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Presents a study that examined the role of papermill sludge in the organic forest carbon cycle of paper products. Prediction on the global production of papermill sludge; Impact of paper production and wastepaper recycling trends on the woody carbon components of sludge; Implications of the organic content and carbon content of sludge for dealing with disposal policy and problems.

Freshwater biodiversity is under great threat across the globe as evidenced by more severe declines relative to other types of ecosystems. Some of the main stressors responsible for these concerning trends is habitat fragmentation, degradation, and loss stemming from anthropogenic activities, including energy production, urbanization, agriculture, and resource extraction. Habitat protection and restoration both play an integral role in efforts to save freshwater biodiversity and associated ecosystem services from further decline. In this paper, we summarize the sources of threats associated with habitat fragmentation, degradation, and loss and then outline response options to protect and restore freshwater habitats. Specific response options are to legislate the protection of healthy and productive freshwater ecosystems, prioritize habitats for protection and restoration, enact durable protections, conserve habitat in a coordinated and integrated manner, engage in evidence-based restoration using an adaptive management approach, ensure that potential freshwater habitat alterations are mitigated or off-set, and future-proof protection and restoration actions. Such work should be done through a lens that engages and involves local community members. We identify three broad categories of obstacles that could arise during the implementation of the response options outlined: (a) scientific (e.g., inaccessible data or uncertainties), (b) institutional and management (e.g., capacity issues or differing goals across agencies), and (c) social and political (e.g., prioritizing economic development over conservation initiatives). The protection and restoration of habitats is key to Bend the Curve for freshwater biodiversity, with a comprehensive, connected, and coordinated effort of response options needed to protect intact habitats and restore fragmented, degraded, and lost habitats and the biodiversity and ecosystem services that they support. [ABSTRACT FROM AUTHOR]

Cyanobacteria blooms represent a global problem with human health and economic and ecosystem nuisance effects. Until now, we have used arbitrary and sometimes confusing criteria to decide whether we are in the presence of a Cyanobacteria bloom. Through scientometric analysis of studies published between 1953 and 2022, I aimed to identify a threshold value that can be used to quantify Cyanobacteria blooms numerically. I considered several methodological approaches (field, field-experimental, and satellite data) and kinds of environments (coastal, marine, and continental ecosystems). The analysis revealed that 48% of the papers used "cyanobacteria bloom" or similar terms qualitatively without providing or employing a quantitative definition. These papers were focused on other topics related to the ecology of Cyanobacteria (78%), while some others (21%) defined blooms by using visual criteria (scum visualization or water discoloration). Of the other half (52%), a few were mathematical models or review papers (5%), while the rest (65%) defined blooms quantitatively. Of these, most reports (approximately 80%) were from eutrophic inland waters and reported mean values for blooms between 80 000 and 249 000 cells mL−1 or 41 and 69 µg L−1 of chlorophyll-a. Calculations were also carried out for oligotrophic to mesotrophic inland waters and marine-coastal waters, which had fewer reports available in the literature. This is a first attempt to identify a consensual definition based on values reported as blooms in nature, a threshold that can undoubtedly be useful in the future to make possible comparisons among several environments and temporal scales. [ABSTRACT FROM AUTHOR]

In this paper, a review of Indigenous engagement in renewable energy projects is conducted and the main elements of energy partnerships between stakeholders and Indigenous partners are discussed. In recent years, Canada has witnessed more significant Indigenous involvement in economic and energy development projects than ever before. For large-scale energy partnerships, the focus is on engagement, financial capital, community buy-in (readiness, and entrepreneurial and business skills), and benefits-sharing with community partners. Equity-ownership, reconciliation, and self-determination intersect with and impact the benefits and sustainability of energy projects, as they are interrelated in the framework of most energy partnerships. This paper illustrates policy disconnects in connection with partnership-making, social outcomes, and decision-making among Indigenous communities. Furthermore, findings from relevant literature explore the nuanced discourse on social implications and capacity challenges that interlink with climate adaptation and reconciliation when promoting large-scale renewable energy partnerships with Indigenous communities. Through a systematic review and a meta-analysis of the literature, we found 80 relevant studies during the screening process, of which 33 were selected for the synthesis. Findings demonstrate that the Crown, energy companies, and community partners need to coordinate and collaborate closely to achieve energy security and sustainable renewable energy. The review suggests that Indigenous engagement in energy partnerships supports positive outcomes for social development and environmental protection among Indigenous communities. The literature suggests that when government and industry mentor in the project implementation process, important positive impacts on energy transitions, and self-sufficiency can be realized. [ABSTRACT FROM AUTHOR]

Climate change (CC) causes extreme meteorological events such as floods, droughts, water scarcity, heat waves, wildfires, and extreme cold. CC may also damage public infrastructures such as drinking water systems (DWSs) and reduce water quality from source to tap. The objective of this review paper is to provide a critical analysis of (1) the impact of CC on the three components of the DWSs: source, treatment, and distribution; (2) the perspectives of DWS employees on CC impacts and adaptation solutions for maintaining water quality; and (3) decision support systems (DSSs) that could be used by DWS employees for CC adaptation. A bibliographic research was conducted using international databases and search engines. The search for scientific articles resulted in the selection of 5234 articles, 78 of which were analyzed in more detail for the elaboration of this scoping review. This review shows that the impacts of CC on water quality are significant, but DWS employees are not enthusiastic about developing adaption measures. This review also shows that DSSs can help DWS employees facilitate the CC adaptation process for the protection of source water, improve water treatment plant operations, and enhance routine management of water quality in the distribution system. Further research is needed to identify strategies that might increase the awareness of and interest in climate change impacts, adaptation, and the use of DSSs among DWS employees. [ABSTRACT FROM AUTHOR]

Much of Canada's industrial sector is driven by natural resources and relies heavily on provisioning services supplied by the boreal zone. However, the sometimes intensive processes used by resource-based industries and their associated infrastructure have significantly altered the region, creating concerns over the future socio-ecological health of the boreal zone. Addressing these concerns will require industries reliant on natural resources from the boreal zone to innovate their processes, management, and infrastructure to improve extraction efficiency while contributing to society's increasing expectations related to sustainability. Here, we explore past, current, and future trends in industrial innovation and infrastructure in the boreal zone for forestry, mining, pulp and paper, oil and gas, and renewable sources of power generation. We assess the role of innovation on the future socio-ecological state of the boreal zone by considering interactions between innovation in industry and infrastructure and other key drivers of change in the boreal, such as atmospheric changes, changing demands for nonprovisioning and provisioning ecosystem services, governance, and demographics and social values. We present future scenarios highlighting three divergent trajectories of change in boreal ecosystems based on past and current states of innovation in industry and infrastructure. We suggest that minimizing impacts of natural resource extraction activities in the boreal zone will only be possible through innovation directly focused on reducing the human footprint on the landscape. Innovation in the information technology sector related to process, management, and end products within these industries and placing greater emphasis on cross-sectoral collaboration will be key to achieving this goal. [ABSTRACT FROM AUTHOR]

Decision-making tools have become a prominent methodology in watershed management for many years due to the complexity of environmental systems and requirement for multi-disciplinary expertise. Multi-Criteria Decision Analysis (MCDA) is a systematic methodology, which combines hierarchical structures of a problem and priorities for the alternatives in many fields. This study reviews MCDA applications in pollution risk assessment in the abiotic environments of watersheds for multi-pollutants. Over 80 papers published between 2000 and 2021 are identified in three categories of the Web of Science Core Collection database: "Environmental Sciences", "Environmental Studies", and "Water Resources". The publications are further classified according to different environmental compartments: surface water, groundwater, and soil to investigate MCDA applications in these matrices. Finally, the distribution of the publications according to contaminants and MCDA methods used are also examined. The results reveal that the number of the studies focusing on pollution risk assessment within watersheds has been significantly increasing, especially over the last decade. However, there are still limited MCDA applications linking environmental compartments. Despite several MCDA studies focusing on the vulnerability of watersheds to multiple pollutants, studies related with emerging pollutants are scarce. Moreover, compared to non-point source pollution, studies adopting MCDA to investigate pollutant concentrations coming from point sources are relatively few. According to the overall distributions of MCDA methods, Analytic Hierarchy Process, a commonly found method in the literature that adopts a technique of pairwise comparison to prioritize criteria of prominence, dominates 34% of the publications. [ABSTRACT FROM AUTHOR]

Satellite data are vital for understanding the large-scale spatial distribution of particulate matter (PM2.5) due to their low cost, wide coverage, and all-weather capability. Estimation of PM2.5 using satellite aerosol optical depth (AOD) products is a popular method. In this paper, we review the PM2.5 estimation process based on satellite AOD data in terms of data sources (i.e., inversion algorithms, data sets, and interpolation methods), estimation models (i.e., statistical regression, chemical transport models, machine learning, and combinatorial analysis), and modeling validation (i.e., four types of cross-validation (CV) methods). We found that the accuracy of time-based CV is lower than others. We found significant differences in modeling accuracy between different seasons (p < 0.01) and different spatial resolutions (p < 0.01). We explain these phenomena in this article. Finally, we summarize the research process, present challenges, and future directions in this field. We opine that low-cost mobile devices combined with transfer learning or hybrid modeling offer research opportunities in areas with limited PM2.5 monitoring stations and historical PM2.5 estimation. These methods can be a good choice for air pollution estimation in developing countries. The purpose of this study is to provide a basic framework for future researchers to conduct relevant research, enabling them to understand current research progress and future research directions. [ABSTRACT FROM AUTHOR]

Climate change is altering the dynamics of New Brunswick's forests. To mitigate the effects of climate change, it is crucial to account for future uncertainties in climate projections and natural disturbance trajectories when designing forestry practices. This paper presents the projected changes in key climatic drivers for New Brunswick's forests, examines the impacts of climate change on forest stand dynamics, and reviews adaptive silviculture tools for climate change adaptation. By 2071–2100, a projected 4–6 °C increase in mean annual temperature will lead to a 39%–77% rise in growing degree-days and a reduction in summer atmospheric water balance by 48–79 mm across New Brunswick. Foresters should anticipate a doubling of annual area burned, the northward migration of spruce budworm (Choristoneura fumiferana (Clemens)), and the introduction of novel insects and diseases. Forest simulation models project a severe decline in boreal tree species abundance, including a 50% decline in balsam fir (Abies balsamea (L.) Mill) and black spruce (Picea mariana (Mill.) Britton et al.), offset by an increase in temperate species, notably red maple (Acer rubrum L.; +200%) and American beech (Fagus grandifolia Ehrh; +135%). Forests in the highlands and lowlands ecoregions, with 40%–50% and 15%–30% spruce and balsam fir composition, respectively, are particularly vulnerable. To limit climate change effects on forest values, foresters must prioritize climate resiliency in their management plans. Strategies should ensure the steady provision of forest goods and services under changing climatic conditions. Forest thinning enhances stand productivity and resilience, while shelterwood and two-age harvest balances timber production with diversity. Clearcutting, despite drawbacks, establishes younger, more vigorous forests with higher carbon sequestration potential. Assisted migration offers promise in helping threatened tree species adapt. Climate change will have a significant impact on New Brunswick's forests, leading to changes in key climatic drivers, increased risks of disturbances, and a shift toward more temperate tree species. However, there are existing adaptation strategies available. It is crucial to consider future uncertainties when designing and evaluating forestry practices, as this is essential for mitigating the effects of climate change on forest values and ensuring the continued provision of forest goods and services over time. [ABSTRACT FROM AUTHOR]

Similar to many freshwater ecosystems, the Laurentian Great Lakes of North America have undergone numerous anthropogenic stressors resulting in considerable loss of biodiversity and habitat. Among Great Lakes fishes, the coregonine sub-family has endured the most extensive declines, including extinction of several species (Coregonus johannae, C. alpenae, and C. kiyi orientalis) and at least 10 instances of local extirpations of other species (C. nigripinnis, C. reighardi, C. zenithicus, C. hoyi, and C. artedi) across all 5 lakes, much of which occurred prior to the 1960s owing to overfishing, interactions with non-indigenous species, and habitat loss. Despite these declines, no federal-, provincial-, or state-mandated actions were ever implemented to conserve coregonine diversity, potentially because so much of the coregonine declines occurred prior to the enactment of federal conservation legislation. Possible explanations for inaction since enactment of that legislation include insufficient data on biological vulnerability or threats, unresolved taxonomy, and limited support from the fishery management agencies and their stakeholders prior to the 2000s. In recent decades, however, several fishery management agencies have undertaken efforts to re-introduce coregonine diversity. These efforts helped lead to development of a science-based framework to restore coregonines that was universally endorsed by fishery managers representing eight U.S. states, four U.S. tribal organizations, and the province of ON, Canada, in May 2018. The basin-wide framework is based on principles of conservation biology and adaptive management. We describe details of its key steps, including planning, restoring, and evaluating, while also describing recent implementation efforts to develop methods, improve available resources, and enhance coordination across the basin. Although our paper describes a regional effort to restore native coregonines, our adaptive-management approach could be used by other multi-agency stakeholders seeking to conserve or restore native fishes. [ABSTRACT FROM AUTHOR]

The increasing number of studies covering different life cycle sustainability assessment (LCSA) tools and urban water systems (UWSs) emphasize the need to synthesize current research. While LCSA studies focus on an integrated approach considering the life cycle assessment (LCA), Life Cycle Costing (LCC), and social life cycle assessment (S-LCA) methodologies, these tools are typically applied separately, disregarding the trade-offs amongst economic, social, and environmental impacts. In this context, this review aims to critically analyze the literature on LCSA tools to enhance the integrated application in the future. Furthermore, we aim to identify technological trends, current challenges, and future research directions to improve sustainability. The ProKnow-C methodology was applied using a combination of four keyword sets and three databases. We selected 72 relevant papers that were analyzed in detail. Results demonstrate that authors apply different boundaries when using different LCSA tools, and lack of data was also a common issue. Furthermore, papers lack system description in the scope definition, leading to a biased interpretation of results. Another important issue was the functional unit selection, which did not represent the complexity of UWSs, lacking important details such as water loss, water quality, and population served. Water treatment is the most researched process in UWSs, and stormwater systems (collection or treatment) are rarely included, representing only 25% of the analyzed literature. In conclusion, the application of LCSA tools faces fundamental challenges, such as data quality and availability. Concerning the engineering improvements, future works should use LCSA data to support design and technology development, also focusing on human behaviour and frugal technology alternatives. Finally, new paradigms need to be developed and applied to enhance sustainability and integrate UWS. [ABSTRACT FROM AUTHOR]

As the global population increases, the expansion of road networks has led to the destruction and disturbance of terrestrial and aquatic habitats. Road-related stressors have significant effects on both lotic and lentic habitats. While there are several systematic reviews that evaluate the effects of roads on lotic environments, there are none that consider their effects on lentic habitats only. We conducted a literature review to achieve two objectives: (1) to summarize the effects of roads on the physical, chemical, and biological properties of lentic environments; and (2) to identify biases and gaps in our current knowledge of the effects of roads on lentic habitats, so that we could find promising areas for future research. Our review found 172 papers published between 1970 and 2020. The most frequently studied stressors associated with roads included road salt and heavy metal contamination (67 and 43 papers, respectively), habitat fragmentation (37 papers), and landscape change (14 papers). These stressors can lead to alterations in conductivity and chloride levels, changes in lake stratification patterns, increases in heavy metal concentrations in water and organisms, and significant mortality as amphibians disperse across roadways. We also identified a variety of other stressors that may be understudied based on their frequency of appearance in our search results, including polycyclic aromatic hydrocarbons, road dust, increased accessibility, hydrological changes, noise pollution, dust suppressants, sedimentation, invasive species introductions, and water withdrawal. Our review indicated that there are strong geographic biases in published studies, with 57.0% examining North American sites and 30.2% examining European sites. Furthermore, there were taxonomic biases in the published literature, with most studies focusing on amphibians (41.7%), fish (15.6%), and macroinvertebrates (14.6%), while few considered zooplankton (8.3%), diatoms (7.3%), amoebas (5.2%), water birds (3.1%), reptiles (2.1%), and macrophytes (1.0%). Based on our review, we have identified promising areas for future research for each of the major stressors related to roadways. However, we speculate that rectifying the geographic and taxonomic bias of our current knowledge could significantly advance our understanding of the impacts of roads on lentic environments, thereby better informing environmental management of these important habitats. [ABSTRACT FROM AUTHOR]

Military training areas (MTAs) are special environments with specific anthropogenic activities. The aims of this review are (1) to understand the interactions between military training activities and biodiversity, (2) to quantify the available scientific literature on this subject, (3) and to highlight the origin of the studies. Queries were carried out on two literature databases: Scopus and Wiley. The queries returned a large number of papers, but few actually matched the research topics. These two databases contain nearly 400 articles that discuss the interactions between military training and biodiversity at different scales. These articles come from all over the world, but the majority were conducted in the United States. In Europe, the studies are mainly conducted on German, English, and Czech sites. Impacts on biodiversity from all types of military training and from restricted areas were studied. The impacts on these areas are multiple and affect the landscape, the soil, fauna, and flora. They can be directly or indirectly related to military activities. Responses to disturbance by military trainings can be complex as they are variable. Thus, the same training may result in positive, neutral, or negative impacts depending on the habitats or taxa targeted and the country studied. Training methods are constantly evolving and vary between countries, and it appears important to maintain research about conservation in those particular areas, which paradoxically represent opportunities for nature conservation. [ABSTRACT FROM AUTHOR]

Arctic warming is occurring at a much faster rate than in other parts of the globe, with potentially devastating consequences for the diverse array of species within ecologically and biologically sensitive areas in the Arctic marine region. However, climate change research in this region is sparse compared to other biomes, hindering conservation efforts. In this article, we review and synthesize the available literature to understand the observed and potential impacts of climate change on different species and ecosystems in the Arctic marine region. We reviewed 253 articles reporting changes in species and ecosystems in the Arctic marine region in response to climate change (225 studies documenting observed impacts and 28 reporting predicted impacts). The review revealed that most research effort has been concentrated in only a subset of Arctic Large Marine Ecosystems (LMEs) (5/18 LMEs), with the majority of Arctic LMEs being poorly studied. The majority of the reviewed papers focused on marine mammals (19%) followed by microalgae (17%). A number of studies documented variability in planktonic communities (microalgae, macroalgae, zooplankton), resulting in alteration in ecosystem structure and function. Reproductive failure, decline in populations, and changes in diet composition, behavior, and breeding biology were reported for sea birds and mammals. Further, shifts in spatial distribution of fishes were observed by several studies. This review provides persuasive evidence that multiple climate change indices in the Arctic region are changing, with impacts on almost all components of marine biotic ecosystems (from plankton to top predators). We identify a number of gaps (such as limited inventory of biota, robustness of data supporting climate change indices on an Arctic Ocean scale, and climate suitability assessment for all species) in climate change research in Arctic marine ecosystems where future studies can help to quantify the impacts of climate change on species and ecosystems and advance understanding for their adaptive management. [ABSTRACT FROM AUTHOR]

This review paper aims at understanding natural and anthropogenic sources of rare earth elements (REEs) in the environment, their mechanisms of action, individual toxicity of REEs, and individual toxicity of their mixtures, including with other toxicants. We also summarized the scientific knowledge on REE bioaccumulation by plants, animals, and fungi. The purpose of the work was to analyze published scientific information and identify unsolved scientific issues in the selected areas. At present, both natural positive geochemical anomalies of REEs and "spots" of anthropogenic origin are discovered. There is a relationship between natural and anthropogenic sources of REEs in the environment. Increasing REE mining leads to the exposure of rock layers rich in target elements, which are then leached from natural and waste rocks. As a result, the total content of REEs in soils of their extraction areas reaches 2.3 µg/kg, and in the snow of cities it ranges from 0.411 to 1.463 µg/kg, which is comparable with natural anomalies of elements. Most often such levels of REE accumulation are not dangerous for biota. REEs, like many trace elements, have an essential effect in low concentrations and have harmful effects only when the dose is increased. However, stimulation effects proven for agricultural plants and animals in the natural environment can influence the change in population and community structures. The effects of REE compounds have many uncertainties under the conditions of their joint action with each other and with other substances containing biogenic or potentially toxic elements. The article provides examples of additive, synergistic, and antagonistic actions of a mixture of elements. Further, it is shown that the bioaccumulation of REEs is comparable to the accumulation of heavy metals in living organisms. Data on the transfer of REEs along trophic chains are single and contradictory. Thus, REEs contribute to the toxic load on living organisms. The main "blank spots" in knowledge about the action of REEs that require further research are identification of the most sensitive and vulnerable species, establishment of long-term effects and clarification of the joint action of REEs with other substances. [ABSTRACT FROM AUTHOR]

Wildfires are a natural landscape disturbance in many climates and forest types, but the cumulative impact of human-caused climate change, historical fire management and suppression, and changing species diversity in forests has led to an increase in the size and (or) severity of wildfires in certain regions across the globe. There are a significant number of research studies on the effects of wildfire on human health, forest ecology, hydrology, and the physical, chemical, and biological properties of soils. However, research on the impact of wildfire on watersheds including toxicity in aquatic organisms, water chemistry, and fluvial sediment quality is less extensive, focusing primarily on water quality indicators such as nutrients and sediment flux. Recent research has shown that wildfires contribute to the environment significant amounts of polycyclic aromatic hydrocarbons (PAHs), which are compounds produced during the incomplete combustion of organic material, and are known to be toxic and mutagenic compounds. The primary objective of this paper is to review the recent literature that pertains to the contamination of surface waters and sediments and source apportionment of wildfire-derived PAHs to determine where research gaps remain. Additional objectives are to assess the use of molecular ratios to apportion PAH sources and, finally, to create a roadmap for future studies in designing and conducting research that seeks to determine sources of wildfire-derived PAHs in water and sediment. [ABSTRACT FROM AUTHOR]

This article applies the tools of bibliometric analyses to explore the evolution and strategic orientation of research focusing on the temporal dynamics of land use, which can be considered as an important proxy to assess soil vulnerability. With 1416 papers published in 417 different journals, the investigation showed a growing interest in the subject during the period ranging from 2001 to 2020. The main countries working on that topic are the USA, China, and certain countries of the European Union with a worldwide collaboration regarding coauthors. A cluster analysis of the keywords generated 6 main themes of research, each focusing on different issues and approaches, that is, greenhouse gas emissions, soil nutrients, climate change, erosion risk, human disturbances as well as resilience of soil functioning. Finally, it appears that the effect of land use legacy is poorly considered in the context of climate change, which could represent a future line of research. [ABSTRACT FROM AUTHOR]

The ecological and societal impacts of plastics production, use, and waste are a complex global challenge. Management strategies to mitigate the impacts of plastics, such as recycling, waste-to-energy, and replacement with alternative materials have impacts of their own. Achieving long-term sustainability of plastics use therefore requires considering the externalized impacts of such management strategies. Here, we assessed the literature on the most common plastic waste management strategies to identify their impacts in relation to the sustainable development goals. We reviewed impacts of bans, levies, and taxes; alternative products; recycling; waste-to-energy; plastic recovery; and extended producer responsibility. Our analysis identified a total of 259 measured impacts of plastic waste mitigation strategies, from 113 papers. Ninety-three impacts were negative, 104 were positive, 11 were neutral, and 51 depended on the context of implementation. Consideration of the impacts of both plastic materials and management strategies is necessary to avoid perverse outcomes of plastic pollution mitigation efforts. [ABSTRACT FROM AUTHOR]

Abnormalities in climate in recent years have been attributed to climate change. In particular, an increase in the frequency of droughts has started to influence the way we live. There is an urgent need to study and monitor droughts to prevent severe damage. Drought monitoring research is conducted using the meteorological drought index, a compilation of weather data. Although weather data are highly dependent on climatic zones, existing studies have not considered the drought index by climatic zones. This study aims to identify the spatial and climatic distribution of meteorological drought index studies and provide a well-matched combination of the drought index and climatic classification through a meta-analytic review. Data were used in the form of research papers covering the Palmer Drought Severity Index (PDSI), Standardized Precipitation Index (SPI), and Standardized Precipitation Evapotranspiration Index (SPEI) published from 2011 to 2021. The trends showed that SPEI has become a leading index for the study of drought monitoring among the three drought indices since 2015. Additionally, Asia was the focus of much of this drought research due to climate events in China. Each continent and climate classification was assigned to a different dominant drought index. For example, PDSI was commonly used in North America and continental climates, SPI in Africa, Europe, South America, and tropical and dry climates, and SPEI in Asia and temperate climates. This evaluates countries, in which drought monitoring studies are rare, using a meteorological index based on the same climatic zones. Monitoring and predicting drought patterns would improve the basic needs of humankind. [ABSTRACT FROM AUTHOR]

In the last two decades, several process-based models had been developed to describe the transport and fate of contaminants in subsurface flow constructed wetlands (SSF CWs) under a variety of conditions. These models have become valuable tools to better design, control, and optimize the SSF CW system. Moreover, they can aid investigations on the effects of variables of interest on the system. While excellent review papers on these models have been published, the ability of the existing process-based models to simulate the nitrogen transformations in the SSF CWs have not been highlighted. Consequently, a critical review of the simulation of nitrogen transformation processes is desirable. This paper presents an overview of the available models that are capable of modelling the nitrogen dynamics in the SSF CWs. The existing process-based models can be mainly categorized as process-dedicated models and Gujer matrix models. A process-dedicated model is a feasible tool for design purposes. Meanwhile, the Gujer matrix model delivers valuable insights into scientific studies. In this paper, the existing models are summarized and critically discussed with regards to their capability and practicality in simulating the nitrogen dynamics in SSF CWs. Organic nitrogen, ammonium, and nitrate are the common nitrogen compounds considered in the process-based models of SSF CWs. Meanwhile, nitrite was frequently considered together with nitrate, owing to its low concentration in the effluent of SSF CWs. By comparison, ammonification, nitrification, denitrification, plant uptake, and ammonium adsorption are the typical nitrogen transformation and degradation processes found in the existing models, whereas ammonia volatilization processes are rarely found in the literature. Oxygen and organic matter are the major limiting reactants of nitrogen transformation and degradation processes in the modelling, and other factors such as microbial population, temperature, and pH are also considered. The recommendations and future research directions on the influence of microorganism distribution, resting period, oxygen release, ammonium adsorption, and plants are outlined. [ABSTRACT FROM AUTHOR]

The management of hazardous municipal waste is a challenge. Added to this burden is the management of huge and growing quantities of electrical and electronic waste, which is emerging as one of the most important environmental challenges and health problems in developing countries, particularly in Africa. This has been accelerated by rapid growth and development in the information and communication technology (ICT) industries. The growth in waste electrical and electronic equipment (e-waste) has brought several challenges including introducing effective management practices that are environmentally sound to reduce the negative impacts on human health and the environment. This review aimed to show the extent of e-waste as a growing issue to the environment and human health in developing countries where waste management problems pose immense challenges. Seven electronic databases (Scopus, Web of Science, PubMed, ScienceDirect, DOAJ, JSTOR, and Google Scholar) were used to access published scientific articles. Systematic reviews, case studies, analytical cross-sectional studies, policy review papers, and available relevant studies were considered. The findings of this review show that the volume of electronic waste destined for developing countries is increasing from year to year. Most countries did not have specific policies on e-waste but relied on hazardous waste policies. Dumping and improper recycling and handling of e-waste cause problems such as contamination of soil and water, depletion of grazing land, health problems such as respiratory infections, various cancers, congenital disabilities, and other health issues that affect the brain and other vital organs. [ABSTRACT FROM AUTHOR]

Forest succession is a dynamic process of progressive compositional development of ecological communities of species following natural or anthropogenic disturbance. Despite a rich history of conceptual frameworks, models, and empirical advances, the complex interactions among climatic conditions, disturbances, edaphic factors, and silvicultural treatments still challenge our ability to accurately predict forest succession, hindering application to forest management. Our goal was to improve understanding of forest succession in the managed boreal forests of North America by clarifying advances in knowledge and limitations in our understanding. We reviewed 152 peer-reviewed papers to: (i) document conceptual developments in forest succession; (ii) summarize drivers of North American boreal forest succession, including changes to forest composition and successional trajectories given climate change; and (iii) discuss the implications of the synthesized information for boreal forest management. While the element of stochasticity is expected to increase under climate change, successional dynamics are anticipated to remain predominantly deterministic. Southern boreal forests are at increased risk of mortality due to warming-driven drought and increased fires. Following disturbance, regeneration is likely to favor deciduous hardwoods. In boreal mixedwoods, increased fires would promote jack pine, and also black spruce on hydric and xeric sites. Dynamics of the northern boreal will depend on the balance between precipitation and evapotranspiration. Forest management must carefully select prescriptions to promote forest regeneration and composition that consider the long-term effects of changing climate and disturbance regimes. For instance, combining retention cut with mechanical site preparation would maintain site productivity and reverse open black spruce stand development in northern boreal stands. Our work shows that multiple disturbances have compounding effects on forest development, but further work is needed to better define thresholds for synergistic and buffering interactions. Modeling of boreal forest succession can be improved by incorporating more of the influential factors, but this is often limited by the lack of data. This information will guide the development of forest management strategies by exploring combinations of prescribed fire and variable intensity selection cutting systems to reproduce the effects of multiple interacting natural disturbances under climate change on successional dynamics. [ABSTRACT FROM AUTHOR]

In the past three decades, the field of sanitation has attracted much academic attention, and a large volume of relevant research results have emerged. To explore the characteristics and trends of global sanitation research literature, this paper presents a bibliometric analysis of 9559 articles published between 1990–2019 and extracted from the Web of Science Core Collection database. With the rapid increase in the number of related publications, both the breadth and depth of sanitation studies have increased significantly in the 21st century. In terms of multiple criteria, the comprehensive research strength of developed countries is greater than that of developing countries. The field is highly interdisciplinary, meaning that collaborations between research institutions are increasing. Keyword clustering analysis shows that the main research topics in the domain of sanitation are: (i) drinking water, (ii) sustainability, (iii) biofilm, (iv) epidemiology, and (v) WaSH (water, sanitation and hygiene). Meanwhile, keyword burst analysis showed that the new research hotspots and frontiers mainly concentrated on: (i) sustainable development of sanitation services adapting to climate change, (ii) main determinants affecting child malnutrition, (iii) research based on global and multi-national data, and (iv) evaluations on various aspects of performance. This paper provides a better understanding of sanitation research trends that have emerged over the past 30 years and can serve as a reference for future research. [ABSTRACT FROM AUTHOR]

Contaminant levels and trends have been monitored in the eggs of seabirds from the Canadian Arctic since 1975. Nearly 50 years of monitoring have provided key information regarding the temporal and spatial variation of various contaminant classes in different seabird species. However, previous work has primarily assessed individual or related contaminant classes in isolation. There is therefore a need to collectively consider all of the contaminants monitored in seabird eggs to determine where monitoring has been successful, to find areas for improvement, and to identify opportunities for future research. In this review, we evaluated monitoring data for the major legacy and emerging contaminants of concern in five seabird species from three High Arctic and three Low Arctic colonies in Canada. We review the history of Canada's Arctic seabird egg monitoring program and discuss how monitoring efforts have changed over time; we summarize temporal, spatial, and interspecies variations in Arctic seabird egg contamination and identify important knowledge gaps; and, we discuss future directions for ecotoxicology research using seabird eggs in Arctic Canada. Ultimately, this paper provides a high-level overview of the egg contaminant monitoring program and underscores the importance of long-term and continued seabird contaminant monitoring in Arctic Canada. [ABSTRACT FROM AUTHOR]

Disposable diapers are considered indispensable hygiene products, which is reflected in their massive levels of consumption globally and waste generation. Most of the diaper waste is neither segregated nor treated and ends up in landfills or incinerators. The reported life cycle assessment highlights that the diaper waste is not solely generated after single-use but begins as early as the raw materials acquisition stage. Although what is done cannot be undone, diaper waste can be recycled. Diaper waste valorization has been explored on laboratory- and commercial-scales for years, with varying degrees of success. Leading diaper manufacturers such as Procter & Gamble, Kimberly–Clark, and Unicharm are making progress in establishing closed-loop recycling of used diapers and converting diaper waste into new diapers. However, the broad potential for possible new products made from diaper waste has yet to be fully exploited. This review focuses on the enormous promise of diaper waste from the perspective of emerging open-loop recycling pathways. We demonstrate that diaper waste can be harnessed and converted into nondiaper products, including energy pellets, anode material for lithium-ion batteries, concrete admixture, catalysts, soil amendment, and mushroom cultivation substrates. We also explore several active, commercial-scale diaper recycling approaches and provide a comprehensive blueprint to encourage open-loop recycling. Open-loop recycling is a practical strategy for managing diaper waste, rectifying environmental damage, and contributing to circular supply chains. [ABSTRACT FROM AUTHOR]

The presence of cadmium (Cd) in food produced in Latin America has been highlighted in recent years. Cadmium can be toxic to humans at low levels, and therefore monitoring its presence in food is relevant for public health. Cadmium concentrations from different sources, such as water, soil, sediment, food, and beverages were examined and discussed to address the non-occupational exposure of the Latin American population to Cd. A literature review was conducted examining publications from 2015 to 2020 and data available in the ScienceDirect and PubMed databases. Twenty-eight papers reported on Cd in water, 49 reported Cd in soil and sediments, and 86 reported on Cd in food. We have identified and discussed the factors affecting the environmental behavior and bioaccumulation of Cd, the main species used in monitoring studies, and the necessity for future research. Brazil and Mexico are the countries that provided the most available information, whereas for some countries in Central America, no information was found. The Cd levels in food examined in these studies (mostly fish and cacao) were generally below the established maximum levels, indicating a low risk. When considering the presence of Cd in food, water, and soil, Cd fractionation and chemical speciation studies are fundamental to understanding which forms of Cd are the most toxic. In turn, studies on bioaccessibility and bioavailability of Cd in food are also needed for more adequate risk assessment, but they are currently scarce within Latin America. [ABSTRACT FROM AUTHOR]

Ecological forestry is based on the idea that forest patterns and processes are more likely to persist if harvest strategies produce stand structures, return intervals, and severities similar to those from natural disturbances. Taylor et al. (2020) reviewed forest natural disturbance regimes in Nova Scotia, Canada, to support implementation of ecological forestry. In this follow-up paper, we (i) review the use of natural disturbance regimes to determine target harvest rotations, age structures, and residual stand structures; and (ii) describe a novel approach for use of natural disturbance regimes in ecological forestry developed for Nova Scotia. Most examples of ecological forestry consider only the local, dominant disturbance agent, such as fire in boreal regions. Our approach included: (i) using current ecological land classification to map potential natural vegetation (PNV) community types; (ii) determining cumulative natural disturbance effects of all major disturbances, in our case fire, hurricanes, windstorm, and insect outbreaks for each PNV; and (iii) using natural disturbance regime parameters to derive guidelines for ecological forestry for each PNV. We analyzed disturbance occurrence and return intervals based on low, moderate, and high severity classes (<30, 30–60, and >60% of biomass of living trees killed, respectively), which were used to determine mean annual disturbance rates by severity class. Return intervals were used to infer target stand age-class distributions for high, moderate, and low severity disturbances for each PNV. The range of variation in rates of high severity disturbances among PNVs was from 0.28%·year–1 in Tolerant Hardwood to 2.1%·year–1 in the Highland Fir PNV, equating to return intervals of 357 years in Tolerant Hardwood to 48 years in Highland Fir PNVs. As an example, this return interval for the Tolerant Hardwood PNV resulted in target rotation lengths of 200 years for 35% of the PNV area, 500 years for 40%, and 1000 years for 25%. The proposed approach of determining natural disturbance regimes for PNV communities and calculating target disturbance rates and corresponding harvest rotation lengths or entry times appears to be a feasible method to guide ecological forestry in any region with a strong ecological land classification system and multiple disturbance agents. [ABSTRACT FROM AUTHOR]

An urban water system (UWS) has three main service components: (i) drinking-water; (ii) waste-water; and (iii) storm-water. Historically, each component in urban water development evolved over time with different objectives for "different" types of water. Even today, the trend continues, as different urban water services are managed in silos. This trend is less sustainable, resilient, and reliable, mainly because of significant pressures on freshwater supplies exerted by the increasing population, demand for high living standards, rapid urbanization, and climate change. To cope with these challenges, the conventional thinking needs to change. This paper identifies a number of significant research gaps related to inter-relationships among various UWS service components. An innovative paradigm, the "one water" approach (OWA), which considers "urban water" as a single entity, is investigated herein. Currently, Australia, the USA, and Singapore are leading the implementation of the OWA, whereas only a few Canadian municipalities have embraced OWA at a very basic level. Among the EU nations, the Netherlands have emphasized the need for integrated water resource management in an urban environment. This review highlights the challenges in adopting the OWA, and also proposes guiding principles in ongoing water management practices. Institutional complexities involving an intricate regulatory structure for different UWS service components, a wider fragmentation in decision making at government levels, and insufficient stakeholder engagement within and between water utilities and other institutions present serious challenges. Various strategies such as, data sharing between water utilities, use of novel technologies (e.g., artificial intelligence, sensor technologies), and visionary leadership at different government levels have been identified as key drivers for the adoption and implementation of the OWA. The authors believe that a paradigm shift from "conventional" approach to OWA is needed to increase resiliency and reliability of water services and assist decision-makers of UWSs. [ABSTRACT FROM AUTHOR]

This study is a broad and critical review of the transdisciplinary literature on the construction of culverts and their impacts on stream hydrology and geomorphology as well as on stream habitats and biota. For engineers, a culvert is a structure, usually of the tunnel type, that transfers a stream or open drain under a road, railway line, or other obstacle from one side to the other. In fact, culverts are complex hydraulic structures whose impacts on stream ecosystems must be evaluated and understood before they are designed. The objective of this paper is to analyse and discuss recent knowledge about culvert functioning in terms of their negative effects on the passage of freshwater biota, particularly fish, and on entire stream ecosystems. We present the results of many studies showing that improperly designed culverts are barriers for migrating animals and usually have serious ecological consequences (mainly disturbances to fish life history). We also pay attention to different culvert modification methods that increase their passability for organisms and mitigate the impacts of culverts on the surrounding environment. The other purpose of this review is therefore to emphasize that the integration of the knowledge and professional experience of biologists and ecologists with those of river managers, river engineers, hydraulic engineers, hydrologists, and geomorphologists is necessary to design culverts that preserve the natural properties of streams. [ABSTRACT FROM AUTHOR]

Wastewater stabilization ponds (WSPs) have been proven to be economical alternatives to conventional wastewater treatment technologies due to their unique advantages including ease of operation, minimal energy input, and minimal maintenance requirements. Their reported high pathogen removal efficiencies have made WSPs a popular choice for wastewater treatment, especially as tertiary lagoons. This paper provides a critical overview of the various disinfection processes and mechanisms that occur in WSPs. A thorough review of the removal or attenuation mechanisms for bacterial, viral, protozoan, and helminthic pathogens is presented. Factors that impact the removal efficiency of pathogenic organisms may include sunlight, pH, dissolved oxygen, temperature, sedimentation, attachment, hydraulic retention time, pond depth, predation and nutrient availability; the relationship between these factors is also discussed. The purpose of this review paper is to utilize the current understanding of pathogen removal mechanisms in pond systems to improve the operation and design of WSPs, and more importantly, to provide guidance for the definition of regulations with respect to pathogen removal in eco-engineered wastewater treatment systems such as WSPs. [ABSTRACT FROM AUTHOR]

Wildlife management is predicated upon the use of scientific research to assist decision-making. However, assessment of the effectiveness of the management–research relationship is rarely undertaken. Polar bears (Ursus maritimus) have benefitted from an international agreement that required each of the countries within the species' range to manage them using the best available scientific data. The objective of this paper is to conduct a systematic review of peer-reviewed literature on polar bears to describe research trends and to assess how effectively research has met management needs. We analyzed 1191 peer-reviewed scientific papers from 1886–2016 covering 24 research topics. Annual counts of papers within each research topic were assessed for temporal trends, spatial coverage, and the extent to which they have facilitated management and monitoring needs. The annual number of papers increased from <10 in the early 1960s to >50 in recent years with a mean of 2.2 papers per subpopulation per year with great variation between the 19 global subpopulations. We conclude that there is an imbalance in the geographic and thematic focus of peer-reviewed research in recent years, and that only four subpopulations appear to have had a research focus covering most parameters essential for conservation and sound management. [ABSTRACT FROM AUTHOR]

Dyes are xenobiotic compounds widely used by textile, leather, paper, printing, food, pharmaceutical, and cosmetic industries. Decolorization and dye degradation in the effluents is a prime hurdle in its treatment, and there is still a shortage of economically attractive and easy-to-operate treatments that can eliminate dye pollution. In recent years, chemical-based treatments are being replaced by greener technologies at the laboratory and industrial scale to combat dye pollution. It is noteworthy that immobilization is a biotechnological tool that greatly enhances bioremediation's potential. The present review has covered the basic concepts of immobilization, including the different immobilization techniques and the various carriers used for immobilization. The efficient immobilization of a biocatalyst depends on the proper choice of a carrier combined with a suitable immobilization technique. Hence, this review provides a comparative analysis of the different immobilization techniques and carriers used. Further, there is an in-depth discussion on the potential of immobilized enzymes and cells as bioremediation agents for dye degradation. Nearly all the studies indicated that immobilization enhanced the biodecolorization of colored wastewater compared with free systems. Further, the potential of immobilized systems for large scale industrial implementation was also examined. The article ends with a note on the loopholes of research on immobilization and future scopes of this technique. [ABSTRACT FROM AUTHOR]

Freshwater unionid mussels are among the most imperiled fauna in North America, and their decline has been partially attributed to sediment from anthropogenic activities. However, there remains a debate regarding the role played by sediment in mussel declines due to a lack of field and laboratory evidence. If sediment is responsible for mussel declines, then a lack of information will likely impede efforts to mitigate species declines and protect remaining habitat. However, if the impacts of sediment are overstated, time and resources may be wasted on a threat that has little bearing on mussel declines or habitat loss. Given this knowledge gap, the purpose of this paper is to review the literature focused on the potential impact of suspended sediment and sedimentation on freshwater mussels. We focused our search on suspended sediment, expressed either as suspended sediment concentration (SSC) or total suspended solids (TSS), and sediment deposition and scour. We found increases in suspended solids could impact mussels by decreasing food availability, physically interfering with filter feeding and respiration, and impeding various aspects of the mussel–host relationship. We also found mussel–sediment thresholds, wherein certain concentrations of sediment caused significant declines in population performance, which could serve as reference points for ecological research and management. Specifically, we found clearance rates (a measure of feeding) were negatively impacted by TSS concentrations >8 mg/L, and respiratory stress occurred at ∼600 mg/L. Declines in fertilization success and glochidial (i.e., mussel larvae) development were observed at TSS values of 15 mg/L, and reproductive failure occurred at 20 mg/L. Impacts on host fish attachment and glochidial encystment occurred at TSS concentrations of 1250–5000 mg/L. Impacts on fish varied depending on the biological endpoint but typically occurred at TSS values ranging from 20 to 5000 mg/L. We also found mussels were sensitive to smothering and mortality occurred at depths as low as 0.6–2.5 cm of substrate. Finally, we found relative shear stress (RSS) values >1, which is a measure of substrate stability in response to scour and entrainment, resulted in significant declines in mussel biodiversity. [ABSTRACT FROM AUTHOR]

Traditionally, forest management has focused on forestry-related practices whereas other industries have been managed separately. Forest management requires the integration of all natural resource development activities, along with other anthropogenic and natural forest disturbances (e.g., climate change, pollution, wildfire, pest disturbance) to understand how human activities can change forested ecosystems. The term cumulative effects has been used to describe these attempts to integrate all disturbances to develop an understanding of past, current, and future impacts on environmental, social, and economic components of the system. In this review, we focus on the science required to understand the past, current, and future impacts of the cumulative effects of anthropogenic and natural disturbances on forested ecosystems or their components. We have primarily focused on the terrestrial system with an emphasis on northern forests in Canada. Our paper is not intended to be a comprehensive review of all cumulative effects science but a synthesis of the challenges and approaches currently being used. Central repositories were identified as an approach to deal with issues of availability of remotely sensed data on anthropogenic and natural disturbances. Data integration projects, open data, and well-designed large-scale data collection efforts are needed to provide sufficient data on environmental responses to cumulative effects. As well, large-scale integrated, modularized ecosystem models are needed to bring stressor and environmental response data together to explore responses to, and interactions between, multiple stressors to project these effects into the future and to identify future data collection needs. [ABSTRACT FROM AUTHOR]

Ecotoxicology evolved as a scientific field as awareness of the unintended effects of anthropogenic pollutants in biota increased. Polar bears ( Ursus maritimus) are often the focus of Arctic contaminant exposure studies because they are apex predators with high contaminant loads. While early studies focused on describing and quantifying pollutants, present-day polar bear toxicological papers often incorporate ecological variables. This systematic literature review investigates the ecological and physiological variables that have been integrated in such studies. The systematic literature search resulted in 207 papers, published between 1970 and 2016. Representation of each of the 19 polar bear subpopulations varied from 0 to 72 papers; East Greenland, Barents Sea, Southern Beaufort Sea, and Lancaster Sound had the most published research, with over 30 papers each. Samples were collected between 1881 and 2015, primarily from harvested bears (66%); most from the 1990s and 2000s. Adipose tissue, liver, and blood were the most common tissues examined, and mean number of bears analyzed per paper was 76 (range 1-691). Papers investigating temporal trends did so using a mean sample of 61 bears over a 6-year period.The frequency with which ecological and physiological variables were integrated into toxicological papers varied. Age and (or) sex was the only ecological variable(s) considered in 51% of papers. Further, a total of 37% of the papers included in the review investigated physiological effects in relation to contaminant concentrations. Of the papers, 98% dealt with contaminant exposure at the individual level, leaving population level effects largely unstudied. Solitary subadult and adult polar bears were included in 57% and 79% of the papers, respectively. Younger bears were included in fewer papers: yearlings in 20% and cubs-of-the-year in 13%. Only 12% of the papers examined reproduction relative to contaminants. Finally, body condition was included in 26% of the research papers, whereas variables related to polar bear diet were included in ≤9%. Based on our findings, we suggest future polar bear toxicology studies increase sample sizes, include more ecological variables, increase studies on family groups, and increase the applicability of studies to management and conservation by examining pollution effects on reproduction and survival. [ABSTRACT FROM AUTHOR]

The specific mechanisms of faecal bacterial removal by constructed wetland (CW) mechanisms are inadequately understood. In several circumstances, CWs have been compared to 'black box' systems involving poorly understood waste removal mechanisms despite being an emerging environmentally friendly waste management approach. This has therefore attracted numerous scientific studies to further unlock CWs' functional mechanisms and to increase its efficiencies. This review paper covers detailed information on the status of detection techniques and removal efficiencies of faecal coliforms, with an emphasis on Escherichia coli. A comprehensive literature search was undertaken that involved a comparative review of various study results and critical analysis of previous scientific and review papers. The ultimate objective is to shed further light on the role of wetlands on wastewater purification for improved aquatic ecosystem health and clean water for humans and other organisms. [ABSTRACT FROM AUTHOR]

Oil sands development within the Athabasca Oil Sands Region (AOSR) has accelerated in recent decades, causing alteration to natural ecosystems including wetlands that perform many vital ecosystem functions such as water and carbon storage. These wetlands comprise more than half of the landscape, and their distribution and local hydrology are the result of interactions among a subhumid climate, topography, and spatially heterogeneous surficial and bedrock geology. Since hydrology plays a fundamental role in wetland ecological functioning and determines wetland sensitivity to human disturbances, the characterization of anthropogenic impacts on wetland hydrology in the AOSR is necessary to assess wetland resilience and to improve current best management practices. As such, this paper reviews the impacts of oil sands development and related disturbances including infrastructure construction, gravel extraction, and land clearing on wetland function in the AOSR. Hydrologic disturbances in wetlands in the AOSR include changes to soil hydrophysical properties that control water table position, the interruption of recharge–discharge patterns, and alteration of micrometeorological conditions; these in turn govern wetland ecological structure and wetland ecosystem processes (e.g., evapotranspiration, nutrient cycling). Given that anthropogenic disturbance can affect natural wetland succession, long-term hydrological monitoring is crucial for predicting the response of these ecosystems to varying levels of human impact. [ABSTRACT FROM AUTHOR]

Although land system research has made important progress in land change monitoring, long-term histories of land use change, land system change modeling, and case-study synthesis, it still faces some challenges in system integration and comprehensive analysis. To better understand and explore the comprehensiveness of land systems, system integration theory should be combined with system generation theory that emphasizes historical accumulation. Therefore, this paper revisits some of the basic connotations and theories of land system science by reviewing relevant research and proposes the concept of generated land systems based on system generation theory with an aim to providing a reference base for future research. As coupled human–environment systems are generated by mankind's transformation, utilization, and adaptation of the land surface and its upper and lower spaces of Earth, generated land systems evolve in the mutual generation and restriction of the biophysical environment, land use, and social economy. The evolution forms of generated land systems can be classified as fluctuation, degradation, and optimization based on the ascendency and resilience of the system. The need for generated land systems to be multi-functional is what motivates the direction and form of generated land system evolution. Generation mechanism, process, adaptability, scale effect, and tele-coupling are important issues of generated land system research. In addition, how generated land systems can enter a new evolutionary cycle through functional transformation is also crucial to achieving sustainable management and utilization of land resources. [ABSTRACT FROM AUTHOR]

Over the last few decades, resilience and its related practices have been at the core of responding challenges in the Global South and North. We should, however, be conscious of its gaps for many reasons. First, environmental plans not attuned to local traditions can create cultural conflicts. Second, the politicised nature of international agreements poses unintended consequences as societies find it hard to engage in such agreements. Third, uncertainties about changes in socio-ecological systems reduce people's adaptive capacity. Without an awareness of these inconsistencies, policymakers risk impeding societies' adaptation to environmental change. By doing a systematic review of articles from academic and policy publications, this paper explores repercussions for environmental governance, illuminating key concerns in protected areas, climate change policy, and hydropower systems. [ABSTRACT FROM AUTHOR]

The intensified degradation of regional air quality in recent years has prompted an increase in research teams to pursue various aspects of air pollution research including source apportionment (SA) resulting in rapidly growing output of this literature, a rapid shift in research emphasis, and an extensive inter-institutional and international collaboration. To explore these recent trends in air pollution research, we present a spatial and cluster bibliometric evaluation of atmospheric SA research, ascertaining the relationship among the main research bodies and knowledge clusters. The evolution trend of the knowledge clusters was depicted with an emphasis on the recent surge of research in Asia. We retrieved relevant articles from the Web of Science and Scopus data set with the key words "air" and "source apportionment". In this field, the annual output of peer-reviewed papers has increased dramatically since 2005. Initially, air SA research was concentrated in developed countries from Europe and North America, but more recently it has been receiving substantial contributions from developing countries, most notably China and India. Meanwhile, there has been a methodological shift from single methods, such as source diffusion models or receptor models, to the integration of online high-resolution data monitoring with multiple models. In recent years, the main research objectives for atmospheric pollution research have changed from being focused predominantly on coarse particles to more focus on fine and ultrafine particles. Our bibliometric analysis yielded 666 knowledge nodes, forming 26 major co-citation clusters. Focusing on recently emerged knowledge clusters 7, 22, and 23, we identified four research themes based on the research frontier analysis: (i) practical research conducted to inform pollution-reducing policy, (ii) assessment of pollution-related health risks of human activities, (iii) analysis of pollutant composition and formation, and (iv) improvement of SA methods. The study provides an efficient and economical means to understand the history and the prospects for air SA research through a temporal and spatial analysis on the relationships among the main research bodies and knowledge clusters. [ABSTRACT FROM AUTHOR]

Among pharmaceuticals, cytostatics are a category of emerging contaminants that are of particular environmental concern, because of their mutagenic and carcinogenic characteristics. Concern about the presence of these drugs in the environment has increased in the last decades because of their potential harm to aquatic organisms and human health and their long-term cumulative impact on the environment, even at low concentrations in the order of ppb to ppt (μg/L to ng/L). In this paper we provide of an overview of the use of ozone and (or) advanced oxidation processes to eliminate cytostatics from the pharmaceutical wastewaters focusing on studies undertaken in Cuba. The review revealed that these treatments are suitable to degrade several antineoplastic drugs of different chemical structures and to safety dispose of wastewaters to the environment. In addition, we describe the analytical methods used for the determination of the fundamental by-products of applied treatments. [ABSTRACT FROM AUTHOR]

Increased temperatures and changing amounts of precipitation may alter environments, increasing the challenges faced by mines. This is a paper on topics relevant to metal mine biogeochemical environments, related waste management, element transport, and environment health south of 60° latitude. Mine waste can contain elements of interest (EOI) that may have adverse environmental and biological effects at concentrations that are higher than in undisturbed sites. Elevated concentrations of EOIs are transported by water as solutes and particles. Wind erosion also transports particles, and establishing its contribution and effects is challenging. Dispersal of EOI can be controlled at the source using water covers, geomembranes, geosynthetic clay liners, and covers with capillary barrier effects. Drainage that can be produced over a wide range of pH must be treated to meet environmental requirements. Water treatment can produce sludge that must be stored or processed. The success of these mitigation measures can be observed in the biological health of organisms at the site and vicinity. Processes responsible for EOI dissolution and transport, waste control and water management systems, and the stress experienced by biota near mines are all subject to climate change effects. Understanding and adapting to challenges from a rapidly changing environment will require cooperation between industry, government, mining communities, and scientists. Ideally, adaptation measures should correspond to temperature and precipitation projections, but this information is not always available at the relevant geographic scale. To anticipate emerging risks, it may be necessary to explore a variety of scenarios at lab and field scales, and to implement robust and flexible management techniques. [ABSTRACT FROM AUTHOR]

Artificial floating islands (AFIs) are a variation of wetland treatment systems for water quality improvement. This paper provides a review concerning AFIs in terms of their development, classification, and applications in the removal of nutrients, heavy metals, and chemical oxygen demand on waterways. The role of microorganisms, aquatic plants, and aquatic animals in AFIs for water decontamination and purification was also discussed. Additionally, some key factors influencing the AFIs' performances were discussed and comparisons between AFIs and constructed wetlands were reviewed. Finally, further perspectives of artificial floating islands were identified to possibly improve their performances. The understanding of the mechanisms in AFIs that drive removal of various contaminants to improve water quality is crucial, and is also highlighted in this paper. [ABSTRACT FROM AUTHOR]

Water resources in dry environments are becoming scarcer, especially under the changing climate. In response, rainwater harvesting (RWH) is being reemphasized with calls to revive the practice. Ancient knowledge on RWH - mainly the collection through runoff, storage, and use of rainwater for various purposes - is still relevant, especially for dry environments. However, many old practices and technologies may not be suitable or feasible for the present and future. Little has been done to modernize and (or) develop new practices and technologies based on ancient indigenous knowledge. Modernizing old practices or developing new ones and using them in integrated rangelands restoration packages with enabling policy environment can unlock their potential in many water-scarce regions of the world. This paper reviews the state-of-the-art of micro-catchment rainwater harvesting (MIRWH) in dry environments and discusses the opportunities available and the major obstacles faced in using it to restore degraded agro-pastoral ecosystems and support their sustainability. The review highlights the knowledge behind it, the practices developed over the years, and their relevance to today and the future. The paper indicates areas of modernization that can make it more feasible for the future of the dry environments, especially their role in mitigating and adapting to climate change. Conventional and passive approaches to restoring/rehabilitating degraded dry agro-pastoral ecosystems are either too slow to show an obvious impact or not progressing satisfactorily. One main reason is that, because of land degradation, the majority of rain falling on such ecosystems and needed for revegetation is lost with little benefit being gained. Adopting a more progressive intervention to alter the processes of degradation and move towards new system equilibrium is required. MIRWH can enable a large portion of this otherwise lost rainwater to be stored in the soil, and, if used in an integrated packages including suitable plant species and sound grazing management, it may support meaningful vegetation growth and help system restoration. The Badia Benchmark project, implemented by ICARDA in Jordan and Syria, has demonstrated the potential for adoption at large scale in similar environments. This case study illustrates the potential and the constraints of this practice. [ABSTRACT FROM AUTHOR]

The objective of this review was to summarize the aquatic environmental research through time in the oil sands to provide an understanding of the composition and toxicity of oil sands process-affected water (OSPW) as reported in the published literature and to propose future research directions. Literature from the results of two search engines using key words that contained 'oil sands tailings pond water', 'oil sands process water', and 'oil sands process-affected water' over the period of 1975-2013 was examined. Results indicate that process water, while referred to using similar terminology (OSPW), included many different water types. In some cases, the description of the waters was absent in the papers reviewed. Inconsistent terminology and variance in the water types assessed confounded comparisons of OSPW composition and toxicity. Of the 342 articles sourced in this review, 105 focused on raw OSPW; that is, OSPW collected from active settling basins. Of the 35 studies that conducted exposures to assess raw OSPW toxicity, only 18 studies reported toxicity concurrent with chemistry. Of these, eight studies reported Microtox as the only toxicological endpoint. Thus, only 10 of the 342 papers reviewed (2.9%) included chemical analysis concurrent with standard acute and chronic bioassay assessments of fish and invertebrate toxicity. Some of the papers provided limited information on sampling procedures and method QA/QC. Differences in methodology for naphthenic acids also confounded interpretation or comparison across studies. These results suggest that future research must better elucidate the composition and toxicity of OSPW with consideration of ( i) clear differentiation and reporting of different OSPW types and sources; ( ii) use of consistent terminology for process waters; ( iii) providing detail on mine type and processing that can affect raw OSPW composition (e.g., source, froth treatment, tailings management practices, etc.); ( iv) the use of consistent and standardized chemical and toxicological methods; ( v) concurrent chemical and toxicological analysis; and ( vi) toxicological assessments at environmentally relevant exposure concentrations. [ABSTRACT FROM AUTHOR]

Tree diversity is crucial to urban forest management. More diverse urban forests provide habitat for a wider range of organisms, increase resilience to pests and disease and, in cases where native tree species are well represented, contribute to local biodiversity protection. Studies have shown that tree diversity can peak in the low- to mid-density neighbourhoods found in suburban and peri-urban areas, emphasizing the potential for biodiversity enhancement during and after subdivision development. Most studies quantifying tree species composition in suburban areas focus on one or two major drivers of tree diversity, such as land use, socioeconomics and demographics, or the presence of natural features like parks or greenways. Furthermore, relatively little attention has been paid to the drivers of diversity for the variety of land types that make up the entire urban forest, which represent differences in tree planting and establishment practices, ownership, and maintenance. This paper presents an overview of drivers of tree species composition based on the literature, as well as factors that require further study because they play a role in determining the structure of the (sub)urban forest. These factors are examined in the context of four land types: street, residential property, park, and remnant woodland, and are organized under the following major themes: biophysical characteristics, community design, historical paradigms and influences, municipal management, and demographics and cultures. Based on what is known so far, a research agenda is also presented outlining major gaps in research on urban tree diversity in North America (USA and Canada). The information presented in this paper can thus serve as a guideline to inform urban forest management practices and strategically enhance tree diversity. [ABSTRACT FROM AUTHOR]

Efforts to stem global change include the application of new technological developments that aim to reduce atmospheric carbon dioxide (CO2) through the carbon capture and storage (CCS) of this greenhouse gas in stable geological structures. In this paper, we assess the potential risks related to the application of CCS technology and the acidification of aquatic ecosystems through CO2 enrichment. We use the multiple lines of evidence approach (LOEs) to characterize the effects of the acidification with contamination in aquatic sediments. We highlight and discuss the effects of acidification on the LOEs including contamination and mobility of contaminants in sediments, toxicity, macrobenthic community structure, in situ effects, and bioaccumulation–biomagnification processes. We further assess the results of acidification on the toxicity of organic contaminants such as antibiotics or illicit drugs like the freebase form of cocaine (crack). The main goal of using the LOE approach is to distinguish between adverse effects that are associated with contaminants and those related to acidification by enrichment of CO2 as a result of CCS technology. Previous assessments were not designed or conducted to incorporate an integrative point of view, nor did they employ a weight of evidence approach (WOE) in risk characterization and management of CCS operations and other situations related to acidification by enrichment of CO2 in the aquatic ecosystem. Based on the findings of this review, the WOE can identify the effects of the acidification on the different LOEs used for sediment quality: contaminant mobility, the adverse effects in organism under laboratory and field conditions, and the bioaccumulation–biomagnification of contaminants. The main strength in using the WOE is the ability of this method to discriminate between LOE responses associated with contamination by different organic and inorganic substances from those related to CO2 acidification itself. The WOE will significantly improve the risk assessment in areas affected by potential leakages of CO2 during CCS operations. [ABSTRACT FROM AUTHOR]

The Canadian boreal forest is primarily public land, owned and managed by provincial governments on behalf of the public interest. Boreal forest governance consists of a complex patchwork of federal and provincial legislation, policies, tenures, and delegated authorities designed to achieve multiple (and often conflicting) social, ecological, and economic objectives. We examine the implications of boreal governance arrangements for sustainable management of ecosystem services. The paper shows how current multi-level governance arrangements that evolved from Canada's Constitution Act are not effective at managing the cross-scale and cross-sectoral challenges of ecosystem services and have created a crisis of legitimacy for forest decisions. We show how the rise of nonstate arrangements, marketization, and decentralization are partly a response to governance gaps for ecosystem services as well as a reflection of global trends in forest governance. Past trends related to governance themes (the role and scope of government, the level of integration and coordination, Indigenous empowerment, and geopolitical influences) are used to motivate future governance scenarios. [ABSTRACT FROM AUTHOR]

Plastic pollution is now recognized as a global environmental issue that can affect the health of biota and ecosystems. Now that a growing number of species and taxa are known to ingest a diverse range of sizes and types of plastics and retain the plastics in their guts, there are increasing questions relating to the movement of plastics through food webs, and how biota may directly and indirectly ingest plastics. Here, we synthesize what is known from the published, peer-reviewed literature about plastic ingestion by animals and identify critical gaps in our knowledge. We systematically reviewed and examined the literature for studies that reported ingested plastics in marine and freshwater biota at a global scale. Our objective was to inform discussions and future studies regarding what we know about plastic ingestion and fate in food webs. We assessed what regions, ecosystems, and food webs have been studied to date and whether potential information may already be available to assess if trophic transfer of plastics may be occurring. We found 160 relevant publications through 2016. Most studies were concentrated in specific regions and in specific ecosystem types, with freshwater studies being the most limited. Moreover, most studies examined one species at a time with only a handful of regions with multiple taxa examined across multiple studies. Twenty-one percent of the regions have no published data on plastic ingestion to date. Although some studies have measured ingestion in multiple species across trophic levels, few have tested the hypothesis that plastics are transferred across trophic levels. Moreover, none have addressed questions related to biomagnification. While our review suggests that numerous papers have recorded the ingestion of plastics by biota across many trophic levels, habitats, and geographic regions, many questions regarding how or whether biota retain, bioaccumulate, biomagnify, and trophically transfer plastics still need to be addressed. [ABSTRACT FROM AUTHOR]

In response to global climate change, Canada is transitioning towards a low-carbon economy and the need for policy approaches that are effective, equitable, coordinated, and both administratively and politically feasible is high. One point is clear; the transition is intimately tied to the vast supply of ecosystem services in the boreal zone of Canada. This paper describes four contrasting futures for the boreal zone using scenario analysis, which is a transdisciplinary, participatory approach that considers alternative futures and policy implications under conditions of high uncertainty and complexity. The two critical forces shaping the four scenarios are the global economy's energy and society's capacity to adapt. The six drivers of change are atmospheric change, the demand for provisioning ecosystem services, the demand for nonprovisioning ecosystem services, demographics, and social values, governance and geopolitics, and industrial innovation and infrastructure. The four scenarios include: (i) the Green Path, where a low-carbon economy is coupled with high adaptive capacity; (ii) the Uphill Climb, where a low-carbon economy is instead coupled with low adaptive capacity; (iii) the Carpool Lane, where society has a strong capacity to adapt but a reliance on fossil fuels; and (iv) the Slippery Slope, where there is both a high-carbon economy and a society with low adaptive capacity. The scenarios illustrate the importance of transitioning to a low-carbon economy and the role of society's adaptive capacity in doing so. However, they also emphasize themes like social inequality and adverse environmental outcomes arising from the push towards climate change mitigation. [ABSTRACT FROM AUTHOR]