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Assessing the drivers shaping global patterns of urban vegetation landscape structure
Abstract
We studied urban vegetation at the landscape scale for one hundred cities and its relation to sociodemographic and climate • The landscape metrics best describing urban vegetation structure: amount, fragmentation and distribution of green cover • The climate and socioeconomic context relates to the degree of fragmentation and amount of urban vegetation • Planning can improve vegetation structure by increasing, connecting and better distributing vegetation in cities G R A P H I C A L A B S T R A C T a b s t r a c t Vegetation is one of the main resources involve in ecosystem functioning and providing ecosystem services in urban areas. Little is known on the landscape structure patterns of vegetation existing in urban areas at the global scale and the drivers of these patterns. We studied the landscape structure of one hundred cities around the globe, and their relation to demography (population), socioeconomic factors (GDP, Gini Index), climate factors (temperature and rain) and topographic characteristics (altitude, variation in altitude). The data revealed that the best descriptors of landscape structure were amount, fragmentation and spatial distribution of vegetation. Populated cities tend to have less, more fragmented, less connected vegetation with a centre of the city with low vegetation cover. Results also provided insights on the influence of socioeconomics at a global scale, as landscape structure was more fragmented in areas that are economically unequal and coming from emergent economies. This study shows the effects of the social system and climate on urban landscape patterns that gives useful insights for the distribution in the provision of ecosystem services in urban areas and therefore the maintenance of human well-being. This information can support local and global policy and planning which is committing our cities to provide accessible and inclusive green space for all urban inhabitants.
... While the multiple benefits of urban vegetation are widely recognized, its conservation becomes challenging as cities continue to densify or sprawl (Richards and Belcher, 2020). Thus, evaluating urban vegetation landscape patterns and their spatio-temporal dynamics is essential for monitoring the socioecological consequences of urbanization (Turner and Gardner, 2015;Dobbs et al., 2017). In this sense, landscape-level approaches using GIS and remote sensing data have proven useful to study the spatio-temporal changes in urbanization and vegetation (e.g., Kaza, 2013;Zhou et al., 2018;Keita et al., 2021). ...
... Studies on the quality and dynamics of urban vegetation have been prolific in the past three decades with global (Zhong et al., 2019;Dobbs et al., 2017;Zhou and Wang, 2011) and regional foci, particularly in North America, Europe, and Australia (Timilsina et al., 2021;Morgan et al., 2006;Kabisch and Haase, 2013). However, only a handful of examples from LAC, mainly at the country level or including the city as a whole (Dobbs et al., 2018;Hernández-Moreno and Reyes-Paecke, 2018). ...
... To understand the fluctuation in spatio-temporal patterns of urban vegetation in LAC cities, we selected and evaluated changes in six landscape metrics for two periods, 2000-2010 and 2010-2020. The selected metrics were the following: total area (ha) and mean patch size (ha) which measure composition; average Euclidean distance to the nearest neighbor (m), patch density in 100 ha, and path cohesion index (%), which measures the physical connectedness of the vegetated patches; and index of the largest patch (%), which represents the percentage of the landscape occupied by the largest vegetated patch and measures configuration (McGarigal et al., 2012;Dobbs et al., 2017;Hesselbarth et al., 2019). A description of each metric can be found in the Supplementary Material (Table S1, but also see McGarigal et al., 2012). ...
As cities opt for green policies to address urban socio-ecological challenges it becomes important to evaluate how the urban landscape responds to them, and if these responses are strengthening the benefits of nature for all. The Latin American and Caribbean (LAC) region is one of the most biodiverse and urbanized regions of the world, which makes it imperative to understand how greening policies have impacted the distribution, accessibility, and quantity of vegetated areas in cities through time. Using a landscape ecology approach, we explored the effects of local urban dynamics on the pathways of urban vegetation in ten LAC capital cities in the last 20 years. Our results showed a great fluctuation of vegetation cover change for the region, with Santiago (Chile) losing more than 10% of its urban vegetation to Brasilia gaining 19%, while fragmentation and inequities in the distribution of vegetation increased in all cities. Cities followed four pathways of vegetation change, displaying different patterns of change in fragmentation, size of the vegetated patches and their clustering. This discloses that the greening policies and actions adopted in LAC cities led to increased vegetation cover, or avoided its loss, but did not assure a better distribution of the green and its benefits. Vegetation in LAC cities are still fragmented, where vegetation is not connected and is not equitably distributed, showing that policies in place have not addressed distributional injustice yet. This is corroborated by the assessment of drivers of change where we found social factors were the most important determinants of urban vegetation dynamics. Results from our study provide evidence for developing policies towards urban greening and connectivity, not only to prevent further biodiversity loss but also for creating more resilient communities and cities that address environmental inequities.
... As florestas urbanas, compreendem toda vegetação da área urbana, incluindo árvores individuais, ao longo de ruas, jardins, parques, espaços verdes e infraestrutura relacionada (Konijnendijk et al., 2006;Nitoslawski, 2019) tem a capacidade de fornecer uma série de serviços ecossistêmicos (Wirtz et al., 2021). Estes serviços, que contribuem diretamente para a qualidade de vida, abrangem desde a regulação climática e a prevenção de inundações até a manutenção da qualidade do solo, a redução da poluição do ar, o suporte à biodiversidade e a promoção de espaços recreativos Nitschke;Kendal, 2017;Nyelele;Kroll;Nowak, 2019). Durante a pandemia de COVID-19, a relevância das florestas urbanas tornou-se ainda mais evidente, visto que essas áreas verdes serviram como recursos para a saúde física e mental da população em períodos de isolamento social (Azevedo et al., 2020). ...
... As florestas urbanas, compreendem toda vegetação da área urbana, incluindo árvores individuais, ao longo de ruas, jardins, parques, espaços verdes e infraestrutura relacionada (Konijnendijk et al., 2006;Nitoslawski, 2019) tem a capacidade de fornecer uma série de serviços ecossistêmicos (Wirtz et al., 2021). Estes serviços, que contribuem diretamente para a qualidade de vida, abrangem desde a regulação climática e a prevenção de inundações até a manutenção da qualidade do solo, a redução da poluição do ar, o suporte à biodiversidade e a promoção de espaços recreativos Nitschke;Kendal, 2017;Nyelele;Kroll;Nowak, 2019). Durante a pandemia de COVID-19, a relevância das florestas urbanas tornou-se ainda mais evidente, visto que essas áreas verdes serviram como recursos para a saúde física e mental da população em períodos de isolamento social (Azevedo et al., 2020). ...
Technological trends for urban forest management in smart and sustainable cities: a systematic literature review
The study addresses the role of digital technologies in urban forest management in the context ofsmart and sustainable cities. The research is justified by the growing urbanization andsustainability demands that pressure cities to adopt advanced technological solutions. The mainobjective was to map and systematize emerging technologies applied in urban forestmanagement, identifying technological trends in the sustainable development of cities. Themethodology is based on a Systematic Literature Review (SLR), using the Methodi Ordinatiomethod to classify relevant articles based on multicriteria decision-making. As a result, the studyidentifies technologies such as IoT, Big Data, LiDAR, and Artificial Intelligence, highlightingtheir applications and benefits for monitoring and optimizing urban forests. It is concluded thatthese technologies facilitate urban governance and planning, contributing to sustainability andenvironmental resilience. However, challenges such as the scarcity of real-time data and highimplementation costs are still limiting
Tendências tecnológicas para a gestão de florestas urbanas em cidades inteligentes e sustentáveis: Uma revisão sistemática da literatura.
O estudo aborda o papel das tecnologias digitais na gestão de florestas urbanas no contexto de cidades inteligentes e sustentáveis. A pesquisa justifica-se pela crescente urbanização e pelas demandas de sustentabilidade que pressionam as cidades a adotar soluções tecnológicas avançadas. O objetivo principal foi mapear e sistematizar as tecnologias emergentes aplicadas na gestão de florestas urbanas, identificando tendências tecnológicas no desenvolvimento sustentável das cidades. A metodologia baseia-se em uma Revisão Sistemática da Literatura (RSL), utilizando o método Methodi Ordinatio para classificar artigos relevantes a partir de decisão multicritério. Como resultado, o estudo identifica tecnologias como IoT, Big Data, LiDAR e Inteligência Artificial, destacando suas aplicações e benefícios para o monitoramento e otimização das florestas urbanas. Conclui-se que essas tecnologias facilitam a governança e o planejamento urbano, contribuindo para a sustentabilidade e resiliência ambiental. Contudo, desafios como a escassez de dados em tempo real e os altos custos de implementação ainda sejam limitantes. Palavras-chave: tecnologias digitais, gestão, florestas urbanas, cidades inteligentes e sustentáveis.
... While compact cities are promoted as a concept for spatial planning to combat urban sprawl and enhance economic growth (OECD, 2012), pressure is growing on urban green spaces (Haaland and Konijnendijk van den Bosch, 2015;Pauleit et al. 2005). Although the ecological, social and thus also economic value of the latter is becoming increasingly evident in the property development sector (Jerome et al. 2019;Sinnett et al. 2018), urbanization typically leads to reduced, fragmented and dispersed vegetation patterns (Dobbs et al. 2017). This is problematic, because particularly urban trees have been shown to have a significant impact on human well-being and health (Kardan et al. 2015), and to play an important role in regulating ecosystem services within the built environment (Grêt-Regamey et al. 2020). ...
... It has been shown to be positively associated with urban vegetation cover, however, sometimes a quadratic relationship has been reported, as well as interaction with other independent variables (Bigsby et al. 2014;Daniel et al. 2016;Grove et al. 2006;Kendal et al. 2012;Landry and Chakraborty, 2009;Lowry et al. 2012;Pham et al. 2017;Troy et al. 2007). Conflicting results have been reported regarding the relationship of population density with urban vegetation (Bigsby et al. 2014;Dobbs et al. 2017;Hilbert et al. 2019;Kendal et al. 2012;Troy et al. 2007). ...
... The natural forests within an urban setting offer a similar image in terms of trees, shrubs, and an upper canopy, but are usually less dense than a natural forest. Natural forests in urban area assemblies are frequently regarded as new and complex because they feature a mix of human-cultivated, naturally regenerating, and non-native plant species [19,21]. Human intervention, such as pruning trees, is a characteristic that identifies natural forests in urban areas. ...
... Additionally, there are multiple water elements present, such as rivers, lakes, streams, canals, and man-made ponds. Ultimately, urban forests are typically diverse due to a wide range of goals and complex management decisions, setting them apart from the diversity found in natural forests [18,21,23,24]. Connectedness in the urban environment is considered another key attribute of urban forests, as it describes the intensity and consistency between different components. ...
Permanent forest reserves (PFR) in urban areas are an integral aspect of the urban forest concept and the basis of a city’s green infrastructure. The preservation of natural forests in urban areas has become a widely researched topic due to the environmental, social, and economic benefits provided by it. Although several studies have shown that visual aesthetics play a role in preserving natural forests in urban areas, visual aesthetic value is typically not prioritized in preservation plans since it varies based on the physical characteristics of natural forests in urban areas, making it difficult to measure universally. Therefore, this research aims to identify the suitable variables for assessing the visual aesthetic quality of permanent forest reserves within urban areas in Malaysia. This study selected two permanent forest reserves based on four criteria. Data were collected via participant-generated images taken along selected forest trails based on participant visual aesthetic preferences. Researchers and experts analyzed and classified the data according to content to identify suitable visual aesthetic quality variables. This research identified 14 suitable variables for assessing the visual aesthetics of PFRs in urban areas, with a dominant preference for information-processing theory variables. Mystery was the most present variable for the visual aesthetic quality assessment of PFRs. Furthermore, participants’ educational and emotional backgrounds, categorized as design, environmental, social, and technical, impacted their visual aesthetic preferences. Our findings serve as a foundation for assessing the visual aesthetic quality of natural forests within urban areas in Malaysia.
... The urban development process reflects the interaction between population dynamics and economy growth. We use GDP as a measure of economic growth, which is a widely recognized primary indicator of urban economic development (Dobbs et al., 2017;Wu and Kim, 2021a), and population numbers to assess changes in the urban population. ...
Urban blue-green spaces (UBGS) play a vital role in providing ecological services and enhancing human well-being in high-density cities. In this study, the spatiotemporal dynamics and drivers of UBGS in the Beijing-Tianjin-Hebei (BTH) region, a key economic and ecological hub in China, were examined using Landsat satellite data from 2010 to 2023 to analyze UBGS changes within urban areas. Subsequently, the relationship between UBGS changes and economic and population growth were assessed. Our results reveal a general increase in Urban Green Spaces (UGS) and Urban Blue Spaces (UBS) across BTH cities, with significant UGS quality improvements , especially in Beijing, Shijiazhuang, and Tianjin. Here, over 25% of the area experienced a significant increase in NDVI (Normalized Difference Vegetation Index) values, reflecting improved vegetation health. Landscape pattern analysis indicated UGS became more contiguous, with increased connectivity and structural integrity, as the aggregation index rose by 6.7% and the largest patch index by 239.2%. The BTH Coordinated Development strategy has helped reduce population pressures, supporting economic and environmental balance. Our findings offer valuable insights into sustainable urban development and UBGS conservation, relevant for urbanizing regions worldwide.
... Water bodies, soil, and canal bed sediments in urban parks may experience a variety of anthropogenic inputs, including potentially toxic elements (PTEs) and organic pollutants, primarily depending on the population density [22,23] and ongoing urbanization. Major PTE sources in urban settings include vehicle traffic and industrial activities located nearby [24][25][26][27][28]; furthermore, the use of pesticides (such as herbicides, insecticides, fungicides) in an urban environment may affect ecological and human health [29]. ...
The present study focuses on the sources and spatial distribution of potentially toxic elements (PTEs) and organic pollutants in water, canal bed sediment, and soil in the Versiliana urban park, an inclusive green area near the coast in the densely populated Versilia Plain of Tuscany. Surface water and bed sediments from canals crossing the urban park were collected at 10 stations during four different surveys to account for hydrological seasonality. Groundwater was collected in a survey through 10 piezometers. Eleven shallow soil samples were also collected, with the aim of evaluating the potential release of pollutants. Groundwater ranged from Ca-HCO3, to NaCl, CaCl2, and Na-HCO3 water types, indicating conservative mixing and cation exchange processes during seawater intrusion. Most waters from canals belonged to the Ca-HCO3 hydrofacies; a salinization shift, due to hydraulic connection with saline groundwater and soil sea salt dissolution, is observed. The concentration of most PTEs in groundwater and canal water is below Italian regulatory thresholds, with the only exception being As, which exceeds the legal limit in some samples. In most sediments, Ni, Cr, Zn, and As exceed the threshold effect concentration, and in some cases, the probable effect concentration. Geogenic PTE sources are attributed to metalliferous mineralization that characterizes the upstream Versilia River basin catchment. However, local PTE inputs from vehicular emissions and local industrial activities have been highlighted. Arsenic in sediments originated from geogenic sources and from arsenical pesticides, as indicated by the analysis of organic compounds, highlighting the legacy of the use of organic pesticides that have settled in bed sediments, in particular malathion and metalaxyl. The arsenic risk-based screening level in soil is lower compared with the regulatory threshold and with the measured concentration.
... As a consequence of rising urbanisation, environments in cities exhibit altered microclimates, which trend towards higher temperatures, alongside elevated air, water, noise, and light pollution (LLUR 2001;Grimm et al. 2008;Nikulina, Polovodova, and Schönfeld 2008). They also experience increased habitat fragmentation (Dobbs, Nitschke, and Kendal 2017), lower diversity and abundance of native species, high numbers of non-native species (Aronson et al. 2014;McKinney 2008), and lower phylogenetic diversity within communities (Knapp et al. 2012;Sol et al. 2017). Still, urban environments are successfully exploited by many non-human species (Johnson and Munshi-South 2017;Perry and Gottert 2024). ...
Anthropogenic activities have drastically changed environmental conditions worldwide, negatively impacting biodiversity and ecosystem services. At the same time, the majority of the human population lives in urban areas that are greatly altered from natural habitats. Nevertheless, many species thrive in these urban environments. To improve our knowledge of evolution and adaptation in these anthropogenically impacted habitats, we conducted the widest series of stress experiments to date with three marine taxa: one mussel and two gammarid species. We compared intraspecific populations from protected and human‐altered habitats to determine their tolerance to salinity, temperature and partial pressure of CO2 in water (pCO2) regimes. Populations from impacted habitats typically outperformed protected habitat populations, with individuals from the most impacted habitat being the most robust. We propose that urban populations are adapting to life in disturbed environments—this adaptation concurrently promotes more resilient rescue populations but potentially confers increased invasion risk from non‐native species.
... Socioeconomic and population factors, such as wealth, population density, and Human Development Index (HDI), are crucial for understanding the distribution and functionality of green spaces in urban areas [59,60]. Additionally, urban vegetation landscape structure is shaped by population dynamics, socioeconomic conditions, climate, and topographic features, with economically unequal and developing regions often experiencing more fragmented vegetation patterns [61]. Therefore, socioeconomic and population factors, such as wealth and population density, may correlate with the greater or lesser provision of green areas in cities [62][63][64]. ...
Ecosystem services (ESs) are extremely important, specifically in urban areas. Urban forests, even representing a pivotal role in global sustainability, have been converted into different human-modified landscapes. This paper aims to analyze the ES provided by the urban areas of 25 cities of the Atlantic Forest in Brazil. We used i-Tree Canopy v.7.1 to classify the land use. We quantified the monetary benefits of the urban vegetation and used socioeconomic variables (i.e., total population, population density, Human Development Index (HDI), and Gross Domestic Product (GDP) per capita) to analyze if the ecosystem services or the land uses are associated with this. Our data reveal that together, the cities studied sequester a significant total of 235.3 kilotonnes of carbon and a substantial 864.82 kilotonnes of CO2 Equivalent (CO2 Equiv.) annually. Furthermore, together, they also store a total of 4861.19 kilotonnes of carbon and 17,824.32 kilotonnes of CO2 Equiv. We found out that the average monetary estimate of annual carbon sequestration was USD 3.57 million, while the average stored estimate was USD 73.76 million. Spearman’s correlogram showed a strong positive correlation between density and the percentage of impervious cover non-plantable no trees (IN) in urban areas (p < 0.001). IN was also positively correlated with HDI (p = 0.01), indicating that urban areas with higher HDI tend to have larger impervious areas. Our data suggest essential insights about the ecosystem services provided by urban areas and can serve as significant findings to drive policymakers’ attention to whether they want to provide more ecosystem services in cities.
... [19] Features of the natural environment such as topography, soils, and climatic conditions shape the conditions for vegetation growth and vegetation types. [20][21][22] Built environment with its buildings and infrastructure layouts and land-use regulations determine the availability of land for urban green space. [21] Rapid urbanization, population growth and urban sprawl can threaten existing green space and limit opportunities for new green space creation. ...
Green spaces are as essential as other infrastructural elements, despite being the most needed yet ignored concepts in this rapid urbanization and industrialization era. This study focuses on the current conditions of green spaces in urban and peripheral contexts and the challenges associated with green space development in these zones, particularly emphasizing informal green spaces. This study used mixed-method approaches for data collection and analysis, including key informant interviews and observation techniques. A total of 105 data were collected. Findings reveal that total household area and income range affect having green spaces and the size of green spaces. While more than half of the respondents had access to green spaces at their homes, mostly in the format of indoor plants, residents from urban and peripheral zones had different opinions about the green space issue. Limited space was identified as a common hindrance by both urban and peripheral residents. Lack of time and safety concerns for children are the main hindrances to having proper green spaces, according to urban dwellers, while peripheral dwellers mentioned limited knowledge of plant, care, and maintenance costs. Urban residents mentioned the health benefits mostly of having proper green spaces, while peripheral residents highlighted relaxation and social cohesion. The findings of this research will help to advance urban development through improved green space integration. Focusing on limited space, how urban areas can adapt to green spaces, and how peripheral zones can increase their knowledge to maintain green space, this study recommends a solution to this.
... Many of the quantitative studies failed to report on the selection and recruitment criteria for participants and attrition rates. Natural areas are often unequally distributed across cities, with more affluent areas having more nature (Dobbs et al., 2017). Underreporting participant characteristics could mean that observed positive associations might stem from self-selection bias, where individuals living in areas with more nature may already have higher incomes, engage in healthier activities, and may also be more likely to participate in research studies (Yu and Zhu, 2015). ...
... However, these cities had a higher density of green space patches and greater isolation of these patches but also had more urban parks per capita. environment such as topography, soils and climatic conditions shape the conditions for vegetation growth and vegetation types [9][10][11] . Built environment with its buildings and infrastructure layouts and land-use regulations determine the availability of land for UGS 10 . ...
Urban green spaces play a critical role in regulating air temperature, reducing air pollution and enhancing people’s well being. Yet, existing data and research on potential drivers of urban green space availability in Latin America are limited. Here, focusing on 371 large cities in 11 countries in Latin America, we described the total and per capita variability of urban green space, its spatial configuration and green urban parks across the categories of cities’ natural, built and socioeconomic environments. We tested the relative importance of geographic (climate) versus city-level built environment (population, population density, street intersection density) and socioeconomic (city gross domestic product per capita, unemployment, education) drivers in explaining urban green space availability. We found a high level of heterogeneity in green space quantity across cities and across categories of cities’ environments. Relative to other city factors, climate zone had the largest influence in explaining the quantity of green space, whereas education, street intersection density and population density were the most important drivers of urban park availability. The significance of climate for green space availability, combined with the inequitable quantity of green space, indicates that cities have differing capacities to implement nature-based solutions for heat mitigation and health promotion.
... Literature [18] assessed landscape changes in European mountainous regions over the past fifty years, with fragmentation of grasslands, increasing restoration of woodlands, and expanding urban areas all characterizing landscape changes, and discussed the feasibility of landscape monitoring for the protection of endangered ecosystems. Literature [19] reveals the influence of social systems and climate on urban landscape patterns and the effective allocation of ecosystem services in urban areas to provide inclusive green spaces for urban residents. ...
The impact assessment of vegetation ecosystems is inevitably combined with vegetation, soil, hydrothermal conditions, and topographic factors. This paper utilizes a combination of remote sensing imaging, monitoring, on-site data collection, and spatial information visualization to provide data information on landscape vegetation ecosystems and builds a GIS database for the process of landscape vegetation ecological analysis. Define landscape vegetation types and analyze landscape vegetation pattern indices. Combining the evolution of landscape vegetation areas with the change in vegetation type levels, the vegetation cover of landscape vegetation in the study area was calculated. Surface temperature inversion model based on Landsat atmospheric correction algorithm to get the surface temperature of the region from 2014 to 2020. Combined with the soil erosion classification and grading standards, the soil erosion model RUSLE was used to derive the soil erosion class. In 2020, the landscape vegetation of Jiuzhaigou had a high coverage of 62.79%, and the mean surface temperature generally showed a trend of increasing and then decreasing. Mild and moderate soil erosion decreases. The synthesis of vegetation cover, surface temperature, and soil erosion can indicate that the landscape vegetation ecological environment of the study area is good and in ecological balance.
... Nature serves as the foundation for of ecosystem services that sustain the wellbeing of people in both rural and urban ecosystems . However, urban development repeatedly reduces green areas to promote higher population density, while also prioritizing the construction of durable and efficient road networks (Abass et al., 2018;Dobbs et al., 2017). When waterways obstruct the path of urban expansion, they are often covered or eliminated to facilitate the construction of streets and other urban infrastructure. ...
Blue–Green infrastructure (BGI) consists of spaces with water bodies and vegetation inside the urban territory. Due to their characteristics, they have the potential to provide many functions and benefits to the inhabitants of the city, such as open space, places for social encounters and a healthy lifestyle, shady and humid environments for climate regulation and education, and economic well-being. The accumulation of these functions is denominated multifunctionality. The BGI multifunctionality depends on social and physical factors. In this chapter, two of these factors are reviewed: the size of the BGI and the urban legislation for the City of Puebla and its metropolitan area, in central Mexico. The measurement of multifunctionality is carried out with the satellite images of Google Maps Streetview and Google Earth Pro. Subsequently, a cluster analysis is done to classify those BGIs that were similar in their size and number of functions provided. Most of the BGI in Puebla are relatively small, on average 0.56 ha, and provide less than 3 functions. The larger ones (average 2.02 ha) can provide up to 5 functions, the largest number of functions observed. Additionally, there is a relationship between the size of the BGI and the number of functions provided, and the presence of water bodies. On the other hand, the instruments of urban legislation of different governmental scales are consulted, locating in their content the normativity related to BGI. According to the analysis of the urban legislation, the multifunctionality of the BGI is not addressed in a relevant way at the various levels of government, i.e., municipality, state, and federation. In conclusion, most of the Blue–Green Infrastructure (BGI) in the city of Puebla is relatively small and could enhance its functionality through redesign and modifications in urban legislation.
... Previous studies have typically examined climatic (precipitation) and geographical factors, such as average elevation, as natural variables influencing the distribution of urban green spaces. Demographic factors, such as population density (PD), and economic indicators, such as per capita gross domestic product (GDP), are commonly used as socioeconomic determinants (Dobbs et al., 2017;Fuller and Gaston, 2009;Zhao et al., 2013). Urban green spaces vary both spatially and temporally because these elements interact with each other (Dwyer, 2000). ...
Urban open spaces offer both environmental and social benefits. However, comprehensive studies that integrate both quantitative and qualitative evaluations of the factors driving change in these spaces and their long-term predictions are lacking. Most existing studies concentrate on land-use development rather than conducting empirical research specific to urban open spaces in Shanghai. This study addresses this gap by employing a geographic detector (geodetector) to analyze the influence of various driving factors on open-space changes. These factors were then used as weight values in a multicriteria CA-Markov model to simulate and predict change in Shanghai's urban open spaces by 2050. The advantage of analyzing driving forces lies in their ability to capture the multifactor synergy influencing change in urban open spaces, aligning with the aim of this study to quantitatively evaluate the interaction between natural, climatic, and socioeconomic factors. Additionally, semi-structured interviews were conducted with 10 policymakers and planners to assess the reliability of the quantitative predictions. The results indicate that socioeconomic factors are the primary drivers of change in urban open spaces. Specifically, the interaction between the normalized difference vegetation index (NDVI) and population density (PD) emerged as the most influential variables. For prediction outcomes, the unconstrained scenario predicts a decrease in open-space area from 5610.94 km2 in 2020 to 5124.36 km2 in 2050. The planning intervention scenario anticipates minimal changes in Shanghai's total urban open-space area with almost no floating changes. However, the economic development scenario predicts a rapid decline in open spaces. Experts and planners evaluated these three scenarios and confirmed the reliability and accuracy of the prediction models. The methods and findings of this study can support zoning planning for urban open-space systems in other cities and regions.
... In contrast, deteriorating ecological conditions constrain sustainable urbanization [62]. With the rapid growth of the economy, population, and impervious surfaces, conflicts between urbanization and vegetation have become increasingly prominent [11,63]. This issue is particularly apparent in urban agglomerations. ...
Rapid global urbanization and its progress have profoundly affected urban vegetation. The ecological quality of urban vegetation is a vital indicator of regional ecological stability and health. A comprehensive assessment of the coupling coordination and coercive relationship between urbanization and the vegetation ecological quality is essential for promoting sustainable regional green development. Using the rapidly urbanizing Guangdong–Hong Kong–Macao Greater Bay Area (GBA) urban agglomeration in China as an example, this study evaluates the vegetation quality condition and the level of urbanization and explores the dynamic relationship between vegetation ecological quality and urbanization processes. This study introduces the vegetation ecological quality index (VEQI) based on net primary productivity (NPP) and fractional vegetation cover (FVC), as well as the comprehensive urbanization index (CUI) derived from gross domestic production (GDP), population density, and nighttime lighting data. The coupling coordination and Tapio decoupling models are employed to assess the degree of coupling coordination and the decoupling relationship between the VEQI and CUI across different periods. The results showed that (1) from 2000 to 2020, the VEQI in the GBA showed a significant increase, accompanied by continuous urbanization, particularly evident with the high CUI values in central areas; (2) the coupling coordination degree (CCD) exhibits high values and significant change slopes in the central GBA, indicating dynamic interactions between urbanization and vegetation ecological quality; (3) the decoupling states between the VEQI and CUI are dominated by weak decoupling (WD), strong decoupling (SD), expansive negative decoupling (END), and expansive coupling (EC), suggesting improvements in the relationship between urbanization and vegetation ecological quality; (4) the coordinated development level of the VEQI and CUI in the study area shows improvement, and their decoupling relationship displays a positive trend. Nevertheless, it remains crucial to address the impact of urbanization pressure on vegetation ecological quality and to implement proactive measures in response. The results of this study provide theoretical support for mesoscale development planning, monitoring vegetation ecological conditions, and formulating environmental policies.
... Although the numerous advantages of urban vegetation are well documented, its preservation is becoming a major challenge as urban areas continue to expand or become denser [12]. Also, assessing urban vegetation patterns and their spatiotemporal evolution is crucial for following up on the socioecological repercussions of urban sprawl [13,14]. An increasing amount of research has shown that the proportion of urban vegetation has recently changed considerably due to changes in urban land use [15]. ...
Urban vegetation is a fundamental element and the keystone of urban ecological systems. Therefore, better comprehending the patterns of change over time and space in this vegetation is crucial for more effective urban environment management to enhance urban habitat and counteract the negative impacts of accelerated urbanization. This study examined 1,081 articles listed in the Scopus database on urban vegetation between 2000 and 2023. After being exported in CSV format, these data were analyzed using VOSviewer for data visualization, Scopus Analytics for performance evaluation, MS Excel for organizing data in graphical form, and CiteSpace for examining the emergence of keywords. The objective was to offer guidance on current topics and forecast future research trends related to this theme. This analysis shows that in 2000, only 5 articles on urban vegetation were published, which has risen by 2840% to 142 in 2023, following a quadratic function (R2=0.9524). China is the country most interested in this topic, with 273 articles (25.25%). Thus, China and the United States are the most cooperative nations on the urban vegetation subject. Over the past 24 years, the environmental science field has contributed the most, with 33.3% of papers published. Concerning sources, the journal Urban Forestry and Urban Greening comes first with 73 articles and 2127 citations. The keyword “urban vegetation” is the most frequently used by authors (occurrences: 330, links: 115, and total link strength: 459). In terms of cocitations, an analysis of 75887 authors revealed that X. Li came out first with a total link strength of 21626 and 507 citations while G. D. Jenerette takes first place, concerning the co-authorship with 11 publications and 899 citations. Moreover, the Chinese Academy of Sciences is the most effective and influential institution on the subject. Keyword emergence analysis revealed that urban growth, urban development, and ecosystem services have become current research hotspots with considerable impact over the past three years. This work has provided structured data, guidelines, and useful recommendations for further investigations, which can contribute to a better comprehension of the environmental features of urban vegetation.
... Second, this result could be supported by the weakness of effective urban planning policies that prioritize GA development and conservation. Moreover, these findings offer valuable insights into the distribution (uneven distribution) of urban ecosystem services in the city [45] and can support decision-making and planning for inclusive GA benefits for residents. Finally, the configuration and distribution of green areas (GA) and the provision of ecosystem services should impact residents' opinions on the degradation risk of each GA category and the factors driving this threat. ...
Green areas (GAs) are swiftly declining in urban areas worldwide, amplifying adverse local climate impacts on the well-being of city residents. Despite this, there is limited empirical research on the changing patterns and distribution of GAs and their vulnerability. This is especially notable in dry tropical cities where these spaces function as vital microclimate areas that control against climate change effects such as flooding and heat islands. This study focused on examining the changing GA coverage, scrutinizing the spatial distribution of different GA categories, and investigating threat factors associated with their perceived sustainability in Parakou. Employing a mixed-methods approach, open-source geospatial data and collected primary data were acquired through on-site observations as well as semi-structured interviews. Data analysis involved the application of geospatial, statistical, and textual techniques. The results indicated that, from 2000 to 2020, the city experienced a loss of 16.48 km² (24.73%) in its GA cover. The predominant land use change observed was the conversion of sparse vegetation (21.86%) into built-up areas. A notable difference (P < 0.0001) was observed among GA categories, revealing an aggregated spatial pattern [g (r) > 1] that emphasizes the necessity for tailored strategies to enhance and conserve each GA category within the city. Furthermore, there is a perception of critical degradation in various GA categories, namely city bush, cropland, and forest plantation. The primary causes identified for GA depletion in the city were poor management strategies and lack of planning. These results could provide valuable guidance for policymakers, urban planners, and cityscape architects with a focus on urban sustainability, particularly regarding the development of GAs in the Republic of Benin.
... The accurate and objective quantification of street greenery is essential for its scientific enhancement [11][12][13]. Traditional studies on street greenery primarily relied on overheadview remotely sensed imagery. However, this approach has its limitations as it is unable to detect components like vertical green walls or shrubs that are obscured by a canopy [14,15]. ...
Understanding the determinants of the availability and spatial fairness of street greenery is crucial for improving urban green spaces and addressing green justice concerns. While previous studies have mainly examined factors influencing street greenery from an aerial perspective, there has been limited investigation into determinants at eye level, which more closely aligns with people’s actual encounters with green spaces. To address this, the Green View Index (GVI) and Gini coefficient were used to assess the availability and spatial fairness of street greenery from a pedestrian’s perspective, using Baidu Street View (BSV) images across 49 subdistricts in Changchun City, China. A dataset of 33,786 BSV images from 1877 sites was compiled. Additionally, 21 explanatory factors were collected and divided into three groups: socioeconomic, biogeographic, and landscape patterns. The Boosted Regression Tree (BRT) method was employed to assess the relative influence and marginal effects of these factors on street greenery’s availability and spatial fairness. The results showed that street greenery’s availability and spatial fairness are predominantly influenced by landscape patterns. Specifically, the percentage of landscape and edge density emerged as the most significant factors, exhibiting a threshold effect on the availability and fairness of street greenery. Increasing the proportion and complexity of urban green spaces can efficiently enhance the availability and spatial fairness of street greenery. These findings lay a new foundation for urban green infrastructure management.
... Urbanization has been increasingly recognized by ecologists because it has led to many problems related to the living conditions of human beings, such as changes in land uses, higher landscape complexity, fragmentation, the loss of biodiversity, and urban heat islands [1][2]. Studies related to urban forestry have shown that forests have been facing severe anthropogenic pressures, and forests near settlements have been found to be more disturbed than those located far away [3]. The process of urbanization has also been closely linked to the rapid transformation of habitats, destruction of ecologies, and the production of pollutants. ...
... This is because the changing nature of green space in a society is a reflection of that society's socio-economic decision to allocate land-revenue resources 42 . Notably, green infrastructure has frequently been installed in typically affluent areas with pre-existing access to various types of green spaces, rather than in regions lacking such amenities [43][44][45][46] . Lower socio-economic regions, in contrast, may prioritize alternative economic development, leading to a trade-off with green space, as land use in such areas can be more readily repurposed or redeveloped for affordable housing and other infrastructure 47 . ...
Climate change adaptation efforts are challenged by rapid population ageing and thus an increased proportion of vulnerable individuals. Despite its importance for adaptation planning, the link between ageing demographics and climate adaptation, particularly green infrastructure development, remains unexplored. Here we employ high-resolution satellite images and the difference-in-differences framework to assess the spatiotemporal relationship between ageing demographics and green space coverage change patterns across 26,885 Southeast Asian communities over the past two decades. We find that cities with an increased concentration of elderly residents exhibit greater vulnerability due to inadequate green infrastructure provision. The findings reveal green space reduction in ageing communities, which is more pronounced in socio-economically disadvantaged, rapidly ageing cities. Nonetheless, coastal cities, facing higher climate risks, exhibit no such decline due to their functional demand. Our results support considering socio-demographic shifts and geospatial disparities in city adaptation strategies.
... According to existing research [33,34], the influencing factors of the spatial-temporal change in green space have included climatic factors, socioeconomic determinants, and natural geographic factors. All the factors selected were proved to affect the change in green space. ...
Although there is extensive research demonstrating the significant loss and fragmentation of urban spaces caused by rapid urbanization, to date, no empirical research in Shanghai has investigated the spatiotemporal dynamics of urban open spaces using a comprehensive set of integrated geospatial techniques based on long-sequence time series. Based on the Google Earth Engine (GEE) platform and using the Random Forest (RF) classifier, multiple techniques, namely landscape metrics, trend analysis, open space ratio, transition matrix, Normalized Difference Vegetation Index (NDVI), and fractal dimension analysis, were applied to analyze the Landsat satellite data. Next, Geographic Detector (GeoDetector) methods were used to investigate the driving forces of such spatial variations. The results showed that (1) the RF classification algorithm, supported by the GEE, can accurately and quickly obtain a research object dataset, and that calculating the optimal spatial grain size for open space pattern was 70 m; (2) open spaces exhibited declining and contracting trends; and open spaces in the city experienced a decline from 91.83% in 1980 to 69.63% in 2020. Meanwhile, the degree of open spaces in each district increased to different extents, whilst connectivity markedly decreased. Furthermore, the open space of city center districts showed the lowest rate of decrease, with open space patterns fragmenting due to encroaching urbanization; (3) the contribution of socioeconomic factors to the spatial–temporal changes in open space continually has increased over the past 40 years, and were also higher than natural geographic factors to some extent. Apart from offering policy insights guiding the future spatial planning and development of the city, this paper has contributions from both methodological and empirical perspectives. Based on integrated remote sensing and geographic information science (GIS) techniques, this paper provides updated evidence and a clearer understanding of the spatiotemporal variations in urban spaces and their influencing mechanisms in Shanghai.
... For example, based on the Normalized Difference Vegetation Index (NDVI) products generating from remote sensing data, Huang and Xu (2022) determined that greenness of 3,535 urban areas in the contiguous United States varied significantly, ranging from 2.20% to 89.36%; Y. observed contrasting NDVI trends in Shenzhen city, China, and Bangkok city, Thailand, since 2006; Jin et al. (2018) investigated vegetation dynamics in 71 large cities across China from 1998 to 2012 and discovered that most cities experienced a decrease in greenness in urban areas, while suburban areas showed an increase in greenness. On a global scale, the urban greenness has shown a general increase in Europe and North America over the past few decades, while it has predominantly decreased in Asia, South America, and Africa (Dobbs et al., 2017; Richards and Belcher, 2019; W. M. Yan et al., 2022). These studies demonstrated that NDVI data can accurately indicate the state of vegetation cover in urban areas. ...
... This leads us to four policy recommendations: (1) Conduct a comprehensive examination of the local climate, considering actual temporal and spatial constraints to tailor interventions to the local environment. The design and implementation of UGS should comprehensively scrutinize the city's characteristics and be executed from multiple perspectives, encompassing economic and environmental sustainability (Dobbs et al., 2017). ...
The World Cup stands as the most momentous global sporting event, and significantly impacts the urban green space (UGS) of host cities. However, the impacts, processes, and pattern characteristic of the World Cup on UGS have not yet been fully understood. To fill this gap, we employ time-series satellite imagery and compute the normalized difference vegetation index (NDVI) across detailed maps of UGS in Qatar from 2000 to 2022. In our quantitative assessment, we investigate UGS coverage, landscape patterns, and exposure both before and after the World Cup. Additionally, we compile seven instances of greening in Qatar, and compare them with greening processes in three cities located in neighboring countries. This contextual analysis aims to unravel the nuanced impact of the World Cup on UGS in Qatar. Our results demonstrate: (1) The World Cup emerges as a significant contributor to UGS growth, with UGS expansion accounting for 94.3% of the overall increase in the built-up area during the tournament. This surge in growth is equivalent to an additional area equivalent to 38 Manhattan Central Parks. (2) The World Cup induces a transformation in UGS landscapes, rendering them more complex and fragmented. The degree of change in the landscape index within the built-up area is 35 times greater than those changes observed in the pre-World Cup period. (3) The World Cup brings about a significant enhancement in the minimum level of green exposure for citizens, marking an 8.7-fold increase. This event has proven to be instrumental in propelling Qatar towards multifaceted urban greening, establishing the country as a leading model for regional greening processes. Our study thus confirms the World Cup's role in promoting and reshaping urban green space in Qatar, offering fresh insights into its contribution to urban greening and sustainable urban development.
... The effects of climate change on ecosystems are widespread, making it a major worldwide concern of our time (IPCC, 2021). In the climate change dialogue, vegetation's role in ecosystem functioning is significant (Dobbs et al., 2017), as it contributes to the deterrence of desertification and aids in soil and water conservation (Mohammad & Adam, 2010). The vegetation growth (VG) pattern over time can be analyzed by assessing the landscape surroundings and improving land vegetation forecasting models (Musau et al., 2018). ...
Seasonality and volatility of vegetation in the ecosystem are associated with climatic sensitivity, which can have severe consequences for the environment as well as on the social and economic well-being of the nation. Monitoring and forecasting vegetation growth patterns in ecosystems significantly rely on remotely sensed vegetation indices, such as Normalized Difference Vegetation Index (NDVI). A novel integration of the Generalized Autoregressive Conditional Heteroskedasticity (GARCH) and the Holt-Winters (H-W) models was used to simulate the seasonality and volatility of the three different agro-climatic zones in Jharkhand, India: the central north-eastern, eastern, and south-eastern agro-climatic zones. MODIS Terra Vegetation Indices NDVI data MOD13Q1, from 2001 to 2021, was used to create NDVI time series volatility and seasonality modeled by the GARCH and the H-W models, respectively. GARCH-based Exponential GARCH (EGARCH) [1,1] and Standard GARCH (SGARCH) [1,1] models were used to check the volatility of vegetation growth in three different agro-climatic zones of Jharkhand. The SGARCH [1,1] and EGARCH [1,1] models for the western agro-climatic zone experienced the best indicator as it has maximum likelihood and minimal Schwarz-Bayesian criterion and Akaike information criterion. The seasonality results showed that the additive H-W model showed better results in the eastern agro-climatic zone with the optimized values of MAE (16.49), MAPE (0.49), NSE (0.86), RMSE (0.49), and R² (0.82) followed by the south-eastern and central north-eastern agro-climatic zones. By utilizing the H-W and GARCH models, the finding demonstrates that vegetation orientation and monitoring seasonality can be predicted using NDVI.
... Furthermore, in general, managing forest stand structure towards denser canopies can provide refuge from the UHI effect for both citizens and urban flora and fauna. Secondly, we advocate the conservation of cool forest microclimates in forest interior areas of urban forests, especially since urban populations are expected to continue to grow (Jiang & O'Neill, 2017) and lead to further fragmentation of urban green (Dobbs et al., 2017;Kowe et al., 2021). In this way, the high proportional presence of forest edges due to fragmentation is complemented with cooler forest interior habitat, which also conserves the heterogeneity of forest habitats present within the urban forest network important to support many functional types of forest plant species. ...
Questions
Forests are highly fragmented across the globe. For urban forests in particular, fragmentation increases the exposure to local warming caused by the urban heat island (UHI) effect. We here aim to quantify edge effects on herbaceous understorey vegetation in urban forests, and test whether these effects interact with forest structural complexity.
Location
We set up a pan‐European study at the continental scale including six urban forests in Zurich, Paris, Katowice, Brussels, Bremen, and Stockholm.
Methods
We recorded understorey plant communities from the edge towards the interior of urban forests. Within each urban forest, we studied edge‐to‐interior gradients in paired stands with differing forest structural complexity. Community composition was analysed based on species specialism, life form, light, nutrient, acidity and disturbance indicator values and species' thermal niches.
Results
We found that herbaceous communities at urban forest edges supported more generalists and forbs but fewer ferns than in forests' interiors. A buffered summer microclimate proved crucial for the presence of fern species. The edge communities contained more thermophilous, disturbance‐tolerant, nutrient‐demanding and basiphilous plant species, a pattern strongly confirmed by corresponding edge‐to‐interior gradients in microclimate, soil and light conditions in the understorey. Additionally, plots with a lower canopy cover and higher light availability supported higher numbers of both generalists and forest specialists. Even though no significant interactions were found between the edge distance and forest structural complexity, opposing additive effects indicated that a dense canopy can be used to buffer negative edge effects.
Conclusion
The urban environment poses a multifaceted filter on understorey plant communities which contributes to significant differences in community composition between urban forest edges and interiors. For urban biodiversity conservation and the buffering of edge effects, it will be key to maintain dense canopies near urban forest edges.
... Urbanization, rapid expansion, and development of urban areas are responsible for environmental, evolutionary, and behavioral change. 1,2 By creating barriers that isolate species populations of living organisms, the urban environment contributes to habitat loss and fragmentation, 3,4 negatively influencing gene flow. 5 Specific environmental conditions in cities (e.g., higher temperatures, elevated air, noise, and light pollution) further contribute to a decrease in the diversity and abundance of native plants 6 and animals. ...
Urbanization alters the natural environment, with broad negative impacts on living organisms. Urbanization can also disrupt plant-pollinator networks by reducing the abundance and diversity of invertebrates. Firstly, I investigated whether the field bindweed (Convolvulus arvensis) is an obligatory entomophilous plant because previous reports were ambiguous. Secondly, I investigated how the obligatory entomophilous plant, field bindweed, responds to urbanization by comparing the flowering duration (anthesis) and the reproductive success of field bindweeds in urban and rural populations. Unlike cross-pollinated flowers and controls, flowers experimentally prevented from pollination and self-pollinated flowers did not produce seeds, suggesting that the field bindweed is self-incompatible and obligatory entomophilous. The abundance of urban pollinators was 5–6 times lower than the abundance of rural pollinators, and flies (Diptera), beetles (Coleoptera) and moths (Lepidoptera) were significantly more negatively influenced by the urban environment than hymenopterans (Hymenoptera). Urban plants showed significantly longer anthesis duration and lower reproductive success than rural plants. Illuminance and low pollinator abundance were negatively associated with the duration of the anthesis, but relative humidity did not affect the anthesis. Prolonged duration of the anthesis may be an adaptation to pollinator scarcity because more prolonged flowering increases the likelihood of pollination. Future research should unravel whether the longer anthesis of urban flowers is determined by behavioral plasticity or by the evolutionary selection of plants with a genetically determined longer anthesis.
... Most research on urban vegetation focuses on public spaces and the benefits they provide both to the health of people and biodiversity in cities (Chiesura 2004;Boone et al. 2009;Dobbs et al. 2017). Studies addressing private gardens (Loram et al. 2008;González-García and Sal 2008;Peroni et al. 2016) are underrepresented in the research of urban ecology, although in many growing cities the area they occupy, and their biodiversity may be larger than those of other green areas (Thompson et al. 2003;Gaston et al. 2013). ...
Human population is becoming increasingly urbanized, and in this context, private gardens (home gardens) constitute an important component of urban biodiversity and provide access to ecosystem services. This study aims at identifying spatial patterns to understand the socio-ecological processes that influence the urban landscape.
In our study, we analyze private gardens in one of the main urban agglomerations of Argentina to understand whether socio-economic structure or spatial distribution is more strongly influencing the species composition of private gardens.
We selected 50 gardens from the urban area of Gran San Miguel de Tucumán. We surveyed the sociodemographic characteristics of garden owners and we performed vegetation censuses in each of the gardens. In the survey, we also evaluated the main mechanisms of plant acquisition. We used the species composition of each garden to perform a non-metric multidimensional scaling, which reflected the botanical distance between gardens. We used Mantel tests to correlate these botanical distances with the geographic and socio-economic distances between gardens to determine which variable controls the ecological attributes of the garden. To spatially characterize the socio-economic level, we used data from the national population census.
The species composition of the gardens is more strongly associated with socioeconomic conditions than with geographical distance. The exchange of species is the main method of obtaining plants.
Our study permits understanding how socio-economic structure influences the construction of private gardens, which are important components of the landscape and urban ecology. Our results could be explained by the willingness to belong to certain socio-economic groups but also by the interchange of propagules, which may reinforce social ties. Our results highlight the importance of addressing social issues to understand private decisions and design strategies toward a fair distribution of urban vegetation services.
... In the 21st century, global urbanisation, the concentration of populations in urban areas in the world, has largely altered ecological environments of life. The expansion of man-made surfaces in urban and peri-urban areas has resulted in habitat loss and fragmentation for organisms living in natural and semi-natural ecosystems (Dobbs et al., 2017;Pauleit et al., 2005). Additionally, it has caused environmental degradation in the remaining habitats (Pickett et al., 2001;Sukopp 2004;Grimm et al., 2008). ...
Urbanisation has largely altered city landscapes, resulting in habitat loss, fragmentation, and environmental degradation. City plants often have adapting traits and ecologies to such urban habitat environments. The existing literature on urban adaptation has often focused on species that shrink the abundances in urban areas compared to rural areas. Meanwhile, the studies on species that expand their range in cities remain limited, although they would exhibit different trait responses to urban environments, particularly in dispersal-related traits.
In this study, we compared seed dispersal-related traits between Youngia japonica subsp. japonica (Y.j. japonica) , which is expanding its range in urban areas and its closely-relative Y.j. elstonii , which is contracting its range in urban areas along an urban-rural gradient of the Osaka-Kobe megacity area. We also examined relationships between seed traits and terminal velocity which influences seed dispersal ability.
We found that achene length increased with the degree of urbanisation only in Y.j. japonica , while pappus length decreased only in Y.j. elstonii . The terminal velocity had a significant relationship only with pappus length in Y. japonic a.
Seed traits of two subspecies with different urban distributions showed different responses to urbanisation. Our results suggest that species expanding their distribution in urban areas has increased seed competitiveness while maintaining dispersal ability. In contrast, species that has shrunk in urban areas likely showed a passive response to urban fragmentation, indicating a loss of seed dispersal ability.
... An expansion in area of the built-up class has been observed in previous studies within the study area and has been mostly attributed to fast population growth [28]. Similar to other studies, we found that population size had a significant negative effect on urban green space [15,21]. The effect of population density on green space decline is higher for Africa and other low-income countries compared to Europe [15,87]. ...
Green spaces such as forests, grasslands, and croplands (including gardens) can be found in urban environments.
Although they benefit human and animal well-being, they have become threatened due to rapid urban growth
and unplanned development. Yet, little attention has been given to studying the dynamics of urban green spaces
in sub-Saharan Africa. In this study, we examined the dynamics of land use and land cover (LULC) change and
fragmentation (especially, green spaces) within the second fastest urbanising city in Ghana, Tamale. In particular,
we focused our analyses on its urban core (~5 km radius around the city centre) due to its relevance to
urban economy and society. Landsat data was used to estimate fragmentation metrics of past and future LULC
changes in the study area from 1990 to 2052. We found clear patterns of green space decline and fragmentation
within the urban core: i.e., green spaces became patchy over time and the pattern was expected to continue in the
future. Additionally, we found the built-up class benefited from the decline of green spaces with the latter being
significantly negatively correlated with human population size. Our investigation reveals that protected forests
and tree plantations contributed to a significant proportion of available green spaces in the urban core. However,
these areas were becoming increasingly threatened by forest reserve downsizing, indiscriminate activities (e.g.,
logging and encroachment), and sale of public lands to private developers, practices commonly associated with
population growth. Hence, the enforcement of relevant local legislations (e.g., the 2016 Land Use and Spatial
Planning Act [Act 925]) coupled with the integration of urban initiatives and policies that encourage green
spaces are needed to ensure the sustainability of urban ecosystems for the well-being of humans and the
environment.
... Landscape metrics analysis enables the quantification and analysis of the spatial configuration capacity of landscapes. Considering the redundancy among the metrics and their impact on urban forest planning, we selected several indicators that affect CS (Dobbs et al., 2017), namely Patch Density (PD), Aggregation Index (AI), and Connectivity (CONNECT). We utilized these indices to reflect the degree of urban forest fragmentation and changes in patch shape caused by the urbanization process (Qian et al., 2015). ...
... There is broad evidence that human-constructed barriers and environmental change often increase population fragmentation in terrestrial and aquatic taxa (Templeton et al. 2001;Fuller et al. 2015;Dobbs et al. 2017;Johnson and Munshi-South 2017;Littleford-Colquhoun et al. 2017;Langerhans and Kern 2020). For example, common drivers of fragmentation involve roads, agricultural fields, power line easements, dams, and cities (Trombulak and Frissell 2000). ...
Anthropogenic impacts on the environment alter speciation processes by affecting both geographical contexts and selection patterns on a worldwide scale. Here we review evidence of these effects. We find that human activities often generate spatial isolation between populations and thereby promote genetic divergence but also frequently cause sudden secondary contact and hybridization between diverging lineages. Human-caused environmental changes produce new ecological niches, altering selection in diverse ways that can drive diversification; but changes also often remove niches and cause extirpations. Human impacts that alter selection regimes are widespread and strong in magnitude, ranging from local changes in biotic and abiotic conditions to direct harvesting to global climate change. Altered selection, and evolutionary responses to it, impacts early-stage divergence of lineages, but does not necessarily lead toward speciation and persistence of separate species. Altogether, humans both promote and hinder speciation, although new species would form very slowly relative to anthropogenic hybridization, which can be nearly instantaneous. Speculating about the future of speciation,we highlight two key conclusions: (1) Humans will have a large influence on extinction and “despeciation” dynamics in the short term and on early-stage lineage divergence, and thus potentially speciation in the longer term, and (2) long-term monitoring combined with easily dated anthropogenic changes will improve our understanding of the processes of speciation. We can use this knowledge to preserve and restore ecosystems inways that promote (re-)diversification, increasing future opportunities of
speciation and enhancing biodiversity.
... However, the impact of urban vegetation on each of these factors depends on the amount and location of the vegetation. Often, clusters of urban vegetation are found in relation to development, changes in land use, and zoning policies (Dobbs et al., 2017;Mincey et al., 2013;Richards and Thompson, 2019), which may also correspond to differences in the composition, and by extension the health, of the population in those areas (Azzopardi-Muscat et al., 2020). In the Anglo-American context, increased development, typically around the peri-urban areas, is at odds with vegetation cover (Lowry et al., 2012;Ossola and Hopton, 2018). ...
A comprehensive evaluation of the long-term urban vegetation dynamics and its responses to land-cover changes and biogeochemical drivers (e.g., CO 2 concentration increase and nitrogen deposition) at the urban agglomeration scale is pivotal for better understanding of transformations in complex urban environments. In this study, we explored the vegetation change trends identified by the Landsat enhanced vegetation index (EVI) along the urban-rural gradient in 55 cities of the Guanzhong Plain urban agglomeration (GPUA) from 2000 to 2020. Additionally, we investigated the contribution of biogeochemical driving factors and land cover changes. The results showed that the EVI change trends from 2000 to 2020 exhibited a V-shaped pattern along with the urban-rural gradient, that is, EVI increased for urban cores (UC) and urban new towns (UNT), decreased for the urban fringes (UF), and increased again for rural fringes (RF) and rural backgrounds (RB). EVI changes in the city subzones (UC, UNT, and UF) showed an increasing trend with city size. The EVI change trends are influenced by urban biogeochemical drivers (UBD), background biogeochemical drivers (BBD), urban expansion or densification (UED), and urban green recovery (UGR). The significant increase in EVI in UC and UNT is mainly attributed to UBD (51.9% and 37.2%) and BBD (27.3% and 30.7%), respectively. The EVI change trend in UF is positively contributed by both BBD (29.2%) and UBD (15.8%) and weakened by UED (-51.9%). The EVI increase is dominated by UBD and BBD in UC and UNT, and decrease is dominated by UED in UF. These results help assess the impact of complex environmental changes on vegetation in urban agglomeration areas.
Urbanization profoundly impacts biological communities, influencing species composition, ecosystem functions and genetic diversity. Using data on bird functional traits and phylogenetic relatedness, this study examined the taxonomic, phylogenetic, and functional β-diversity of 143 bird communities along an urbanization gradient in the Taipei metropolitan area, and explored the impact of green, blue, grey spaces, and landscape heterogeneity on these β-diversity. We employed pairwise Sørensen dissimilarity to measure total β-diversity and partitioned it into turnover and nestedness components. Partial Mantel test was conducted to explore correlations among the three facets of β-diversity, while generalized dissimilarity modeling assessed the effects of land cover types, landscape heterogeneity, and spatial distance on β-diversity patterns. Our findings indicated that turnover was the predominant component of taxonomic and phylogenetic β-diversity, whereas nestedness primarily characterized functional β-diversity. There were strong correlations between taxonomic and phylogenetic β-diversity, suggesting that the assembly of bird communities in urbanized environments was driven more by phylogenetic than functional structures. Spatial distance was identified as the most influential variable affecting all three β-diversities and their turnovers. Landscape heterogeneity significantly influenced taxonomic and phylogenetic β-diversity, while grey space notably impacted phylogenetic and functional β-diversity as well as three turnovers. A distinct pattern of high taxonomic turnover alongside low phylogenetic and functional turnover was observed, indicating that species closely related and functionally similar were replacing some of those less adapted to highly urbanized environments. Our study concluded that grey spaces play a critical role influencing all facets of turnovers in the region. Preserving less urbanized areas is key to preventing loss of less urban adapted species, maintaining all facets of β-diversity, and enhancing urban ecosystem resilience and sustainability. Such conservation efforts protect diverse bird communities and uphold the ecological integrity vital for sustainable urban development.
The spatial distribution of vegetation across metropolitan areas is important for wildlife habitat, air quality, heat mitigation, recreation, and other ecosystem services. This study investigated relationships between vegetation patterns and parcel characteristics at multiple scales of the Austin Metropolitan Statistical Area (MSA), a rapidly growing region in central Texas characterized by diverse biophysical and socioeconomic landscapes. We used LiDAR data to map vegetation types and distributions across a 6000 km2 study area. Principal component analysis (PCA) and regression models were employed to explore tree, shrub, and grass cover across parcels, cities, and the MSA, considering home value, age, size, and distance to the city center. At the MSA scale, tree and shrub cover were higher in the Edwards Plateau than in the Blackland Prairie ecoregion. Tree cover increased with parcel size and home value, especially in suburban areas. Older parcels had more mature trees, though less so in the grass-dominated Blackland Prairie. Shrub cover was higher on larger parcels in the Edwards Plateau, while the Blackland Prairie showed the opposite trend. PCA explained 60% of the variance, highlighting links between vegetation and urban development. Our findings reveal how biophysical and socioeconomic factors interact to shape vegetation, offering considerations for land use, housing, and green infrastructure planning.
Urbanization is a key contributor to biodiversity loss; however, cities are increasingly recognized as potential conservation sites. Urban conservation often focuses on vegetation management, management that requires understanding of the habitat relationships of urban species. Habitat relationships for species with important ecological roles may be particularly useful in planning such management. Northern short-tailed shrews (Blarina brevicauda), as both predators and prey, represent such species, but are understudied in urban settings. We investigated relationships between urban vegetation and Northern short-tailed shrew occupancy using data from live-trapping surveys of small mammals and field surveys of vegetation. We used these datasets to fit single-species, multi-season occupancy models. We found that occupancy rates increased with increasing understory cover and decreased with increasing turfgrass and tree-canopy cover, the latter potentially due to limitations imposed on understory development by low light in high canopy environments. Our study is the first study of urban Northern short-tailed shrew across a broad gradient of urbanization and suggests that urban vegetation management that maintains understory cover and reduces turfgrass could support this species and, in turn, its community in cities.
Nature-based solutions are informed by how communities think about nature. However, research on how urban communities think about urban nature is seldom carried out across urban contexts. In doing so it can be useful to select specific aspects of urban nature, such as urban forests and urban trees. Our study responds to these needs by measuring the cognitive constructs of values, beliefs, and attitudes towards urban forests and modelling their relationships using a representative survey of >3400 residents living across two different urban contexts: Toronto, Canada, and Melbourne, Australia. Means difference, generalized linear regression, and structural equation analyses, were used to test how values, beliefs, and attitudes differed between metropolitan areas, and how they related to other cognitive constructs, social-ecological context, and demographic factors. We found that resident values and beliefs (more abstract and general constructs) about urban trees were similar across metropolitan areas, but some attitudes (more specific and variable constructs) were different between metropolitan areas, including residents' level of trust in how municipalities manage urban forests and their level of satisfaction with trees and their management. Female residents, and residents who had higher levels of nature relatedness and subjective wellbeing, valued urban forests more. Values, beliefs, and knowledge of trees were significant drivers of resident satisfaction with trees and their management. We discuss implications for urban nature policies.
The vital role of urban trees in mitigating surface runoff issues through the Runoff Reduction Ecosystem Service (RRES) is increasingly threatened by extensive modifications to the urban landscape. To ensure the sustainability of RRES, it is crucial to understand how landscape configuration affects it. This study aims to empirically analyze this relationship and determine which aspects of the urban landscape configuration impact RRES the most. The study applied the i-Tree Eco to quantify RRES. Landscape configuration was calculated using eleven metrics by FRAGSTATS. The impact of various aspects of landscape configuration on RRES was assessed by developing models based on stepwise regression analysis, which were then categorized based on their strength of influence. The results showed that urban trees in Tabriz, a study area in Iran, annually reduced runoff by 196.85 × 103 m3. The regression models underscored the significance of the normalized landscape shape index, the aggregation index, the effective mesh size, and the clumpiness index as the main drivers of RRES (0.962 ≤ r2 ≤ 0.978). Landscape division, patch density, patch cohesion, interspersion, and juxtaposition indexes had moderate impacts (0.733 ≤ r2 ≤ 0.879). In contrast, factors such as the percentage of similar adjacencies, the splitting index, and the number of patches had relatively lower impacts (0.569 ≤ r2 ≤ 0.667). These findings have practical implications for urban planners, emphasizing the importance of arranging patches in aggregated and contiguous patterns to improve RRES provision. Ultimately, this study provides valuable information for effective urban landscape management, ensuring a sustained supply of RRES.
Our aim is to contribute to understanding the role of subtropical trees on carbon storage and CO2 removal in the city of Sao Paulo/Brazil, besides highlighting the surrounding environment implications to sibipiruna trees (Cenostigma pluviosum)’s performance. The case study was conducted with three trees, one planted on a sidewalk in Pinheiros neighborhood, a highly sealed area, and two in a green area, the Ibirapuera Park. To define the stem basal area growth and its pattern, local measurements were taken over a year and a segmented linear regression model was adjusted. The stem growth dependency on microclimate was tested by a Spearman Correlation. The trees’ active stem growth presented a similar pattern. The soil volumetric water content and soil temperatures were the variables with more impact. The total mean radial stem growth for the IBIRA1 and IBIRA2 trees was 1.2 mm year⁻¹ and 3 mm year⁻¹, while at PIN1 it was 1.3 mm year⁻¹. The total biomass increment in IBIRA1 and IBIRA2 was 4.2 kg C year⁻¹ and 12.8 kg C year⁻¹, while in PIN it was 4.9 kg C year⁻¹ and the removal was 15.3 C year⁻¹, 47.1 kg CO2 year⁻¹ and 17.9 kg CO2 year⁻¹, respectively. The results indicated that the land cover difference implies a significant interference with the promotion of carbon fixation and CO2 removal, demonstrating that planting urban trees in soils with better water storage conditions is more efficient.
Increasing land use and land cover change and climate change have considerable impacts on urban green spaces and their ecosystem services. These impacts result in a loss of urban green space and particularly weaken the climate resilience of urban populations. Landsat imagery data from 1990 to 2020 were used to track the spatio-temporal dynamics of urban sprawl and its influence on the loss of urban green space in Bamako and Sikasso in Mali. Furthermore, a survey of local stakeholders was conducted to capture the perceptions of the status of urban green space. The results of the land use/land cover analysis of the cities between 1990 and 2020 showed that most of the vegetation classes, mainly urban green spaces, have been converted into built-up and bare land in both cities during the last 30 years. In Bamako, built-up land has risen from 5421 hectares in 1990 to 13,350 hectares in 2020, and in Sikasso, from 929 hectares in 1990 to 2213 hectares in 2020. Respondents mentioned street trees as the prevalent type of urban green spaces in both cities (20% of the respondents in Bamako and 24% in Sikasso). In addition, the majority of respondents perceived urban green spaces in Sikasso as having a good status and in Bamako as having a good or moderate status. This study recommends improving the number and quality of urban green spaces, which are crucial for the provision of ecosystem services and for the resilience of cities against climate change.
Cities are increasingly recognizing the benefits of incorporating urban greening strategies into their planning and design to improve sustainability and livability. However, the specific contribution of tree versus nontree vegetation has not been adequately studied in the context of urban greening and rapid urbanization. In this study, we investigated the spatiotemporal variations of urban tree and nontree coverage in China during 2000-2020 by using satellite observations. Results show the nationwide mean urban tree coverage increased by 0.073 ± 0.511% per year (mean ± 1 standard deviation), while nontree vegetation coverage decreased by 0.584 ± 1.022% per year. We found that the majority of mega-and large cities had a contrasting vegetation pattern, with significantly ascending trends in both tree and nontree coverages in urban core areas but descending trends in peri-urban areas. These trends were positively associated with multiple greenness indices, suggesting the importance of the vegetation structure for growth and productivity in urban areas. This study highlights the predominance of enhancing vegetation growth in urban areas primarily driven by significantly increasing tree cover in China, and can further serve as a reference for global vegetation study. npj Urban Sustainability (2023) 3:33 ; https://doi.
The development of urbanization and the protection of the ecological environment are important aspects of sustainable development in city clusters, and their coordination and synergy are crucial to achieve this. Regarding the relationship between urbanization and the ecological environment, scholars both in China and internationally have conducted extensive research from the perspective of coordinated development. However, there is a lack of research on the synergistic effects of urbanization and the ecological environment. Taking the Chengdu-Chongqing city cluster as an example, this study uses the Haken model to analyze the synergistic evolution mechanism, development patterns, and future trends of urbanization and the ecological environment. This study draws the following conclusions: (1) while a synergistic development mechanism has been established between urbanization and the ecological environment, the current system is still in a stage of low-level synergy, and the control system’s parameter for the direction and path of evolution is urbanization. (2) From 2001 to 2020, the level of synergistic development between urbanization and the ecological environment was relatively low, mainly moving from low-level synergy to medium-low-level synergy to medium-level synergy. (3) There is a significant spatial disparity in the levels of synergistic development, for which the leading region centers on Chengdu and Chongqing in the northwest and southeast, respectively, and the lagging region comprises the eastern part of the city cluster, mainly represented by Dazhou, Kaizhou, and Yunyang. (4) The future trend of synergistic development between urbanization and the ecological environment in the Chengdu-Chongqing city cluster is promising but requires increased infrastructure construction in mountainous urban areas, enhanced cooperation and circulation in transportation, logistics, information and other aspects, and balanced improvements in the level of synergistic development between urbanization and the ecological environment. The study of the synergistic development effect of urbanization and the ecological environment in city clusters is of great significance for reducing the negative impact of urbanization on the ecological environment, increasing the positive interaction between the two, and promoting sustainable development in city clusters.
Context
With rapidly expanding urban regions, the effects of land cover changes on urban surface temperatures and the consequences of these changes for human health are becoming progressively larger problems.
Objectives
We investigated residential parcel and neighborhood scale variations in urban land surface temperature, land cover, and residents’ perceptions of landscapes and heat illnesses in the subtropical desert city of Phoenix, AZ USA.
Methods
We conducted an airborne imaging campaign that acquired high resolution urban land surface temperature data (7 m/pixel) during the day and night. We performed a geographic overlay of these data with high resolution land cover maps, parcel boundaries, neighborhood boundaries, and a household survey.
Results
Land cover composition, including percentages of vegetated, building, and road areas, and values for NDVI, and albedo, was correlated with residential parcel surface temperatures and the effects differed between day and night. Vegetation was more effective at cooling hotter neighborhoods. We found consistencies between heat risk factors in neighborhood environments and residents’ perceptions of these factors. Symptoms of heat-related illness were correlated with parcel scale surface temperature patterns during the daytime but no corresponding relationship was observed with nighttime surface temperatures.
Conclusions
Residents’ experiences of heat vulnerability were related to the daytime land surface thermal environment, which is influenced by micro-scale variation in land cover composition. These results provide a first look at parcel-scale causes and consequences of urban surface temperature variation and provide a critically needed perspective on heat vulnerability assessment studies conducted at much coarser scales.
Urban ecosystems evolve over time and space as the outcome of dynamic interactions between socio-economic and biophysical processes operating over multiple scales. The ecological resilience of urban ecosystems---the degree to which they tolerate alteration before reorganizing around a new set of structures and processes---is influenced by these interactions. In cities and urbanizing areas fragmentation of natural habitats, simplification and homogenization of species composition, disruption of hydrological systems, and alteration of energy flow and nutrient cycling reduce cross-scale resilience, leaving systems increasingly vulnerable to shifts in system control and structure. Because varied urban development patterns affect the amount and interspersion of built and natural land cover, as well as the human demands on ecosystems differently, we argue that alternative urban patterns (i.e., urban form, land use distribution, and connectivity) generate varied effects on ecosystem dynamics and their ecological resilience. We build on urban economics, landscape ecology, population dynamics, and complex system science to propose a conceptual model and a set of hypotheses that explicitly link urban pattern to human and ecosystem functions in urban ecosystems. Drawing on preliminary results from an empirical study of the relationships between urban pattern and bird and aquatic macroinvertebrate diversity in the Puget Sound region, we propose that resilience in urban ecosystems is a function of the patterns of human activities and natural habitats that control and are controlled by both socio-economic and biophysical processes operating at various scales. We discuss the implications of this conceptual model for urban planning and design.
Our world is increasingly urbanizing which is highlighting that sustainable cities are essential for maintaining human wellbeing. This research is one of the first attempts to globally synthesize the effects of urbanization on ecosystem services and how these relate to governance, social development and climate. Three urban vegetation ecosystem services (carbon storage, recreation potential and habitat potential) were quantified for a selection of a hundred cities. Estimates of ecosystem services were obtained from the analysis of satellite imagery and the use of well-known carbon and structural habitat models. We found relationships between ecosystem services, social development, climate and governance, however these varied according to the service studied. Recreation potential was positively related to democracy and negatively related to population. Carbon storage was weakly related to temperature and democracy, while habitat potential was negatively related to democracy. We found that cities under 1 million inhabitants tended to have higher levels of recreation potential than larger cities and that democratic countries have higher recreation potential, especially if located in a continental climate. Carbon storage was higher in full democracies, especially in a continental climate, while habitat potential tended to be higher in authoritarian and hybrid regimes. Similar to other regional or city studies we found that the combination of environment conditions, socioeconomics, demographics and politics determines the provision of ecosystem services. Results from this study showed the existence of environmental injustice in the developing world.
Residents of the largest metropolitan areas in the continental United States were surveyed about the benefits and problems of trees in urban areas. The public rated the social, environmental, and practical benefits of trees highly. The ability of trees to shade and cool surroundings was the highest-ranked benefit. Their potential to help people feel calmer was ranked second highest. Potential problems with trees were not considered to be reasons not to use trees. Practical problems, such as causing allergies, were bigger concerns than were financial issues. People who strongly agreed that trees were important to their quality of life rated the benefits of trees more highly than people who did not strongly agree. Those who strongly agreed and those who did not strongly agree ranked the benefits and problems similarly. Responses varied slightly based on demographic factors. For example, those who did not strongly agree that trees were important to life quality were more likely than expected to be 18 to 21 years old or to earn US$20,000 or less per year. The general public in urban areas, not just people who volunteer for tree programs, felt very positively toward trees in cities.
Sustainable Development and Sustainability: Landscape Approach as a Practical Interpretation of Principles and Implementation Concepts
The situation for governors and managers of natural resources has increased in complexity. Previously it was enough to sustain the yields of wood, food and energy. Today, maintenance of ecosystem services, conservation of biodiversity, rural development and human wellbeing are new additional objectives. At the same time there are new risks and uncertainties linked to climate change, economic globalisation, energy security and water supply. Consequently, adaptive and holistic research, governance and management are needed. Landscape is a concept and framework that can be used as an approach to enhance implementation of policies about sustainable development as a societal process and sustainability as outcomes on the ground. For our analysis to define the landscape approach we used a hierarchical framework consisting of principles, concepts and initiatives; and included three principles defining SD and sustainability and five international concepts to analyze its implementation for our analysis to define landscape approach. We propose a practical operationalization that consists of five core attributes, (1) a sufficiently large area that matches management requirements and challenges to deliver desired goods, services and values, (2) multi-level and multi-sector stakeholder collaboration that promotes sustainable development as a social process, (3) commitment to and understanding of sustainability as an aim among stakeholders, (4) integrative knowledge production, and (5) sharing of experience, results and information, to develop local or tacit to general or explicit knowledge. Finally, we discuss the need for integrative research to study landscape approach concepts and what local initiatives using different concepts deliver on the ground.
Landscape change is an ongoing process even within established urban landscapes. Yet, analyses of fragmentation and deforestation have focused primarily on the conversion of non-urban to urban landscapes in rural landscapes and ignored urban landscapes. To determine the ecological effects of continued urbanization in urban landscapes, tree-covered patches were mapped in the Gwynns Falls watershed (17158.6 ha) in Maryland for 1994 and 1999 to document fragmentation, deforestation, and reforestation. The watershed was divided into lower (urban core), middle (older suburbs), and upper (recent suburbs) subsections. Over the entire watershed a net of 264.5 of 4855.5 ha of tree-covered patches were converted to urban land use—125 new tree-covered patches were added through fragmentation, 4 were added through reforestation, 43 were lost through deforestation, and 7 were combined with an adjacent patch. In addition, 180 patches were reduced in size. In the urban core, deforestation continued with conversion to commercial land use. Because of the lack of vegetation, commercial land uses are problematic for both species conservation and derived ecosystem benefits. In the lower subsection, shape complexity increased for tree-covered patches less than 10 ha. Changes in shape resulted from canopy expansion, planted materials, and reforestation of vacant sites. In the middle and upper subsections, the shape index value for tree-covered patches decreased, indicating simplification. Density analyses of the subsections showed no change with respect to patch densities but pointed out the importance of small patches (≤5 ha) as “stepping stone” to link large patches (e.g., >100 ha). Using an urban forest effect model, we estimated, for the entire watershed, total carbon loss and pollution removal, from 1994 to 1999, to be 14,235,889.2 kg and 13,011.4 kg, respectively due to urban land-use conversions.
While we know that urban vegetation is often distributed unequally, most studies have been undertaken in cities with relatively high levels of income inequality, using a single measure of distribution (usually tree cover) and in a single land use. This study explores predictors of both tree cover and species richness in gardens, streetscapes and parks in Ballarat, Australia. Spatial regression models found that education level was a more important predictor of tree cover than household income across all land uses in Ballarat which can be explained by some people with high incomes relative to education level choosing to live in new residential developments with disproportionately low levels of tree cover. Inequality in tree cover was greater in streetscapes than in residential gardens, suggesting that ‘top down’ political factors are more important than individual behaviours in determining tree cover in Ballarat. In contrast, physical rather than socioeconomic factors were better predictors of species richness across all land uses, highlighting that different measures of vegetation distribution are not necessarily correlated.
Urban environmental segregation (UES) would differentiate between the environment of poor people and the environment of rich people. We apply selected indicators for the urban environment, especially indicators of urban patterns and of urban environmental quality. These indicators will illuminate the social distribution of environmental quality and the socio-spatial exposure toward urban flooding. The comprehensive approach for the UES assessment is first, to analyze if land-use dynamics expands into areas with high environmental impact, second, to explore where and how social segregation is expressed in the study area, and third, to analyze different indicators for the urban environment. Therefore the key parameters for urban dynamics and UES are the built-up area, degrees of imperviousness, green spaces (indicators of urban patterns), environmental exposure and mitigations measures (indicators of environmental quality). They are linked to the indices of social segregation, i.e. isolation and concentration. The presented approach offers a new dimension in research of social segregation by adding the above mentioned aspects of the urban environment and so gaining a new assessment of UES.
Because we have entered the 'millennium of the cities', urban ecological research needs to account for the provisions ecosystem services provide to urban regions. In urban areas, ecosystem service assessment studies need to account for the complex land use patterns, which change over relatively short periods of time. We discuss an analytical framework for the spatial and temporal integration of different ecosystem services in an urban region to determine synergies, trade-offs and losses, and we employ a case study in Leipzig-Halle, Germany. The following five ecosystem services, which are of special importance for urban areas, were selected: local climate regulation, recreation potential, biodiversity potential, food supply, and above-ground carbon storage. These services were analyzed from 1990 to 2006. Our results identified only slight increases in urbanization (1% or 3 km(2)) and in mining restoration (-11 km(2)). However, the detected land use changes led to synergies with biodiversity and climate regulation of > 50% of the total area, whereas trade-offs of approximately 60% were detected between variables such as climate regulation and recreation. Finally, we address both the opportunities and the challenges that were encountered in the integration study, specifically with respect to the application in land use planning.
Remotely sensed imagery is ideally used to monitor and detect land cover changes that occur frequently in urban and peri-urban areas as a consequence of incessant urbanization. It is a lengthy process to convert satellite imagery into land cover map using the existing methods of manual interpretation and parametric image classification digitally. In this paper we propose a new method based on Normalized Difference Built-up Index (NDBI) to automate the process of mapping built-up areas. It takes advantage of the unique spectral response of built-up areas and other land covers. Built-up areas are effectively mapped through arithmetic manipulation of re-coded Normalized Difference Vegetation Index (NDVI) and NDBI images derived from TM imagery. The devised NDBI method was applied to map urban land in the city of Nanjing, eastern China. The mapped results at an accuracy of 92.6% indicate that it can be used to fulfil the mapping objective reliably. Compared with the maximum likelihood classification method, the proposed NDBI is able to serve as a worthwhile alternative for quickly and objectively mapping built-up areas.
Reducing atmospheric carbon emissions from tropical deforestation is at present considered a cost-effective option for mitigating climate change. However, the forces associated with tropical forest loss are uncertain. Here we use satellite-based estimates of forest loss for 2000 to 2005 (ref. 2) to assess economic, agricultural and demographic correlates across 41 countries in the humid tropics. Two methods of analysis-linear regression and regression tree-show that forest loss is positively correlated with urban population growth and exports of agricultural products for this time period. Rural population growth is not associated with forest loss, indicating the importance of urban-based and international demands for agricultural products as drivers of deforestation. The strong trend in movement of people to cities in the tropics is, counter-intuitively, likely to be associated with greater pressures for clearing tropical forests. We therefore suggest that policies to reduce deforestation among local, rural populations will not address the main cause of deforestation in the future. Rather, efforts need to focus on reducing deforestation for industrial-scale, export-oriented agricultural production, concomitant with efforts to increase yields in non-forested lands to satisfy demands for agricultural products. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Abstract Text Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints
By 2050, 70% of the Earth’s human population will live in urban areas. Urbanization can have a devastating impact on local
ecosystems, but these impacts vary across time and space. Identifying links between spatiotemporal change in urban ecosystems
and neighborhood socio-economics is crucial to management aimed at maintaining flora and fauna in urban areas. Here, we tracked
20 years of socio-economic change and 15 years of vegetation change in 32 residential neighborhoods in south-eastern Australia.
Regression models that explicitly accounted for a time lag between neighborhood socio-economic characteristics and vegetation
response explained more variation in vegetation cover than models that ignored the effects of time. Also, relationships between
vegetation and socio-economic factors were stronger in later years for the same neighborhoods suggesting the influence of
socio-economics is more readily identified in established neighborhoods. Socio-economic variables alone, or in combination
with biophysical variables, were better predictors of vegetation cover than only biophysical variables. Across space, vegetation
cover had a negative quadratic relationship with neighborhood housing density, peaking at mid-density values, and a positive
relationship with education level and immigration status (the percentage of residents with a non-Australian background). Over
time, housing density had a positive relationship with vegetation cover, reflecting an increase in vegetation as neighborhoods
develop. Our results highlight the need to understand temporal context when attempting to explain contemporary patterns in
vegetation cover and the increasing importance of socio-economic factors in influencing cover as neighborhoods become established.
The year 2007 was the first year in which more than half of humanity lived in cities. Over the next 25 years, the world will see the addition of nearly one million km2 of urban area, occurring in tens of thousands of cities around the globe. The form these new neighborhoods take will affect our planet's ecology profoundly. Here, I highlight the connection between urban form and ecosystem service generation and consumption. I also discuss how urban form controls energy use, and hence oil security and climate change. I argue that only by directly addressing the implications of urban growth as a research subject will ecologists meet their responsibility to provide a foundation for a sustainable biosphere, a mandate of the Ecological Society of America.
This article investigates the role of urban political economy, private-public property relations, and race and ethnicity in the social production of Milwaukee's urban forest. By integrating urban-forest canopy-cover data from aerial photography, United States Census data, and qualitative data collected through in-depth interviews, this analysis suggests that there is an inequitable distribution of urban canopy cover within Milwaukee. Since urban trees positively affect quality of life, the spatially inequitable distribution of urban trees in relation to race and ethnicity is yet another instance of urban environmental inequality that deserves greater consideration in light of contemporary and dynamic property relations within capitalist societies.
Planetary stability must be integrated with United Nations targets to
fight poverty and secure human well-being, argue David Griggs and
colleagues.
Urban green space is purported to offset greenhouse-gas (GHG) emissions, remove air and water pollutants, cool local climate, and improve public health. To use these services, municipalities have focused efforts on designing and implementing ecosystem-services-based "green infrastructure" in urban environments. In some cases the environmental benefits of this infrastructure have been well documented, but they are often unclear, unquantified, and/or outweighed by potential costs. Quantifying biogeochemical processes in urban green infrastructure can improve our understanding of urban ecosystem services and disservices (negative or unintended consequences) resulting from designed urban green spaces. Here we propose a framework to integrate biogeochemical processes into designing, implementing, and evaluating the net effectiveness of green infrastructure, and provide examples for GHG mitigation, stormwater runoff mitigation, and improvements in air quality and health.
Policies at multiple levels pronounce the need to encompass both social and ecological systems in governance and management of natural capital in terms of resources and ecosystems. One approach to knowledge production and learning about landscapes as social–ecological systems is to compare multiple case studies consisting of large spaces and places. We first review the landscape concepts’ biophysical, anthropogenic, and intangible dimensions. Second, we exemplify how the different landscape concepts can be used to derive measurable variables for different sustainability indicators. Third, we review gradients in the three dimensions of the term landscape on the European continent, and propose to use them for the stratification of multiple case studies of social–ecological systems. We stress the benefits of the landscape concepts to measure sustainability, and how this can improve collaborative learning about development toward sustainability in social–ecological systems. Finally, analyses of multiple landscapes improve the understanding of context for governance and management.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-012-0368-0) contains supplementary material, which is available to authorized users.
This study aims to give a differentiated picture of urban and suburban development regarding demographic and land-use change as major drivers for urban growth. A set of indicators has been selected to analyze and evaluate the dynamics of these drivers and their implications for environmental conditions and the quality of life. The study is exemplified by the Metropolitan Area of Santiago de Chile (MAS). This metropolis is undergoing rapid urban dynamics, like many other Latin American cities, but shows some idiosyncratic features. The results show demographic growth in suburbia, very densely built-up areas in the urban municipalities with the only growth potential in the suburban landscape, as well as environmental implications of flood-hazard zones and public green spaces relevant for both urban and suburban areas. Furthermore, the indicators assessed show that not all suburban areas underlie the same conditions, nor are they similarly developed.
Human activities are rapidly changing ecosystems, landscapes and ecosystem service provision, yet there remain significant gaps in our understanding of the spatial ecology of ecosystem services. These gaps hinder our ability to manage landscapes effectively for multiple ecosystem services. In particular, we do not fully understand how changes in landscape connectivity affect ecosystem service provision, despite theory suggesting that connectivity is important. Here, we perform a semi-quantitative review of the literature that investigates how landscape connectivity affects the provision of specific ecosystem services. The vast majority of studies, including reviews, models, and field studies, suggest that decreased connectivity will have negative effects on ecosystem service provision. However, only 15 studies provided empirical evidence of these effects. Average effect sizes from these 15 studies suggest negative effects of connectivity loss on pollination and pest regulation. We identify a number of significant gaps in the connectivity-ecosystem services literature, including: a lack of multiple service studies, which precludes identification of trade-offs between services as connectivity changes; few studies that directly measure organism movement and its effects on ecosystem services; and few empirical studies that investigate the importance of abiotic flows on service provision. We propose that future research should aim to understand how different aspects of connectivity affect ecosystem service provision; which services are most influenced by connectivity; and how connectivity influences how humans access and benefit from ecosystem services. Studies that answer these questions will advance our understanding of connectivity-ecosystem service provision relationships and allow for better ecosystem and landscape management and restoration.
Remote sensing images are useful for monitoring the spatial distribution and growth of urban built-up areas because they can provide timely and synoptic views of urban land cover. Although the normalized difference built-up index (NDBI) is useful to map urban built-up areas, it still has some limitations. This study sought to improve the NDBI by using a semiautomatic segmentation approach. The proposed approach had more than 20% higher overall accuracy than the original method when both were implemented simultaneously at the National Olympic Park (NOP), Beijing, China. One reason for the improvement is that the proposed NDBI approach separates urban areas from barren and bare land to some extent. More importantly, the proposed method eliminates the original assumption that a positive NDBI value should indicate built-up areas and a positive normalized difference vegetation index (NDVI) value should indicate vegetation. The new method has improved universality and lower commission error compared with the original method.
The effects of land cover composition on land surface temperature (LST) have been extensively documented. Few studies, however, have examined the effects of land cover configuration. This paper investigates the effects of both the composition and configuration of land cover features on LST in Baltimore, MD, USA, using correlation analyses and multiple linear regressions. Landsat ETM. +. image data were used to estimate LST. The composition and configuration of land cover features were measured by a series of landscape metrics, which were calculated based on a high-resolution land cover map with an overall accuracy of 92.3%. We found that the composition of land cover features is more important in determining LST than their configuration. The land cover feature that most significantly affects the magnitude of LST is the percent cover of buildings. In contrast, percent cover of woody vegetation is the most important factor mitigating UHI effects. However, the configuration of land cover features also matters. Holding composition constant, LST can be significantly increased or decreased by different spatial arrangements of land cover features. These results suggest that the impact of urbanization on UHI can be mitigated not only by balancing the relative amounts of various land cover features, but also by optimizing their spatial configuration. This research expands our scientific understanding of the effects of land cover pattern on UHI by explicitly quantifying the effects of configuration. In addition, it may provide important insights for urban planners and natural resources managers on mitigating the impact of urban development on UHI.
We explore the social dimension that enables adaptive ecosystem-based management. The review concentrates on experiences of adaptive governance of social-ecological systems during periods of abrupt change (crisis) and investigates social sources of renewal and reorganization. Such governance connects individuals, organi-zations, agencies, and institutions at multiple organizational levels. Key persons provide leadership, trust, vision, meaning, and they help transform management organizations toward a learning environment. Adaptive governance systems often self-organize as social networks with teams and actor groups that draw on various knowledge systems and experiences for the development of a common understanding and policies. The emergence of "bridging organizations" seem to lower the costs of collaboration and conflict resolution, and enabling legislation and governmental policies can support self-organization while framing creativity for adaptive comanagement efforts. A re-silient social-ecological system may make use of crisis as an opportunity to transform into a more desired state.
This study examined the dynamics of global urban expansion by defining a new universe of 3,943 cities with population in excess of 100,000 and drawing a stratified global sample of 120 cities from this universe. Population data and satellite images for two time periods⎯a decade apart⎯were obtained and analyzed, and several measures of urban extent and expansion⎯among them the built-up area of cities and the average density of the built-up area⎯were calculated. Data for 90 cities out of the global sample of 120 is presented and analyzed in this report. Weighted averages of the built-up area and the average density, as well as compactness and contiguity measures⎯and their change over time⎯are presented for nine regions, four income groups and four city size groups covering the entire globe. Densities in developing-country cities were found to be some three times higher than densities in cities in industrialized countries, and densities in all regions were found to be decreasing over time. If average densities continue to decline at the annual rate of 1.7%⎯as they have during the past decade⎯the built-up area of developing-country cities will increase from 200,000 km 2 in 2000 to more than 600,000 km 2 by 2030, while their population doubles. Ten econometric models that sought to explain the variation in urban extent and expansion in the universe of cities were constructed, and several hypotheses postulated by neoclassical theories of urban spatial structure were tested. All tests yielded R 2 values in excess of 0.80. The policy implications of the analysis are presented and discussed. The Central message of this study is quite clear: Developing country cities should be making realistic⎯yet minimal⎯plans for urban expansion, designating adequate areas for accommodating the projected expansion, investing wisely in basic trunk infrastructure to serve this expansion, and protecting sensitive land from incursion by new urban development.
Despite growing recognition of the important role of cities in economic, political and environmental systems across the world, comparative, global-scale research on cities is severely limited. This paper examines the similarities and differences in urban form and growth that have occurred across 25 mid-sized cities from different geographical settings and levels of economic development. The results reveal four city types: low-growth cities with modest rates of infi lling; high-growth cities with rapid, fragmented development; expansive-growth cities with extensive dispersion at low population densities; and frantic-growth cities with extraordinary land conversion rates at high population densities. Although all 25 cities are expanding, the results suggest that cities outside the US do not exhibit the dispersed spatial forms characteristic of American urban sprawl.
Private yards provide city residents with access to ecosystem services that can be realized through passive (vegetation availability) and active (time spent in yards: frequency and duration) means. However, urban densification is leading to smaller yards with less vegetation. Here, we examine how urban form and socio-demographic factors affect the potential ecosystem service benefits people can gain via passive (e.g. climate regulation) and active (e.g. recreation) pathways. Two measures of vegetation cover (0.15–2 m, >2 m) are used as a proxy for passive ecosystem service benefits, and two measures of yard use (use frequency, total time spent across a week) are used for active ecosystem service benefits. We use survey and GIS data to measure personal and physical predictors that could influence these variables for 520 residents of detached housing in Brisbane, Australia. We found house age and yard size were positively correlated with vegetation cover, and people with a greater nature relatedness and lower socio-economic disadvantage also had greater vegetation cover. Yard size was an important predictor of yard use, as was nature relatedness, householder age, and presence of children in the home. Vegetation cover showed no relationship, indicating that greater cover alone does not promote ecosystem service delivery through the active use pathway. Together our results show that people who have higher nature relatedness may receive greater benefits from their yards via both passive and active means as they have more vegetation available to them in their yards and they interact with this space more frequently and for longer time periods.
Estimates of air pollution removal by the urban forest have mostly been based on mean values of forest structure variables for an entire city. However, the urban forest is not uniformly distributed across a city because of biophysical and social factors. Consequently, air pollution removal function by urban vegetation should vary because of this spatial heterogeneity. This paper presents a different approach to evaluate how the spatial heterogeneity of the urban forest influences air pollution removal at the socioeconomic subregion scale. estimated using measured urban forest structure data from three socioeconomic subregions in Santiago, Chile. Dry deposition was estimated using hourly climate, mixing height, and pollutant concentration data. Pollution removal rates among the three socioeconomic subregions were different because of heterogeneous urban forest structure and pollution concentrations. Air pollution removal per square meter of tree cover was greatest in the low socioeconomic subregion. Pollution removal during 1997–1998 was different from 2000 to 2001 due to pollution concentration differences. Seasonal air quality improvement also differed among the subregions. Results can be used to design management alternatives at finer administrative scales such as districts and neighborhoods that maximize the pollution removal rates by the urban forest in a subregion. Policies that affect the functionality of urban forest structure must consider spatial heterogeneity and scale when making region-wide recommendations. Similarly, when model-ing the functionality of the urban forest, models must capture this spatial heterogeneity for inter-city comparisons.
Despite increased awareness of the urgency to respond to climate change and to promote sustainable development, there are few powerful initiatives that are decisively shifting urban development in a sustainable, resilient and low-carbon direction. This Special Volume of the Journal of Cleaner Production explores sustainable urban transformation focusing on structural transformation processes - multidimensional and radical change - that can effectively direct urban development towards ambitious sustainability goals. The 20 articles are based on 35 cases and over 130 surveyed examples of urban initiatives on sustainability in many countries. While cities in Europe dominate, there are also examples from North America, South America, Africa, Asia and Oceania. The combined articles in this Special Volume contribute to knowledge and understanding on sustainable urban transformation across a range of areas, including governance and planning, innovation and competitiveness, lifestyle and consumption, resource management and climate mitigation and adaptation, transport and accessibility, buildings, and the spatial environment and public space. Overall, this Special Volume documents and analyses real-life action in cities and communities around the world to respond to sustainability challenges and it provides critical insights into how to catalyse, intensify and accelerate sustainable urban transformation globally. A main finding of the articles is that governance and planning are the key leverage points for transformative
change.
Purpose:
To determine the relationship between urban sprawl, health, and health-related behaviors.
Design:
Cross-sectional analysis using hierarchical modeling to relate characteristics of individuals and places to levels of physical activity, obesity, body mass index (BMI), hypertension, diabetes, and coronary heart disease.
Setting:
U.S. counties (448) and metropolitan areas (83).
Subjects:
Adults (n = 206,992) from pooled 1998, 1999, and 2000 Behavioral Risk Factor Surveillance System (BRFSS).
Measures:
Sprawl indices, derived with principal components analysis from census and other data, served as independent variables. Self-reported behavior and health status from BRFSS served as dependent variables.
Results:
After controlling for demographic and behavioral covariates, the county sprawl index had small but significant associations with minutes walked (p = .004), obesity (p < .001), BMI (p = .005), and hypertension (p = .018). Residents of sprawling counties were likely to walk less during leisure time, weigh more, and have greater prevalence of hypertension than residents of compact counties. At the metropolitan level, sprawl was similarly associated with minutes walked (p = .04) but not with the other variables.
Conclusion:
This ecologic study reveals that urban form could be significantly associated with some forms of physical activity and some health outcomes. More research is needed to refine measures of urban form, improve measures of physical activity, and control for other individual and environmental influences on physical activity, obesity, and related health outcomes.
Heterogeneous land cover patterns contribute to unique ecological conditions in cities and little is known about the drivers of these patterns among cities. We studied tree cover patterns in relationship to urban morphology (for example, housing density, parcel size), socioeconomic factors (for example, education, income, lifestyle characteristics), and historical legacies in Baltimore, Maryland, and Raleigh, North Carolina. Utilizing a multimodel inference approach and bivariate analyses, we analyzed two primary datasets employed in previous research predicting urban tree cover—one comprising continuous data (US Census), and the other consisting of categorical variables (Claritas PRIZM) that incorporate consumer purchasing data. Continuous data revealed that urban morphological characteristics were better predictors of tree cover patterns than socioeconomic factors in Raleigh and Baltimore at the parcel and neighborhood scales. Although the categorical dataset provided some evidence for the importance of socioeconomic and lifestyle characteristics in predicting tree cover patterns, the hierarchical nature of these data preclude separating the impacts of these factors from levels of urbanization. Bivariate analyses of continuous and categorical variables revealed that the highest correlation coefficients were associated with variables describing urban morphology—parcel size, percent pervious area, and house age. In Baltimore, historical census data were better predictors of present-day tree cover than census data from recent years. Most notably, parcel size, a key predictor of tree cover, has decreased with time in Raleigh to sizes consistently seen in Baltimore. Our findings demonstrate that urban morphology, the main driver of tree cover patterns in these cities, may lead to the homogenization of tree canopy in Raleigh and Baltimore in the future.
Based on recent research on erosion of ecosystem services, planetary boundaries and predicted pace of urbanization, it is now apparent that humans need to reconnect to the biosphere and that cities in this context, properly managed, could provide great opportunities and arenas for social ecological change and transformation towards sustainability To take advantage of these opportunities one needs to keep in mind that most of the ecosystem services consumed in cities are generated by ecosystems located outside of the cities themselves, not seldom half a world away. In order to operationalize our knowledge, hypothesis and theories on the connections between the work of nature and the welfare and survival of humans over time, we suggest the use of the ecosystem service framework in combination with the merging of the concept “ecology in cities”, mainly focusing on designing energy efficient building, sustainable logistics and providing inhabitants with healthy and functioning green urban environments, and the “ecology of cities”. The “ecology of cities” framework acknowledges the total dependence of cities on the surrounding landscape and the ever-ongoing dance between urban and rural, viewing the city as an ecosystem.
The ecosystem services approach is an established framework for the balanced evaluation of ecological, economic and social landscape resources. It promotes functional synergies (win–win situations) as well as trade-offs among various benefits resulting from ecosystem processes. Spatial aspects of heterogeneity and configuration play a major role in maintaining biodiversity and ecosystem services and hence in human wellbeing. Cultural artifacts also contribute to landscape functionality. Because of the underlying areal aspects, an additional term, landscape service has been proposed and is increasingly used (Termorshuizen and Opdam, 2009). We take a particular interest in spatial aspects of this framework and the optimization of trade-offs between landscape services.
The world's matrix of vegetation, which includes the spatial heterogeneity of its plants species and soils, is probably the most important component of landscape sustainability because it plays a key role in many ecological processes and helps to secure the intricate web of life. Among landscape ecologists, there is some dissatisfaction with current conceptualizations of spatial heterogeneity; and they suggest broader representations are needed. Key questions and research priorities for landscape ecology are proposed to advance knowledge about the world's matrix of vegetation as a biocultural system.
A large body of the literature has assessed the complicated process of landscape fragmentation, while
few studies have tackled urban green space (UGS) systems in the urban context, especially in compact
cities like Hong Kong. The fragmentation index was modeled using landscape metrics to assess green
space fragmentation in Hong Kong. Our results indicate that the set of parameters that can be used to
analyze the fragmentation of UGS includes: AREA MN, PD, SHAPE MN, ENND MN, CONNECT, DIVISION,
MESH and SPLIT. According to the fragmentation index, five fragmentation levels were identified in the
study area. The built-up areas in Kowloon and along the coast of Hong Kong Island exhibited the highest
fragmentation level of green spaces, while the countryside of the New Territories had the lowest. The
uneven distribution of green cover results in an uneven distribution ofUGSfragmentation levels. The eight
metrics and the PCA technique employed were validated with respect to their applicability to analyzing
green space fragmentation in this study. The results of this study could contribute to our understanding of
fragmentation from a landscape ecological perspective. They will also be useful in the appropriate, future
planning of urban green spaces to increase connectivity, form green networks and realize sustainability
in compact cities.
Climate strongly influences the composition of natural plant communities, but a variety of human activities might release plants in urban areas from some of these climatic constraints. (1) After controlling for minimum temperature, is urban tree species composition related to biome? (2) Do any such patterns result solely from the presence of native species in urban floras? (3) Which climatic, demographic and economic variables are predictive of urban tree species composition?
Continental USA.
We investigated patterns of tree species composition in small cities across the continental USA, specifically exploring relationships to surrounding biomes and their accompanying temperature and precipitation regimes, as well as to key demographic and economic variables. We estimated urban tree species composition by surveying tree experts in randomly selected cities that were stratified by minimum temperature (i.e. ‘hardiness zone’) and biome, and constrained to similar population sizes. We then used non-metric multidimensional scaling to investigate relationships between urban tree species composition, biome classification, native status, individual climate variables and several anthropogenic factors.
We found that urban tree communities were consistently related to the surrounding biome, even after controlling for minimum temperatures. These communities could also be predicted by several individual climatic variables (in models that focused solely on the role of climate as well as models that simultaneously considered key anthropogenic factors). In addition, most of these general patterns were still present when we exclusively examined non-native species. We were unable to identify specific climatic and anthropogenic variables of broad importance because the most predictive variables were highly dependent upon the specific analysis.
Our results demonstrate that, despite substantial human influence, urban tree communities (including their non-native components) are related to the same climate factors that shape wildland plant communities.
Urban land-cover change threatens biodiversity and affects ecosystem productivity through loss of habitat, biomass, and carbon storage. However, despite projections that world urban populations will increase to nearly 5 billion by 2030, little is known about future locations, magnitudes, and rates of urban expansion. Here we develop spatially explicit probabilistic forecasts of global urban land-cover change and explore the direct impacts on biodiversity hotspots and tropical carbon biomass. If current trends in population density continue and all areas with high probabilities of urban expansion undergo change, then by 2030, urban land cover will increase by 1.2 million km(2), nearly tripling the global urban land area circa 2000. This increase would result in considerable loss of habitats in key biodiversity hotspots, with the highest rates of forecasted urban growth to take place in regions that were relatively undisturbed by urban development in 2000: the Eastern Afromontane, the Guinean Forests of West Africa, and the Western Ghats and Sri Lanka hotspots. Within the pan-tropics, loss in vegetation biomass from areas with high probability of urban expansion is estimated to be 1.38 PgC (0.05 PgC yr(-1)), equal to ∼5% of emissions from tropical deforestation and land-use change. Although urbanization is often considered a local issue, the aggregate global impacts of projected urban expansion will require significant policy changes to affect future growth trajectories to minimize global biodiversity and vegetation carbon losses.
The social and ecological processes impacting on urban forests have been studied at multiple temporal and spatial scales in order to help us quantify, monitor, and value the ecosystem services that benefit people. Few studies have comprehensively analyzed the full suite of ecosystem services, goods (ESG), and ecosystem disservices provided by an urban forest. Indicators, however, are one approach that could be used to better understand the structure of an urban forest, the suite of ESG provided by urban forests, and their influence on human well-being using a simple, innovative and repeatable metric. This study presents a framework for developing indicators using field data, an urban forest functional model, and the literature. Urban tree and soil indicators for groups of ecosystem functions were used to statistically analyze the effects of urban morphology and socioeconomics on urban forest ESG. Findings show that the most influential ESG indicators were tree cover, soil pH, and soil organic matter. Indicators were significantly influenced by land use and time since urbanization, while analyses of property values and household income did not yield any particularly significant results. The indicators presented in this paper present a first approach to non-monetary valuation of urban forest ESG and can be used to develop urban forest structure management goals and to monitor the effects of urban greening policies on human well-being.
Research highlights▶ Urban forest ecosystem services and goods are dependent on tree cover. ▶ Indicators for ecosystem services and goods are influence by land use and time since urbanization. ▶ Indicators presented in this study are the first approach for a non-monetary valuation of urban forest ecosystem services and goods. ▶ Indicators can be used as a tool for evaluation of policies or management regimes.
The distribution of public green space within towns is frequently uneven, and influenced by attributes such as its location relative to the commercial core, as well as the ethnicity and relative wealth and education of the residents. Yet most studies are from large cities in developed countries. In contrast, this study reports on the distribution of public green space across 9 small towns in a developing country, namely South Africa, which offers a unique case study because of its former racially defined settlement patterns. We do so using GIS analysis of aerial photographs focusing on 3 types of suburbs in each town, defined on the basis of wealth as well as race-based history under the previous apartheid regime. The more affluent suburbs, inhabited mainly by whites, have the lowest density of housing and the highest area of green space per capita. Proportionally, they have a similar area under public green space as to the previously racially defined townships, but because of the lower housing density, they have a greater area per person. The newly built low-cost housing areas (termed RDP suburbs), occupied largely by poor black South Africans, are poorly endowed with public green space, and fare worse than the other 2 suburb types on all attributes measured. This needs to be addressed in further low-cost housing developments.
Aim Climate change threatens to shift vegetation, disrupting ecosystems and damaging human well-being. Field observations in boreal, temperate and tropical ecosystems have detected biome changes in the 20th century, yet a lack of spatial data on vulnerability hinders organizations that manage natural resources from identifying priority areas for adaptation measures. We explore potential methods to identify areas vulnerable to vegetation shifts and potential refugia.
Location Global vegetation biomes.
Methods We examined nine combinations of three sets of potential indicators of the vulnerability of ecosystems to biome change: (1) observed changes of 20th-century climate, (2) projected 21st-century vegetation changes using the MC1 dynamic global vegetation model under three Intergovernmental Panel on Climate Change (IPCC) emissions scenarios, and (3) overlap of results from (1) and (2). Estimating probability density functions for climate observations and confidence levels for vegetation projections, we classified areas into vulnerability classes based on IPCC treatment of uncertainty.
Results One-tenth to one-half of global land may be highly (confidence 0.80–0.95) to very highly (confidence ≥ 0.95) vulnerable. Temperate mixed forest, boreal conifer and tundra and alpine biomes show the highest vulnerability, often due to potential changes in wildfire. Tropical evergreen broadleaf forest and desert biomes show the lowest vulnerability.
Main conclusions Spatial analyses of observed climate and projected vegetation indicate widespread vulnerability of ecosystems to biome change. A mismatch between vulnerability patterns and the geographic priorities of natural resource organizations suggests the need to adapt management plans. Approximately a billion people live in the areas classified as vulnerable.
Question: Can we interpret how climatic variation limits photosynthesis and growth for one widely distributed species, and then relate these responses to model the geographic distributions of other species?
Location: The forested region of the Pacific Northwest, United States and Canada.
Methods: We first mapped monthly climatic data, averaged for the period 1950 to 1975 at 1 km resolution across the region. The recorded presence and absence of 15 native tree species were next mapped at 1 km resolution from data acquired on 22 771 field survey plots. To establish seasonal limits on photosynthesis and water use, a process-based growth model (3-PG, Physiological Processes to Predict Growth) was parameterized for Douglas-fir (Pseudotsuga menziesii), one of the most widely distributed species in the region. Automated decision tree analyses were used to predict the distribution of different species by creating a suite of rules associated with the relative constraints that soil drought, atmospheric humidity deficits, suboptimal and subfreezing temperatures would impose on the growth of Douglas-fir.
Results: The 3-PG process-based modeling approach, combined with automated decision tree analyses, predicted presence and absence of 15 conifers on field survey plots with an average accuracy of 82±12%. Predictive models of current distribution for each species differed in the number of, order in, and physiological thresholds selected. A deficit in the soil water balance, followed by departures from optimum temperatures in the summer were the two most important variables selected in predicting species distributions.
Conclusions: Although empirical models using different sampling techniques and statistical analyses may be more accurate in predicting current distribution of species, the hybrid approach presented in this paper provides a greater mechanistic understanding of the limits to growth and tree distributions. These attributes of process-based models make them particularly useful in designing mitigating strategies to projected changes in climate.