Global commitments to protected area expansion should prioritize opportunities to protect climate refugia and ecosystems which store high levels of irrecoverable carbon, as key components of an effective response to biodiversity loss and climate change. The United States and Canada are responsible for one-sixth of global greenhouse gas emissions but hold extensive natural ecosystems that store globally significant above- and below-ground carbon. Canada has initiated a process of protected area network expansion in concert with efforts at reconciliation with Indigenous Peoples, and acknowledged nature-based solutions as a key aspect of climate change mitigation. The US, although not a party to global biodiversity conventions, has recently committed to protecting 30% of its extent by 2030 and achieving the UNFCCC Paris Agreement’s mitigation targets. The opportunities afforded by these dual biodiversity conservation and climate commitments require coordinated national and regional policies to ensure that new protected areas maximize biodiversity-focused adaptation and nature-based mitigation opportunities. We address how global commitments can best inform national policy initiatives which build on existing agency mandates for regional planning and species conservation. Previous analyses of global conservation priorities under climate change have been tenuously linked to policy contexts of individual nations and have lacked information on refugia due to limitations of globally available datasets. Comparison and synthesis of predictions from a range of recently developed refugia metrics allow such data to inform planning despite substantial uncertainty arising from contrasting model assumptions and inputs. A case study for endangered species planning for old-forest-associated species in the US Pacific Northwest demonstrates how regional planning can be nested hierarchically within national biodiversity-focused adaptation and nature-based mitigation strategies which integrate refugia, connectivity, and ecosystem carbon metrics to holistically evaluate the role of different land designations and where carbon mitigation and protection of biodiversity’s resilience to climate change can be aligned.
Archives: Publications
The need to ensure that rising investment in nature-based climate solutions delivers expected outcomes hinges on incorporating current and future climate into design and implementation. Technical guidelines and formal planning processes serve a purpose in ensuring the quality of climate-informed strategies for local projects. The inherent complexity, cost, and time required to use these tools, however, can make them inaccessible or daunting. Taking lessons learned from a decade of funding over 100 adaptation initiatives in conservation—some of which also provide mitigation benefits—we describe a simple rapid assessment framework for use by practitioners and funders. This framework, which we refer to as the 5Ws (what, when, where, why, and who) of climate-informed action, serves as a guide to make projects more robust to future climate.
Substantial efforts and investments are being made to increase the scale and improve the effectiveness of marine conservation globally. Though it is mandated by international law and central to conservation policy, less attention has been given to how to operationalize social equity in and through the pursuit of marine conservation. In this article, we aim to bring greater attention to this topic through reviewing how social equity can be better integrated in marine conservation policy and practice. Advancing social equity in marine conservation requires directing attention to: recognition through acknowledgment and respect for diverse peoples and perspectives; fair distribution of impacts through maximizing benefits and minimizing burdens; procedures through fostering participation in decision-making and good governance; management through championing and supporting local involvement and leadership; the environment through ensuring the efficacy of conservation actions and adequacy of management to ensure benefits to nature and people; and the structural barriers to and institutional roots of inequity in conservation. We then discuss the role of various conservation organizations in advancing social equity in marine conservation and identify the capacities these organizations need to build. We urge the marine conservation community, including governments, non-governmental organizations and donors, to commit to the pursuit of socially equitable conservation.
Adverse effects of climate change are increasing around the world and the floods are posing significant challenges for water managers. With climate projections showing increased risks of storms and extreme precipitation, the use of traditional measures alone is no longer an option. Nature-Based Solutions (NBS) offer a suitable alternative to reduce the risk of flooding and provide multiple benefits. However, planning such interventions requires careful consideration of various factors and local contexts. The present paper provides contribution in this direction and it proposes a methodology for allocation of large-scale NBS using suitability mapping. The methodology was implemented within the toolboxes of ESRI ArcMap software in order to map suitability for four types of NBS interventions: floodplain restoration, detention basins, retention ponds, and river widening. The toolboxes developed were applied to the case study area in Serbia, i.e., the Tamnava River basin. Flood maps were used to determine the volume of floodwater that needs to be stored for reducing flood risk in the basin and subsequent downstream areas. The suitability maps produced indicate the potential of the new methodology and its application as a decision-support tool for selection and allocation of large-scale NBS.
Carbon sequestration and storage in mangroves, salt marshes and seagrass meadows is an essential coastal ‘blue carbon’ ecosystem service for climate change mitigation. Here we offer a comprehensive, global and spatially explicit economic assessment of carbon sequestration and storage in three coastal ecosystem types at the global and national levels. We propose a new approach based on the country-specific social cost of carbon that allows us to calculate each country’s contribution to, and redistribution of, global blue carbon wealth. Globally, coastal ecosystems contribute a mean ± s.e.m. of US$190.67 ± 30 bn yr−1 to blue carbon wealth. The three countries generating the largest positive net blue wealth contribution for other countries are Australia, Indonesia and Cuba, with Australia alone generating a positive net benefit of US$22.8 ± 3.8 bn yr−1 for the rest of the world through coastal ecosystem carbon sequestration and storage in its territory.
Ecosystems provide a variety of provisioning, supporting, regulating and cultural services which are key to climate change adaptation and environmental sustainability. Current trends of biodiversity loss and overburdened natural ecosystems further challenge climate adaptation in the developing world. Scientists are trying to develop their understanding of the relationships among different ecosystem services provided by diverse ecosystems given its vital importance for landscape management, decision-making and policy development. The mechanisms in complex socio-ecological systems and their mutual impact have still not been studied, especially from the climate perspective. However, Ecosystem-based Adaptation (EbA) and Nature-based Solutions (NbS) are increasingly gaining importance in climate debates, but methods to bring them into the Paris Agreement’s market and non-market mechanisms are still unclear. Evaluating the ecosystem services in nature-based solutions would instill confidence into the climate strategists, investors, financers and buyers for market and non-market approaches. Such evaluation could include socio-economic parameters so as to also benefit the livelihoods of the local communities. Monitoring of carbon regulating services and provisioning services will help in establishing robust market mechanisms. On the other hand, evaluating social and cultural benefits of the ecosystems are more beneficial for SDGs and non-market mechanism of the Paris Agreement. UNFCCC COP-26 will be instrumental in deciding the guidelines for the much-awaited Paris Mechanisms. In light of the rising concerns regarding the NbS, this chapter discusses the emergence of such a mechanism and assesses the need for the development of appropriate indicators and evaluation of ecosystem services to better monitor NbS projects. Such monitoring and evaluation could be helpful in drawing the benefits of the Paris Mechanisms and climate finance through avenues such as the green climate fund in the post-2020 period.
This paper explores how varied systems of governance work at the European city level to deliver different policy mixes for implementing nature-based approaches which support integrated water management and policy. Urban systems provide unique insights here due to the concentration of consumption, economic activities and excessive land-use pressures. However, few studies are providing generic insights, rooted in policy and political theory perspectives, on the dynamic impact of urban governance systems on different mixes of policies to integrate urban nature and water management approaches. The paper fills this gap through an extensive literature review. It first draws on analysis that focuses on institutional logics of operation to understand how urban institutional arrangements of governance shape the framing of the policy problem and how this influences the choice of policy approaches. It then explores the related administrative processes including decision support tools, participatory approaches, and funding regimes. These administrative approaches deliver, potentially, different policy responses that take into account integrated nature-based policy approaches to urban water governance.
As cities increasingly turn to nature-based solutions to address key urban socio-ecological challenges, approaches to their governance, planning and implementation are increasingly important for ensuring their effectiveness. Nature-based solutions are multifunctional, and so their planning and implementation are by necessity interdisciplinary. As such, to support urban transitions with nature-based solutions, the role of intermediary actors deserves research attention. Intermediaries play key roles in linking between sectors, across different levels of government and between disciplines and policy domains. We identified three key points for research and planning nature-based solutions through intermediaries as key agents for change: intermediaries are creators of enabling institutional spaces needed for mainstreaming nature-based solutions in cities; intermediaries as actor configurations are dynamic over time and in context, and intermediation has to be understood as a fundamental governance activity in cities that want to scale up their climate adaptation planning with nature-based solutions. Using a case study of the development and initial implementation of the metropolitan urban forest strategy in Melbourne Australia, we analyze the multi-actor landscape that emerged, through the lens of intermediation. We systematically investigated which actors, partnerships and platforms acted as intermediaries in the transformative agenda of the Urban Forest strategy, how these actors interacted over the course of the strategy’s development and how their roles and functions shifted during the early implementation stages of the strategy. We found that an ‘ecology of intermediaries’ adopted a range of roles to support key functions including building collaboration, informing and disseminating policy learning, and strengthening political support. While intermediaries’ roles and functions shifted across the strategy’s development, their contributions were critical in the complex metropolitan governance context. Collaborative planning and governance for nature-based solutions in cities require intermediaries to remain topical, focused and inclusive/open to new ideas and lessons from innovations both emerging and driven.
The increased frequency of extreme rain events due to climate change has garnered attention in Japan. In 2018, the country enacted the Act of Climate Change Adaptation to formulate plans at national and local levels. The government has suggested the use of nature-based solutions (NBSs) across the country to address the increased risk of natural disasters. This study employs scenario analysis to examine the effectiveness of NBSs for the mitigation of flood risk and their implications on the provision of ecosystem services (ESs). Shiga prefecture in Japan enacted its own ordinance in 2015. This ordinance considers existing land use and building regulations to mitigate flood risk. The quantitative analysis assumes nine scenarios up to the year 2050, combining the current policy of Shiga and our original assumption of advance policy options to evaluate the future flood risk and ES. The analysis revealed that land use management can partially mitigate the flood risk by banning new residences and relocating residential land from flood-prone areas to safer areas and converting residential land into forest and paddy fields. It also suggests that both flood risk mitigation and provision of ESs can be further improved if local governments introduce a residence growth management strategy.
Healthy ecosystems such as forests and wetlands have a great potential to support adaptation to climate change and are the foundation of sustainable livelihoods. Ecosystem-based adaptation (EbA) can help to protect and maintain healthy ecosystems providing resilience against the impacts of climate change. This paper explores the role of EbA in reconciling socio-economic development with the conservation and restoration of nature in Lake Victoria Basin, Kenya, East Africa. Using selected ecosystems in the Lake region, the paper identifies key EbA approaches and explores trade-offs and synergies at spatial and temporal scales and between different stakeholders. The research methods used for this study include site visits, key informant interviews, focus group discussions, participatory workshops and literature reviews. An analytical framework is applied to advance the understanding of EbA approaches and how they lead to synergies and trade-offs between ecosystem services provision at spatial and temporal scales and multiple stakeholders. Our results show that EbA approaches such as ecosystem restoration have the potential to generate multiple adaptation benefits as well as synergies and trade-offs occurring at different temporal and spatial scales and affecting various stakeholder groups. Our paper underscores the need to identify EbA trade-offs and synergies and to explore the ways in which they are distributed in space and time and between different stakeholders to design better environmental and development programmes.
There has been a recent surge of interest in Nature-based Solutions, a concept encompassing a broad suite of ideas that have arisen from the intersection of ecology, engineering, sociology and economics. Solutions founded in nature are promised to resolve many issues resulting from global change, including reducing flood risk and air pollution, building social cohesion and enhancing resilience. However, what a Nature-based Solution means in practice remains unstructured and vaguely defined. Specifically, what is meant by Nature-based is not well defined and there has been little effort to rigorously understand how a solution is created. In response, we propose an integrated conceptual framework, extending the service-benefit relationship to include solutions, while acknowledging that multiple types of service exist (ecosystem services, technological services and labour). We present a method to measure the degree to which a solution is Nature-based: calculate the relative contribution of ecosystem services, compared with technological services and labour. The method and framework are applied to projects dealing with problems related to water pollution, demonstrating their applicability. The framework can be a useful tool to guide environmental managers in identifying both the scale and context at which, and the problems to which, Nature-based Solutions are applicable.
1. Natural climate solutions (NCS), a set of land management, conservation and restoration practices aimed at mitigating climate change, have been introduced as cost-effective strategies to increase carbon (C) sequestration in terrestrial ecosystems. Improved forest management (IFM) has been identified as one NCS for working forests with substantial climate change mitigation potential. However, there is a disconnect between the policy and carbon markets context and the scientific evidence for verifiable C benefits. Further, forest soil C—the largest forest C pool—has largely been excluded from current forest management guidelines and has not been included in the IFM discourse.
2. Herein, we assess the evidence for the potential of specific IFM practices to sequester C in live forest vegetation and store it in both live and dead organic matter, and forest soil. We review IFM approaches that can enhance forest C storage, and links to best management practices and silvicultural systems to offer guidance for practitioners and researchers in the Great Lakes region of the United States. Finally, we discuss the current challenges and opportunities in including soil C in forest C management guidelines and frameworks.
In recent years, there has been a growth in scholarship on “nature-based solutions” and “natural climate solutions” to climate change. A variety of actors have argued that these natural solutions—variously involving the protection, conservation, restoration, management, enhancement, or imitation of natural ecosystems—can play a crucial role in both mitigating and adapting to climate change. What is more, by virtue of their label, natural solutions promise to be particularly attractive to the public and policymakers and have received significant media and scholarly attention. But what is natural is also social: people, acting in various social groups, can selectively emphasize or deemphasize certain characteristics of climate solutions to make them seem more or less natural. The framing of particular solutions as “natural” or “unnatural” has far-reaching implications for climate policy, but has thus far been overlooked. Here, we undertake a critical review of the ways in which natural solutions to climate change have been framed and examine the normative and practical implications of this framing. We review what counts (and what does not count) as a natural solution, and find that those labeled natural are routinely framed under technical and social appraisal criteria as being more beneficial, cost effective, mature, and democratic than ostensibly artificial counterparts. And yet we show that, under greater scrutiny, the natural framing obscures the reality that natural solutions can be just as risky, expensive, immature, and technocratic. We conclude by reflecting on the dangers of narrowing the range of solutions considered natural and indeed, of selecting solutions through recourse to “nature” at all. Rather, climate solutions must be evaluated in terms of their specific qualities, against a far broader range of framings.
Coral reefs are effective natural coastal flood barriers that protect adjacent communities. Coral degradation compromises the coastal protection value of reefs while also reducing their other ecosystem services, making them a target for restoration. Here we provide a physics-based evaluation of how coral restoration can reduce coastal flooding for various types of reefs. Wave-driven flooding reduction is greatest for broader, shallower restorations on the upper fore reef and between the middle of the reef flat and the shoreline than for deeper locations on the fore reef or at the reef crest. These results indicate that to increase the coastal hazard risk reduction potential of reef restoration, more physically robust species of coral need to be outplanted to shallower, more energetic locations than more fragile, faster-growing species primarily being grown in coral nurseries. The optimization and quantification of coral reef restoration efforts to reduce coastal flooding may open hazard risk reduction funding for conservation purposes.
The global impacts of biodiversity loss and climate change are interlinked, but the feedbacks between them are rarely assessed. Areas with greater tree diversity tend to be more productive, providing a greater carbon sink, and biodiversity loss could reduce these natural carbon sinks. Here, we quantify how tree and shrub species richness could affect biomass production on biome, national and regional scales. We find that GHG mitigation could help maintain tree diversity and thereby avoid a 9–39% reduction in terrestrial primary productivity across different biomes, which could otherwise occur over the next 50 years. Countries that will incur the greatest economic damages from climate change stand to benefit the most from conservation of tree diversity and primary productivity, which contribute to climate change mitigation. Our results emphasize an opportunity for a triple win for climate, biodiversity and society, and highlight that these co-benefits should be the focus of reforestation programmes.
Background
The COVID-19 pandemic has profoundly changed people’s ability to recreate in public green spaces, which is likely to exacerbate the psychological impacts of the pandemic. In the current study, we seek to understand whether greenery can support mental health even with insufficient outdoor exposure in times of physical isolation from the outdoor environment.
Methods
Between 17 May and 10 June, 2020, we conducted an online survey among 323 students (21.99 ± 3.10 years; 31% male) in health-related programs from two universities in the city of Plovdiv, Bulgaria. Severities of depressive and anxiety symptoms over the past two weeks were measured with the Patient Health Questionnaire 9-item and the Generalized Anxiety Disorder 7-item scale. We employed two self-reported measures of greenery experienced indoors (number of houseplants in the home and proportion of exterior greenery visible from inside the home) and two measures of greenery experienced outdoors (presence/absence of a domestic garden and availability of neighborhood greenery). Restorative quality of the home (the “being away” dimension of the Perceived Restorativeness Scale; PRS) and the neighborhood (the “being away” and “fascination” dimensions of the PRS), engagement with outdoor greenery (frequency of different types of interaction) and perceived social support were treated as mediators. Associations between greenery and mental health were tested using generalized linear regression and logistic regression. Structural equation modelling (SEM) techniques were used to test the theoretically-indicated relations among the variables.
Results
Clinically-meaningful symptoms of moderate depression and anxiety were reported by approximately 33% and 20% of the students, respectively. The relative abundance of greenery visible from the home or in the neighborhood was associated with reduced depressive/anxiety symptoms and lower depression/anxiety rates. Having more houseplants or a garden was also associated with some of these markers of mental health. As hypothesized, the mental health-supportive effects of indoor greenery were largely explained by increased feelings of being away while at home. Neighborhood greenery contributed to neighborhood restorative quality, which in turn facilitated social support and more frequent engagement with greenery, and that led to better mental health.
Conclusions
Students who spent most of their time at home during the COVID-19 epidemic experienced better mental health when exposed to more greenery. Our findings support the idea that exposure to greenery may be a valuable resource during social isolation in the home. However, causal interpretation of these associations is not straightforward.
Terrestrial ecosystems remove about 30 per cent of the carbon dioxide (CO2) emitted by human activities each year1, yet the persistence of this carbon sink depends partly on how plant biomass and soil organic carbon (SOC) stocks respond to future increases in atmospheric CO2 (refs. 2,3). Although plant biomass often increases in elevated CO2 (eCO2) experiments4,5,6, SOC has been observed to increase, remain unchanged or even decline7. The mechanisms that drive this variation across experiments remain poorly understood, creating uncertainty in climate projections8,9. Here we synthesized data from 108 eCO2 experiments and found that the effect of eCO2 on SOC stocks is best explained by a negative relationship with plant biomass: when plant biomass is strongly stimulated by eCO2, SOC storage declines; conversely, when biomass is weakly stimulated, SOC storage increases. This trade-off appears to be related to plant nutrient acquisition, in which plants increase their biomass by mining the soil for nutrients, which decreases SOC storage. We found that, overall, SOC stocks increase with eCO2 in grasslands (8 ± 2 per cent) but not in forests (0 ± 2 per cent), even though plant biomass in grasslands increase less (9 ± 3 per cent) than in forests (23 ± 2 per cent). Ecosystem models do not reproduce this trade-off, which implies that projections of SOC may need to be revised.
To counter increasing CO2 emissions and plant biodiversity loss, ecological restoration has been proposed as a means to sequester carbon as well as to increase species diversity in tropical landscapes. Here we examine how natural regeneration is associated with changing plant diversity and carbon stocks in the Atlantic Forest of southern Brazil. Aboveground carbon stocks and plant species diversity (using taxonomic, functional, phylogenetic and conservation metrics) were estimated in areas undergoing natural regeneration, ranging in age from seven to >80 years. Aboveground carbon, diversity and conservation metrics increase rapidly and concomitantly over time during forest natural regeneration, but even with carbon increase over time, we found the maximum taxonomic and phylogenetic diversity possible for the region. These results show the importance of considering regeneration as an alternative to increase carbon stocks, diversity, and species conservation in carbon-focused restoration plans. Our results showed co-benefits between carbon stocks, diversity, and conservation. Diversity (taxonomic, functional, and phylogenetic) increases along with carbon stocks, but functional evenness does not. Age of the areas also influences co-benefits, as they increase over time. Thus, we demonstrate that ecological restoration not only sequesters carbon and has benefits with respect to climate change but is also responsible for increasing biodiversity and conservation. This mutualism between different benefits of natural regeneration attends to a variety of international concerns.
The Billion Trees Afforestation Project (BTAP) was launched in the Khyber Pakhtunkhwa (KP) province of Pakistan to conserve existing forests and to increase the area under forest cover. It also aimed to restore environmental conditions, promote rural livelihoods and reduce poverty. To improve the effectiveness of afforestation projects, it is essential to know the role of various factors and their impacts on community participation in landscape restoration. However, these factors and their impacts remain unexplored for the BTAP. This study identifies the factors that influenced rural household participation in the BTAP in Pakistan. The data were collected from participants and nonparticipants in the BTAP as well as from various officials. We employed both qualitative and quantitative methods to analyze the data. The results of the focus group discussions and the professional evaluation of the BTAP revealed that participant farmers enjoyed all the benefits of the project at the individual and community levels. However, the project provided only partial benefits to nonparticipant farmers at both levels. The household-level results showed that age, income from forest resources, a friendly relationship with forest department staff, a risk-bearing attitude and membership or involvement in village development committee activities had positive and significant effects on farmer participation, while disputes over land and forest resources, household size and experience with/dependence on livestock farming had negative and significant impacts on farmer participation in the BTAP. Our results suggest that policymakers and project designers should pay more attention to the factors that hindered farmer participation in the BTAP. The participation of landless and disadvantaged groups in the 10-BTAP should be increased to ensure equal and widespread benefits for all users and to ensure a win-win situation of sustainable management of the forest, the environment and livelihood opportunities for all types of forest users.
Flood mitigation and protection of coastal infrastructure are key elements of coastal management decisions. Similarly, regulating and provisioning roles of coastal habitats have increasingly prompted policy makers to consider the value of ecosystem goods and services in these same decisions, broadly defined as “the benefits people obtain from ecosystems.” We applied these principles to a study at three earthen levees used for flood protection. By restricting tidal flows, the levees degraded upstream wetlands, either by reducing salinity, creating standing water, and/or by supporting monocultures of invasive variety Phragmites australis. The wetlands, located at Greenwich, NJ, on Delaware Bay, were evaluated for restoration in this study. If unrestricted tidal flow were reestablished with mobile gates or similar devices, up to 226 ha of tidal salt marsh would be potentially restored to Spartina spp. dominance. Using existing literature and a value transfer approach, the estimated total economic value (TEV) of goods and services provided annually by these 226 ha of restored wetlands ranged from $2,058,182 to $2,390,854 y−1. The associated annual engineering cost for including a mobile gate system to fully restore tidal flows to the upstream degraded wetlands was about $1,925,614 y−1 resulting in a benefit-cost ratio range of 0.98–1.14 over 50 years (assuming no wetland benefits realized during the first 4 years). Thus, inclusion of a cost-effective mobile gate system in any engineering design to improve long-term flood resilience in the region would produce dual benefits of protecting people and property from major storms, while preserving and enhancing ecosystem values.
To bring to fruition the capability of nature-based solutions (NBS) in mitigating hydro-meteorological risks (HMRs) and facilitate their widespread uptake require a consolidated knowledge-base related to their monitoring methods, efficiency, functioning and the ecosystem services they provide. We attempt to fill this knowledge gap by reviewing and compiling the existing scientific literature on methods, including ground-based measurements (e.g. gauging stations, wireless sensor network) and remote sensing observations (e.g. from topographic LiDAR, multispectral and radar sensors) that have been used and/or can be relevant to monitor the performance of NBS against five HMRs: floods, droughts, heatwaves, landslides, and storm surges and coastal erosion. These can allow the mapping of the risks and impacts of the specific hydro-meteorological events. We found that the selection and application of monitoring methods mostly rely on the particular NBS being monitored, resource availability (e.g. time, budget, space) and type of HMRs. No standalone method currently exists that can allow monitoring the performance of NBS in its broadest view. However, equipments, tools and technologies developed for other purposes, such as for ground-based measurements and atmospheric observations, can be applied to accurately monitor the performance of NBS to mitigate HMRs. We also focused on the capabilities of passive and active remote sensing, pointing out their associated opportunities and difficulties for NBS monitoring application. We conclude that the advancement in airborne and satellite-based remote sensing technology has signified a leap in the systematic monitoring of NBS performance, as well as provided a robust way for the spatial and temporal comparison of NBS intervention versus its absence. This improved performance measurement can support the evaluation of existing uncertainty and scepticism in selecting NBS over the artificially built concrete structures or grey approaches by addressing the questions of performance precariousness. Remote sensing technical developments, however, take time to shift toward a state of operational readiness for monitoring the progress of NBS in place (e.g. green NBS growth rate, their changes and effectiveness through time). More research is required to develop a holistic approach, which could routinely and continually monitor the performance of NBS over a large scale of intervention. This performance evaluation could increase the ecological and socio-economic benefits of NBS, and also create high levels of their acceptance and confidence by overcoming potential scepticism of NBS implementations.
The climate mitigation potential of urban nature-based solutions (NBSs) is often perceived as insignificant and thus overlooked, as cities primarily pursue NBSs for local ecosystem services. Given the rising interest and capacities in cities for such projects, the potential of urban forests for climate mitigation needs to be better understood. We modelled the global potential and limits of urban reforestation worldwide, and find that 10.9 ± 2.8 Mha of land (17.6% of all city areas) are suitable for reforestation, which would offset 82.4 ± 25.7 MtCO2e yr−1 of carbon emissions. Among the cities analysed, 1189 are potentially able to offset >25% of their city carbon emissions through reforestation. Urban natural climate solutions should find a place on global and local agendas.
Adaptive and collaborative natural resource management has been proposed as a means to navigate the social-ecological system dynamics of resilient systems. However, our understanding of how diverse stakeholders and local actors contribute to collaborative management processes and outcomes is limited, especially with regard to small-scale resource management. This study investigates the role of local people in Korean village grove restoration projects, focusing on bridging linkages and bridging organizations. From a network perspective, we analyze data collected from key informant interviews, document reviews, and field visits to four village groves, to identify key actors and actor groups and to examine their relationships in each restoration project. Along with the relational patterns of local people, the multiple functions of bridging organizations, including accessing critical resources, resolving conflict, enhancing mutual trust, and building local capacity, vary between the four villages. The findings provide insights into the potential of local civil society, through the bridging roles of village-based citizen organizations, to contribute to the emergence of collaborative and adaptive management networks and improved management outcomes.
Different ways of thinking and understanding urban problems and imagining solutions are needed to redress the suite of serious challenges facing cities. Focusing on urban nature, this conceptual paper begins from the standpoint that nature-based solutions (NBS) could help remake cities as places for more than just people; in other words, cities could encourage the flourishing of multiple species and ecosystems, including but not limited to, humans. Although cities were once considered ‘biodiversity wastelands’, they are now recognised as providing important habitat. However, NBS have been plagued by criticisms of anthropocentrism whereby human needs are prioritised over those of other species and ecosystems. To overcome this problem, the paper provides an outline of more-than-human thinking and suggests how relational concepts can help NBS move beyond an inherent anthropocentrism, and also begins to work through some of the complexities of making this shift. More-than-human thinking and theories have arisen in several disciplines, but despite a considerable presence in the literature, they have not yet been brought into conversation with NBS. The paper concludes that more-than-human thinking can generate deeper understanding of the interdependencies between all the entities that comprise cities, such that more inclusive NBS could be implemented.
Urban forests in northern Europe are threatened by climate change and biosecurity risks, and in response, city planners are urged to select a wider portfolio of tree species to mitigate the risks of species die-off. However, selecting the right species is a challenge, as most guidance available to specifiers focuses on ecosystem service delivery rather than the information most critical to tree establishment: the ability of a species to tolerate the stresses found in a given place. In this paper, we investigate the potential of using ecological techniques to describe ecological traits at the level of species selection, and the potential of functional ecology theories to identify species that are not widely discussed or specified at present but might be suitable. We collected trait data on 167 tree species across 37 genera, including 38 species within a case study genus, Magnolia L., and tested four theories that posit ways in which traits trade off against each other in predictable ways. We found that at this scale, most species recommended for urban forestry tend to be ordinated along an axis of variation describing pace of life and stress tolerance, and that most Magnolia species are described as being fast-growing rather than stress-tolerant, although there is a degree of inter-specific variation. Further, we found that only one theory offers a succinct and reliable way of describing physiological strategies but translating ecological theory into a form appropriate for urban forestry will require further work.