Inequity in nature’s contributions to people in Ōtautahi/ Christchurch: A low-density post-earthquake city

Nature’s contributions to people (NCP) include the regulating, material, and non-material benefits of urban vegetation that improve well-being. It is increasingly important to plan cities that provide multiple types of NCP equitably to all residents of the city. However, due to historical legacies and planning policies, it is common for the most socially and economically vulnerable urban residents to suffer reduced access to the benefits of urban ecosystems. Previous studies of urban NCP have drawn attention to inequity in one or several types of NCP, but few have analysed a broad range. Here we analysed inequity in nine diverse forms of urban NCP across an index of economic and social vulnerability designed specifically to characterise vulnerability to environmental pressures. Furthermore, we used spatial analysis to map co-variance in vulnerability and a composite indicator of urban NCP, thus highlighting priority regions for future investments in green infrastructure. We applied this approach to the city of Christchurch/ Ōtautahi in Aotearoa/ New Zealand, which provides a valuable case study due to its multicultural population and recent history of widespread damage and regeneration following the 2011 earthquake. Overall, the distribution of urban NCP is inequitable to the disadvantage of more vulnerable residents. Residents of more vulnerable neighbourhoods experienced reduced provision of carbon stock, runoff retention, air quality enhancement, shade, educational green space, public outdoor space accessibility, private green space, and bird biodiversity contributions. Conversely, more vulnerable neighbourhoods had greater provision of erosion mitigation (although negligible in magnitude). The wide range of indicators used and assessed in response to vulnerability, coupled with an assessment of the type of vegetation cover (i.e. grass, tall trees) provides greater insights into how inequities in urban NCP can be addressed in future redevelopment.     

Where to construct new urban green spaces to be at the recommended distance from users and to complement existing ones? A study in five cities of northern Portugal

The proximity to urban green spaces (UGS) is important to facilitate their use by citizens, mainly by the most vulnerable groups in society who are usually unable to walk long distances. Furthermore, there are several ecosystem services from which the population can only benefit if UGS are close. In addition to being important to identify areas without a UGS nearby, it is also important to indicate possible locations for a new UGS, thus avoiding wasting resources by overlapping coverage areas or leaving gaps in coverage. It is also important to understand among all possible locations where the construction of a UGS is most needed. The present study aims (i) to identify possible locations for future UGS and order them by construction priority, (ii) to develop and test a methodology for decision-makers and urban planners and (iii) to contribute to increasing and developing UGS in cities. Considering residential areas, the results reveal a deficiency in UGS coverage in all the cities studied, as only 43.86–57.09% of residential areas have a UGS within 300 m. Construction of proposed UGS will lead to a 12.30–26.15% increase in coverage. The proposed methodology needs further improvement, but it can be a valuable tool for urban planners and decision-makers, and can encourage the construction of more UGS.     

Gradual or abrupt? An algorithm to monitor urban vegetation dynamics in support of greening policies

While greening becomes a more and more popular strategy to address multiple urban challenges and to enhance wellbeing and human-nature connectedness, there is an increasing need for usable methods and indicators to monitor its implementation. Earth observations produce a wealth of data on vegetation dynamics, but their use for monitoring urban greening policies is still limited. In this article, we develop and test an algorithm for the analysis of urban vegetation dynamics based on NDVI time series. Specifically, we focus on yearly greenest pixel composites that illustrate the maximum value of NDVI during the year (“greenness”): a key structural attribute to monitor urban ecosystems in the European Union. The algorithm is inspired by earlier examples of segmentation algorithms but fits the specific requirements of the targeted use in urban areas. It takes the series of NDVI values associated to each pixel, detects existing (multiple) break points, and quantifies related abrupt changes, as well as significant gradual changes that occurred during a selected period. We tested the algorithm on a 30-year Landsat series in Berlin and partially validated the output through a comparison with infrared ortophotos. The results reveal a net increase in NDVI between 1988 and 2017 in 84% of the pixels, with an average change over the whole city of + 0.096. Around 20% of the pixels show at least one abrupt change. Most abrupt changes (71.5%) were positive, but the negative ones had on average a greater absolute value (−0.170 vs +0.085). However, considering the cumulative impacts during the whole period, 97% of the total change is attributable to gradual changes. The validation proves that abrupt changes successfully capture variations in the extent of vegetation due to land cover changes (e.g., vegetation removal or new greening interventions), while gradual changes can be associated to vegetation growth or decline. We discuss the strengths and limitations of the proposed algorithm, and how the spatially- and temporally-explicit results can be a step forward in the interpretation of urban vegetation dynamics towards an effective monitoring of the impacts of local greening policies.     

Beyond the ‘usual suspects’? Engaging children in diverse communities in co-producing an arboretum-meadow: Professional partner perspectives

Nature-based solutions (NBS) can mitigate the challenges of climate change, biodiversity loss and mental wellbeing prioritised by the global Sustainable Development Goals (SDGs). The advantages of co-producing NBS with local communities have been explored, yet there is a lack of understanding of professional partners’ priorities in relation to specific projects, and their perceptions of the opportunities and challenges encountered during the co-productive process. The benefits of co-producing NBS with children are not understood, particularly in deprived, diverse communities. We addressed these gaps by conducting in-depth, semi-structured interviews with eight professional partners in contrasting roles involved in the co-production of an educational arboretum-meadow on a redundant mini-golf site in Wardown Park, within the High Town ward of Luton, Bedfordshire, UK. Here there is considerable ethnic diversity with 41% residents White British, and 59% other ethnicities. There are significant Black and Minority Ethnic communities (38%). A high percentage of households live with overcrowding (24%) and 31% year six children are obese. All partners prioritised connecting children to nature. The social benefits of the project were prioritised over ecological and climate-related ones. Most participants perceived diverse partner expertise and priorities as an opportunity of co-production. Covid-19 was considered a significant challenge and an opportunity. Our research provides insight into the potential for co-production of NBS in a relatively deprived, ethnically diverse context to contribute to “futureproofing” towns and cities by fostering nature connection amongst children, whilst providing a novel, creative approach to managing and maintaining GI under austerity. Learning from this project has international transferability as a ‘flagship project’ illustrating how the global Sustainable Development Goals (SDGs) can be addressed at the local level.     

Knoxville’s urban wilderness: Moving toward sustainable multifunctional management

The Knoxville Urban Wilderness (KUW) in Eastern Tennessee is part of a larger global trend of acquiring vacant lands within urban landscapes for their natural habitat and recreation value. At 688 ha, the KUW is one of the largest urban wilderness areas in the United States, consisting of loosely-connected land parcels with multiple stakeholders including state, county, and city governments and private foundations. Here we use the KUW as a case study to address critical questions of management that arise for most urban wilderness projects globally: What should these areas be managed for, and how should they be managed? How can multiple stakeholders be efficiently organized to pool their resources most effectively. The KUW is currently used mainly for recreation and its potential for biodiversity conservation and education and ecosystem services is largely unutilized. As a way to promote and manage this unused potential, we began the first ecological inventory, compiling existing data and conducting biodiversity and invasive plant surveys with citizen scientists. We found that the KUW harbors a significant number of plant (250) and bird (193) species, with many other taxa also identified. We also found widespread infestation of invasive plants for which we provide management suggestions. A preliminary visitor survey shows that most visitors (about two-thirds) are from the immediate vicinity, mainly for walking (74.4%) or biking (19.9%). The vast majority (93.7%) of visitors do not want more vegetation management or removal and 98.3% of visitors would like to see the KUW expanded in area.     

Reviewing eight years of Urban Forestry & Urban Greening: Taking stock, looking ahead

Since its launch in 2002, the journal Urban Forestry & Urban Greening (UFUG) has welcomed research from a range of disciplines and perspectives, with the aim of enlarging the body of knowledge on topics related to use, planning, design, values, and establishment of urban and peri-urban woody and non-woody vegetation. Here, we present a review of all scientific contributions published in the journal's first eight volumes (159 in all), and provide suggestions for improving the future content of UFUG. A framework for review was developed based on the journal's Aims and Scope, which set out the journal's ambitions related to, e.g. scientific diversity and international scope. The journal's achievements until now were assessed by analysing all scientific contributions for type of paper, type of green space, research theme, type of science, research method(s), and nationality of first author.Our review shows that the large majority of the contributions have been research papers. Regarding type of green space studied or considered, the overall green structure, woodland, as well as trees have been well covered, with parks having been studied much less. When looking at research themes, UFUG's envisaged variety of topics is evident. The physicality of green space, green space management, and the experience of green space have been given most attention, with less attention for valuation and governance aspects. Most UFUG contributions have been rooted in the social or natural sciences, with about one fifth of all papers involving more than one discipline, and the humanities being almost absent. Scientific diversity can also be seen from the wide range of research methods applied. The journal lives up to its international scope, with a large number of countries present. However, most first authors have been based in Europe and North America, with the USA and Scandinavia being particularly dominant.For the further development of the fields of urban forestry and urban greening, it is important that UFUG helps foster scientific debate and advancement. This will require greater focus on review papers, meta-studies, short communications, and on theoretical and methodological issues in general. Thematically, several relevant topics within urban forestry and urban greening, such as organisational aspects of green space management, could be given more attention. Also, normative issues such as the common understanding of ‘green’ as something inherently ‘good’ need to be addressed more critically.