Restoration Challenges Research Articles

Enhancing Resilience of River Restoration Design in Systems Undergoing Change

Landscape-scale changes in hydrology, sediment dynamics, and riverine ecosystems are raising questions about how resilience to changing conditions should be integrated in the design of river restoration projects. This study synthesized current strategies and challenges for river restoration in systems governed by change, emphasizing (1) an international survey of practitioners to document the state-of-the-practice, including challenges facing practitioners implementing river restoration and (2) a literature review of the state of the art in designing for resiliency, including advantages and limitations of established and more-experimental design approaches and tools. Survey results highlighted fundamental challenges associated with identifying appropriate project objectives within a design practice largely relying on historical data, the significance of social and regulatory barriers, and the need to focus on underlying processes. Important discrepancies between the expectations for resiliency of projects and the practices being implemented emerged. The state-of-the-art literature review summarized how design strategies may be modified to address those discrepancies, and discussed the divergent approaches for increasing resilience through (1) increasing resistance to change (i.e., stabilization) and (2) restoration of a channel’s dynamism to reduce the risk of, and recovery time following, disturbances. Both the state of the practice and the state of the art highlight the lack of resiliency within the practice of river restoration itself, and illustrate the importance of designers, funders, regulators, and stakeholders adapting and innovating as the natural and human landscape they are managing changes.

Preserving a modern housing model: the restoration of Pedregulho Housing Neighborhood

This paper examines the history of Pedregulho Housing Neighborhood, built between 1948 and 1960 by the Department of Popular Housing in Rio de Janeiro, Brazil, from the first concepts to the restoration in 2015. Conceived by the urbanists Carmen Portinho and Affonso E. Reidy, it became one of the most emblematic works of modern Brazilian architecture. After years of neglect, in 2015 housing Block A of the neighborhood underwent restoration, one of the only such projects on social housing complexes in Latin America. The paper discusses the housing complex’s history, focusing on the intervention and restoration project, its criteria and challenges, and also the aims and demands by the residents during the works.

Can transplanting seedlings with protection against herbivory be a cost-effective restoration strategy for seasonally flooded environments?

Transplantation of naturally regenerating seedlings (hereafter wildlings) has great potential as a restoration tool as it involves the use of acclimatized individuals and preservation of local and endemic genotypes. When successfully used, this technique has the added benefits of increasing structural and compositional diversity, preserving local and endemic genotypes, and reducing ecological restoration costs. In wetland ecosystems, flooding is an abiotic filter that may hinder success of restoration efforts. We hypothesized that transplanting “ecologically toughened” wildlings from low-lying, flooded areas into restoration areas of higher relief and lower frequency of flooding, would be a successful strategy. In this study, we transplanted wildlings from periodically flooded areas upslope to test the effect of topographic position (where they were collected and outplanted), and protection against herbivory on seedling survival and growth. The experimental design included two collection times and planting areas (high and low topography), two seedling height, use of protection against mammalian herbivory, and four species that represent different functional types. We also evaluated the costs involved. The best experimental outcome for the four study species (most abundance floodplain species) was found with small seedlings (10–39 cm) collected at low relief and outplanted to higher elevations, with protection against herbivory. Even under unusually extreme flood events (high flooding over 7 months) the tree legume Inga vera has emerged with the highest survival rate. The costs of transplantation are lower (USD 739 ha−1) than those found in previous studies and the use of protection against herbivory was also considerably low (USD 2484 ha−1). That said, these estimated costs are on an experimental scale and do not represent large-scale operations, which could reduce and improve cost-benefits significantly. In remote places such as the Pantanal, the lack of nursery infrastructure, high associated costs of seedling production and vulnerability to herbivory are the main challenges for restoration. Hence, wildling collection can be a useful strategy to overcome such obstacles.

Challenges for Restoration of Coastal Marine Ecosystems in the Anthropocene

Coastal marine ecosystems provide critical goods and services to humanity but many are experiencing rapid degradation. The need for effective restoration tools capable of promoting recovery of coastal ecosystems and remediating their valued services has never been greater. We identify four major challenges for the future development and implementation of coastal marine ecosystem restoration (MER): (1) Development of more effective, scalable restoration tools, (2) adaptation of restoration tools to cope with climate change and global stressors, (3) integration of social and ecological restoration priorities, and (4) promotion of the perception and use of coastal MER as a scientifically-credible management approach. Tackling these challenges should improve restoration success rates, heighten their recognition, and accelerate investment in and promotion of coastal MER. Here, to reverse the currently accelerating decline of marine ecosystems, we discuss potential directions for meeting these challenges by applying coastal MER tools that are science-based and actionable. For coastal restoration to have a global impact, it must incorporate social science, technological and conceptual advances, and plan for future climates.

Understanding the key characteristics and challenges of pine barrens restoration: insights from a Delphi survey of forest land managers and researchers

Pine barrens are open‐canopy ecological communities once prevalent on sandy soils across the northern Great Lakes Region of the United States and Canada, though fire suppression and plantation forestry have now reduced them to a few isolated areas. Efforts to restore pine barrens are underway on some public lands, but lack of knowledge on the social and ecological issues and challenges that affect these projects impedes fuller progress. As a precursor to designing a public preference survey for pine barrens restoration, we sought input from those with expert knowledge about pine barrens. Using a three‐round modified Delphi survey, forest land managers and researchers identified the key characteristics of pine barrens and important current and future management challenges. Key characteristics were related to fire, landscape structure, plant and animal species, soils, and social themes. Current and future challenges were related to landscape, invasive species, social, economic, climate change, and science themes. Four social issues (education, fire acceptance, fire risk, aesthetics) were rated among the top current challenges but none of them maintained prominence as future challenges. Potential explanations for this shift are that the experts felt these social concerns would be resolved in time or that other issues, such as development pressures and budgets for carrying out restoration, would become greater future challenges. Our approach can be used by managers and researchers to better understand the ecosystems they seek to restore and to communicate with public stakeholders about restoration efforts.

River restoration challenges with a specific view on hydromorphology

River restoration challenges with a specific view on hydromorphology

Surgical Implantation of Acoustic Tags in American Shad to Resolve Riverine and Marine Restoration Challenges

AbstractA variety of data needs challenge the successful restoration and management of alosine populations, including information on the migration, mortality, behavior, demographic rates, and distribution of fish, both in riverine and marine environments. Radiotelemetry with gastric‐implanted transmitters has typically been used to answer some of these questions; however, observing alosines over extended periods and in the marine environment has remained beyond the limitations of this technology and implantation technique. To address these issues, we conducted an acoustic telemetry study on American Shad Alosa sapidissima by using surgical implantation methods. We tagged fish during 2015 (n = 46) and 2016 (n = 52) in the Charles River, Massachusetts, an urbanized watershed where American Shad were believed to be extirpated prior to restoration efforts beginning in 2006. Surgical implantation produced rates of in‐river mortality (40% overall) and posttagging fallback (39% overall) that were comparable to those from traditionally used gastric implantation methods. Data from American Shad that were retained for statistical analyses (n = 59) demonstrated that Watertown Dam (at river kilometer 14.3) impeded upstream migration and that New Boston Dam and Locks (at the mouth of the river) delayed postspawn emigration from the river. In total, 49 American Shad were detected outside of the Charles River. The distribution and low number of total detections, despite a large number of nearshore arrays, suggest that American Shad occupy waters farther offshore during their marine phase. American Shad were detected as overwintering on the Scotian Shelf (n = 5) and the Mid‐Atlantic Bight (n = 1). In 2017, 10 of the individuals that were tagged in 2016 returned to spawn, providing the first reported data on total migration timing and migratory behavior free of handling effects. Surgical implantation of acoustic telemetry tags is an effective method that can provide necessary and previously unattainable data on a species of conservation need.

A new restricted boltzmann machine training algorithm for image restoration

A variety of approaches have been proposed for addressing different image restoration challenges. Recently, deep generative models were one of the mostly used ones. In this paper, a new Restricted Boltzmann Machines (RBM) training algorithm for addressing corrupted data has been proposed. RBMs can be trained both supervised and unsupervised, however they are very sensitive to noise and occlusion. The proposed algorithm enables the RBM to be robust against corruptions. Using the new algorithm, we have given the RBM a posterior knowledge about desired or clean data. Despite other methods, the proposed algorithm works fine without changing the architecture of the model or adding any regularization term. Concretely, the RBM can be used as a robust feature extractor, even for unclean data. By creating different corrupted versions for each image instance, and using the original version in the reconstruction phase, the RBM can learn the desired probability distribution of data. Experimental results confirm the robustness of the model against different types of corruption.

Opportunities and challenges for restoration of the Merced River through Yosemite Valley, Yosemite National Park, USA

AbstractSuccessful river restoration requires understanding and integration of multiple disciplinary perspectives, including evaluations of past and ongoing watershed processes, local geomorphic response, and impacts unique to human activity. Nowhere is this more apparent than along the Merced River in Yosemite National Park, USA, where both an outstanding natural landscape and the consequences of over a century of human disturbances continue to interact. An intact upstream watershed highlights the importance here of local impacts on geomorphic response. Incision and the resulting decoupling of the channel from its adjacent late‐Holocene floodplain are consequences of reduced channel roughness, likely from de‐snagging the river, and instream gravel mining in the 19th and early 20th century. Riparian‐zone disturbance by visitor use has damaged riparian vegetation and soils, inducing channel widening. Revetments and channel‐spanning bridges, the latter being visible and oft‐cited impacts to fluvial processes, have distorted the natural evolution of meanders and induced local channel narrowing. The historical rate of sediment export from Yosemite Valley has greatly exceeded replenishment from upstream and lateral sources, creating a deficit that now inhibits recovery via passive restoration of more natural channel form and function. Climate change may amplify now‐diminished fluvial processes but also exacerbate the rate of sediment export. These conditions, reflecting a complex intersection of geologic history, modern geomorphic processes, and human interactions, demonstrate how a limited influx of sediment coupled with intensive human use can have long‐term consequences for riverine conditions, restoration opportunities, and social engagement with the riverine landscape.

Estimated Time to Restoration of Hurricane Sandy in a Future Climate

Power outage restoration following extreme storms is a complicated process that couples engineering processes and human decisions. Emergency managers typically rely on past experiences and have limited access to computer simulations to aid in decision-making. Climate scientists predict that although hurricane frequency may decrease, the intensity of storms may increase. Increased damage from hurricanes will result in new restoration challenges that emergency managers may not have experience solving. Our study uses agent-based modeling (ABM) to determine how restoration might have been impacted for 30 different scenarios of Hurricane Sandy for a climate in 2112 (Sandy2112). These Sandy2112 scenarios were obtained from a previous study that modeled how outages from Hurricane Sandy in 2012 might have been affected in the future as climate change intensified both wind and precipitation hazards. As the number of outages increases, so does the expected estimated time to restoration for each storm. The impact of increasing crews is also studied to determine the relationship between the number of crews and outage durations (or restoration curves). Both the number of outages and the number of crews impact the variability in time to restoration. Our results can help emergency managers and policy makers plan for future hurricanes that are likely to become stronger and more impactful to critical infrastructure.

Post-fire restoration of historic buildings and implications for Notre-Dame de Paris.

The restoration of fire-damaged historical monuments entails a wide range of scientific questions. Taking as a starting point the case of Notre-Dame de Paris, this Comment defines the materials science challenges of post-fire restoration, and also briefly outlines the issues of structural integrity, fire safety and preservation ethics.

Power System Restoration: Meeting the Challenge to Resiliency from Distributed Generation

The paradigm shift in the configuration of the power system in Europe and the United States away from large conventional synchronous generators to small generating units distributed over large geographical areas, many of which are powered by intermittent renewable resources, has a major effect on various aspects of system operations, most importantly dispatch and commitment processes. This article discusses the challenges for power system restoration and how to meet those challenges.

Regenerative rehabilitation of catastrophic extremity injury in military conflicts and a review of recent developmental efforts

ABSTRACT Aim of the review This review aims to describe the current state of regenerative rehabilitation of severe military extremity injuries, and promising new therapies on the horizon. Discussion The nature of warfare is rapidly shifting with information operations, autonomous weapons, and the threat of full-scale peer adversary conflicts threatening to create contested environments with delayed medical evacuation to definitive care. More destructive weapons will lead to more devastating injuries, creating new challenges for limb repair and restoration. Current paradigms of delayed rehabilitation following initial stabilization, damage control surgery, and prolonged antibiotic therapy will need to shift. Advances in regenerative medicine technologies offer the possibility of treatment along the continuum of care. Regenerative rehabilitation will begin at the point of injury and require a holistic, organ-systems approach. Conclusions Both technological improvements and a rapidly advancing understanding of injury pathophysiology will contribute to improved limb-salvage outcomes, and shift the calculus away from early limb amputation.

A Local Initiative to Achieve Global Forest and Landscape Restoration Challenge—Lessons Learned from a Community-Based Forest Restoration Project in Biliran Province, Philippines

Forest and landscape restoration in the tropics is often undertaken by groups of smallholders and communities whose livelihoods are primarily agricultural and forest-based. In the Philippines, the implementation of forest restoration programs involving people’s organizations showed mixed results. We present a case study of a pilot community-based forest restoration project that was undertaken in Biliran Province to understand the impediments, and pilot test interventions to improve restoration outcomes. The project was designed using systems thinking, employing smallholder-based best-practice, and applying the principles of a participatory approach. The results revealed that the initial participation of smallholders is mostly driven by short-term financial incentives. However, long-term commitment to managing the trees is attributed mainly to sustainable livelihood, land and tree rights, equitable sharing of benefits, strong leadership, effective governance and improved human and social capitals. The support of extension officers, use of high-quality seedlings, and participation of women are essential for community-based forest restoration success. Key lessons from our research could contribute to fulfilling the forest and landscape restoration commitments of developing countries in the tropics.

The right trait in the right place at the right time: Matching traits to environment improves restoration outcomes.

The challenges of restoration in dryland ecosystems are growing due to a rise in anthropogenic disturbance and increasing aridity. Plant functional traits are often used to predict plant performance and can offer a window into potential outcomes of restoration efforts across environmental gradients. We analyzed a database including 15yr of seeding outcomes across 150 sites on the Colorado Plateau, a cold desert ecoregion in the western United States, and analyzed the independent and interactive effects of functional traits (seed mass, height, and specific leaf area) and local biologically relevant climate variables on seeding success. We predicted that the best models would include an interaction between plant traits and climate, indicating a need to match the right trait value to the right climate conditions to maximize seeding success. Indeed, we found that both plant height and seed size significantly interacted with temperature seasonality, with larger seeds and taller plants performing better in more seasonal environments. We also determined that these trait-environment patterns are not influenced by whether a species is native or nonnative. Our results inform the selection of seed mixes for restoring areas with specific climatic conditions, while also demonstrating the strong influence of temperature seasonality on seeding success in the Colorado Plateau region.

Nutrient Supply to Seawater from Steelmaking Slag: The Coupled Effect of Gluconic Acid Usage and Slag Carbonation

Vanishing of seaweeds in coastal areas has become a serious environmental problem. Part of the reason is nutrient deficiency in seawater, especially iron. Steelmaking slag is probably one of the best nutrient suppliers in terms of cost and quantity. Utilizing steelmaking slag to fertilize coastal seaweeds may simultaneously address the two challenges of seaweed restoration and byproduct treatment. However, direct usage of slag from a basic oxygen furnace is not practical because of negative effects such as a sharp pH increase and magnesium loss. To address the disadvantages, this work investigated the leaching behavior of a practical steelmaking slag in an artificial seawater and clarified the coupled effect of gluconic acid usage and slag carbonation on aiding the nutrient supply. Slag carbonation prevents a drastic pH increase and Mg loss, while gluconic acid induces formation of stable chelated complexes. The combination of slag carbonation and gluconic acid usage results in significant improvements in the nutrient supply. By leaching the slag, the maximum concentration of Fe in seawater increases to 0.29 mg L−1, 193 times larger than the value in the initial seawater (1.5 μg L−1).

Thresholds in woody and herbaceous component co‐existence inform the restoration of a fire‐dependent community

AbstractQuestionsA paradoxical co‐existence challenges woodland and savanna restoration worldwide: How are shade‐intolerant, flammable herbaceous layers promoted while maintaining the shade‐casting, more fire‐sensitive woody regeneration that sustains overstorey structure? Where restoration success consisted of robust, diverse herbaceous layers and vigorous, well‐stocked Pinus echinata regeneration (hereafter, shortleaf‐bluestem response), we asked: are there targetable conditions of overstorey, understorey, topography, and proximity to mature Pinus echinata that simultaneously maximize desired woody and herbaceous understorey components? Do these conditions and dependent responses differ across canopy disturbance level and fire season?LocationCumberland Plateau, Tennessee, USA (36°04′8.11″ N, 84°50′38.36″ W).MethodsWe measured 12 shortleaf‐bluestem response and 17 explanatory condition variables at 345 plots spanning an experimental restoration gradient (canopy disturbance level and fire season combinations). We ordinated variation and identified response thresholds using a multivariate regression tree. Differences across tree groupings and splits associated response thresholds with specific explanatory conditions.ResultsPockets of substantial Pinus echinata regeneration (>3,000 stems/ha), C4 grass density (>40,000 ramets/ha), and herbaceous diversity (increase from 22 to 205 species) occurred 7–14 years after canopy disturbance and 3–8 fires. Such shortleaf‐bluestem response was maximized at 3 m2/ha residual tree basal area, 11% canopy closure, reduced midstorey density (5,000 small‐sapling stems/ha), and southwesterly aspects within 70 m of mature Pinus echinata. In contrast, shortleaf‐bluestem response was negligible at 11.3 m2/ha basal area and 68% canopy closure. Fire season, snag basal area, slope, and slope position effects were minimal.ConclusionsWe identified specific conditions fostering the co‐existence of desired herbaceous and woody understorey components, addressing a major woodland and savanna restoration challenge and expanding on previous threshold concept applications by simultaneously considering multiple desired responses. Results can direct the restoration of imperiled shortleaf‐bluestem communities east of the Mississippi River, USA, where work has been scarce or ineffective, and similar approaches could inform fire‐dependent woodland and savanna restoration worldwide.

Trade-off’s in Restoration: Using Soil Amendments to Address Restoration Challenges for Plants

Trade-off’s in Restoration: Using Soil Amendments to Address Restoration Challenges for Plants

Annual Understory Plant Recovery Dynamics in a Temperate Woodland Mosaic during a Decade of Ecological Restoration

Temperate woodlands are one of the world's ecosystems in greatest need of ecological restoration, but relatively little is known about their floristic recovery dynamics over decadal timescales. From 2000 to 2012, we monitored understory plant communities in a woodland mosaic in Missouri, USA, as it underwent restoration via prescribed, dormant-season burning and mechanical thinning of red cedar (Juniperus virginiana) and exotic shrubs. Native species richness increased linearly by 36% over this time period, driven primarily by an influx of forb species in thin-soiled upland areas where red cedar was removed. Floristic quality also increased with differential dynamics across local communities; forest floristic quality saturated quickly whereas floristic quality increased gradually over the time series in woodlands and red cedar–dominated woodlands. Species that underlay these patterns were mainly ruderal or matrix forbs and grasses with little dependence on intact, undisturbed habitats. In contrast, conservative species were rare or absent. This case study suggests that understory plant recovery dynamics may be slower in harsher and more degraded sites and faster in more mesic sites within a woodland mosaic. Our observations set a benchmark for woodland understory plant recovery dynamics and indicate that a future restoration challenge is to prioritize the managed translocation of dispersal-limited, conservative species.

Challenges and considerations of applying nature-based solutions in low- and middle-income countries in Southeast and East Asia

AbstractLow- and middle-income countries in Southeast and East Asia face a range of challenges related to the rapid pace of urbanisation in the region, the scale of pollution, climate change, loss of ecosystem services and associated difficulties for ecological restoration. Possible pathways towards a more sustainable future lie in the applications of nature-based solutions (NBS). However, there is relatively little literature on the application of NBS in the region, particularly Southeast Asia. In this paper we address this gap by assessing the socio-ecological challenges to the application of NBS in the region – one of the most globally biodiverse. We first provide an overview and background on NBS and its underpinnings in biodiversity and ecosystem services. We then present a typology describing five unique challenges for the application of NBS in the region: (1) Characteristics of urbanisation; (2) Biophysical environmental and climatic context; (3) Environmental risks and challenges for restoration; (4) Human nature relationships and conflicts; and (5) Policy and governance context. Exploiting the opportunities through South-South and North-South collaboration to address the challenges of NBS in Southeast and East Asia needs to be a priority for government, planners and academics.