Urban Intensity Research Articles

Dynamic Responses of Soil Organic Carbon to Urbanization: A Global Perspective.

Rapid global urbanization has a complex impact on soil organic carbon (SOC) stocks. Through its direct and indirect impacts on soil formation and development, urbanization greatly influences SOC stocks. However, the extent to which urbanization affects SOC stocks globally remains unclear. In this study, we utilized an urban-rural gradient approach to assess the effects of urbanization on SOC stocks at both global and national scales. First, we calculated the urbanization intensity (UI) at a 1 km scale globally, categorizing urbanization into three stages: low (0 ≤ UI ≤ 25), medium (25 < UI ≤ 75), and high (75 < UI ≤ 100). Additionally, we distinguished the contributions of natural factors and human activities and analyzed the effects of land-use changes in eight representative cities. We found the following: (1) The SOC stocks exhibit distinct trends with increasing UI, but when UI is low or high, an increase in UI is associated with decreasing SOC stocks (reductions of 6.8% and 5.4% at a depth of 30 cm; 6.4% and 3.2% at a depth of 100 cm, respectively). (2) Changes in human activities are the main drivers of SOC stock changes during urbanization. At low and medium urban intensities, the contributions of human activities reach 98% and 89%, respectively. Additionally, land-use transitions are closely correlated with SOC stock changes, particularly in areas near the urban core, across different climate zones. (3) The response of SOC to urbanization varies across climatic zones. In water-scarce arid climates, attention should be given to the negative effects of urbanization, and more targeted measures should be taken to enhance the carbon sequestration capacity of urban soils. This study provides valuable insights into the dynamic interplay between urbanization and SOC stocks, underscoring the need for tailored strategies to manage soil carbon in urban environments.

Bird Leg Skin Lesions and Urbanization in a Neotropical Savanna City.

Urban sprawl threatens biodiversity and is responsible for significant changes in the species that live in these environments. Given the high cost of comprehensive surveillance, monitoring disease indirectly, such as detecting skin lesions in birds, may help us better understand the prevalence of diseases affecting wild populations. We assessed the frequency of leg skin lesions, as a proxy of disease presence, in 1,565 individuals of 25 species, along the urban matrix of a large Neotropical city, Brasília, Federal District, Brazil. We tested the hypothesis that there is an increase in the frequency of skin lesions in birds due to urban intensification. We observed an increasing trend in some bird species between the frequency of occurrence of lesions and the intensity of urbanization. Species with a higher number of captures had an increase in the percentage of lesions, indicating that the occurrence of lesions may be linked to higher population density or that detection of the effect occurs only when sample sizes are high and controlled among urbanization categories. Our study highlights how the intensity of urbanization may increase the risk of disease transmission for these species. Unfortunately, studies on this topic are scarce in Neotropical regions, despite the region's high biodiversity and urban expansion.

Unveiling riverine N2O dynamics along urbanization gradients by integrating hydrological, biogeochemical and microbial processes

Human-disturbed rivers are globally significant sources of atmospheric nitrous oxide (N2O). Yet, the underlying mechanisms of urbanization impact on riverine N2O dynamics are not well understood. This study unveiled the effects of urbanization on N2O dynamics by integrating hydrological, biogeochemical and microbial processes in a river with various urbanization intensities. Riverine NO3− concentration enhanced with increasing urban land percentage, primarily because of the increased proportional contribution of sewage & manure source. The 15N site preference and relevant isotopic evidences revealed that the proportion of denitrification derived N2O increased from 60% to 76%, with the urban land percentage increasing from < 5% to > 22%, which was caused by decreases in flow velocity and dissolved oxygen saturation, increases in NO3− concentration and N2O-denitrifying genes. The non-negligible contribution of nitrification to N2O production (∼ 40%) in lower-urbanized river stretches may be attributed to aerobic conditions and lower impermeable riparian zone facilitating the occurrence of in-river nitrification and the access of in-soil nitrification to river. Urbanization-mediated decreases in flow velocity and dissolved oxygen and increases in nitrogen availability and denitrification process resulted in an increase in N2O concentration and flux, with N2O concentration approximately four times higher in higher-urbanized river reaches (50.7 ± 26.3 nmol/L) than in lower-urbanized river reaches (14.4 ± 2.5 nmol/L). In addition, increased proportional contribution of sewage & manure source also provides the possibility for exogenous N2O inputs with urban expansion. These findings contribute to deepening our understanding of how urbanization drives N2O dynamics in river systems.

Metal concentration in honeybees along an urbanization gradient in Central Mexico

Urbanization is rapidly increasing worldwide, leading to rising levels of pollution, one of the major drivers of environmental change; yet little is known about the relationship between urbanization intensity and pollution levels in pollinator taxa. Toxic metals are among the most common contaminants in urban environments, but few data exist on their presence in the flora and fauna of cities in Latin America, one of the world's most urbanized and biologically diverse regions. In this study, we used an urban-rural gradient approach to analyze the relationship between the concentrations of eleven metals present in adult honeybees (Apis mellifera) and the degree of urbanization within twelve landscapes in the metropolitan area of Pachuca, Hidalgo, which forms part of the megalopolis of Mexico City. Metal concentrations were compared with previously reported values contrasting honeybees from urban and rural areas after standardizing urbanization levels among published reports. The concentrations of Ag, Cr, Cu, and Zn in honeybees increased significantly with the degree of urbanization. Urbanization was not found to influence the levels of Al, Ba, Cd, Mn, and Sr in honeybees. The maximum concentrations of six metals in our urban sites (Al, Ba, Cd, Cu, Mn, and Sr) were higher than the maximum values reported for bees in other urban areas. The concentrations of two metals measured in our study (Cr and Zn) were within the range of values previously published for urban areas. Compared to other studies, we did not detect Pb in the body of honeybees. We conclude that the concentrations of Ag, Cr, Cu, and Zn present in honeybees are a quantitative reflection of the degree of urbanization in central Mexico. Our results highlight the need to monitor metal emission sources in this and other areas and investigate their effects on bees and other pollinator taxa.

Investigation of urban biodiversity and factors influencing it based on modern technologies

In the article, the development of the cities of the Shirvan plain, located in the central part of the Republic of Azerbaijan, and the impact of this development on the loss of biodiversity of the cities were analyzed. Currently, cities, where more than 50% of the world’s population live, are the main reasons for the change of natural landscapes. The development of cities and the intensity of urbanization accelerate these changes. Therefore, our research is dedicated to the current issue. During the research, preference was given to modern methods. Landsat 5, 8 and 9 satellite images of 6 cities located on the Shirvan plain were obtained. As a result of the processing and analysis of these satellite images, the development of the territory and population of the cities was studied, and their effects on the natural landscape, its components, vegetation and water bodies were analyzed. The boundaries of cities in 1975 and 2023 were determined and compared. As a result of the conducted studies, it was determined by the processing of the 1975 topo plans and the 2023 satellite images that the area of the cities has increased by at least 2 times. The high average annual growth of the population has led to the transformation of cities from small towns to medium and large cities in a short period of time. This causes the loss of biodiversity as soon as possible and accelerates this process.

Spatial and Temporal Variations of Vegetation Phenology and Its Response to Land Surface Temperature in the Yangtze River Delta Urban Agglomeration

In the Yangtze River Delta urban agglomeration, which is the region with the highest urbanization intensity in China, the development of cities leads to changes in land surface temperature (LST), while vegetation phenology varies with LST. To investigate the spatial and temporal changes in vegetation phenology and its response to LST in the study area, this study reconstructed the time series of the enhanced vegetation index (EVI) based on the MODIS EVI product and extracted the vegetation phenology indicators in the study area from 2002 to 2020, including the start of the growing season (SOS), the end of the growing season (EOS), and the growing season length (GSL), and analyzed the temporal–spatial patterns of vegetation phenology and LST in the study area, as well as the correlation between them. The results show that (1) SOS was advanced, EOS was postponed, and GSL was extended in the study area from 2002 to 2020, and there were obvious differences in the vegetation phenology indicators under different land covers and cities; (2) LST was higher in the southeast than in the northwest of the study area from 2002 to 2020, with an increasing trend; and (3) there are differences in the response of vegetation phenology to LST across land covers and cities, and SOS responds differently to LST at different times of the year. EOS shows a significant postponement trend with the annual mean LST increase. Overall, we found differences in vegetation phenology and its response to LST under different land covers and cities, which is important for scholars to understand the response of vegetation phenology to urbanization.

Intra-annual variability of urban effects on streamwater quality: An examination of watersheds in the Atlanta, Georgia USA region

There has been considerable research on urban impacts on streamwater quality, but studies have mostly ignored intra-annual variations in water-quality variables and thus seasonally-varying impacts. Therefore, this study uses daily water-quality data over eight years for 38 streams in the Atlanta, Georgia USA region and watershed-level, urbanization variables to assess month-specific impacts of urbanization on water quality. The water-quality variables were mean specific conductance, mean temperature, mean dissolved oxygen, median pH, and median turbidity. The watershed-level variables were population density, housing density, proportion of watershed that is high-intensity developed land, imperviousness, proportion of watershed that is urban land use, an urban-intensity index, and change in developed land. Both differences in water quality between urban, suburban, and exurban streams and correlations between water quality and the watershed-level variables were examined. During all months, urban streams had significantly higher specific conductance than suburban and exurban streams, and the urban intensity of a watershed was significantly positively correlated with specific conductance. Differences and correlations were intensified during winter and spring. For temperature and dissolved oxygen, only during non-winter months did urban streams have significantly higher temperatures and significantly lower dissolved oxygen as well as significant positive correlations between urban intensity and temperature and significant negative correlations between urban intensity and dissolved oxygen. Urban streams had the highest pH during all months, but none of the differences were significant. Significant correlations between pH and urban intensity were restricted generally to winter and spring months. Turbidity was highest for exurban watersheds and thus was not significantly positively correlated with urban intensity. Seasonal and stream-group differences in the weathering of concrete, use of road salts, solar heating of streams, urban surface temperatures, baseflow, and land-disturbance activities explain the water-quality findings. Most of the findings should be applicable to urban areas in humid subtropical climates within the Piedmont physiographic region.

Low-intensity urbanisation alters community composition across multiple trophic levels on Lipsi Island, Greece.

Urbanisation has reduced the abundance and diversity of many taxonomic groups, and the effects may be more pronounced on islands, which have a smaller regional species pool to compensate. Green spaces within urban environments may help to safeguard wildlife assemblages, and the associated habitat heterogeneity can even increase species diversity. Here, total abundance and species diversity of butterflies, birds, and vegetation at nine rural and nine urban locations were quantified on Lipsi Island, Greece. Sites were assessed using Pollard walks for butterflies, point-count surveys for birds, and quadrats for vegetation. There was no significant difference in the abundance or species diversity of butterflies or vegetation among rural and urban locations, which could pertain to the low building density within urbanised areas and the minimal extent of urbanisation on the island. However, urban areas hosted a significantly greater abundance, richness, and diversity of birds compared to rural sites. The community composition of butterflies, birds, and vegetation also differed significantly between urban and rural locations, highlighting the impact of urbanisation on species across a broad range of trophic groups. This study contributes to ecological knowledge on the impacts of urbanisation across multiple trophic levels in island ecosystems, with comparisons across a gradient of island size and urbanisation intensity needed in future research.

Is urbanization a driver of aboveground biomass allocation in a widespread tropical shrub, Turnera subulata (Turneroideae - Passifloraceae)?

Plant biomass allocation is mainly affected by the environment where each individual grows. In this sense, through the rapid global expansion of impermeable areas, urbanization has strong, albeit poorly understood, consequences on the biomass allocation of plants found in this environment. Nevertheless, the comprehension of biomass allocation processes in urban shrubs remains unclear, because most studies of urban ecology focus on tree species. This is an important gap of knowledge because a great part of urban vegetation is composed of shrubs and their association with trees have positive impacts in urban ecosystem services. In this study, we explored the ecological and potential selective pressure effects of an urbanization gradient on the biomass allocation patterns of aboveground organs of Turnera subulata, a widely distributed tropical shrub. We have demonstrated that, for certain reproductive organs, biomass allocation decreases in locations with higher urbanization. Unlike expected, the biomass of vegetative organs was not affected by urbanization, and we did not observe any effect of urbanization intensity on the variance in biomass allocation to vegetative and reproductive organs. We did not record urbanization-mediated trade-offs in biomass allocation for reproductive and vegetative organs. Instead, the biomass of these structures showed a positive relationship. Our data suggest that urbanization does not result in radical changes in biomass allocation of T. subulata, and neither in the variation of these traits. They indicate that the ability of T. subulata to thrive in urban environments may be associated with life history and morphological mechanisms. Our findings contribute to the understanding of shrub plant responses to urbanization and highlight urbanization as a potential factor in resource allocation differences for different structures and functions in plants living in these environments.

Does Urbanization Exacerbate Asymmetrical Changes in Precipitation at Divergent Time Scales in China?

AbstractUrbanization alters the thermal and dynamic environment of the local climate system, resulting in significant impacts on precipitation in both urban and adjacent areas. Nevertheless, there remains a significant gap in our understanding of urbanization‐induced effects on asymmetrical, symmetrical, and other precipitation patterns in urban agglomerations (UAs) with divergent background climates and geographic regions at different timescales. Specifically, this asymmetrical change pattern is characterized by an increase in heavy (or light) rainfall and a decrease in light (or heavy) rainfall. Here, we assessed the effects of urbanization on precipitation patterns across 18 UAs situated in diverse background climates and geographical areas in China at different timescales. The results demonstrate that urbanization predominantly alters precipitation patterns in UAs located in the humid region. Specifically, urbanization amplified asymmetrical changes in Yangtze River Delta, Pearl River Delta, Beibu Gulf, Middle Yangtze River, and Guanzhong, but exacerbated symmetrical changes in precipitation in some regions such as Chengdu‐Chongqing. Notably, the urbanization effect demonstrates greater significance at the hourly scale, as exemplified in the Yangtze River Delta, Pearl River Delta, and Middle Yangtze River, where the urban impact is nearly twice as pronounced when compared to the daily scale. Moreover, urbanization had either no effect or has a negative impact on precipitation patterns in UAs located within continental and arid regions. This is related to the intensity of urbanization, background climate and complex topography. This finding implies that urban managers should consider the impact of urbanization on precipitation patterns in different contexts to provide scientific guidance for urban planning.

Dynamic indirect impacts of urbanization on vegetation growth in Chinese cities

Numerous studies have examined the potential impacts of urban expansion on vegetation growth. However, the impacts of urbanization on vegetation growth (Urbi) across urban-rural gradients and its driving forces remain poorly understood. In this study, we used satellite observations of MODIS Enhanced Vegetation Index (EVI) from 2001 to 2019 to quantify the spatial–temporal dynamics of indirect urbanization impacts on vegetation growth and analysed their driving forces in 60 prefectural cities across China. The relationship between the Urbi and urban intensity (β) was S-shaped, with a turning point where the indirect impact changed from negative to positive. The left-moving trend of the turning point in the southeastern cities indicated the expansion of areas with positive Urbi during the last two decades. We further investigated the spatially heterogeneous effects of two natural and three anthropogenic driving factors on the Urbi across the urban-rural gradient in different climate zones. The results showed that in temperate cities, as urban intensity increased, the presence of turning points was probably attributed to population increase. In cold cities, the change in the Urbi was most likely induced by the enlarging population and increasing economic level from rural to urban areas. However, in arid cities, it was mainly determined by water supply and the cool island effect in urban cores rather than socioeconomic factors.

Metropolitan pressures: Significant biodiversity declines and strong filtering of functional traits in fish assemblages

Accelerating global urbanization is leading to drastic losses and restructuring of biodiversity. Although it is crucial to understand urban impacts on biodiversity to develop mitigation strategies, there is a dearth of knowledge on the functional structure of fish assemblages spanning the entire city-scale spectrum of urbanization intensity. Here, using environmental DNA sampled from 109 water sites in Beijing, we investigated the taxonomic and functional diversity patterns of fish assemblages across the city and uncovered community-, trait-, and species-level responses to various environmental stressors. By ranking sampling sites into three disturbance levels according to water physiochemical and landcover conditions, we found that both native and non-native fish taxonomic and functional α-diversity decreased significantly with elevating disturbance, as strong disturbance led to the disappearance of many species. However, the quantitative taxonomic and functional β-diversity components of native and non-native fish showed distinct patterns; assemblage turnover dominated native fish β-diversity and decreased with increasing disturbance, whereas species/trait richness differences dominated non-native fish β-diversity and increased with disturbance intensity particularly in lotic waters. RLQ and fourth-corner analyses revealed that fish size, fecundity, diet, and reproductive behaviors were significantly correlated with water quality, with pollution-tolerant, larger-sized native and omnivorous non-native fishes being urban winners, which indicates strong trait-dependent environmental filtering. Potential ecological indicator species were identified based on the sensitivity of fish responses to pollution loads; these were mostly small native species, and many have bivalve-dependent reproduction. Our results demonstrate that, along with native fish assemblage simplification and homogenization, urban stressors exert profound impacts on community trait composition, highlighting the need to consider both biodiversity loss and functional reorganization in combating disturbance of aquatic ecosystems under global urbanization. Furthermore, correlations between cropland cover and water nutrient level suggested that the management of agricultural runoff might be critically important for safeguarding urban water quality.

Using unstructured crowd-sourced data to evaluate urban tolerance of terrestrial native animal species within a California Mega-City.

In response to biodiversity loss and biotic community homogenization in urbanized landscapes, there are increasing efforts to conserve and increase biodiversity within urban areas. Accordingly, around the world, previously extirpated species are (re)colonizing and otherwise infiltrating urban landscapes, while other species are disappearing from these landscapes. Tracking the occurrence of traditionally urban intolerant species and loss of traditionally urban tolerant species should be a management goal of urban areas, but we generally lack tools to study this phenomenon. To address this gap, we first used species' occurrences from iNaturalist, a large collaborative dataset of species observations, to calculate an urban association index (UAI) for 967 native animal species that occur in the city of Los Angeles. On average, the occurrence of native species was negatively associated with our composite measure of urban intensity, with the exception of snails and slugs, which instead occur more frequently in areas of increased urban intensity. Next, we assessed 8,348 0.25 x 0.25 mile grids across the City of Los Angeles to determine the average grid-level UAI scores (i.e., a summary of the UAIs present in a grid cell, which we term Community Urban Tolerance Index or CUTI). We found that areas of higher urban intensity host more urban tolerant species, but also that taxonomic groups differ in their aggregate tolerance of urban areas, and that spatial patterns of tolerance vary between groups. The framework established here has been designed to be iteratively reevaluated by city managers of Los Angeles in order to track the progress of initiatives to preserve and encourage urban biodiversity, but can be rescaled to sample different regions within the city or different cities altogether to provide a valuable tool for city managers globally.

Urbanization reduces diversity, simplifies community and filter bird species based on their functional traits in a tropical city

Understanding how organisms are coping with major changes imposed by urban intensification is a complex task. In fact, our understanding of the impacts of urbanization on biodiversity is scarce in the global south compared to the north. In this study, we evaluated how bird communities are affected by impact of urban intensification in a tropical city. Thus, we assessed whether increased urban intensification 1) jeopardizes bird diversity (taking into account taxonomic-TD, phylogenetic-PD, and functional-FD dimensions), 2) drives changes in bird community composition and enables the detection of indicator species of such impact, and 3) leads to changes in bird functional traits linked to reproduction, resource acquisition, and survival. We found that urban intensification has a direct impact on the bird community, reducing all three types of diversity. Communities in areas of greater urban intensity are represented by fewer species, and these species are PD and FD less distinct. In addition, we detected at least ten species of areas of lower urban intensity that proved to be more sensitive to urban intensification. With regard to bird traits, we found no significant responses from reproductive, habitat use and feeding variables. Body weight and tail length were the only variables with significant results, with higher urbanization intensity areas selecting for species with lower weights and longer tails. Given the global biodiversity loss we are observing, this information can guide urban managers and planners in designing urban landscapes to maintain biodiversity in cities.

Unveiling Urban Evolution: Assessing Patterns of Transformation in Guangzhou's Net Production

Urban evolution refers to the continuous changes and adaptation of urban environments to social, economic, technical, and environmental changes, acknowledging that cities are dynamic systems. Urbanization and land use/cover change (LULCC), which are mostly caused by human activity, which have a big impact on the environment. These two variables also affect urban vegetation when combined with climate change. We choose Guangzhou City to examine how urban growth processes and spatial changes in urban areas affect net production (NP). A Machine learning [ML] approach such as Support Vector Machine (SVM) was utilized to examine the relationship between NP and urbanization intensity. This study examined to analyze urban evolution, focusing on the patterns of change in the NP in Guangzhou City, China. The findings demonstrated between 2011 and 2023, the NP in the studied region decreased overall and had distinct geographic variation. The mean Urban Development Index (UDI) in Guangzhou increased significantly between 2011 and 2023. In both years, metropolitan exurbs constituted the majority of the urban geographic category, but the most notable increase in urban fringe areas, which accounted for about 2,320.24 km2 of the urban exurbs. Regarding UDI and NP, there was an opposite relationship, suggesting that the growing intensity of the growth of urban expansion negatively affected NP. Urban development intensity negatively influenced NP, with urban fringes experiencing the most significant losses due to an increase in urbanization and a decrease in agriculture.

Raccoons and opossums respond similarly to high and low development in the East Texas Pineywoods

Over the last half-century, cities across the southeastern United States have experienced consistent human population growth, which has increased the rate of urban sprawl and subsequent habitat fragmentation with resource subsidies from development. The northern raccoon (Procyon lotor) and Virginia opossum (Didelphis virginiana) are mesopredators commonly associated with and benefiting from urbanized areas. We conducted a small-scale study of raccoons and opossums within the Nacogdoches, Texas, in January 2014. We captured and marked individual raccoons and opossums and used occupancy and spatial-capture-recapture models to examine habitat use, detection, and population density in high- and low-density urban study areas. We predicted to find high densities of each mesopredator, relative to other studies in larger metropolitan areas. We also expected to find a response to landscape features in the high-development study area to be closely associated with anthropogenic features and proximity to water, but less pronounced in the low-development study area. Contrary to our predictions, the detectability of each species in the high-development study area had a positive association with areas further from buildings, and raccoon habitat use had a positive association farther from natural water. Similarly, in the low-development study area, we found raccoon detectability had a positive association with areas farther from the urban edge and opossums had a positive association with areas with smaller forest patches (i.e., edge habitat). We were able to estimate 13.66 raccoons/km2 (95% CI 7.10–26.30) in the high-development study area and 12.55 opossums/km2 (95% CI 04.36–36.15) in the low-development study area. Our results indicate high densities of each species, and the first urban density of Virginia opossum using spatial-capture-recapture methods which further supports that these mesopredators are adapted to and benefit from urban-derived resources in urban areas. This study highlights the adaptability of these small mesopredators and the need for managers to consider adaptive strategies across different urban intensities as the ecology of these species may differ as compared to larger cities.

Echoes of Conflict: Exploring the Parallels Between The Red Badge of Courage and the Socioeconomic Dynamics of Post-Civil War America

This article is an attempt to analyze The Red Badge of Courage as a socio-political allegory of the period in which it was written. Two facts cannot be ignored when characterizing post-Civil War America: one of them is the rise of industrial production with the support of scientific developments and subsequent economic expansion. The other is the increasing migration due to the economic destruction in the South and higher standards of living promised by the industrial cities of the North. In this period, changes in production techniques created an advantage in favor of employers in wage competition. Therefore, factory owners began to prefer unskilled migrant workers instead of skilled workers and this also increased the intensity of urbanization. While rapid population growth turned the cities into industrial jungles, life for the rural migrant workers, who were destitute of supportive social networks, was no different than a battlefield of problems. It was at such a time that the novel was written, and the 304th infantry regiment, made up of young and inexperienced soldiers in the story, is in many ways reminiscent of young industrial workers.

TOWARD SPATIAL AND SOCIAL EQUALITY: INVESTIGATING AND MODELING THE LINK BETWEEN OPPORTUNITY AND URBAN INTENSITY IN METRO MANILA, PHILIPPINES

Abstract. This paper employed an interdisciplinary mixed-method approach combining geomatics, geography, and sociology to investigate the link between opportunity and urban intensity across the 32 legislative districts of Metro Manila. Eighteen opportunity indicators, weighted within their opportunity dimensions using Analytic Hierarchy Process (AHP) were used to output Opportunity Scores, while annual VIIRS DNB nighttime light was used as proxy data to approximate the region’s Urban Intensity Score. Two regression models were developed with different sets of explanatory variables: an AHP-based model that used the top two weighted indicators from each opportunity dimension, and a model that used Exploratory Regression Analysis (ERA) to determine the appropriate variable combination. Modeling via Ordinary Least Squares Regression (OLS) produced a properly specified global model, while OLS modeling of the ERA-based model exhibited non-stationarity between variables which necessitated performing Geographically Weighted Regression (GWR). Our quantitative findings, combined with insights from our mini focus group discussion (FGD), provided evidence of the unequal distribution of opportunities across Metro Manila and the spatially varying relationship between urban intensity and opportunity, which have significant implications for urban framework as well as housing choice.

The contested value of parklets

ABSTRACT This paper examines the different values that stakeholders associate with parklets: small open spaces temporarily installed onto curbside car-parking spaces. It explores the growing debate in policy, research and the media around parklets’ value for the public and for the hospitality businesses that host most of them. The paper aims to inform policy deliberations around parklets by identifying and analyzing the diverse values that have been associated with them. It locates these values within the key policy concerns that shape the broader practices of temporary and tactical urbanism: urban intensity, community engagement, innovation, resilience and place identity. It evaluates whether parklets can have detectable and achievable impacts on different policy aims associated with them: whether the various specified policy values are strong, weak, wishful or hidden. The findings illuminate the contours of policy debates around parklets and indicate why certain policy objectives have been better served by parklets than others.

How urbanization shapes the ecosystem carbon sink of vegetation in China: A spatiotemporal analysis of direct and indirect effects

Rapid urbanization has led to extensive effects on the spatio-temporal patterns of the carbon sources and sinks in ecosystems. However, due to the lack of long-term continuous land use/cover change (LUCC) data, there has been limited discussion on the spatio-temporal impacts of urbanization on carbon sources/sinks and the non-linear characteristics of urban changes over time. This study focused on the impact of urbanization on vegetation net ecosystem productivity (NEP) in 31 provincial capital cities in China from 1990 to 2019, using land use change data and NEP indicators, to analyze the change patterns and response modes of urbanization intensity and NEP. The study found that: (1) During the period of 1990–1995, almost all cities in China experienced a turning point of urbanization rate from decreasing to increasing, while after 2000, the urbanization rate declined significantly; (2) Climate background affects the negative impact of urbanization on NEP, especially in warm and humid climate background, while the direct impact of urbanization on vegetation is more significant; (3) Overall, urbanization in China aggravated the negative impact of urbanization on NEP from 1990 to 2019, especially in cold and arid climate background, which would further exacerbate the negative impact of urbanization. This study helps us better understand the impact of Chinese urbanization on ecosystem carbon sinks and mitigating the carbon emissions pressure of urban environments.