Reducing air pollution does not necessarily reduce related adults' mortality burden: Variations in 177 countries with different economic levels.

Prolonged exposure to PM2.5 is associated with increased mortality. However, reducing air pollution concentrations does not necessarily reduce the related burden of deaths. Here, we aim to estimate the variations in PM2.5-related mortality due to contributions from key factors - PM2.5 concentration, population exposure, and healthcare levels - for 177 countries from 2000 to 2018 at the 1-km grid scale according to the Global Mortality Exposure Model (GEMM) model. We find that global reductions in PM2.5-related deaths mainly come from high and upper-middle income countries, where lowered air pollutant concentration and better healthcare can offset mortality burdens caused by increasing exposed populations. Changes in population exposure to PM2.5 contribute the most (54 %) to change in global related deaths over the examined period, followed by changes in healthcare (-42 %) and pollution concentrations (4 %). The impacts vary across countries and regions within them due to other drivers, which are significantly influenced by development status. Policies aiming at reducing PM2.5 associated health risks need to account for country-specific balances of these key socioeconomic drivers.

Global synergy of carbon and pollution emissions among countries with different income levels and development stages.

The world was drift away on the sustainable development goals (SDGs), whatever global countries claimed fighting for. It's thus essential to illustrate the status of development and environmental quality simultaneously. Resource consumption and energy consumption as the basic needs in supporting human societal development, are commonly used, because they come from the same source and are most directly observed in the open air. We thus examined nexus of carbon and pollution emissions, which also directly indicate residents' livelihood and lifestyle. The possibility of the nexus shifts among income levels with population stack analysis was further investigated. Our findings indicate that the diverse nexus is strongly correlated with development levels, with urban areas being the primary contributor to high carbon and/or pollution emissions despite occupying only 0.5% of global territory. We conclude that expecting leapfrog stages of the nexus is unrealistic, as cross-income-level change requires approximately 80% of the population to significant change its livelihood and lifestyle. Therefore, we recommend setting science-based targets for decoupling carbon and pollution emissions from development are necessary, but should be adapted and tailored to each country's local practice.

Determination of the role of hippocampal astrocytes in the bilateral common carotid artery stenosis mouse model by RNA sequencing.

INTRODUCTION: Bilateral common carotid artery stenosis (BCAS) is used experimentally to model vascular dementia (VaD). Previous studies have primarily focused on the degradation of brain white matter after BCAS. However, hippocampal abnormalities are equally important, and hippocampal astrocytes are specifically involved in neural circuits that regulate learning and memory. Whether hippocampal astrocytes participate in the pathogenesis of BCAS-induced VaD has not been well studied. Therefore, in the present study, we attempted to explore the role of hippocampal astrocytes in BCAS. METHODS: Two months after BCAS, behavioral experiments were conducted to investigate changes in neurological function in sham and BCAS mice. A ribosome-tagging approach (RiboTag) profiling strategy was used to isolate mRNAs enriched in hippocampal astrocytes, and the RNA was sequenced and analyzed using transcriptomic methods. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was utilized to validate the results of RNA sequencing. Immunofluorescence analyses were conducted to evaluate the number and morphology of hippocampal astrocytes. RESULTS: We observed significant short-term working memory impairment in BCAS mice. Moreover, the RNA obtained through RiboTag technology was specific to astrocytes. Transcriptomics approaches and subsequent validation studies revealed that the genes that showed expression changes in hippocampal astrocytes after BCAS were mainly involved in immune system processes, glial cell proliferation, substance transport and metabolism. Furthermore, the number and distribution of astrocytes in the CA1 region of the hippocampus tended to decrease after modeling. CONCLUSION: In this study, comparisons between sham and BCAS mice showed that the functions of hippocampal astrocytes were impaired in BCAS-induced chronic cerebral hypoperfusion-related VaD.

Selenium Alleviates Cerebral Ischemia/Reperfusion Injury by Regulating Oxidative Stress, Mitochondrial Fusion and Ferroptosis.

To clarify the potential role of selenium (Se) on cerebral ischemia/reperfusion (I/R) injury, we utilized mouse middle cerebral artery occlusion (MCAO) followed by reperfusion as an animal model and oxygen-glucose deprivation and reoxygenation (OGD/R) to treat N2a cells as a cell model, respectively. MCAO model was established in mice and then divided into different groups with or without Se treatment. TTC staining was used to observe whether the cerebral I/R modeling was successful, and the apoptosis level was determined by TUNEL staining. The expression of GPx-4 and p22phox was assessed by western blot. In vitro experiments, the OGD/R induced oxidative stress in N2a cells was assessed by levels of GSH/GSSG, malondialdehyde, superoxide dismutase and iron content, respectively. QRT-PCR was used to detect the mRNA levels of Cox-2, Fth1, Mfn1 and mtDNA in N2a cells. JC-1 staining and flow cytometry was performed to detect the mitochondrial membrane potential. Se treatment alleviated cerebral I/R injury and improved the survival rate of mice. Additionally, Se treatment apparently attenuated oxidative stress and inhibited iron accumulation in MCAO model mice and OGD/R model of N2a cells. In terms of its mechanism, Se could up-regulate Mfn1 expression to alleviate oxidative stress and ferroptosis by promoting mitochondrial fusion in vivo and vitro. These findings suggest that Se may have great potential in alleviating cerebral I/R injury.

Beyond city expansion: multi-scale environmental impacts of urban megaregion formation in China.

Environmental degradation caused by rapid urbanization is a pressing global issue. However, little is known about how urban changes operate and affect environments across multiple scales. Focusing on China, we found urbanization was indeed massive from 2000 to 2015, but it was also very uneven, exhibiting high internal city dynamics. Urban areas in China as a whole became less green, warmer, and had exacerbated PM2.5 pollution. However, environmental impacts differed in newly developed versus older areas of cities. Adverse impacts were prominent in newly urbanized areas, while old urban areas generally showed improved environmental quality. In addition, regional environmental issues are emerging as cities expand, connect and interact to form urban megaregions. To turn urbanization into an opportunity for, rather than an obstacle to, sustainable development, we must move beyond documenting urban expansion to understand the environmental consequences of both internal city dynamics and the formation of urban megaregions.

The impacts of urban structure on PM2.5 pollution depend on city size and location.

Many cities across the world face the challenge of severe fine particulate matter (PM2.5) pollution. Among the many factors that affect PM2.5 pollution, there is an increasing interest in the impacts of urban structure. However, quantifying these impacts in China has been difficult due to differences of study area and scale in existing research, as well as limited sample sizes. Here, we conducted a continental study focusing on 301 prefectural cities in mainland China to investigate the effects of urban structure, including urban size and urban compactness, on PM2.5 concentrations. Based on PM2.5 raster and land cover data, we used quantile regression and a general multilinear model to estimate the effects and relative contributions of urban size and urban compactness on urban PM2.5 pollution, with explicit consideration for pollution level, urban size and geographical location. We found: (1) nationwide, the larger and more compact that cities were, the heavier the PM2.5 pollution tended to be. Additionally, this relationship became stronger with increasing levels of pollution. (2) In general, urban size played a more important role than urban form, and there were no significant interactive effects between the two metrics on urban PM2.5 concentrations at the national scale. (3) The impacts of urban size and form varied by city size and geographical location. The impacts of urban size were only significant for small or medium-large cities but not for large cities. Among large cities, only urban form had a significantly positive effect on urban PM2.5 concentrations. The further north and west that cities were, the more dependent PM2.5 pollution was on urban form, whereas the further south and east that cities were, the greater the impact of urban size. These results provide insights into how urban design and planning can be used to alleviate air pollution.

Shortened duration and reduced area of frozen soil in the Northern Hemisphere.

The changes in near-surface soil freeze-thaw cycles (FTCs) are crucial to understanding the related hydrological and biological processes in terrestrial ecosystems under a changing climate. However, long-term dynamics of soil FTCs at the hemisphere scale and the underlying mechanisms are not well understood. In this study, the spatiotemporal patterns and main driving factors of soil FTCs across the Northern Hemisphere (NH) during 1979-2017 were analyzed using multisource data fusion and attribution approaches. Our results showed that the duration and the annual mean area of frozen soil in the NH decreased significantly at rates of 0.13 ± 0.04 days/year and 4.9 × 104 km2/year, respectively, over the past 40 years. These were mainly because the date of frozen soil onset was significantly delayed by 0.1 ± 0.02 days/year, while the end of freezing and onset of thawing were substantially advanced by 0.21 ± 0.02 and 0.15 ± 0.03 days/year, respectively. Moreover, the interannual FTC changes were more drastic in Eurasia than in North America, especially at mid-latitudes (30°-45° N) and in Arctic regions (>75° N). More importantly, our results highlighted that near-surface air temperature (T a ) and snowpack are the main driving factors of the spatiotemporal variations in soil FTCs. Furthermore, our results suggested that the long-term dynamics of soil FTCs at the hemisphere scale should be considered in terrestrial biosphere models to reduce uncertainties in future simulations.

Transformation of China's urbanization and eco-environment dynamics: an insight with location-based population-weighted indicators.

Within a short period, rapid urbanization has reshaped China's eco-environment, especially at the beginning of the new century. Many studies have focused on the changes in certain physical indicators of eco-environments; however, these indicators cannot directly explain or only slightly consider the eco-environmental benefits of urban residents. Therefore, we analysed location-based population-weighted eco-environmental changes with indicators of the vegetation index and fine particulate matter (PM2.5) concentration at each pixel in China's prefectures and combined the changes with urban expansion to provide an expanded understanding of the transformation of China's urbanization and its eco-environmental dynamics. We discovered that China's urban areas expanded by 38,350 km2 from 2000 to 2015 with an increase in the population-weighted vegetation and PM2.5 concentration, but the changes varied among different periods. From 2005 to 2010, urban areas expanded by 20,970 km2 with an increase in the population-weighted vegetation and PM2.5 concentration. The period from 2000 to 2005 was a key transforming period that experienced an urban expansion of 9081 km2 with a decrease in the population-weighted vegetation and an increase in the population-weighted PM2.5 concentration. An urban expansion of 8299 km2 with an increase in the population-weighted vegetation and a decrease of the population-weighted PM2.5 concentration occurred from 2010 to 2015. The results of this research indicate that China's urbanization and environmental changes have facilitated eco-environmental improvements.

A review of current air quality indexes and improvements under the multi-contaminant air pollution exposure.

The air quality is one of the major concerns in the urban environment due to the rapid changes in pollutant emissions driven by complex and intensive human activities. Therefore, quantification of the urban air quality has become an essential need for both urban residents and authorities to quickly assess air quality conditions. To reach this aim, the air quality index (AQI) is the primary way to better understand the urban air quality. However, the varied AQIs in different countries are difficult to directly compare due to the varied calculation methods. Thus, this research presents an updated review of the major AQIs worldwide by dividing them into two categories: single- and multi-contaminant-oriented AQIs. Single-contaminant-oriented AQIs are based on the maximum value of individual pollutants and are applied in most countries with location-dependent standards, such as the United States, China, the United Kingdom and New South Wales, Australia. However, these may greatly underestimate the impact of multiple contaminants, be difficult to dynamically update or to be compared internationally. Moreover, multi-contaminant-oriented AQIs are available in the literature, which consider the combined effects of exposure to multiple contaminants. Among these AQIs, arithmetic pollutant aggregation simply integrates pollutants in a linear or nonlinear way, and weighted pollutant aggregation further assigns varied weights from different perspectives. Combining the advantages and disadvantages of the existing AQIs, the general air quality health index (GAQHI) is proposed as a pollutant-aggregated, local health-based AQI paradigm suitable for the present complex multi-contaminant situation. It provides a direction for the construction of a more accurate, consistent and comparable AQI system and can help both researchers and governments improve human well-being and achieve sustainable development.

Blood neurofilament light chain in Parkinson disease and atypical parkinsonisms: A protocol for systematic review and meta-analysis.

BACKGROUND: Neurofilament light chain (NfL), an index of neuroaxonal injury, is a promising diagnostic and prognostic fluid biomarker with high translational value in many neurodegenerative disorders. Blood NfL measurement has been an exciting and active field of research in idiopathic Parkinson disease (PD) and atypical parkinsonisms. However, blood NfL levels in these parkinsonisms from existing literature were inconsistent. No comprehensive meta-analysis has ever been conducted. METHODS: Three major biomedical electronic databases PubMed, Embase, and Web of Science were comprehensively searched from inception to July 10, 2020. This protocol will be prepared based on the guidelines recommended by the statement of Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). Original observational studies that measured blood (serum/plasma) NfL concentrations in patients with parkinsonisms (multiple system atrophy [MSA], progressive supranuclear palsy [PSP], corticobasal syndrome [CBS], and dementia with Lewy bodies [DLB]), and healthy controls (HCs) will be included. Quality assessment of the included studies will be performed using the Newcastle Ottawa Scale (NOS). Meta-analyses will be conducted using the STATA software version 13.0. The standardized mean differences as the measure of effect size and 95% confidence intervals were calculated for each comparison of blood NfL levels. Heterogeneity analysis, sensitivity analysis, publication bias, subgroup analysis, and meta-regression analysis will be carried out to test the robustness of the results. RESULTS: The meta-analysis will obtain the effect sizes of blood NfL levels in the following comparisons: PD versus HC, MSA versus HC, PSP versus HC, CBS versus HC, DLB versus HC, MSA versus PD, PSP versus PD, CBS versus PD, and DLB versus PD. CONCLUSIONS: The present meta-analysis will provide the quantitative evidence of NfL levels in idiopathic PD and atypical parkinsonisms, hoping to facilitate differential diagnoses in clinical practice. REGISTRATION NUMBER: INPLASY202070091.

Cerebrospinal fluid and blood levels of neurofilament light chain in Parkinson disease: A protocol for systematic review and meta-analysis.

BACKGROUND: Parkinson disease (PD) is a common neurodegenerative disorder. Elevations of neurofilament light chain (NfL) concentrations in the cerebrospinal fluid (CSF) and blood are a marker of neuronal/axonal injury and degeneration. However, CSF and blood NfL alterations in patients with PD from existing studies remain inconclusive. To better understand these conflicting data, we will conduct a meta-analysis. METHODS: We will comprehensively search PubMed, Embase, and Web of Science databases from each database's inception to 7th June, 2020. This protocol will conform to the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols. We will only include original studies published in English that evaluated differences of NfL concentrations in the CSF or blood between idiopathic PD patients and healthy controls. The Newcastle-Ottawa Scale will be used to evaluate the quality of the included studies. Meta-analyses will be carried out using the STATA software version 13.0. Between-group difference of NfL concentrations in the CSF and blood will be expressed as the weighted standardized mean difference. A random-effects model will be used. Supplementary analyses, such as heterogeneity analysis, sensitivity analysis, publication bias, subgroup analysis, and meta-regression analysis will be performed. RESULTS: The meta-analysis will provide the differences of NfL concentrations in the CSF and blood between patients with PD and healthy controls and will show the magnitudes of their effect sizes. CONCLUSIONS: This meta-analysis will provide the evidence of NfL concentrations in the CSF and blood in PD and we hope that our study has an important impact on clinical practice. REGISTRATION NUMBER: INPLASY202060025.

China's Complex Urban Air Pollution: An Improved Understanding with Ground Operational Measurements.

Complex urban air quality has long been assessed by a single (or major) contaminant, for example, fine particulate matter (PM2.5), but scant attention has been given to multicontaminant air pollution, especially in countries with severe air pollution, for example, China. We thus proposed an improved method for quantifying both single- and multicontaminant air pollution. Our approach uses China's major cities as an example because they have an operational national urban air quality monitoring network. We found that our proposed method could remove the duplicated consideration under both single- and multicontaminant conditions, thus proving to be an improved and more accurate way to understand complex urban air pollution conditions. Our method involved monitoring 3 contaminants (PM2.5, PM10, and SO2 ) in cities in Shanxi, Shandong, Henan, and Hebei Provinces and 2 contaminants (PM2.5 and PM10) in the cities between the Yellow River and the Yangtze River, and these pollutants were the major contributors to multicontaminant air pollution. We argue that both the research community and the government should pay increased attention to multicontaminant air pollution beyond the current single major pollutant-based air pollution method when building a sustainable city. Integr Environ Assess Manag 2020;16:306-313. © 2020 SETAC.

Multi-scale effects of urban agglomeration on thermal environment: A case of the Yangtze River Delta Megaregion, China.

The phenomenon of urban heat islands has been extensively investigated in recent decades. Due to the complexity of urban systems, this phenomenon may be scale-dependent, particularly for large megaregions where a cluster of cities gather together. Despite many studies focusing on urban heat islands at scales from single-site to regional, and further to global, there are few studies addressing multi-scale effects of large urban agglomeration on thermal environment. In this study, we used the Yangtze River Delta (YRD), one of China's most important megaregions, as a pilot case to examine the spatial-temporal variations of thermal environment and its driving forces at two spatial scales in 2000, 2005 and 2010. At regional scale, the effect of the entire megaregion on thermal environment was characterized by the distribution of the highest surface temperature zone (HTZ), which was closely related to the occurrence of continuously developed land. At city scale, the effect of individual city on thermal environment was characterized by the mean land surface temperature difference (LSTD) between urban and rural areas, which showed a significant positive correlation with the economic factors. In the YRD, the secondary industry output could explain approximately 58% and 39% of the variation of the LSTD in 2000 and 2005, respectively, while in 2010 the tertiary industry output became the important factor and accounted for 36% of the variation of LSTD. Finally, cities with fast urban economic growth rate and large size of urban areas were the priority for adopting more efficient strategies to urban thermal management.

Spatiotemporal variation in PM2.5 concentrations and their relationship with socioeconomic factors in China's major cities.

The air quality issues caused by extreme haze episodes in China have become increasingly serious in recent years. In particular, fine particulate matter (PM2.5) has become the major component of haze with many adverse impacts and has therefore become of great concern to scientists, government, and the general public in China. This study investigates the spatiotemporal variation in PM2.5 in 269 Chinese cities from 2015 to 2016 and its associations with socioeconomic factors to identify the possible strategies for PM2.5 pollution mitigation. Specifically, we first quantified the spatial pattern of PM2.5 concentrations in both 2015 and 2016, and then changes between the two years. Next, we examined the relationship between socioeconomic factors and PM2.5 concentrations and changes. The results showed that most cities in eastern China experienced decreases in PM2.5 concentration, although most of these cities already had high PM2.5 pollution level. Cities with low PM2.5 concentrations experienced increases in PM2.5 concentrations and were mostly located in southern and southwestern China. The PM2.5 concentration was the highest in winter, followed by in spring, autumn and summer; for changes in PM2.5 concentrations, the highest magnitude of decrease occurred in summer, followed by the decreases in winter, autumn and spring. Cities with high PM2.5 concentrations tended to be clustered, but the clustered characteristics were not clearly related to the changes in PM2.5 concentrations. The relationship between PM2.5 concentration and urban size was an inverse U-shaped curve, suggesting the existence of the Environmental Kuznets Curve for air quality in China. Population density and secondary industry share are the keys factors relating to air pollution control. In comparison to other cities, most moderately developed cities had a greater magnitude of decrease in PM2.5 concentrations and the key factor for pollution improvement was industrial structure; however, smaller cities tended to have a greater increase in PM2.5 concentrations and population density was the most important influencing factor. As a result, for air pollution control in China, specific regulations should be carried out according to different regions and different developmental stages based on the locations of cities.

Reduction of wheat photosynthesis by fine particulate (PM2.5) pollution over the North China Plain.

The negative impact of rapid urbanization in developing countries has led to a deterioration of urban and regional air quality. Much attention has been given to the impact of fine particulate pollution on urban public health. However, very little attention has been given to its impact on the regional ecosystem such as the agricultural ecosystem. Thus, we evaluate the direct impact of air pollution on the reduction of wheat photosynthesis by fine particulate matter (PM2.5) pollution in the world's most heavily polluted area, the North China Plain, using remote sensing observations and ground measurements. We found the following to be true: (1) Heavy PM2.5 pollution could significantly reduce wheat photosynthesis and cause an expositional relationship between the PM2.5 concentration and wheat photosynthesis (R2 = 0.9824, P < 0.05); (2) Heavy PM2.5 pollution makes up 2% for the reduction in wheat photosynthesis at all wheat-plant farmlands in the North China Plain, approximately covering an area of 354,400 km2; (3) Increasing heavy PM2.5 pollution significantly reduced wheat photosynthesis by 87% in wheat-planted farmland during 1999-2011. We hope the results presented here could draw attention to the effect of PM2.5 pollution on the agricultural ecosystem and encourage further studies to evaluate the feedback of atmospheric pollution on the agricultural ecosystem using remote sensing. Abbreviation: Northern China Plain (NCP); normalized difference vegetation index (NDVI); The Moderate Resolution Imaging Spectroradiometer (MODIS); fine particulate matter (PM2.5).

Urbanization strategy and environmental changes: An insight with relationship between population change and fine particulate pollution.

Fine particulate (PM2.5) pollution, along with the rapid urbanization process, has been given much attention in China during the recent decades. However, the relationships between urban population dynamics and PM2.5 changes have not been well examined. We therefore analyzed their relationship using full-coverage remotely sensed PM2.5 and population density data. The results showed that 1) both population density and PM2.5 concentration increased rapidly from 2000 to 2014, especially in East and Central China, as well as China's high population density urban areas and the major cities; 2) A total of 723 million people was exposed to PM2.5 pollution in 2014, an increase of 105 million from 2000; 3) most of the urban areas exhibited population density increase/decrease with PM2.5 concentration increase, while a total of 42% of China's territory, mainly in East and Central China's rural areas were found to have population decrease but PM2.5 concentration increase. We hope the results in this work can serve as an example to other countries in designing their urbanization strategy by paying more attention to environmental degeneration accompanying rapid development. CAPSULE ABSTRACT: Most of urban areas were observed to have population density increase/decrease along with PM2.5 concentration increase.

Multicontaminant air pollution in Chinese cities.

OBJECTIVE: To investigate multicontaminant air pollution in Chinese cities, to quantify the urban population affected and to explore the relationship between air pollution and urban population size. METHODS: We obtained data for 155 cities with 276 million inhabitants for 2014 from China's air quality monitoring network on concentrations of fine particulate matter measuring under 2.5 µm (PM2.5), coarse particulate matter measuring 2.5 to 10 µm (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2) and ozone (O3). Concentrations were considered as high, if they exceeded World Health Organization (WHO) guideline limits. FINDINGS: Overall, 51% (142 million) of the study population was exposed to mean annual multicontaminant concentrations above WHO limits - east China and the megacities were worst affected. High daily levels of four-contaminant mixtures of PM2.5, PM10, SO2 and O3 and PM2.5, PM10, SO2 and NO2 occurred on up to 110 days in 2014 in many cities, mainly in Shandong and Hebei Provinces. High daily levels of PM2.5, PM10 and SO2 occurred on over 146 days in 110 cities, mainly in east and central China. High daily levels of mixtures of PM2.5 and PM10, PM2.5 and SO2, and PM10 and SO2 occurred on over 146 days in 145 cities, mainly in east China. Surprisingly, multicontaminant air pollution was less frequent in cities with populations over 10 million than in smaller cities. CONCLUSION: Multicontaminant air pollution was common in Chinese cities. A shift from single-contaminant to multicontaminant evaluations of the health effects of air pollution is needed. China should implement protective measures during future urbanization.

The rapid but "invisible" changes in urban greenspace: A comparative study of nine Chinese cities.

Quantifying the spatial pattern and change of urban greenspace is a prerequisite to understanding the myriad ecosystem services provided by urban greenspace. Previous studies have largely focused on loss of greenspace due to urban expansion, using medium resolution imagery. This paper presents a comparison study on the spatiotemporal patterns of urban greenspace in nine major cities in China, using 2.5m resolution ALOS and SPOT image data collected in 2005 and 2010, respectively. The changes in urban greenspace were further compared with those based on the commonly used 30m Landsat TM data. The results show: 1) Urban greenspace was highly fragmented and heterogeneous, characterized by a mix of a large number of small-sized patches (smaller than 0.1ha) with relatively few dispersed large patches in nine cities. 2) In contrast to findings from previous research that greenspace in inner cities tends to remain largely unchanged, urban greenspace in all nine cities was highly dynamic, experiencing both gain and loss, with net change ranging from 0.51% to 11.26% over five years. Most of the changes in urban greenspace, however, tended to occur as small patches, and could only be revealed by high spatial resolution imagery. 3) Spatial patterns of greenspace varied greatly across cities in terms of patch size, patch and edge density, and shape. Urban greenspace became increasingly fragmented and complex in the southern cities, but the opposite in the northern cities. The high turnover dynamics of urban greenspace in cities proper provide opportunities for better design and planning to achieve urban sustainability, but also call for better protection of small-sized urban greenspaces in Chinese cities.