Developing a vision for improved monitoring and reporting of riparian restoration projects

Representatives from agencies involved in natural resource management in the Murray‐Darling Basin gathered for a workshop in November 2010 to develop a vision for improved monitoring and reporting of riparian restoration projects. The resounding message from this workshop was that the effectiveness of riparian restoration depends on having sound, documented and agreed evidence on the ecological responses to restoration efforts. Improving our capacity to manage and restore riparian ecosystems is constrained by (i) a lack of ecological evidence on the effects of restoration efforts, and (ii) short‐termism in commitment to restoration efforts, in funding of monitoring and in expected time spans for ecosystem recovery. Restoration at the effective spatial scope will invariably require a long‐term commitment by researchers, funding agencies, management agencies and landholders. To address the knowledge gaps that constrain riparian restoration in the Basin, participants endorsed four major fields for future research: the importance of landscape context to restoration outcomes; spatio‐temporal scaling of restoration outcomes; functional effects of restoration efforts; and developing informative and effective indicators of restoration. To improve the monitoring and restoration of riparian zones throughout the Basin, participants advocated an integrated approach: a hierarchical adaptive management framework that incorporates long‐term ecological research.     

Habitat preferences and habitat restoration options for small‐bodied and juvenile fish species in the northern Murray–Darling Basin

Degradation of instream habitats in the northern Murray–Darling Basin has occurred through numerous stressors, including siltation, clearing of bankside vegetation, intrusion of livestock and impacts of pest species. A better understanding of habitat preferences of native fish species could help guide future instream habitat restoration actions. The habitat choices of seven native fish species, juvenile Murray Cod (Maccullochella peelii), juvenile Golden Perch (Macquaria ambigua ambigua), juvenile Silver Perch (Bidyanus bidyanus), adult Murray–Darling Rainbowfish (Melanotaenia fluviatilis), adult Olive Perchlet (Ambassis agassizii), adult Un‐specked Hardyhead (Craterocephalus stercusmuscarum fulvus) and adult carp gudgeons (Hypseleotris spp.) were tested in preference troughs to help inform potential habitat restoration actions in the Condamine catchment. Each species was given a choice between pair combinations of open sandy habitat, submerged macrophytes, emergent plants and rocky rubble. Habitat preferences varied between species. Murray Cod, Golden Perch, carp gudgeons and Olive Perchlets preferred structure over open sandy habitat, whilst juvenile Silver Perch, Un‐specked Hardyhead and Murray–Darling Rainbowfish did not avoid open sandy habitats. Juvenile Murray Cod preferred rocky rubble habitat over all other habitat choices. Use of complex rock piles to provide nursery habitat for Murray Cod populations is a potential restoration option. Introduction of rock could also benefit Golden Perch and carp gudgeons. Use of emergent plants, submerged macrophytes and rocky rubble for habitat restoration all appear to have merit for one or more species of small‐bodied fishes or juvenile stages of larger sized fishes. Rocky rubble or floating attached macrophytes could be viable restoration options in areas too turbid to establish submerged macrophytes. These habitat interventions would complement existing actions such as re‐snagging and provision of fish passage to assist with sustainable management of native fish populations.     

Public Perceptions of the Attractiveness of Restored Nature

Ecological restoration efforts often encounter public resistance. Recreational visitors resist imposition of restoration efforts they fear may result in a visually unattractive area. Public support is, however, essential for restoration efforts on public lands. This study seeks insight into hiker perceptions of perceived attractiveness of nature before and after efforts to restore exotic conifer plantations to native communities containing bog and wet forest communities. Visitors (N = 247) to a Dutch National Park sorted 32 photographs depicting landscapes before and after restoration efforts. Findings show that the most attractive landscape types (bog and wet forest communities containing visible water) are results of restoration efforts and the least attractive landscape types (young deciduous and coniferous forest) are representative of traditional nature before restoration. However, the “middle category” consists of landscape types existing both before and after restoration efforts. Visitors value old coniferous and old deciduous forests as much as products of restoration that lack water. These perceptions are unrelated to either visitor characteristics or the provision of information to visitors explaining restoration goals. The continued existence of resistance to restoration strategies despite their effect on perceived landscape attractiveness implies that the experience of nature has more than only visual dimensions. We expect that more acceptable results of restoration efforts will emerge from the active engagement of the public before restoration practices take place in processes that specifically address feelings of attachment and resistance to change.     

Recovery from a fish kill in a semi‐arid Australian river: Can stocking augment natural recruitment processes?

Localized catastrophic events can dramatically affect fish populations. Management interventions, such as stocking, are often undertaken to re‐establish populations that have experienced such events. Evaluations of the effectiveness of these interventions are required to inform future management actions. Multiple hypoxic blackwater events in 2010–2011 substantially reduced fish communities in the Edward‐Wakool river system in the southern Murray‐Darling Basin, New South Wales, Australia. These events led to extensive fish kills across large sections of the entire system following a period of prolonged drought. To expedite recovery efforts, 119 661 golden perch Macquaria ambigua and 59 088 Murray cod Maccullochella peelii fingerlings were stocked at five locations over 3 years. All fish stocked were chemically marked with calcein to enable retrospective evaluation of wild or hatchery origin. Targeted collections were undertaken 3 years post‐stocking to investigate the relative contribution of stocking efforts and recovery via natural recruitment in the system. Of the golden perch retained for annual ageing (n = 93) only nine were of an age that could have coincided with stocking activities. Of those, six were stocked. The dominant year‐class of golden perch were spawned in 2009; before the stocking programme began and prior to blackwater events. All Murray cod retained (n = 136) were of an age that coincided with stocking activities, although only eight were stocked. Among the Murray cod captured, the dominant year‐class was spawned in 2011, after the blackwater events occurred. The results from this study provide first evidence that natural spawning and recruitment, and possibly immigration, were the main drivers of golden perch and Murray cod recovery following catastrophic fish kills. Interpreted in the context of other recent examples, the collective results indicate limited benefit of stocking to existing connected populations already naturally recruiting in riverine systems.     

Ecological restoration in the age of apocalypse

Billions of dollars are spent annually on ecological restoration efforts around the world and yet successful attainment of restoration targets still falls short in many regions. Globally, ecosystem restoration is becoming increasingly challenged with changes in climate. Years with extreme climatic events that limit plant establishment, such as severe drought, heatwaves, and floods are projected to increase in frequency. A critical evaluation of current ecological restoration practices and changes to those practices are needed to attain global restoration targets. For plant restoration, many efforts globally focus on planting in a single year following disturbance. The odds of restoration efforts being conducted in a year that is inconducive to plant establishment may be calculated using climatic risk data. We propose a risk-mitigation approach to restoration wherein plantings are conducted across multiple years for projects in a bet-hedging strategy and evaluated through an adaptive management approach.     

Isolation and characterization of 102 new microsatellite loci in Murray cod,Maccullochella peelii peelii (Percichthyidae), and assessment of cross‐amplification in 13 Australian native and six introduced freshwater species

We have isolated 102 polymorphic microsatellite loci from an enriched Murray cod DNA library and also assessed their amplification success in 13 native and six introduced freshwater fish species. The loci will serve the dual purpose of assessing wild population genetic structure for future conservation efforts, and for identifying markers for key quantitative trait loci important for aquaculture.     

Effects of flooding on recruitment and abundance of Golden Perch (Macquaria ambigua ambigua) in the lower River Murray

Flooding is often considered a stimulus for production of fish in floodplain rivers. In the southern Murray–Darling Basin (MDB), Australia, however, few native fish species have been shown to use the floodplain for spawning, and recruitment has been positively and negatively associated with flooding. In 2010/11, extensive flooding in the lower River Murray provided an opportunity to investigate the recruitment response of Golden Perch (Macquaria ambigua ambigua) following 10 years of drought and floodplain isolation. Annual variation in Golden Perch abundance and recruitment were investigated in anabranch and main channel habitats at Chowilla in the floodplain geomorphic region of the lower River Murray over a 7‐year period incorporating the flood and 6 years of in‐channel flow. Spatial variation in recruitment in the lower River Murray was also investigated by comparing the age structure of Golden Perch in the swamplands/lakes, gorge and floodplain geomorphic regions. Golden Perch abundance in the Chowilla region increased significantly postflooding compared with drought years. Age structures indicated that increased abundance was due predominantly to fish spawned during the flood (2010/11) and the previous year (2009/10), which was characterised by in‐channel flows. Age structure was similar in the nearby Katarapko Anabranch system indicating a uniform postflood recruitment response in the floodplain geomorphic region. Juvenile Golden Perch from the 2010/11 and 2009/10 cohorts were less apparent in the gorge and swamplands/lakes regions. Golden Perch have flexible life histories and will spawn and recruit in association with in‐channel rises in flow and overbank flows, but significant increases in abundance in the lower River Murray may result from overbank flooding. Contemporary approaches to flow restoration in the MDB emphasise overbank flows and floodplain processes. We suggest, however, that environmental flow management that incorporates floodplain and in‐channel processes, at appropriate spatio‐temporal scales, will result in more robust populations of Golden Perch.     

Behavior change and sustainability of ecological restoration projects

Addressing socio‐economic factors in ecological restoration projects is critical for the effectiveness of restoration practices and scaling of restoration efforts. To achieve sustainability of restoration projects, the drivers of human activity leading to the degradation need to be addressed. An under‐researched concept in ecological restoration is the impact of behavior change of stakeholders and communities involved, despite the strong link prior research has shown to exist between environmental quality and human behavior. This article explores the importance of addressing the behavioral change of stakeholders engaged in restoration to achieve sustainability of efforts; it investigates how behavior change models are linked and represented in global environmental governance documents, and it discusses how behavioral intervention and policy instruments could be included in ecological restoration projects. For future work, the article proposes the integration of behavior change interventions in the design of restoration projects and policies.     

Habitat Loss,Fragmentation, and Restoration

The loss and fragmentation of habitat is a major threat to the continued survival of many species. We argue that, by including spatial processes in restoration management plans, the effects of habitat loss and fragmentation can be offset. Yet few management plans take into account spatial effects of habitat conservation/restoration despite the importance of spatial dynamics in species conservation and recovery plans. Tilman et al. (1997) found a “restoration lag” in simulations of species restoration when randomly selecting habitat for restoration. Other studies have suggested that the placement of restored habitat can overcome effects of habitat loss and fragmentation. Here we report the findings of simulations that examine different regional management strategies, focusing on habitat selection. We find that nonrandom restoration practices such as restoring only habitat that is adjacent to those occupied by the target species can dramatically reduce or negate any restoration lag. In fact, we find that the increase in patch occupancy of the landscape can be greater than two-fold in the adjacent versus the random scenarios after only two restoration events, and this increase can be as great as six-fold during the early restoration phase. Many restoration efforts have limitations on both funds and available sites for restoration, necessitating high potential success on any restoration efforts. The incorporation of spatial analyses in restoration management may drastically improve a species' chance of recovery. Therefore, general principles that incorporate spatial processes and sensible management are needed to guide specific restoration efforts.     

Hidden Costs of Passive Restoration

The first few years of tropical forest restoration can be expensive, especially when applied to expansive areas. In light of this, passive restoration has been recommended as a considerably cheaper or even free alternative. There are, however, both direct and indirect costs associated with passive restoration. First, the longer recovery time that is typically required in passive restoration can be perceived as project failure, especially when compared with nearby active restoration efforts. In the worst‐case scenario, this can lead to the premature termination of a project by a landowner who would like to see more rapid or visible results. Second, passive restoration may be viewed as land abandonment, and in developing nations where land tenure is not always strictly enforced this may invite unanticipated uses, such as ranchers who may unintentionally or intentionally allow livestock to take advantage of the “unused” forage grass, thus setting back recovery efforts. Lastly, passive restoration does have direct financial costs, including material costs for establishing fences and repairing them, and labor costs for site vigilance. These upfront investments may need to be made repeatedly in passive restoration efforts, and for a longer time period than for an active restoration project. Both the direct and indirect costs should be considered prior to choosing passive restoration as a strategy in a particular restoration project.     

Restoration Ecology and Invasive Riparian Plants: An Introduction to the Special Section on Tamarix spp. in Western North America

River systems around the world are subject to various perturbations, including the colonization and spread of non‐native species in riparian zones. Riparian resource managers are commonly engaged in efforts to control problematic non‐native species and restore native habitats. In western North America, small Eurasian trees or shrubs in the genus Tamarix occupy hundreds of thousands of hectares of riparian lands, and are the targets of substantial and costly control efforts and associated restoration activities. Still, significant information gaps exist regarding approaches used in control and restoration efforts and their effects on riparian ecosystems. In this special section of papers, eight articles address various aspects of control and restoration associated with Tamarix spp. These include articles focused on planning restoration and revegetation; a synthetic analysis of past restoration efforts; and several specific research endeavors examining plant responses, water use, and various wildlife responses (including birds, butterflies, and lizards). These articles represent important additions to the Tamarix spp. literature and contain many lessons and insights that should be transferable to other analogous situations in river systems globally.     

生态系统修复国内外研究进展与展望

气候变化和人类活动的增加不仅导致生态系统退化、生物多样性丧失、生物圈资源供给能力降低, 而且极大地制约了社会经济的可持续发展。尽管在全世界范围内已实施了大量的保护工作, 但全球生态系统退化仍在继续, 逐渐成为备受关注的全球性问题。文章首先厘清生态系统修复的发展历程、相关概念与理论。其次, 归纳生态系统修复的全球议题, 涉及生态系统服务及其价值评估、生物多样性保护、应对气候变化与碳储存、自然保护地、监测体系与适应性管理、公平性与多主体参与等方面。然后, 总结我国森林、草原、河流与湿地、海洋与海岸带的生态系统退化问题与修复进展, 梳理生态保护红线、自然保护地生态系统修复和国土空间生态保护修复3种措施的进展与不足。最后, 对山水林田湖草沙一体化保护与系统治理、生态系统修复的多元融资政策与渠道、荒野生态保护修复的探索与实践、城镇生态系统修复的研究与应用以及生态系统修复对生物多样性的保护与维持等五个方面进行展望, 以期为我国进一步开展生态系统保护修复的相关研究与实践提供指导。     

Alternative states and positive feedbacks in restoration ecology

There is increasing interest in developing better predictive tools and a broader conceptual framework to guide the restoration of degraded land. Traditionally, restoration efforts have focused on re-establishing historical disturbance regimes or abiotic conditions, relying on successional processes to guide the recovery of biotic communities. However, strong feedbacks between biotic factors and the physical environment can alter the efficacy of these successional-based management efforts. Recent experimental work indicates that some degraded systems are resilient to traditional restoration efforts owing to constraints such as changes in landscape connectivity and organization, loss of native species pools, shifts in species dominance, trophic interactions and/or invasion by exotics, and concomitant effects on biogeochemical processes. Models of alternative ecosystem states that incorporate system thresholds and feedbacks are now being applied to the dynamics of recovery in degraded systems and are suggesting ways in which restoration can identify, prioritize and address these constraints.     

Interactions between coral restoration and fish assemblages: implications for reef management

Corals create complex reef structures that provide both habitat and food for many fish species. Because of numerous natural and anthropogenic threats, many coral reefs are currently being degraded, endangering the fish assemblages they support. Coral reef restoration, an active ecological management tool, may help reverse some of the current trends in reef degradation through the transplantation of stony corals. Although restoration techniques have been extensively reviewed in relation to coral survival, our understanding of the effects of adding live coral cover and complexity on fishes is in its infancy with a lack of scientifically validated research. This study reviews the limited data on reef restoration and fish assemblages, and complements this with the more extensive understanding of complex interactions between natural reefs and fishes and how this might inform restoration efforts. It also discusses which key fish species or functional groups may promote, facilitate or inhibit restoration efforts and, in turn, how restoration efforts can be optimised to enhance coral fish assemblages. By highlighting critical knowledge gaps in relation to fishes and restoration interactions, the study aims to stimulate research into the role of reef fishes in restoration projects. A greater understanding of the functional roles of reef fishes would also help inform whether restoration projects can return fish assemblages to their natural compositions or whether alternative species compositions develop, and over what timeframe. Although alleviation of local and global reef stressors remains a priority, reef restoration is an important tool; an increased understanding of the interactions between replanted corals and the fishes they support is critical for ensuring its success for people and nature.     

A restoration suitability index model for the eastern oyster (Crassostrea virginica) in the Mission-Aransas Estuary, TX, USA

Oyster reefs are one of the most threatened marine habitats on earth, with habitat loss resulting from water quality degradation, coastal development, destructive fishing practices, overfishing, and storm impacts. For successful and sustainable oyster reef restoration efforts, it is necessary to choose sites that support long-term growth and survival of oysters. Selection of suitable sites is critically important as it can greatly influence mortality factors and may largely determine the ultimate success of the restoration project. The application of Geographic Information Systems (GIS) provides an effective methodology for identifying suitable sites for oyster reef restoration and removes much of the uncertainty involved in the sometimes trial and error selection process. This approach also provides an objective and quantitative tool for planning future oyster reef restoration efforts. The aim of this study was to develop a restoration suitability index model and reef quality index model to characterize locations based on their potential for successful reef restoration within the Mission-Aransas Estuary, Texas, USA. The restoration suitability index model focuses on salinity, temperature, turbidity, dissolved oxygen, and depth, while the reef quality index model focuses on abundance of live oysters, dead shell, and spat. Size-specific Perkinsus marinus infection levels were mapped to illustrate general disease trends. This application was effective in identifying suitable sites for oyster reef restoration, is flexible in its use, and provides a mechanism for considering alternative approaches. The end product is a practical decision-support tool that can be used by coastal resource managers to improve oyster restoration efforts. As oyster reef restoration activities continue at small and large-scales, site selection criteria are critical for assisting stakeholders and managers and for maximizing long-term sustainability of oyster resources.     

A system to evaluate the scientific quality of biological and restoration objectives using National Wildlife Refuge Comprehensive Conservation Plans as a case study

It is widely accepted that plans for restoration projects should contain specific, measurable, and science-based objectives to guide restoration efforts. The United States Fish and Wildlife Service (USFWS) is in the process of developing Comprehensive Conservation Plans (CCPs) for more than 500 units in the National Wildlife Refuge System (NWRS). These plans contain objectives for biological and ecosystem restoration efforts on the refuges. Based on USFWS policy, a system was developed to evaluate the scientific quality of such objectives based on three critical factors: (1) Is the objective specific, measurable, achievable, results-oriented, and time-fixed? (2) What is the extent of the rationale that explains the assumptions, logic, and reasoning for the objective? (3) How well was available science used in the development of the objective? The evaluation system scores each factor on a scale of 1 (poor) to 4 (excellent) according to detailed criteria. The biological and restoration objectives from CCPs published as of September 2004 (60 total) were evaluated. The overall average score for all biological and restoration objectives was 1.73. Average scores for each factor were: Factor 1–1.97; Factor 2–1.86; Factor 3–1.38. The overall scores increased from 1997 to 2004. Future restoration efforts may benefit by using this evaluation system during the process of plan development, to ensure that biological and restoration objectives are of the highest scientific quality possible prior to the implementation of restoration plans, and to allow for improved monitoring and adaptive management.     

Do we know enough about controlling sediment to mitigate damage to stream ecosystems?

Stream and river ecosystems have suffered extensive degradation, and billions are expended annually on restoration efforts. However, few of these projects are monitored, and restoration effectiveness is often unknown. Consequently, there is a poor scientific foundation for restoration designs. Since many stream restoration efforts are at least partially targeted at controlling erosion of channel banks and beds, the effects of a large-scale, long-term stream erosion control effort in six Mississippi watersheds was assessed using 10–16 years of suspended sediment and water discharge records. Flow-adjusted suspended sediment concentrations showed no trends in five of the watersheds and a slight downward trend in one watershed, which was treated with small reservoirs as well as bed and bank erosion protection. Results indicate the inability of orthodox stream management structures (weirs and bank protection) to reduce watershed sediment yield and the need for a stronger scientific basis for stream restoration.     

National standards: Reasserting the ecological restoration framework in uncertain times

National ecological restoration standards – produced in 2016 through the collaboration of 13 of Australia's leading ecological restoration organisations – are increasingly influencing practitioners. This paper elucidates two of the Key Principles that underpin standards to encourage highest and best efforts across all sectors and help resolve uncertainty about the role of restoration in a changing world.     

The Return of the King or Bringing Snails to the Garden? The Human Dimensions of a Proposed Restoration of European Bison (Bison bonasus) in Germany

Human dimensions research can help resource and wildlife managers make informed decisions, target information efforts, and gain a greater understanding of the factors that comprise attitudes toward wildlife management efforts. Despite these often-stated merits, studies addressing the human dimensions of resource and wildlife management efforts are rare in Europe. A proposed restoration of free-ranging European bison ( Bison bonasus ) in North Rhine-Westphalia, Germany, has presented an opportunity to help address this research gap. During May to July 2006, we used a randomly distributed, self-administered questionnaire ( n = 398) to assess local residents' attitudes, beliefs, and levels of support or opposition toward the proposed restoration. These factors were compared across two administrative regions spanned by the proposed restoration area. We found that respondents from the Siegen-Wittgenstein region held significantly more positive attitudes and significantly higher knowledge levels than respondents from the Hochsauerlandkreis region. Principal components analysis revealed that attitudes comprised a general attitude factor pertaining to issues such as the importance of conserving bison for future generations and a lifestyle impact factor, which included items pertaining to bison-caused damages to trees and crops. Logistic regression was used to show the influence of fear of bison on attitudes. We discuss the likely causes and management implications of our findings and provide suggestions to managers wishing to target information efforts and address the concerns of those affected by the proposed restoration.     

“How Local Is Local?”—A Review of Practical and Conceptual Issues in the Genetics of Restoration

In plant conservation, restoration (the augmentation or reestablishment of an extinct population or community) is a valuable tool to mitigate the loss of habitat. However, restoration efforts can result in the introduction of novel genes and genotypes into populations when plant materials used are not of local origin. This movement is potentially important because many plant species are subdivided into populations that are adapted to local environmental conditions. Here we focus on genetic concerns arising from ongoing restoration efforts, where often little is known about “How local is local?” (i.e., the geographic or environmental scale over which plant species are adapted). We review the major issues regarding gene flow and local adaptation in the restoration of natural plant populations. Finally, we offer some practical, commonsense guidelines for the consideration of genetic structure when restoring natural plant populations.