Urban Land Use Intensity Research Articles

Do development zones increase urban land use intensity? Empirical analysis from 235 cities in China

The development zone has been considered the engine of China's urban development in recent decades. However, the prosperity of development zones has also brought many land use problems. Given the lack of high-resolution time-series land-use data, the impact of development zone construction on urban land use has not been adequately addressed within the existing literature. Employing new annual high-resolution satellite data, this article for the first time quantifies the impact of development zones on the expansion of urban areas and on changes in land-use intensity across China, identifying spatial and temporal differences in their impact using Propensity Score Matching with a Difference-in-Difference (PSM-DID) model. Using panel data for 235 Chinese cities from 1990 to 2015, we found that establishing development zones increased the expansion of urban areas and reduced the urban land-use intensity in the short term (usually 2 years). From spatial perspectives, the impact of development zones on land use displayed spatial heterogeneity. Finally, we put forward policy suggestions to improve the land use intensity of development zones in the context of sustainable development.

A Quantitative Study of a Directional Heat Island in Hefei, China Based on Multi-Source Data

Surface urban heat islands (SUHIs) are essential for evaluating urban thermal environments. However, current quantitative studies of SUHIs ignore the thermal radiation directionality (TRD), which directly affects study precision; furthermore, they fail to assess the effects of TRD characteristics at different land-use intensities, on the quantitative studies of SUHIs. To bridge this research gap, this study eliminates the interference of atmospheric attenuation and daily temperature variation factors, in quantifying the TRD based on land surface temperature (LST), from MODIS data and station air temperature data for Hefei (China) from 2010-2020. The influence of TRD on SUHI intensity quantification was evaluated by comparing the TRD under different land-use intensities in Hefei. The results show that: (1) daytime and nighttime directionality can reach up to 4.7 K and 2.6 K, and occur in areas with the highest and medium urban land-use intensity, respectively. (2) There are two significant TRD hotspots for daytime urban surfaces, where the sensor zenith angle is approximately the same as the forenoon solar zenith angle, and where the sensor zenith angle is near its nadir in the afternoon. (3) The TRD can contribute up to 2.0 K to the results of assessing the SUHI intensity based on satellite data, which is approximately 31-44% of the total SUHI in Hefei.

Disparity and Spatial Heterogeneity of the Correlation between Street Centrality and Land Use Intensity in Jinan, China

In the existing literature on the correlation between street centrality and land use intensity (LUI), only a few studies have explored the disparity of this correlation for different types of LUI and the differences across various locations. In response to the above shortcomings, in this study, the main urban area of Jinan, China, was taken as an example, and the disparity and spatial heterogeneity of the correlation between street centrality and LUI were explored for different categories of land use. The multiple centrality assessment (MCA) model was used to calculate the closeness centrality, betweenness centrality, and straightness centrality of the traffic network. Based on the floor area ratio (FAR) of each parcel, the utilization intensities of the residential, industrial, commercial, and public service land uses were measured. Employing the kernel density estimation (KDE) method, the street centrality of the traffic network vis-à-vis the urban LUI was rasterized into the same spatial analysis framework. The Pearson correlation coefficient and geographically weighted regression (GWR) were used to measure the correlation between the two variables and the spatial heterogeneity of the correlation, respectively. The results showed that traffic network street centrality strongly correlated with the LUI of the residential, commercial, and public service land use types, but it had a very weak association with the LUI of industrial land use. The GWR results also confirmed the spatial heterogeneity of the correlation. The results of this research highlighted the important role of traffic network street centrality in understanding the urban spatial structure. The study also helped to explain the dynamic mechanism of the road network form and the topological structure of urban spatial evolution.

How urban land-use intensity affected CO2 emissions at the county level: Influence and prediction

Currently, China will promote county towns’ urbanization, and few studies have analyzed spatial effects of urban land-use intensity on CO2 emissions and predicted CO2 emissions at the county level accurately. Here, taking data from 2010 to 2015 at the county level of Zhejiang Province as an example, we analyzed the spatial effect of urban land-use intensity from three aspects of input, density and output on CO2 emissions by the spatial Durbin model (SDM). And then a machine learning method of Back Propagation Neural Network (BPNN) was proposed to predict CO2 emissions for 2035 nonlinearly under the different promotions of urban land-use intensity. The main result and conclusion showed that: (1) The spillover effects of urban land-use density were negatively related to CO2 emissions, and urban land-use output intensity showed positive spillover effects on CO2 emissions; (2) The prediction of BPNN showed that the improvement of urban land-use intensity would not be effective in CO2 emissions reductions for southwestern counties with both low levels of urbanization and urban land-use intensity; (3) It was effective in CO2 emissions reduction by slowing down the growth rate of urban land-use capital input intensity, especially for the northeast region which was developed by the port economy. Our study encouraged a regional differentiated urban land-use intensity improvement strategy for Zhejiang to achieve low carbon development.

The association of physical development density, prevalence and types of microbes in colonized façade finishes in Enugu metropolis, Nigeria

PurposeThis research examines the association of physical development density, prevalence and types of microbes in colonized façade finishes of buildings in Enugu metropolis, Nigeria.Design/methodology/approachSurvey and experimental research designs were adopted. A total of 383 buildings were investigated with samples collected from those with colonized façade finishes. The microbes were identified using the standard procedure for genomic sequencing with descriptive statistics, and the chi-square test used to analyse the data.FindingsThe results revealed a 64% prevalence of microbial colonization and a significant association between this and physical development density with 71.0% of the colonized buildings located in high-density neighbourhoods of the metropolis. The sequencing also showed 24 different microbes with Trichophyton tonsurans, Trichophyton mentagrophytes and Trichoderma harzianum species being the most common in the colonized façade finishes.Practical implicationsThe research informs building professionals and owners of the specific microbes involved in the colonization of façade finishes of buildings in high-density urban areas. It also provides a clue about the nature of damages and defects associated with microbial colonization of building façades and the type of biocide additives required for the production of microbial-resistant façade finishes in the hot-humid tropical environment of Nigeria and beyond.Originality/valueThe study has shown that there is a significant relationship between the intensity of urban land use and microbial colonization of façade finishes of buildings. It also identified some new or less known microbes responsible for the biodeterioration of façade finishes and the effects this has on the buildings and public health in the hot-humid tropics of Enugu, Southeast Nigeria.

The Impact of Urbanization Growth Patterns on Carbon Dioxide Emissions: Evidence from Guizhou, West of China

Little attention has been paid to the impact of future urban expansion patterns on carbon emissions based on the existing urban pattern of a region. This study used the Central Guizhou Urban Agglomeration as the study area, and the relationships between regional urbanization and CO2 emissions in the study area were analyzed based on historical data. Urban growth patterns were then simulated in four scenarios that focused on the next 15 years, and they were based on the cellular automaton model. In each different scenario, the CO2 emissions were predicted, and some implications regarding the impact of those emissions were provided. The results showed that as urban land-use intensity increases, CO2 emissions first increase then decrease; however, the rate of decline for CO2 emissions is much slower than the rate at which it rises. Moreover, in the next 15 years, urban expansion will lead to a significant increase in CO2 emissions. The CO2 emissions were found to be lowest in the spatial agglomeration scenario and highest in the spatial dispersion scenario. The spatial agglomeration scenario was conducive to understanding how CO2 emissions eventually peak; however, different cities in the study area should adopt different urban expansion patterns. These research results can provide a reference guide for the government with regard to urban planning.

Optimizing distribution of urban land on the basis of urban land use intensity at prefectural city scale in mainland China

Urban land use intensity (ULUI) reflects the utilization status of urban land use. However, few studies have allocated urban land distribution across provinces or cities based on the ULUI. We propose an optimization method to allocate the urban land based on ULUI to make it effective and decrease the loss of ecosystem services. Using mainland China as the research area, we first estimated ULUI at the prefectural city level in 2015 and evaluated its spatial heterogeneity; urban land distribution in 2030 was then optimized by coupling the estimated ULUI and the LAND System Cellular Automata model for Potential Effects (LANDSCAPE). Specifically, we generated two scenarios: ULUI, and quota (QT). Results showed the following: (1) ULUI demonstrated a spatially heterogenous distribution in 2015. Cities with high ULUI were mainly centralized around urban agglomerations; those with low ULUI were distributed in the northwest and northeast of the research area, where there were economically undeveloped regions. (2) Using optimization, the total economic benefits (EBs) increased and the loss of ecosystem service value (ESV) decreased. Many prefectural cities increased economic output, and reduced ecological losses, even in some rapidly cities. Our research highlights that optimizing urban land based on ULUI is a reasonable method to increase EBs and reduce ESV loss.

Impacts of high-speed rail development on urban land expansion and utilization intensity in China

Urban land expansion (ULE) is a crucial factor for socioeconomic and environmentally sustainable development. However, nowadays, the unprecedented scale of high-speed railway (HSR) construction in China could exert an important influence on ULE. This manuscript first reveals the influence mechanism of HSR on ULE and then employs difference-in-difference (DID) models to investigate this effect based on the data of 280 prefectures and above level cities of 2001-2016. We analyze that HSR exerts a joint effect on ULE from the territorial and local levels and then affects urban land-use intensity (ULUI). HSR opening and HSR station distance both have notably positive effects on ULE, with elastic coefficients of 4.1% and 0.5%, respectively. HSR opening and HSR station distance also both exert positive effects on ULE of the central, eastern region cities and large cities of China, while for the western region and small to medium cities, they are not significant. The impact of HSR station distance on ULUI is negative with a significance level of 0.073, while the impact of HSR opening on ULUI is not significant. Lastly, relevant policy implications are proposed to alleviate urban land waste and spatial disequilibrium under the context of HSR building. This study can provide an important basis for sustainable urban land allocation.

Urban land use effects of high-speed railway network in China: A spatial spillover perspective

In the past decade, China’s high-speed railway (HSR) system has expanded rapidly and become the longest and most complex network in the world. To fully exploit the HSR dividend, many cities have constructed HSRs in new locations, triggering urban land use change, especially around the HSR stations. This study has used the difference-in-difference (DID) method to explore the effect of HSRs on urban land use using long-term nighttime light (NTL) data. The main conclusions are that the operation of HSRs has increased the intensity of urban land use by about 4.4%, with the land use effect of the “renewed HSR stations” being significantly higher than that of the “newly-built stations”; further the development of tertiary industry has promoted a siphoning effect, that is the spillover of HSR stations in large cities is strengthened relative to that for small cities. Based on these results, the study further analyzed the performance of areas with new HSR installations and the factors controlling the inter-city heterogeneities.

THE IMPACT OF URBAN GROWTH BOUNDARIES IN MELBOURNE ON URBAN SUSTAINABLE DEVELOPMENT

The consensus of using the compact city as a model for urban sustainable development has inevitably led to governments restricting outer urban expansion as an urban management tool. Urban growth boundaries (UGBs) have become one of the most widely used policy tools to achieve this goal. To evaluate the impact of UGBs on urban sustainable development in Melbourne, Australia, we compare the temporal and spatial changes of population, dwelling density, and growth before and after the implementation of the UGB policy in the Melbourne metropolitan area. The results indicate that, since the implementation of the UGB policy, the urban population, dwelling density, and growth have significantly accelerated; however, nearly half of the new population is located on the urban fringe. Based on the pressure of population growth, the UGB in Melbourne has been adjusted frequently, which has reduced its binding force on urban growth. Herein, we focus on the reasons for amendments to the Melbourne UGB, namely, urban density and the intensity of urban land use and compare the UGB policies of the Melbourne and Portland, Oregon (USA), metropolitan areas. We argue that the state government should restrict urban growth boundaries and increase urban density. At the same time, UGB policy must be coordinated with broader government policy, such as urban land use, urban transportation, and environmental planning, and a mechanism should be established to release land supply in defined areas. In addition, governments should expand public participation in the UGB amendment process and in supporting the implementation of the UGB policy

Detecting Urban Polycentric Structure from POI Data

It is meaningful to analyze urban spatial structure by identifying urban subcenters, and many methods of doing so have been proposed in the published literature. Although these methods are widely applied, they exhibit obvious shortcomings that limit their further application. Therefore, it is of great value to propose a new urban subcenter identification method that can overcome these shortcomings. In this paper, we propose the density contour tree (DCT) method for detecting urban polycentric structures and their spatial distributions. Conceptually, this method is based on an analogy between urban spatial structure and terrain. The point-of-interest (POI) density is visualized as a continuous mathematical surface representing the urban terrain. Peaks represent the regions of the most frequent human activity, valleys represent regions with small population densities in the city, and slopes represent spatial changes in urban land-use intensity. Using this method, we have detected the urban “polycentric” structure of Beijing and determined the corresponding spatial relationships. In addition, several important properties of the urban centers have been identified. For example, Beijing has a typical urban polycentric structure with an urban center area accounting for 5.9% of the total urban area, and most of the urban centers in Beijing serve comprehensive functions. In general, the method and the results can serve as references for the later research on analyzing urban structure.

东南诸河流域1990-2015年土地利用时空变化特征及驱动机制

PDF HTML阅读 XML下载 导出引用 引用提醒 东南诸河流域1990-2015年土地利用时空变化特征及驱动机制 DOI: 10.5846/stxb201810102187 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金地区基金项目（31660233）；国家自然科学基金项目（51711520317） Spatial and temporal variability characteristics and driving mechanisms of land use in the Southeastern River Basin from 1990 to 2015 Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:土地利用/覆被变化作为影响全球环境变化的重要因素，是人类活动最直接的反映，其驱动力分析能够很好地揭示人类活动对土地资源的影响机制。运用ArcGIS空间分析和SPSS主成分分析等方法，从整个东南诸河流域片区的尺度上，研究了包含中国台湾地区在内的1990-2015年间的土地利用时空变化特征，并探究其主要驱动机制。研究结果为：（1）全流域各土地类型面积占比为：林地 > 耕地 > 草地 > 城乡建设用地 > 水域 > 未利用土地，林地与耕地的空间分布特征均为"北聚南散，北多南少"，城乡建设用地集中分布在经济较为发达的台湾海峡两岸沿海地区以及流域大陆北部靠近长江三角洲的地区。（2）全流域土地类型的面积变化量为：城乡建设用地 > 耕地 > 草地 > 林地 > 水域 > 未利用土地。流域土地利用综合动态度为0.68%，整体用地类型转化程度先降低再增加，并以城乡建设用地和耕地为主要变化类型。流域南部各市的土地利用变化较北部剧烈，台湾地区主要土地利用变化类型为耕地和城乡建设用地。（3）大陆地区城乡建设用地变化的主要驱动力为人口数量及结构、城市化和社会经济发展，台湾地区在此基础上增加了社会工农产业结构调整因素。大陆耕地变化的主要驱动力为人口数量及结构、城市化水平和社会工农产业结构，社会工农产业结构和农业生产水平是台湾地区耕地变化的主要驱动力。本研究为东南诸河流域土地资源规划管理提供科学依据，为自然流域尺度的土地利用变化及其驱动机制研究提供可靠实例。 Abstract:Land use change, an important factor affecting global environmental change, is one of the most crucial human activities. Research on land use change is critical to reveal the mechanism of impacts of human activities on land resources. In this study, we used the ArcGIS spatial analysis function and the SPSS principal components method to analyze the spatial and temporal changes of land use in the Southeastern River Basin (including Taiwan) from 1990 to 2015 and explore the possible driving mechanisms. The main results are as follows:(1) From 1990 to 2015, the proportions of different land types throughout the basin was forest land > farmland > grassland > urban and rural construction land > water area > unused land. Forest and cultivated land largely gather on the north of the basin, while they are more scattered and less in the south. Urban and rural construction land is concentrated in the coastal areas of Taiwan province, where the economy is relatively well developed, as well as in the northern basin near the Yangtze River Delta. (2) The comprehensive dynamic degree of land use in the basin is 0.68%, and the degree of conversion of overall land use type first declined and then increased from 1990 to 2015. Most changes occurred on urban and rural construction lands and cultivated land. Land usage change in the southern region of the basin is more intense than that in the north. The main type of land use change in Taiwan province was cultivated land and urban and rural construction land. The comparison of changes in the area of land types in the basin is:urban and rural construction land > cultivated land > grassland > forest land > water area > unused land. The most significant increases in urban and rural construction comes from cultivated land. Hence, the increases in cultivated land begins with forest land and then gradually transitions to urban and rural construction land. There is a certain degree of synergy between the intensity of urban land use and cultivated land. The latter has maintained a large degree of change and dominates the changing structure of each period. The average annual dynamics of other construction land in the past 25 years was 17.30%, showing clear growth trends. (3) The main driving forces behind urban and rural construction land usage changes in mainland China are population quantity and structure, urbanization level, and level of social and economic development. On this basis, Taiwan province has increased the social industrial and agricultural industrial structure adjustment factors. Additionally, the main driving forces behind changes in cultivated land in mainland China are population size and structure, urbanization level, and social and agricultural industrial structures. In Taiwan province, the social and agricultural industrial structures and agricultural production levels are the main forces driving changes in cultivated land. In this study, we analyzed the spatial and temporal variability and driving mechanisms of land use changes in the southeastern river basins. This study provides theoretical support for the rational planning for land resources in the region, and provides baseline data support for the comprehensive management of resources and the environment at the basin-wide scale. 参考文献 相似文献 引证文献

How to Measure Urban Land Use Intensity? A Perspective of Multi-Objective Decision in Wuhan Urban Agglomeration, China

Urban land intensive use is an important part of regional planning and plays an important role in the sustainable development of cities. However, the research on how to measure urban land use intensity is still controversial. This paper gives a perspective of multi-objective decision to explore the criterion of urban land use intensity in the process of urbanization. The theory of factor substitution was applied to analyze the mechanism of urban land intensive use in different urbanization stage. Additionally, the matching degree model (MDM), curve estimation model, and multi-objective programming model were employed in the case study of Wuhan urban agglomeration to give a multi-objective decision on urban land intensive use. The results show that the level of urban land intensive use lagging behind the level of urbanization development in more than 60% of the counties. When the level of urbanization is less than 30%, 30–70% and greater than 70%, the optimal intensity of urban land use characterized by fixed investments of unit land is 2.6252, 4.6132, and 6.7648 million RMB respectively. Based on optimal intensity, the counties in Wuhan urban agglomeration were divided into key development zone and optimized development zone. Finally, different management strategies were designed for different zones for urban land intensive use.

Impact of the top-down quota-oriented farmland preservation planning on the change of urban land-use intensity in China

Although the National General Land Use Plan (1997–2010) came into effect in 1999, there has been no research investigating whether the farmland protection planning embedded within the top-down general land-use plans has contributed to promoting intensive utilization of urban land. This paper aims to assess the impact of farmland preservation efforts in the plans on the changes in urban land-use intensity, by focusing on two policy tools – prime farmland preservation and farmland conversion quotas. The study developed an approach to categorize and measure the change in urban land-use intensity by combining the changes in population density (in terms of population per unit of urban land area) and economic density (in terms of GDP per unit of urban land area). An ordinal dependent variable was generated based on the categories of changes in urban land-use intensity and a multilevel ordinal logit model was used in this study. The study indicates that (1) the farmland conversion quota system did not contribute to promoting urban land-use intensification between 2000 and 2010; (2) the prime farmland preservation had very limited impact on the intensity of urban land-use intensification. The prime farmland preservation would not influence urban land-use intensity when it was not high enough. The increase in the prime farmland preservation ratio in prefectural-level regions could lead to urban land-use intensification but only when the prime farmland preservation ratio was above 93%; and (3) the central government's supervision of local land-use played a significant role in promoting urban land-use intensification.

Gradients of Atmospheric Temperature and Humidity Controlled by Local Urban Land-Use Intensity in Boston

AbstractCities are home to the majority of humanity. Therefore, understanding the mechanisms that control urban climates has substantial societal importance to a variety of sectors, including public health and energy management. In this study, data from an urban sensor network (25 stations) and moderate-resolution remote sensing were used to explore how spatial variation in near-surface air temperature Ta, vapor pressure deficit (VPD), and land surface temperature (LST) depend on local variations in urban land use, both diurnally and seasonally, in the Boston, Massachusetts, metropolitan area. Positive correlations were observed between the amount of local impervious surface area (ISA) and both Ta and VPD. Heat-island effects peaked during the growing-season nighttime, when mean Ta and VPD increased by up to 0.02°C and 0.008 kPa, respectively, per unit ISA. Air temperature and VPD were strongly coupled, but their relationship exhibited significant diurnal hysteresis during the growing season, with changes in VPD generally preceding changes in Ta. Over 79% of the urban–rural difference in VPD was explained by differences in near-surface atmospheric water content, which the authors attribute to reduced evapotranspiration from lower canopy cover in Boston’s urban core. Changes in daytime heat-island intensity were mediated by seasonal feedbacks between vegetation transpiration and VPD forcing. Differences between LST and Ta showed weaker coupling in highly urbanized areas than in rural areas, with summertime surface-urban-heat-island intensity (based on LST) being up to 14°C higher than corresponding urban–rural differences in Ta.

A New Approach for Detecting Urban Centers and Their Spatial Structure With Nighttime Light Remote Sensing

Urban spatial structure affects many aspects of urban functions and has implications for accessibility, environmental sustainability, and public expenditures. During the urbanization process, a careful and efficient examination of the urban spatial structure is crucial. Different from the traditional approach that relies on population or employment census data, this research exploits the nighttime light (NTL) intensity of the earth surface recorded by satellite sensors. The NTL intensity is represented as a continuous mathematical surface of human activities, and the elemental features of urban structures are identified by analogy with earth’s topography. We use a topographical metaphor of a mount to identify an urban center or subcenter and the surface slope to indicate an urban land-use intensity gradient. An urban center can be defined as a continuous area with higher concentration or density of employments and human activities. We successfully identified 33 urban centers, delimited their corresponding boundaries, and determined their spatial relations for Shanghai metropolitan area, by developing a localized contour tree method. In addition, several useful properties of the urban centers have been derived, such as 9% of Shanghai administrative area has become urban centers. We believe that this method is applicable to other metropolitan regions at different spatial scales.

Management of urban land expansion in China through intensity assessment: A big data perspective

Rapid urbanization and widespread urban sprawl have induced a new era of urban resource management that focuses on efficiency, particularly in megacities in China. Big data is a platform for multi-source data fusion that helps to create spatially explicit decisions in regulating urban land expansion. In this study, we use big data to assess the intensity of urban land use in the metropolitan areas of China. OpenStreetMap and point-of-interest data are used to infer the urban function of each established parcel. Geographical weighted regression (GWR) is used to generate input–output matchups and to formulate integrated urban land use intensity values. To incorporate spatial relations among cities into a final assessment, spatial networks derived from check-in data of the social media platform, “Weibo,” are used to rank through the technique for order preference by similarity to the ideal solution (TOPSIS). Results show that Guangzhou has the most efficient urban land use system, followed by Shanghai and Shenzhen, and that Suzhou has the lowest urban land intensity. It is also revealed that the megalopolises in the Pearl River Delta and the Yangtze River Delta are superior in urban land use in general, whereas urban land use in the northern and western areas of China are less efficient. The megacities have strengths and weaknesses with respect to urban land use efficiency, and they advance at different stages when characteristic input–output relationships are identified. This advancement is largely attributed to their unique political, economic, and cultural roles in China. Further improvements in each land use function will be proposed in the future and the profound networked big data from each city will be utilized to improve urban resource management.

Interactions between urban vegetation and surface urban heat islands: a case study in the Boston metropolitan region

Many studies have used thermal data from remote sensing to characterize how land use and surface properties modify the climate of cities. However, relatively few studies have examined the impact of elevated temperature on ecophysiological processes in urban areas. In this paper, we use time series of Landsat data to characterize and quantify how geographic variation in Boston’s surface urban heat island (SUHI) affects the growing season of vegetation in and around the city, and explore how the quality and character of vegetation patches in Boston affect local heat island intensity. Results from this analysis show strong coupling between Boston’s SUHI and vegetation phenology at the scale of both individual landscape units and for the region as a whole, with significant detectable signatures in both surface temperature and growing season length extending 15 km from Boston’s urban core. On average, land surface temperatures were about 7 °C warmer and the growing season was 18–22 days longer in Boston relative to adjacent rural areas. Within Boston’s urban core, patterns of temperature and timing of phenology in areas with higher vegetation amounts (e.g., parks) were similar to those in adjacent rural areas, suggesting that vegetation patches provide an important ecosystem service that offsets the urban heat island at local scales. Local relationships between phenology and temperature were affected by the intensity of urban land use surrounding vegetation patches and possibly by the presence of exotic tree species that are common in urban areas. Results from this analysis show how species composition, land cover configuration, and vegetation patch sizes jointly influence the nature and magnitude of coupling between vegetation phenology and SUHIs, and demonstrate that urban vegetation provides a significant ecosystem service in cities by decreasing the local intensity of SUHIs.

Applying AHP and Maximal Value Normalization to Evaluate Intensity of Urban Land Use in Sujiatun District, Shenyang City

In order to explore the intensive extent of urban land use in Sujiatun District of Shenyang City, the AHP and maximal value normalization were taken to analyze the level of intensive use of urban land. Results indicated that land use is extensive and land functions are mixed in the study area. Land use intensity should be strengthened and more land should be reserved for construction so as to improve the land use efficiency.

Sex in the city: Reproductive success of Digitalis purpurea in a gradient from urban to rural sites

Urbanization of natural habitats is considered to have large impacts on local plant populations and their associated pollinator faunas, which are expected to cause changes in both plant-pollinator interactions and increased pollen limitation. This study investigated the effects of increasing intensity of urban land use on pollinator diversity, flower visitation rates and reproductive success in Digitalis purpurea. To this end, we set up experimental populations of D. purpurea in three urban–rural gradients and contrasted these against two large, natural populations. In the experimental populations we quantified the number of flower visits per 20min and applied supplemental hand-pollinations to determine the impact of pollen limitation on fruit-level seed set. We found no impact of urbanization intensity on pollinator diversity at all locations studied, and also the number of flower visits did not differ significantly between urban and rural populations. Reproductive success appeared, however, pollen limited in all sites, even in the large and optimal reference populations. This led us to conclude that the pollen limitation was caused by a bet-hedging strategy of the species rather than by insufficient pollination.