Green Infrastructure In Cities Research Articles

Microclimatic effects of introduced tree plantings in urban environment

Ecological role of urban green spaces is increasing in order to provide citizens with comfortable and safe living conditions in the new climatic realities through the use of ecosystem services of tree and shrub stands in the setting of reduced forest areas, native forest decline and acceleration of urbanization processes. However, in Europe and, in particular, in Ukraine, deterioration of the environmental condition and loss of ecological functions of urban green spaces are observed. One of the reasons for the loss of ecological potential of tree and shrub plantings is unbalanced approach to the development of green infrastructure in cities, when socio-cultural ecosystem services (decorative, aesthetic) are preferred over environmental and regulatory ones, including over climate-regulating services. The active use of introduced tree species has always been driven by the development of green infrastructure in modern cities; the share of these species in dendroflora of urban ecosystems is steadily increasing in Europe. Introduced tree species comprise the basis of urban green infrastructure; therefore, the issue of determining the potential microclimatic effects of these species becomes relevant. The influence of tree species (Acer pseudoplatanus, Fraxinus pennsylvanica, Gleditsia triacanthos, Morus alba, Quercus rubra, Robinia pseudoacacia, Tilia platyphyllos) introduced in the Steppe zone of Ukraine on the formation of microclimatic parameters (light intensity, temperature and relative air humidity) in the space beneath the tree canopy within monodominant group plantings is analyzed in Botanical Garden of Oles Honchar Dnipro National University and park areas of Dnipro city. Beneficial effect of group plantings consisting of introduced tree species on the processes of optimizing the microclimatic conditions of the urban environment is revealed. Beneath the canopy of introduced tree species (compared to the reference open sites), light intensity decreased from 86.9% to 97.9% at midday in late July. The air temperature decreased from 3°C to 6.5°C, and the relative humidity increased by 2.5–9.8%, depending on the species of the tree. By increasing the microclimatic efficiency, the studied tree introducents were determined to form the following series: Gleditsia triacanthos – Robinia pseudoacacia – Fraxinus pennsylvanica – Quercus rubra – Tilia platyphyllos – Acer pseudoplatanus – Morus alba. Along with a significant climate-regulating effect, monodominant group plantings consisting of dense- and semi-dense crowned introduced tree species become "cooling islands" and play a significant role in optimizing the microclimatic conditions of urban ecosystems during the daytime and summer periods. At the same time, introduced tree species with naturally developed dense and semi-dense crowns can be prioritized for creating and reconstructing green spaces with recreational purposes in the cities situated in Steppe zone. The results obtained regarding the microclimatic effects of introduced tree species expand the scientific and theoretical base for the development of methods for optimizing the functionality of green infrastructure in cities by the construction of green spaces using tree species that have significant climate-regulating properties.

Weak geostrophic wind driven ventilation in street canyons with trees and green walls: Cooperating or opposing dispersions of airborne pollutants?

Urban high-rise buildings and dense street canyons significantly disrupt synchronised wind flows, potentially exacerbating urban heat island effect. Fortunately, urban heat island effect can be mitigated by the green infrastructure in cities, particularly through the presence of roadside trees and green walls. However, the combined mechanisms of tree resistance, shading effects, and cooling effect, along with sensible thermal buoyancy flows within canyon ventilation and pollution dispersion, remain undisclosed. This study employs refined computational fluid dynamics numerical simulations to analyse airflow and pollutant dispersion within urban street canyons. Air exchange rate and pollutant retention time are employed to evaluate ventilation and pollutant dispersion, respectively, inside the street canyons.In scenarios with leeward green wall layout, higher tree canopy spread and trunk height lead to a shift in high pollutant concentrations from the region near the windward side to that near the leeward side of the typical canyon (H/W = 1). Conversely, in deep canyons (H/W = 5), most pollutants are retained near the bottom leeward side. Moreover, differences in pollutant dispersion between typical and deep canyons increase with with rising tree canopy spread. Additionally, higher tree canopy spread and trunk height values result in longer pollutant retention time, which are unfavourable for pollutant removal, and particularly limiting pollutant dispersion as street canyon depth increases. Similarly, increasing tree canopy spread reduces the difference in air exchange rate between windward and leeward green wall layout patterns. Regarding Richardson number variations —indicating thermal buoyancy effects—lower Richardson number values lead to reduced differences in pollutant retention time between typical and deep canyons. Furthermore, ventilation performance of the windward green pattern surpasses that of the leeward pattern. This research provides valuable insights for implementing green infrastructure to locally mitigate urban air pollution.

Green infrastructure development as a factor of Moscow metropolis sustainable development

The research is aimed at improving the sustainable development of cities, which focuses on the systemic goal setting of environmental development tasks, social policy and economic responsibility. The development of green infrastructure has been among the sustainable development goals of many cities around the world since the early 2000s. The study showed that the modern understanding of green infrastructure in Russia is still not widespread, which creates problems for the sustainable development of Russian cities in the future, since the implemented greening programs generally reflect a more simplified and fragmented meaning of the city’s green infrastructure. It has been established that the situation in Russia has begun to change over the past few years: new scientific, methodological and practical approaches to the development of green infrastructure in Russian cities have been developed, leading state and public institutions presented ratings reflecting the ideology of the development of green infrastructure in cities within the framework of the principles of sustainable development. Based on the method of comparative and statistical analysis, the article identifies the features of the development of green infrastructure in Moscow, shows its advantages and problems, and suggests directions for its sustainable development based on innovative approaches to vertical gardening.

Sustainable management of urban forest "Kosutnjak"

Urban forests represent networks, that is systems, that include forests, groups of trees, and individual trees in urban and peri-urban areas. They are one of the primary types of green infrastructure in cities, enhancing living conditions for residents and providing a wide range of ecosystem services. This paper analyzes the urban forest of Kosutnjak, whose area extends into the urban core of Belgrade. The needs of its users have been analyzed, as well as the current management practices, all with the aim of formulating proposals for measures to achieve a resilient ecosystem and establish sustainable management of this protected area. Additionally, the goal of the conducted research is to raise awareness among residents about the benefits provided by this urban forest, as well as its cultural and historical significance, which gives this area national importance.

Assessing whether peri-urban agricultural land or plantation forest is a better green infrastructure for ground arthropods at local and landscape scales

City agencies across multiple continents have invested millions of funds in ambitious afforestation projects in urban and peri-urban areas to enhance the city green infrastructure. One example is the Beijing One Million Mu Plain Afforestation Project, which has established 146,000 ha of plantation forests, mainly on arable lands. This contradicts the national arable land conserving policies and has dramatically changed local habitat types and landscape context. However, the impact of these processes on biodiversity is not well understood. To investigate this impact at local and landscape scales, we explored a space-for-time approach. We selected 12 plantation forests and their nearby arable lands along a gradient of plantation forest cover in the surrounding landscapes. We surveyed ground spiders and carabids and analyzed their responses to local habitat type, landscape context, and their interaction. In the sampled landscapes, plantation forest cover increased (12.0%–35.9%), while arable land cover decreased (58.3%–31.8%). 96.3% of the new plantation forests were established on arable lands. Intensive afforestation on arable lands did not increase local ground arthropod diversity. In fact, ground arthropod abundance and species richness in plantation forests were significantly lower than in arable lands when the surrounding arable land cover was relatively high. With surrounding arable land cover decreasing, ground arthropod abundance and species richness in plantation forests increased but did not exceed those in nearby arable lands. Hence, the overall ground arthropod diversity at landscape scale was not improved. These findings suggest that, from a biodiversity conservation perspective, plantation forests did not surpass peri-urban agricultural lands as a better green infrastructure . However, ground arthropods benefit from rich local non-crop herb communities. Conserving peri-urban agricultural lands and implementing extensive management regimes for agricultural lands and existing plantation forests are more effective tools than ambitious afforestation of agricultural land in peri-urban areas of Beijing and other metropolises.

A comprehensive study of the city's green infrastructure. The case of Yekaterinburg

The subject of the study is green city infrastructure. The content of the concept ‘green infrastructure’ is expounded, and the reasons why the term ‘green infrastructure’ is now mostly used. Special attention is paid to the structural properties of the green infrastructure, in particular to the main element that ensures its sustainability - the green framework. As a case in point, we considered the condition of the green infrastructure framework in the city of Ekaterinburg. Issues around the green infrastructure framework were identified and described regarding its structural properties. Long-term risks arising from the mismatch between the structural properties of the green infrastructure framework and the needs of city development are assessed. The novelty of the study lies in the fact that we used not only the traditional methods such as mapping, graphical analytic technique, and photo surveying, but also new modern approaches such as geo-referenced data, multispectral space images from which different indices are calculated, in particular combinations of images in different channels. The article shows how different indices can be applied and used to analyze green infrastructure. It is concluded that in a number of cases it is the use of geo-referenced data that allows obtaining unique information about the condition of the green infrastructure and the causes of long-term changes occurring in it. All the identified regularities are used to evaluate the design decisions laid down in the general plan of the city to forecast risks and create recommendations that contribute to the sustainable development of green infrastructure.

Enhancing green infrastructure in cities: Urban car parks as an opportunity space

Interest in radical solutions to embedding Green Infrastructure (GI) into the built environment are at an all-time high. With land value often preventing more mundane forms of GI, key actors, such as planners, developers, architects and others, are increasingly exploring novel methods for embedding the features. This innovation involves a surge in green roofs, living walls and other systems which enables nature to thrive in otherwise hostile environments. Many of these systems are embedded on or within office complexes, universities and various ‘clean’ buildings within cities. However, there is a nascent movement to using urban car parks to enhance GI. In this opinion piece, we reflect on the opportunity space here and the potential to upscale work around embedding GI into urban car parks: exploring good practice, barriers to implementation and recommendations for moving the activity forward.

Development of flower meadows in an urbanized environment

Abstract With increasing urbanization, it is necessary to create green infrastructure in cities and urban areas to improve not only the quality of life for residents, but also the health and sustainability of local ecosystems. One effective way to create green spaces is by establishing meadows filled with diverse plant species. These meadows can provide numerous benefits, such as aiding pollinator conservation, improving air and water quality, and increasing biodiversity. Therefore, creating these meadows is an important component of urban ecology. Seven types of flower meadow mixtures from a Czech company were sown in 12 plots within the Hliník Urban Park in Nové Zámky, Slovak Republic. The development of the vegetation and the impact of maintenance management and climatic factors were monitored during the vegetation period of 2021‒2022, and the plots are still being monitored. The results of the flower meadow research in 2021 showed that improper maintenance and insufficient precipitation negatively influenced the vegetation’s development. Grasses were most prevalent during the summer months, while legumes were more common in the spring months. The analysis of the plots revealed that four out of 12 plots were dominated by annuals and grasses, which were the most abundant throughout the entire vegetation period. In 2022, it was observed that grasses were most prevalent in May, legumes in June and July, and annuals occurred sporadically in all plots. Insufficient precipitation and high temperatures in 2022 created unfavorable conditions for the thriving of the flower meadow vegetation, resulting in a high proportion of opportunistic species. Due to the impact of stress factors, the vegetation in the plots dried up.

English

Urban parks are an important part of the city's green infrastructure and serve as an indicator for the city's natural environment. Six urban parks in Faisalabad were evaluated, split into two categories: Old parks (OP) and New parks (NP). A thorough census of tree populations was conducted in specified urban parks, and many parameters were studied. The composition of trees, species richness, and distribution of native and exotic trees were evaluated among two types of parks. Tree stem count was used to calculate the diversity benchmark (10/20/30) for tree inventories in selected urban parks. The major objective of the study was to determine the difference in species richness and diversity indices of selected urban parks in both categories. Evaluation of the plantation of Urban parks on the basis of the proposed benchmark (10/20/30) was also the key objective of the present study. The results revealed that 2978 trees from 52 species, 45 genera, and 22 families had been counted, with 2004 trees in the OP and 794 in the NP. A few common species hold the majority of the distribution. OP have higher share of native trees (67.07%) while NP have higher share of exotic trees (59.32%). The dominance of exotic tree species in NP depicted that change in time has significantly affected the plantation pattern of urban parks in Faisalabad. OP had higher tree species richness (47) as compared to NP (36). The dominance of exotic species in new parks is the major cause of low tree diversity. Results of the tested benchmark indicated that the plantation of selected urban parks approximately failed to achieve the proposed diversity benchmark. In urban parks, more attention should be paid to the plantation design and species selection. The pressing need of the hour is to have a tree mix that promotes biodiversity while also maximizing ecological services

Green infrastructure in cities for the achievement of the un sustainable development goals: a systematic review

Green infrastructure in cities for the achievement of the un sustainable development goals: a systematic review

Green infrastructure inequality in the context of COVID-19: Taking parks and trails as examples

Urban green infrastructures play a critical role in enhancing the well-being of residents, yet their equitable access remains a concern, particularly during the COVID-19 outbreak. There is a lack of knowledge on how people respond to the pandemic regarding the usage of green infrastructure in cities. This paper explores the shifts in visitation to parks and trails, two popular types of green infrastructures in Salt Lake County, Utah, by analyzing the results of a survey conducted during the pandemic. Our conceptualization considers personal and neighborhood level factors, including personal socioeconomic status, existing inequalities of green infrastructures, urban form, and neighborhood conditions. People who reside close to the city center tend to go to parks more often, while those living in urban edges use trails more. Visiting green infrastructures less often is more likely in areas with higher COVID-19 infection rates. The regression results confirm the importance of neighborhood level factors and illustrate the intricate elements influencing people's decisions to visit different green infrastructures during the pandemic, which shows non-linear relationships. Wealthier, white, and younger people seem to enjoy green infrastructures more often, leading to the concern of amplified inequality. Higher COVID-19 cases result in higher demands for green infrastructures, which are not fulfilled during the pandemic, especially for vulnerable communities, leading to spatial exclusion. The findings highlight the importance of smart growth, including compact development, public transit, and pocket parks, in promoting the urban resilience of park and trail visits, as they may provide more opportunities for access and alternatives to green infrastructures even in the context of the pandemic.

Perceptions and preferences of urban residents for green infrastructure to help cities adapt to climate change threats

Green infrastructure in cities is increasingly acknowledged as a way to contribute to tackling the challenges posed by climate change. However, studies analyzing urban inhabitants' attitudes towards green infrastructure when dealing with climate change effects are still scarce. Using as case studies two Portuguese cities of different sizes and socio-cultural and geographic contexts, this work analyzes inhabitants' awareness of climate change, the sensations they associate with green infrastructures, as well as the elements that they value, and uncovers their determinants using binary logistic models. These models allow to determine the association between the dependent variables and a set of variables such as the way inhabitants deal with heatwaves and perceive what GI is, among others. Inhabitants in the two cities show high awareness of climate change and similarities in the most relevant sensations associated with green infrastructure, as well as in the most valued elements in it. However, different determinants explain such results in each city. This finding highlights the need to consider the specificities of each city when green infrastructures are chosen, thus providing insights for other southern European countries facing the same extreme climatic events.

Features of the of the Katowice city green infrastructure: problems and prospects

Purpose. To assess the provision of green infrastructure in the city of Katowice (Poland) based on the analysis of the peculiarities of its formation and spatial distribution on the territory of urban landscapes. Methods: Historical (study of the historical path of the formation of Katowice as a modern green city), mathematical and statistical for calculating the green index of the provision of the population with green infrastructure and methods of systematization and generalization. Results. Katowice is a city in southern Poland, which was formed in the middle of the 19th century as a result of the development of the coal industry in the Silesian region. It now has an area of 164.73 km2 and a population of 290 thousand people. In order to level the negative consequences of the industrial depletion of urban landscapes in the city, the development of green infrastructure has been introduced, which currently makes up 42% of the city's area, which is not evenly distributed. It has been established that green infrastructure has a significant positive impact on the quality of life of residents of urbanized areas of the city of Katowice. Among the districts, Podlasie stands out - more than 300 m2/person. Murky and Paderevsky-Mukhovets - more than 250 m2/person. Shopenice-Burovets, and Brynow - Os. Zgrzebnska - more than 100 m2/person and Domb, Zarzeche and Dombruvka Mala - from 50 to 100 m2/person. These areas have a sufficient level of provision of green infrastructure for the population according to WHO norms (50 m2). But Zavodze, Zelenska and Os districts. Tysenklech (ZI less than 10 m2/person) need to take measures to increase the provision of green infrastructure to the population. Conclusions. On the basis of the calculation of the Green Index, areas that meet greening standards and areas that require the use of the latest green infrastructure development technologies (installation of vertical gardens and greening of roofs, etc.) are determined.

Assessment of the allelopathic potential of some naturalized tree and shrubby introducents under conditions of the northern steppe Dnieper region

Nowadays, introduced alien tree and shrubby species have become integral components of the green infrastructure in cities and suburban artificial forest plantations around the world, and their participation in regional dendroflora is steadily increasing. Along with autochthonous species, tree and shrubby introducents perform a wide range of ecological functions and ecosystem services, but, with successful naturalization and increased invasive activity, they can cause negative biological, environmental, social, and economic consequences. The potential for the evolution of adventive species in secondary habitats in the direction of increasing allelopathic activity and competitiveness compared with native species determines the need for assessment of allelopathic potential as a possible predictor of their successful invasive activity. The allelopathic activity of the species was determined by the bioassay method based on the effect of water extracts of different concentrations obtained from dry biomass of leaves on the germination of testing culture seeds of Raphanus raphanistrum subsp. sativus (L.) Domin and biometric indicators of seedlings of Lepidium sativum L. It was determined that in the conditions of the northern steppe Dnieper region, naturalized tree and shrubby introducents Celtis occidentalis L., Morus alba L., Lonicera tatarica L., Mahonia aquifolium (Pursh) Nutt., Prunus virginiana L., Prunus serotina Ehrh., Rhus typhina L. have significant allelopathic potential, which can be a predictor of increasing their competitiveness compared with native species and increasing invasive activity within the region. Water extracts from dry leaves of the studied tree and shrubby species had an inhibitory effect on seed germination and biometric indicators of testing cultures seedlings; the intensity of this effect varied depending on the plant species and extract concentration. Assessment of the allelopathic potential of the alien tree and shrubby species used in urban and suburban green planting is a necessary measure for preliminary identification of potentially invasive species, which will contribute to the increase of efficiency of green infrastructure management.

Formation of the ecological infrastructure of the Lviv city

A modern city is a complex, dynamically changing natural and anthropogenic system that must provide its residents with a comfortable and safe living environment. Along with the traditional elements of the city's infrastructure: the transport system, sewerage, water supply, heat and electricity supply, and elements of the social infrastructure (schools, hospitals, etc.), the role of the city's ecological infrastructure is growing. The latter includes both artificial and natural objects that provide environmental services and reduce the negative anthropogenic impact of the urban environment on nature and living organisms. Such components are the city's green space and communal systems that neutralize the most pronounced manifestations of anthropogenic influence, such as ensuring waste disposal. The state of the urban ecosystem depends on a complex combination of structure, activity, risks, and intentions of its inhabitants, the state of the economic and financial and economic system, the stability of the natural base expressed in the landscape, and the city's visibility, the intensity of industrial activity and the level of environmental education. The prerequisite for developing the city as a dynamic system is ensuring its sustainability. According to the modern vision, a sustainable city is based on three pillars: economic, ecological, and social, which must develop harmoniously. Therefore, the ecological infrastructure of the city should be based on the appropriate level of technology and economic development. Lviv is a large city in Ukraine and the largest city in the territory of the western regions, a logistical and cultural center. At the same time, the ecological infrastructure of the city is mainly at the formation stage. A meaningful sign of its puberty is the lack of an effective waste management system and an imperfect air quality monitoring system. Municipal sewage treatment facilities and the city's transport system need improvement. The city's green infrastructure as a subsystem of the ecological infrastructure causes relatively few comments. However, it should be noted that its main structure has been updated for decades, and new microdistricts with active construction may need more green space. In order to improve the environment of Lviv, it is necessary to improve the elements of its ecological infrastructure with the involvement of best practices of well-known cities of the world.

A collaborative learning model for a flourishing green roofs, walls and facades sector: Exploring two major Australian cities

The combined challenges of climate change, urban densification, and pandemic-related isolation and stress have strengthened the case for increased greening in cities where their social and environmental benefits have captured the interest of policy-makers. Green roofs, walls, and facades (GRWF) are an established solution in many space-constrained northern hemisphere cities. This is not the case in Australia where GRWF sector growth is slower. To understand how to accelerate the uptake of GRWF, we ran appreciative inquiry summits in Sydney and Melbourne. We examined (1) actions for flourishing GRWFs and (2) collaboration for rapid innovation. Our results highlight collaborative learning and link this to phases of sector evolution through government-led research partnerships, policy, and incentives; a national body advocating, and supporting, engaging, and developing expertise; and cross-sector co‑leading for alignment and building sector capacity and knowledge. We integrate these into our model, revealing adoption, legitimation, and diffusion and sector growth phases, finding stalled progress and new initiatives signalling recent change. This work is relevant to GRWF and other forms of green infrastructure in cities where these technologies are new or not widely implemented.

On the mitigation potential and urban climate impact of increased green infrastructures in a coastal mediterranean city

An increase of the green infrastructure (GI) in cities contributes to sharing the common goals of reducing energy usage, mitigating pollution emissions, and improving the urban climate. The synergy between urban heat island (UHI) and extreme urban heat in Athens (Greece), during the summer, is inevitable, while its green cover is considerably low. However, very few studies have reported the biophysical effects of the GI on the surface standard meteorological field and urban boundary layer (UBL) that are triggered by changes in the GI at a seasonal scale. The present study sheds light on the complex synergies between UHI and extreme urban heat focusing on warm coastal cities like Athens.To this end, we hypothetically designed and simulated three scenarios of increased GI, such as GI30, GI50, and GI70. The mosaic approach is used, and the portion of each urban grid cell is replaced with different types of vegetation patches, by 30%, 50%, and 70% using the weather research and forecasting (WRF) model, coupled with a single-layer urban canopy model (SLUCM) at city-level for assessing mitigation potential and urban climate impact. The results showed that the daily peak decrease of the ambient temperature at 17:00LT is close to 0.0157 °C per unit of increase of the GI, while the maximum expected daytime summer temperature decrease is 0.7 °C, 1 °C, and 1.1 °C for GI30, GI50, and GI70 scenarios respectively compared to the control case. The corresponding decrease of the nighttime ambient temperature is found to be 0.0375 °C per unit of increase of the GI, whereas the maximum temperature reduction for the G70 scenario is close to 1.9 °C. Increased GI is found to significantly lower the height of the planetary boundary layer (PBL), thus increasing the risk of higher pollution concentration, while a significant impact on the strength of the sea breeze and the level of humidity is observed increasing the risk of thermal discomfort. Results are also compared with the findings of thirty similar projects from other cities to provide a global assessment of the mitigation potential of additional GI in cities. Our results contribute significantly to understanding the mitigation potential and urban climate impact of increased GIs at a seasonal scale.

Effects of heat and drought stress on the health status of six urban street tree species in Leipzig, Germany

Trees are one of the most important elements of green infrastructure in cities. Climate change is specifically affecting trees in many European cities. Trees are experiencing negative impacts from the increase in heat waves and droughts, both of which begin, in some cases, early in the year and continue through the growing season. Current studies on the regionalization of climate change indicate that important water reservoirs such as soil and tree canopies have been drying out for years/decades, and these impacts can be observed in various parts of Europe. Trees react to stress as they age through mechanisms such as crown defoliation, early wilting, shedding of branches and, ultimately, lowered resistance to pests. As a result, massive tree death, both in park trees and street trees, can be observed in many cities. The present study provides a current inventory of street tree damage caused by heat and drought in the city of Leipzig, Germany, in 2020, the third extreme dry year after 2018 and 2019. The field maps focus on different age groups of Quercus, Tilia, Aesculus, Platanus, Fraxinus and Acer along a periurban-urban gradient. The results are clear: significant damage was found in all tree species. Older trees and newly planted trees are most likely to die as a result of extreme conditions, while younger trees with narrow trunks and crowns that have not yet expanded cope better with both heat and drought. Four out of five mapped street trees showed recognizable damage, indicating severe impacts of climate change on important elements of green infrastructure in cities.

Exploring the Integration Between Colour Theory and Biodiversity Values in the Design of Living Walls

Designing green infrastructure in cities requires vegetation that has multiple outcomes and functions, particularly using plants that have both attractive visual or aesthetic features and high biodiversity values. Plantings that have high visual appeal are more highly valued by people and increase their feeling of wellbeing. Increasing biodiversity in cities is one of the major challenges facing urban planning and design. However, balancing biodiversity and aesthetic outcomes in urban planting design is complex, and to date there are few methods that can be used to guide plant selection. To address this knowledge gap, we investigated the use of a colour theory framework for planting arrangements to see if we could design vegetation that is highly aesthetic and has high biodiversity. We did this by configuring planting combinations for living walls in Malmö, Sweden, using principles based on Johannes Itten’s colour theories. The plant combinations on each wall were graphically arranged using (1) colour analysis of each plant and (2) design of the plant species into two colour schemes: light-dark colour concept and a complementary colour concept. For each species used in the compositions we created a biodiversity classification, based on its pollination value, “nativeness” and conservation value as a cultivar; and a plant visual quality classification, based on the performance from living walls studies. The graphical colour composition and interlinked biodiversity value were then compared to designs created with randomly selected plant species. The results showed that it is possible to design a living wall based on colour theory without compromising with biodiversity outcomes, namely species richness, pollination and the nativeness of the species. The results also indicate the potential application of this design approach to deliver greater aesthetic appreciation and enjoyment from plantings. While more work is needed, this study has shown that a theoretical colour framework can be a useful tool in designing green infrastructure to improve delivery of both cultural and regulatory ecosystem services.

Green Fences for Buenos Aires: Implementing Green Infrastructure for (More than) Air Quality

Schoolyards in North America and Europe are increasingly using green fences as one measure to protect vulnerable populations from localised air pollution. This paper assesses the possibilities and limits for mobilising this format of site-specific green infrastructure in cities in low- and middle-income countries beset by air pollution and multiple other socio-environmental challenges, and particularly questions the definition of green fences as a green infrastructure for air quality (GI4AQ). We applied several qualitative and action research methods to the question of green fence implementation in Buenos Aires, Argentina—a Latin American city with weak air-quality policies, limited green infrastructure, and little experience with nature-based solutions. Firstly, we conducted a literature review of the role that urban vegetation and ecosystem services may play in AQ policy and the implementation barriers to such approaches globally and in the city. Secondly, we planned, designed, constructed, maintained, and evaluated a pilot green fence in a school playground. Thirdly, we carried out supplementary interviews with stakeholders and expert informants and compiled project members’ narratives to respectively characterise the barriers that the project encountered and delineate its attributes based on the associated actions that we took to overcome such barriers to implementation and complete the pilot. Our findings identify multiple barriers across seven known categories (institutional, engagement, political, socio-cultural, built environment and natural landscape, knowledge base and financial) and highlight examples not previously considered in the extant international literature. Furthermore, learning from this experience, the paper proposes an expanded model of green infrastructure for air quality plus multi-dimensional co-benefits (GI4AQ+) to increase implementation chances by attending to local needs and priorities.