvania, USA)

Urban stream restoration continues to be used as an ecological management tool, despite uncertainty about the long‐term sustainability and resilience of restored systems. Evaluations of restoration success often focus on specific instream indicators, with limited attention to the wider basin or parallel hydrologic and geomorphic process. A comprehensive understanding of urban stream restoration progress is particularly important for comparisons with nonurban sites as urban streams can provide substantial secondary benefits to urban residents. Here, we utilize a wide range of indicators to retrospectively examine the restoration of Nine Mile Run, a multi‐million dollar stream restoration project in eastern Pittsburgh (Pennsylvania, USA). Examination of available continuous hydrological data illustrates the high cost of failures to incorporate the data into planning and adaptive management. For example, persistent extreme flows drive geomorphic degradation threatening to reverse hydrologic connections created by the restoration and impact the improved instream biotic communities. In addition, human activities associated with restoration efforts suggest a positive feedback as the stream restoration has focused effort on the basin beyond the reach. Ultimately, urban stream restoration remains a potentially useful management tool, but continued improvements in post‐project assessment should include examination of a wider range of indicators.     

USING TECHNICAL ADAPTIVE MANAGEMENT TO IMPROVE DESIGN GUIDELINES FOR URBAN INSTREAM STRUCTURES1

ABSTRACT: Adaptive management is a heuristic approach to treating stream restoration projects as continuous, cyclic experiments, yielding results to be incorporated into future decisions. This comprehensive assessment views failures as surprises that are valuable lessons. Monitoring, evaluation of data, and communication of results are critical; the monitoring results trigger feedback mechanisms to invoke adaptation to the newly acquired information and communication of new hypotheses, treatments, or policies. The principles of adaptive management were applied to a monitoring study of three urban stream restoration sites in Maryland. Data were collected and evaluated for various restoration techniques, including vanes, cross vanes, step pools, root wads, imbricated riprap walls, and coir fiber rolls. Improvements to the existing Maryland design guidelines and policies were developed as the feedback mechanism. With the increasing application of adaptive management in stream restoration efforts, it is likely that repeated failures will be prevented and future restoration projects will be more successful in achieving their goals.     

Effects of River Restoration on Riparian Biodiversity in Secondary Channels of the Pite River, Sweden

Between 1850 and 1970, rivers throughout Sweden were channelized to facilitate timber floating. Floatway structures were installed to streamline banks and disconnect flow to secondary channels, resulting in simplified channel morphologies and more homogenous flow regimes. In recent years, local authorities have begun to restore channelized rivers. In this study, we examined the effects of restoration on riparian plant communities at previously disconnected secondary channels of the Pite River. We detected no increase in riparian diversity at restored sites relative to unrestored (i.e., disconnected) sites, but we did observe significant differences in species composition of both vascular plant and bryophyte communities. Disconnected sites featured greater zonation, with mesic-hydric floodplain species represented in plots closest to the stream and mesic-xeric upland species represented in plots farthest from the stream. In contrast, restored sites were most strongly represented by upland species at all distances relative to the stream. These patterns likely result from the increased water levels in reconnected channels where, prior to restoration, upland plants had expanded toward the stream. Nonetheless, the restored fluvial regime has not brought about the development of characteristic flood-adapted plant communities, probably due to the short time interval (ca. 5 years) since restoration. Previous studies have demonstrated relatively quick responses to similar restoration in single-channel tributaries, but secondary channels may respond differently due to the more buffered hydrologic regimes typically seen in anabranching systems. These findings illustrate how restoration outcomes can vary according to hydrologic, climatic and ecological factors, reinforcing the need for site-specific restoration strategies.     

Integrating Environmental Restoration and Ecological Restoration: Long-Term Stewardship at the Department of Energy

With the ending of the Cold War, several federal agencies are reclaiming land through remediation and restoration and are considering potential future land uses that are compatible with current uses and local needs. Some sites are sufficiently contaminated that it is likely that the responsible federal agency will retain control over the land for the foreseeable future, providing them with a stewardship mission. This is particularly true of some of the larger Department of Energy (DOE) facilities contaminated during the production of nuclear weapons. The use of the term “restoration” is explored in this paper because the word means different things to the public, ecologists, and environmental managers responsible for contaminated sites, such as Superfund sites and the DOE facilities. While environmental restoration usually refers to remediation and removal of hazardous wastes, ecological restoration refers to the broader process of repairing damaged ecosystems and enhancing their productivity and/or biodiversity. The goals of the two types of restoration can be melded by considering environmental restoration as a special case of ecological restoration, one that involves risk reduction from hazardous wastes, and by broadening environmental restoration to include a more extensive problem-formulation phase (both temporal and spatial), which includes the goal of reestablishing a functioning ecosystem after remediation. Further, evaluating options for the desired post remediation result will inform managers and policy-makers concerning the feasibility and efficacy of environmental restoration itself.     

Assessment of the use of selected rodents in ecological monitoring

Rodents can be useful in detecting environmental impacts because they are easy to study (easy to capture and handle), they can occur in densities adequate for statistical analysis, and they are ecologically important. In this study the usefulness of rodent populations for ecological monitoring was investigated by examining the effect of variation on the possibility of detecting differences among populations of rodents on 10 trapping grids. The effects of sampling frequencies and dispersal on detecting differences in population parameters among grids was also investigated, as was the possibility of inferring population parameters from correlations with habitat data. Statistically significant differences as small as 4.3Peromyscus maniculatus/ha were detected between grids. Of 10 populations, this comprised 12% of the highest-density population and 44% of the lowest-density population. Smaller and more differences among grids were found by examining only animals surviving from previous months. Dispersal confounds detection of direct impacts to populations, especially during the breeding season. Infrequent sampling fails to detect impacts that occur between sampling periods and will indicate impacts when observed changes result from natural variation. Correlations between population parameters and habitat variables exist but should only be used in predicting, not measuring, impacts. It is concluded that some rodent populations can be used in ecological monitoring. However, intensive sampling is required to account for variation and dispersal.     

Ecological Responses to Trout Habitat Rehabilitation in a Northern Michigan Stream

Monitoring of stream restoration projects is often limited and success often focuses on a single taxon (e.g., salmonids), even though other aspects of stream structure and function may also respond to restoration activities. The Ottawa National Forest (ONF), Michigan, conducted a site-specific trout habitat improvement to enhance the trout fishery in Cook’s Run, a 3^rd-order stream that the ONF determined was negatively affected by past logging. Our objectives were to determine if the habitat improvement increased trout abundances and enhanced other ecological variables (overall habitat quality, organic matter retention, seston concentration, periphyton abundance, sediment organic matter content, and macroinvertebrate abundance and diversity) following rehabilitation. The addition of skybooms (underbank cover structures) and k-dams (pool-creating structures) increased the relative abundance of harvestable trout (>25 cm in total length) as intended but not overall trout abundances. Both rehabilitation techniques also increased maximum channel depth and organic matter retention, but only k-dams increased overall habitat quality. Neither approach significantly affected other ecological variables. The modest ecological response to this habitat improvement likely occurred because the system was not severely degraded beforehand, and thus small, local changes in habitat did not measurably affect most physical and ecological variables measured. However, increases in habitat volume and in organic matter retention may enhance stream biota in the long term.     

Restoration of a Canadian Prairie Wetland with Agricultural and Municipal Wastewater

3 /day (800,000 US gallons) of municipal wastewater and beef processing wastewater. A large nongovernmental organization hastened restoration with a development process that outlined restoration goals and management objectives to satisfy a dual mandate of wastewater treatment and wildlife habitat creation. In 1995, after five years of wastewater additions, the basins had been refilled and the surrounding uplands had been acquired and restored. The Frank Lake Conservation Area currently provides high-quality habitat for a variety of wildlife in a region where many of the native plants and animals species have been lost due to habitat loss and fragmentation. The success of upland and water management strategies is reflected in the increase of target species' abundance and richness: 50 shorebird species, 44 waterfowl species, 15 raptor species, and 28 other new bird species have returned to the marsh since restoration. As well, significant N and P reduction occurs as waters flow through the first basin of the marsh. The management strategies of this project that satisfied a dual mandate serve as a model to guide managers of other large-scale wetland restoration projects.     

Determining Ecological Equivalence in Service-to-Service Scaling of Salt Marsh Restoration

The amount of ecological restoration required to mitigate or compensate for environmental injury or habitat loss is often based on the goal of achieving ecological equivalence. However, few tools are available for estimating the extent of restoration required to achieve habitat services equivalent to those that were lost. This paper describes habitat equivalency analysis (HEA), a habitat-based “service-to-service” approach for determining the amount of restoration needed to compensate for natural resource losses, and examines issues in its application in the case of salt marsh restoration. The scientific literature indicates that although structural attributes such as vegetation may recover within a few years, there is often a significant lag in the development of ecological processes such as nutrient cycling that are necessary for a fully functioning salt marsh. Moreover, natural variation can make recovery trajectories difficult to define and predict for many habitat services. HEA is an excellent tool for scaling restoration actions because it reflects this ecological variability and complexity. At the same time, practitioners must recognize that conclusions about the amount of restoration needed to provide ecological services equivalent to those that are lost will depend critically on the ecological data and assumptions that are used in the HEA calculation.     

LANDSCAPE‐SCALE ANALYSIS AND MANAGEMENT OF CUMULATIVE IMPACTS TO RIPARIAN ECOSYSTEMS: PAST,PRESENT, AND FUTURE1

ABSTRACT: Analyses of cumulative impacts to riparian systems is an important yet elusive goal. Previous analyses have focused on comparing the number of hectares impacted to the number of hectares restored, without addressing the loss of riparian function or the effect of the spatial distribution of impacts. This paper presents an analysis of the spatial distribution of development‐related impacts to riparian ecosystems, that were authorized under Section 404 of the Clean Water Act. Impacts on habitat structure, contiguity, and landscape context were evaluated using functional indices scaled to regional reference sites. Impact sites were mapped using GIS and analyzed for spatial associations. Positive spatial autocorrelation (i.e. clustering of impact sites) resulted from the piecemeal approach to impact assessment, which failed to prevent cumulative impacts. Numerous small projects in close proximity have resulted in adverse impacts to entire stream reaches or have fragmented the aquatic resources to a point where overall functional capacity is impaired. Additionally, the ecological functions of unaffected areas have been diminished due to their proximity to degraded areas. A proactive approach to managing cumulative impacts is currently being used in Orange County, California as part of a Corps of Engineers sponsored Special Area Management Plan (SAMP). The SAMP process is evaluating the ecological conditions and physical processes of the study watersheds and attempting to plan future development in a manner that will guard against cumulative impacts.     

Landscape-scale spatial population dynamics in human-impacted stream systems

The movement of individuals among populations can be critical in preventing local and landscape-scale species extinctions in systems exposed to human perturbation. Current understanding of spatial population dynamics in streams is largely limited to the reach scale and is therefore inadequate to address species response to spatially extensive perturbation. Using model simulations, I examined species response to perturbation in a drainage composed of multiple, hierarchically arranged stream-patches connected by in-stream and overland pathways of dispersal. Patch extinction probability, the proportion of initially occupied patches extinct after 25 years, was highly sensitive to the extent of species occupancy and perturbation within the drainage, longitudinal species distribution, perturbation decay rate and the covariance pattern of stochastic effects on colonization and extinction probabilities. Results of these simulations underscore the importance of identifying and preserving source populations and dispersal routes for stream species in human-impacted landscapes. They also highlight the vulnerability of headwater specialist taxa to anthropogenic perturbation, and the strong positive effect on species resilience of habitat rehabilitation when recolonization is possible. Efforts to conserve and manage stream species may be greatly improved by accounting for landscape-scale spatial population dynamics.     

Optimal Environmental Management Strategy and Implementation for Groundwater Contamination Prevention and Restoration

An innovative management strategy is proposed for optimized and integrated environmental management for regional or national groundwater contamination prevention and restoration allied with consideration of sustainable development. This management strategy accounts for availability of limited resources, human health and ecological risks from groundwater contamination, costs for groundwater protection measures, beneficial uses and values from groundwater protection, and sustainable development. Six different categories of costs are identified with regard to groundwater prevention and restoration. In addition, different environmental impacts from groundwater contamination including human health and ecological risks are individually taken into account. System optimization principles are implemented to accomplish decision-makings on the optimal resources allocations of the available resources or budgets to different existing contaminated sites and projected contamination sites for a maximal risk reduction. Established management constraints such as budget limitations under different categories of costs are satisfied at the optimal solution. A stepwise optimization process is proposed in which the first step is to select optimally a limited number of sites where remediation or prevention measures will be taken, from all the existing contaminated and projected contamination sites, based on a total regionally or nationally available budget in a certain time frame such as 10 years. Then, several optimization steps determined year-by-year optimal distributions of the available yearly budgets for those selected sites. A hypothetical case study is presented to demonstrate a practical implementation of the management strategy. Several issues pertaining to groundwater contamination exposure and risk assessments and remediation cost evaluations are briefly discussed for adequately understanding implementations of the management strategy.     

Compensatory Mitigation for Streams Under the Clean Water Act: Reassessing Science and Redirecting Policy1

Doyle, Martin W. and F. Douglas Shields, 2012. Compensatory Mitigation for Streams Under the Clean Water Act: Reassessing Science and Redirecting Policy. Journal of the American Water Resources Association (JAWRA) 48(3): 494-509. DOI: 10.1111/j.1752-1688.2011.00631.x Abstract: Current stream restoration science is not adequate to assume high rates of success in recovering ecosystem functional integrity. The physical scale of most stream restoration projects is insufficient because watershed land use controls ambient water quality and hydrology, and land use surrounding many restoration projects at the time of their construction, or in the future, do not provide sufficient conditions for functional integrity recovery. Reach scale channel restoration or modification has limited benefits within the broader landscape context. Physical habitat variables are often the basis for indicating success, but are now increasingly seen as poor surrogates for actual biological function; the assumption “if you build it they will come” lacks support of empirical studies. If stream restoration is to play a continued role in compensatory mitigation under the United States Clean Water Act, then significant policy changes are needed to adapt to the limitations of restoration science and the social environment under which most projects are constructed. When used for compensatory mitigation, stream restoration should be held to effectiveness standards for actual and measurable physical, chemical, or biological functional improvement. To achieve improved mitigation results, greater flexibility may be required for the location and funding of restoration projects, the size of projects, and the restoration process itself.