Knowledge Repository

Coal fly ash dumps represent contaminated sites that pollute the environment and affect the health of living organisms. Vegetation development at ash dumps is an ecological solution to minimize the environmental threats of ash; however, low content of nutrients, organic matter and moisture pose a challenge for plant growth at the dumps. Bacterial indole acetic acid (IAA) facilitates plant recruitment and growth, more crucially in degraded ecosystems. Bacteria with different levels of IAA determine the plant-bacterial interactions as pathogenesis or symbiosis, therefore, form microbial functional types. Understanding plant-soil feedback and identifying environmental predictors of bacterial IAA producers at ash dump would help in improving biostimulation strategies for vegetation development. Therefore, to evolve a nature-based solution for vegetational restoration of ash dumps, we analyzed the role of geochemical factors, host species and age of dump on the assembly of rhizobacterial IAA functional types of naturally colonizing grasses (Saccharum ravennae and Cynodon dactylon). Analyses showed that the rhizosphere effect on geochemical traits was distinct in the dumps, irrespective of the host plant and age of the dumps. The rhizobacterial communities from the dumps produce relatively high mean IAA levels and harbor a high micro-diversity of IAA producers as compared with the region as a whole (non-rhizosphere or bulk ash). Canonical correspondence analysis showed that the host species and specific nutrients, i.e., NO3-N, PO4-P, Fe, and Na are the significant predictors of bacterial IAA functional types. S. ravennae and C. dactylon provided evidence of driving assembly of different IAA functional types in their rhizosphere via enrichment of NO3-N and PO4-P, respectively. The identification of environmental predictors of rhizobacterial IAA functional types of S. ravennae and C. dactylon has provided basic guidelines to improve the biostimulation strategies to accelerate vegetation restoration at the ash dumps. Both controlled and field experiments involving grass species with supplementation of specific nutrients would be required to develop an effective biostimulation strategy for the on-field application. © 2017 Malhotra, Mishra, Karmakar and Sharma.

Link: https://doi.org/10.3389/fenvs.2017.00059

Actions: Enhancing Ecosystems' Insurance Value, Sustainable use of Matter & Energy

Goals: Restoring Degraded Ecosystems Using NbS

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Nature-based solutions have been identified by the European Union as being critical for the enhancement of environmental qualities in cities, where urban and peri-urban forests play a key role in air quality amelioration through pollutant removal. A remote sensing and geographic information system (GIS) approach was applied to the Metropolitan City (MC) of Rome to assess the seasonal particulate matter (PM10) removal capacity of evergreen (broadleaves and conifers) and deciduous species. Moreover, a monetary evaluation of PM10 removal was performed on the basis of pollution externalities calculated for Europe. Deciduous broadleaves represent the most abundant tree functional group and also yielded the highest total annual PM10 deposition values (1769 Mg). By contrast, PM10 removal efficiency (Mg· ha-1) was 15%-22% higher in evergreen than in deciduous species. To assess the different removal capacity of the three functional groups in an area with homogeneous environmental conditions, a study case was performed in a peri-urban forest protected natural reserve (Castelporziano Presidential Estate). This study case highlighted the importance of deciduous species in summer and of evergreen communities as regards the annual PM10 removal balance. The monetary evaluation indicated that the overall PM10 removal value of the MC of Rome amounted to 161.78 million Euros. Our study lends further support to the crucial role played by nature-based solutions for human well-being in urban areas.

Link: https://doi.org/10.3390/f7070150

Actions: Carbon Sequestration, Enhancing Ecosystems' Insurance Value, Urban Regeneration, Well-being in Urban Areas

Goals: Climate Change Adaptation and Mitigation, Sustainable Urbanisation in cities

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Traditionally, most irrigation practices in Southern Europe have been based on gravity-fed surface irrigation systems. Currently, these systems remain a relevant typology in the European Union (EU) member states of the Mediterranean areas, where it is often the only sustainable method for farmers due to the small size of agricultural holdings, their reduced capacity and readiness to invest and the low ratio between yield profits and irrigation costs. In the last several years, in response to European and national directives, surface irrigation has garnered increasing attention at the political and bureaucratic levels due to frequent criticisms of its postulated low efficiency and high water wastage. However, these systems commonly provide a number of ecosystem services and nature-based solutions that increase the positive externalities in different rural socio-ecological contexts and often have the potential to extend these services and provide solutions that are compatible with economical sustainability. This study aims to discuss the prospects for new practices and for the rehabilitation and modernization of the gravity-fed surface irrigation systems in EU Mediterranean areas to enhance water efficiency, thus gaining both economic advantages and environmental benefits. The difficulties, stimuli for improvements and peculiarities of the irrigation water management of four rural environments located in Italy, Spain and Portugal were analyzed and compared to the current state of the gravity-fed surface irrigation systems with hypothetical future improvements achievable by innovative technologies and practices. In these different case studies, the current gravity-fed surface irrigation systems have an obsolete regulatory structure; water-use efficiency is not a driving criterion for the management of the conveyance and distribution canal network, and farmers are not yet adequately encouraged to adopt more efficient gravity-fed irrigation practices. A continuous knowledge exchange is thus necessary for the interaction of all irrigation water managers and farmers to improve their eco-efficiency and to preserve and promote their cultural heritage across the entire water supply and delivery chains. We argue that the best way forward will require precisely targeted rehabilitation measures of gravity-fed surface irrigation systems based on the integrated use of decision support services, gate automation, remote and feedback controls and real-time flow optimization. © 2017 by the authors.

Link: https://doi.org/10.3390/w9010020

Actions: Enhancing Ecosystems' Insurance Value

Goals: Climate Change Adaptation and Mitigation, Restoring Degraded Ecosystems Using NbS

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Nature-based approaches to flood risk management are increasing in popularity. Evidence for the effectiveness at the catchment scale of such spatially distributed upstream measures is inconclusive. However, it also remains an open question whether, under certain conditions, the individual impacts of a collection of flood mitigation interventions could combine to produce a detrimental effect on runoff response. A modelling framework is presented for evaluation of the impacts of hillslope and in-channel natural flood management interventions. It couples an existing semidistributed hydrological model with a new, spatially explicit, hydraulic channel network routing model. The model is applied to assess a potential flood mitigation scheme in an agricultural catchment in North Yorkshire, United Kingdom, comprising various configurations of a single variety of in-channel feature. The hydrological model is used to generate subsurface and surface fluxes for a flood event in 2012. The network routing model is then applied to evaluate the response to the addition of up to 59 features. Additional channel and floodplain storage of approximately 70,000 m3 is seen with a reduction of around 11% in peak discharge. Although this might be sufficient to reduce flooding in moderate events, it is inadequate to prevent flooding in the double-peaked storm of the magnitude that caused damage within the catchment in 2012. Some strategies using features specific to this catchment are suggested in order to improve the attenuation that could be achieved by applying a nature-based approach. Copyright © 2017 John Wiley & Sons, Ltd.

Link: https://doi.org/10.1002/hyp.11140

Actions: Coastal Resilience

Goals: Climate Change Adaptation and Mitigation, Risk Management and Resilience

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Urban areas’ population has grown during the last century and it is expected that over 60% of the world population will live in cities by 2050. Urban parks provide several ecosystem services that are valuable to the well-being of city-dwellers and they are also considered a nature-based solution to tackle multiple environmental problems in cities. However, the type and amount of ecosystem services provided will vary with each park vegetation type, even within same the park. Our main goal was to quantify the trade-offs in ecosystem services associated to different vegetation types, using a spatially detailed approach. Rather than relying solely on general vegetation typologies, we took a more ecologically oriented approach, by explicitly considering different units of vegetation structure and composition. This was demonstrated in a large park (44 ha) located in the city of Almada (Lisbon metropolitan area, Portugal), where six vegetation units were mapped in detail and six ecosystem services were evaluated: carbon sequestration, seed dispersal, erosion prevention, water purification, air purification and habitat quality. The results showed that, when looking at the park in detail, some ecosystem services varied greatly with vegetation type. Carbon sequestration was positively influenced by tree density, independently of species composition. Seed dispersal potential was higher in lawns, and mixed forest provided the highest amount of habitat quality. Air purification service was slightly higher in mixed forest, but was high in all vegetation types, probably due to low background pollution, and both water purification and erosion prevention were high in all vegetation types. Knowing the type, location, and amount of ecosystem services provided by each vegetation type can help to improve management options based on ecosystem services trade-offs and looking for win-win situations. The trade-offs are, for example, very clear for carbon: tree planting will boost carbon sequestration regardless of species, but may not be enough to increase habitat quality. Moreover, it may also negatively influence seed dispersal service. Informed practitioners can use this ecological knowledge to promote the role of urban parks as a nature-based solution to provide multiple ecosystem services, and ultimately improve the design and management of the green infrastructure. This will also improve the science of Ecosystem Services, acknowledging that the type of vegetation matters for the provision of ecosystem services and trade-offs analysis. © 2017 The Authors

Link: https://doi.org/10.1016/j.envres.2017.10.023

Actions: Carbon Sequestration, Urban Regeneration, Well-being in Urban Areas

Goals: Climate Change Adaptation and Mitigation, Sustainable Urbanisation in cities

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As exposure to coastal hazards increases there is growing interest in nature-based solutions for risk reduction. This study uses high-resolution flood and loss models to quantify the impacts of coastal wetlands in the northeastern USA on (i) regional flood damages by Hurricane Sandy and (ii) local annual flood losses in Barnegat Bay in Ocean County, New Jersey. Using an extensive database of property exposure, the regional study shows that wetlands avoided $625 Million in direct flood damages during Hurricane Sandy. The local study combines these models with a database of synthetic storms in Ocean County and estimates a 16% average reduction in annual flood losses by salt marshes with higher reductions at lower elevations. Together, the studies quantify the risk reduction ecosystem services of marsh wetlands. Measuring these benefits in collaboration with the risk modelling industry is crucial for assessing risk accurately and, where appropriate, aligning conservation and risk reduction goals. © 2017 The Author(s).

Link: https://doi.org/10.1038/s41598-017-09269-z

Actions: Coastal Resilience

Goals: Risk Management and Resilience

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Accumulation of fine grained sediment and natural regeneration of mangrove species are normally prioritized to control erosion on mangrove dominated muddy coasts. Current solutions to manage eroded mangrove dominated muddy coasts have been not as cost-effective as expected. Entrapping microsites, although mainly used for restoring eroded terrestrial resources, were first tested for restoring an eroded mangrove dominated muddy coast of Vam Ray, Hon Dat, Kien Giang, Vietnam. Entrapping microsites, constructed with a 50 cm layer of discarded Melaleuca small sticks that were overlain on the surface of the site, accumulated a high level of fine grained sediment and promoted robust natural regeneration or regrowth of local mangrove species after approximately two years. The effectiveness and efficiency of the Vam Ray Melaleuca entrapping microsites provide a good basis on which further research and ground works can proceed. © 2018 Elsevier Ltd

Link: https://doi.org/10.1016/j.ocecoaman.2018.02.005

Actions: Coastal Resilience, Enhancing Ecosystems' Insurance Value

Goals: Climate Change Adaptation and Mitigation, Restoring Degraded Ecosystems Using NbS, Risk Management and Resilience

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Cities undergoing climate change and rapid urbanization are faced with significant transformational processes that affect the environment and society, challenging them to become more sustainable and resilient. The promotion of nature-based solutions represents an efficient approach to meet sustainability targets in cities and improve the quality of life of citizens. The association of large components of green infrastructure, such as urban parks, with physical activity can counteract the sedentary lifestyle endemic to cities and improve the overall health and well-being of individuals (Carrus et al., 2013; Scopelliti et al., 2016). By promoting a sustainable means of transport and connecting green spaces within a highly urbanized city, bicycle lanes represent an effective tool for associating physical activity with nature in cities allowing bicycle users to benefit from the positive health effects of nature-based solutions. Our study focuses on the potential of bicycle lanes to improve functional connectivity among green spaces. We administered 820 questionnaires in 34 green spaces (i.e., urban parks) in Bucharest, Romania, to identify the factors influencing the use of bicycle lanes connecting urban parks and to understand which planning criteria for bicycle lanes are considered as the most important by park visitors. We applied binary and ordinal logistic regressions and found that the factors affecting bicycle lane use are illegally parked cars and lack of accessibility to urban parks. The criteria preferred by park visitors for bicycle lane planning are determined by experience level and frequency of bicycle use. To develop a functional and integrated bicycle lane network that can make cities healthier and more sustainable, policy makers are advised to engage in a public participatory process and focus on the needs of bicycle users. © 2017 Elsevier Inc.

Link: https://doi.org/10.1016/j.envres.2017.10.007

Actions: Carbon Sequestration, Urban Regeneration, Well-being in Urban Areas

Goals: Climate Change Adaptation and Mitigation, Sustainable Urbanisation in cities

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The ecosystem services (ES) concept refers to benefits that humanity receives from nature. Investigating how this concept has been embraced within urban planning is important when assessing the awareness of human dependence on natural functions and the potential for the ES concept to increase this awareness. We analyzed planning documents from three small and three large municipalities in southern Sweden to see how explicitly the ES concept was addressed and which individual services were mentioned. We found that five of the municipalities mentioned the ES concept explicitly and the remaining municipality addressed it implicitly. Comprehensive and green plans referred to the ES concept more explicitly than did plans that focused on a single issue. We used 23 individual ES as a reference; each was mentioned in at least one document, but those concerning habitat and recreation were mentioned most frequently. Individual ES were generally described at an elaborate level. No major differences were identified between large and small municipalities except that large ones mentioned more individual ES. Our study demonstrates that municipalities in southern Sweden have started to integrate the ES concept into their planning documents. However, there is great potential to increase and concretize the awareness of ES. © 2017 by the author(s).

Link: https://doi.org/10.5751/ES-09420-220326

Actions: Enhancing Ecosystems' Insurance Value, Urban Regeneration, Well-being in Urban Areas

Goals: Climate Change Adaptation and Mitigation, Restoring Degraded Ecosystems Using NbS, Sustainable Urbanisation in cities

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Air temperatures are increasing because of global climate change. A warming phenomenon strongly related to global climate change is the urban heat island. It has been shown that the hotter temperatures occurring in cities during the summer negatively affect human wellbeing, but little is known about the potential mechanisms underlying the relationships between hotter temperatures, cognitive psychological resources and wellbeing. The aim of the present research is to understand whether, and how, spending time in urban green spaces, which can be considered as a specific kind of Nature-Based Solution (NBS), helps the recovery of cognitive resources and wellbeing. The main hypothesis is that contact with urban green is related to wellbeing through the depletion of cognitive resources (i.e., ego depletion). Moreover, we expected that individuals showing higher scores of ego depletion also report a higher estimate of the maximum temperature reached during the summer. The results of a survey (N = 115) conducted among visitors to Parco Nord Milano, a large urban park located in Milan (Italy), point out that people visiting the park during the summer show a higher level of wellbeing as well as a lower level of ego depletion. A mediation analysis shows that visiting urban green spaces is associated with greater wellbeing through less ego depletion. Our results also point out that, as expected, people showing a higher level of ego depletion tend to overestimate the maximum air temperature. Implications for future studies and applied interventions regarding the role of NBS to promote human wellbeing are discussed. © 2017 Elsevier Inc.

Link: https://doi.org/10.1016/j.envres.2017.08.016

Actions: Carbon Sequestration, Urban Regeneration, Well-being in Urban Areas

Goals: Climate Change Adaptation and Mitigation, Sustainable Urbanisation in cities

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