Effects of urbanization and forest type on species composition and diversity,forest characteristics,biomass carbon sink,and their associations in Changchun,Northeast China:implications for urban carbon stock improvement

Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban forests and improvement of function.To clarify the effect of two forest types with different urbanization intensities,we determined differences in vegetation composition and diversity,structural traits,and carbon stocks of 152 plots(20 m×20 m)in urban park forests in Changchun,which had the largest green quantity and carbon density effectiveness.We found that 1.1-fold thicker and healthier trees,and 1.6-to 2.0-fold higher,healthier,denser,and more various shrubs but with sparser trees and herbs occurred in the central urban forests(p<0.05)than in the outer forests.The conifer forests exhibited 30–70%obviously higher tree aboveground carbon sequestration(including stem and leaf)and 20%bigger trees,especially in the outer forests(p<0.05).In contrast,1.1-to 1.5-fold higher branch stocks,healthier and more diverse trees were found in broadleaved forests of both the inner and outer forests(p<0.05).Plant size and dominant species had similarly important roles in carbon stock improvement,especially big-sized woody plants and Pinus tabuliformis.In addition,a higher number of deciduous or needle species positively affected the broadleaved forest of the central urban area and conifer forest of the outer urban area,respectively.These findings can be used to guide precise management and accelerate the improvement of urban carbon function in Northeast China in the future.

Examining the Spatiotemporal Dynamics and Determinants of Land Urbanization in Prefecture-level Cities,China

Examining the spatiotemporal dynamics and determinants of land urbanization is critical for promoting healthy urban development and the rational use of land resources.Based on the dataset consisting of land use change data and selected factors in 2010 and2020,this study used visual analysis to reveal the spatiotemporal dynamics of land urbanization across prefecture-level cities in China.Meanwhile,the driving forces underlying land urbanization were examined by using geographical detector technique.Following are the findings:1)we find that there exist notable spatial variances in land urbanization across prefecture-level cities.Currently,the differentiation in land urbanization between the northern and southern cities is more pronounced than that between the coastal and inland cities,or between the eastern and western cities.Prefecture-level cities located in central and western China have experienced the most rapid growth in land urbanization.Conversely,the growth rate in northeastern China is the lowest,while the velocity in eastern China remains relatively stable.By using spatial autocorrelation analysis,this study reveals that the land urbanization level in prefecture-level cities has significant spatial agglomeration.2)We further find that land urbanization in China is influenced by factors related to urban land supply and demand,and urban population growth,economic growth,land financial and political incentive have greater impact on land urbanization than other factors.3)We also find that the impacts of determinants on China’s land urbanization vary over time,the explanatory power of economic development increased,while the explanatory power of state forces declined.We argue that integrating the supply and demand factors of land urbanization can provide a more comprehensive understanding of the driving mechanisms underlying land urbanization in China and other transitional countries,and help decision-makers in these countries formulate more detailed and specific land urbanization policies.

Spatio-temporal Evolution Characteristics and Driving Forces of Winter Urban Heat Island:A Case Study of Rapid Urbanization Area of Fuzhou City,China

Under the influence of anthropogenic and climate change,the problems caused by urban heat island(UHI)has become increasingly prominent.In order to promote urban sustainable development and improve the quality of human settlements,it is significant for exploring the evolution characteristics of urban thermal environment and analyzing its driving forces.Taking the Landsat series images as the basic data sources,the winter land surface temperature(LST)of the rapid urbanization area of Fuzhou City in China was quantitatively retrieved from 2001 to 2021.Combing comprehensively the standard deviation ellipse model,profile analysis and GeoDetector model,the spatio-temporal evolution characteristics and influencing factors of the winter urban thermal environment were systematically analyzed.The results showed that the winter LST presented an increasing trend in the study area during 2001–2021,and the winter LST of the central urban regions was significantly higher than the suburbs.There was a strong UHI effect from 2001 to 2021with an expansion trend from the central urban regions to the suburbs and coastal areas in space scale.The LST of green lands and wetlands are significantly lower than croplands,artificial surface and unvegetated lands.Vegetation and water bodies had a significant mitigation effect on UHI,especially in the micro-scale.The winter UHI had been jointly driven by the underlying surface and socio-economic factors in a nonlinear or two-factor interactive enhancement mode,and socio-economic factors had played a leading role.This research could provide data support and decision-making references for rationally planning urban layout and promoting sustainable urban development.

Impact of air pollution on urbanization:evidence at China’s city level

This paper investigates the effect and transmission mechanism of air pollution on urbanization based on data from China’s 107 cities during 2005–2018.In order to identify the impact of air pollution on China’s urbanization,we utilized night light data to represent the level of urbanization and used temperature inversion as an instrumental variable to mitigate endogeneity within the two-stage least squares framework.The results suggest that air pollution significantly slowed China’s urbanization process with economic growth acting as the transmission mechanism.The heterogeneity analyses revealed that air pollution had a greater negative impact on urbanization in northern regions than that in southern regions,and a greater negative impact in resource-oriented cities than that in non-resource-based cities.We also find that air pollution was to the detriment of urbanization in larger cities,which have more than 3 million residents,while it did not have a significant impact on Type II large cities,which have fewer than 3 million residents.

Weak influence of natural vegetation in urban green spaces compared to agricultural ecosystems on House Martin populations:Insights from nationwide citizen science data in the Czech Republic

The House Martin(Delichon urbicum)is a common farmland bird species in the European landscape,yet its population numbers are currently in decline.However,it is not yet sufficiently explained why this long-term decline occurs.To fill this gap in our knowledge,we investigated how land cover composition affects the abundance of House Martins on the landscape scale by using nationwide citizen science data.Utilizing a generalised linear mixed-effect model(GLMM),we evaluated 12,094 records from the Czech Republic spanning 2009-2017.Our analysis underscores the significance of land cover type in shaping House Martin abundance.More specifically,our results indicate that within agricultural land covers“naturally managed arable lands”exhibited significant positive effect,while forests,orchards,and vineyards were deemed less favourable for House Martin populations.Within urban land covers,we found a clear distinction in the impact on House Martin populations,with a positive effect observed in urban infrastructure,development areas,and post-industrial sites(i.e.,UrbanAreas),while an indifferent impact was noted within urban green spaces and landscaped areas(i.e.,GreenUrban).Notably,our findings suggest that the simple spatial,age,and species structure typical of forests in Europe,and similarly,the uniform structure of parks and gardens,may be responsible for the decline in the abundance of the House Martin.We advocate for the preservation or enhancement of urban greenery,expansion of natural vegetation in rural areas and adoption of ecological management practices in orchards and vineyards to mitigate further declines in House Martin populations.

Local Climate Change Induced by Urbanization on a South China Sea Island

The South China Sea is a hotspot for regional climate research.Over the past 40 years,considerable improvement has been made in the development and utilization of the islands in the South China Sea,leading to a substantial change in the land-use of the islands.However,research on the impact of human development on the local climate of these islands is lacking.This study analyzed the characteristics of local climate changes on the islands in the South China Sea based on data from the Yongxing Island Observation Station and ERA5 re-analysis.Furthermore,the influence of urbanization on the local climate of the South China Sea islands was explored in this study.The findings revealed that the 10-year average temperature in Yongxing Island increased by approximately 1.11℃from 1961 to 2020,and the contribution of island development and urbanization to the local warming rate over 60 years was approximately 36.2%.The linear increasing trend of the annual hot days from 1961–2020 was approximately 14.84 days per decade.The diurnal temperature range exhibited an increasing trend of 0.05℃per decade,whereas the number of cold days decreased by 1.06days per decade.The rapid increase in construction on Yongxing Island from 2005 to 2021 led to a decrease in observed surface wind speed by 0.32 m s^(-1)per decade.Consequently,the number of days with strong winds decreased,whereas the number of days with weak winds increased.Additionally,relative humidity exhibited a rapid decline from 2001 to 2016 and then rebounded.The study also found substantial differences between the ERA5 re-analysis and observation data,particularly in wind speed and relative humidity,indicating that the use of re-analysis data for climate resource assessment and climate change evaluation on island areas may not be feasible.

Research on the Digital Economy's Impact on China's Economic Growth:Based on the Variations in Urbanization Levels Across China's Eastern,Central,and Western Regions and Sectoral Heterogeneity

This paper uses inter-provincial panel data from 2011 to 2017,a linear regression model,and a threshold model to conduct empirical analyses of the impact of the digital economy on China's overall economic growth and the three main sectors of industry.The paper then investigates the impact and effects the digital economy has had on the economic growth of the three main sectors of industry in China's eastern,central,and western regions.Finally,the paper investigates the most significant differences among the various regions and the threshold effects of urbanization levels on the relationship between the digital economy and economic growth.The findings indicate a significantly positive correlation between the digital economy and regional economic growth.Moreover,geographical factors notably influence this correlation.The digital economy exerts a positive effect on all sectors of industry.It may not substantially impact industrial development in regions with highly developed infrastructure.Regarding the other regions,the digital economy exhibits varying degrees of impact due to the differences in the specific indicators.The conclusion drawn by the threshold model is that the magnitude of the threshold effect correlates with geographic factors.No threshold effect was observed in the eastern region,while the threshold effect occurred in the central region when the urbanization levels for the provinces were below 0.6645.Similarly,the threshold effect was noted in the western region when the urbanization level was below 0.3931.Considering all of this,the study also offers policy recommendations that will help balance the regional development of digital economies,accelerate the digital transformation of traditional industries,enhance digital infrastructure construction,refine the formulation and implementation of data policy,and establish relevant incentive mechanisms.

Carbon efficiency evaluation method for urban energy system with multiple energy complementary

Urban energy systems(UESs)play a pivotal role in the consumption of clean energy and the promotion of energy cascade utilization.In the context of the construction and operation strategy of UESs with multiple complementary energy resources,a comprehensive assessment of the energy efficiency is of paramount importance.First,a multi-dimensional evaluation system with four primary indexes of energy utilization,environmental protection,system operation,and economic efficiency and 21 secondary indexes is constructed to comprehensively portray the UES.Considering that the evaluation system may contain a large number of indexes and that there is overlapping information among them,an energy efficiency evaluation method based on data processing,dimensionality reduction,integration of combined weights,and gray correlation analysis is proposed.This method can effectively reduce the number of calculations and improve the accuracy of energy efficiency assessments.Third,a demonstration project for a UES in China is presented.The energy efficiency of each scenario is assessed using six operational scenarios.The results show that Scenario 5,in which parks operate independently and investors build shared energy-storage equipment,has the best results and is best suited for green and low-carbon development.The results of the comparative assessment methods show that the proposed method provides a good energy efficiency assessment.This study provides a reference for the optimal planning,construction,and operation of UESs with multiple energy sources.

Grid System Analysis of Urban Flora of Bukhara City (Uzbekistan)

This article presents information on the study of the flora of Uzbekistan based on grid system mapping. The urban flora of the city of Bukhara was researched in it. As a result of research, the territory of Bukhara city was divided into 85 indexes based on 1 × 1 km2 grid mapping system. The diversity and density of species in the indexes are determined. The influence of anthropogenic factors on the diversity of species in the indexes is determined.

Spatiotemporal Characteristics of Typical Ecosystem Services and Their Spatial Responses to Driving Factors in Ecologically Fragile Areas in Upper Yellow River,China

The identification of dominant driving factors for different ecosystem services(ESs)is crucial for ecological conservation and sustainable development.However,the spatial heterogeneity of the dominant driving factors affecting various ESs has not been adequately elucidated,particularly in ecologically fragile regions.This study employed the integrated valuation of ESs and trade-offs(InVEST)model to evaluate four ESs,namely,water yield(WY),soil conservation(SC),habitat quality(HQ),and carbon storage(CS),and then to identify the dominant driving factors of spatiotemporal differentiation of ES and further to characterize the spatial heterogeneity characteristics of the dominant driving factors in the eco-fragile areas of the upper Yellow River,China from 2000 to 2020.The results demonstrated that WY exhibited northeast-high and northwest-low patterns in the upper Yellow River region,while high values of SC and CS were distributed in central forested areas and a high value of HQ was distributed in vast grassland areas.The CS,WY,and SC exhibited decreasing trends over time.The most critical factors affecting WY,SC,HQ,and CS were the actual evapotranspiration,precipitation,slope,and normalized difference vegetation index,respectively.In addition,the effects of different factors on various ESs exhibited spatial heterogeneity.These results could provide spatial decision support for eco-protection and rehabilitation in ecologically fragile areas.

Greenway Non-mortorized System Planning from the Perspective of Public Health

The important role of greenway non-mortorized systems in urban sustainable development was summarized,pointing out their potential value in improving the ecological environment,promoting healthy living,and enhancing community connections.Based on the analysis on some cases of urban greenway construction in China,specific transformation models and strategies were proposed for greenway construction,which could integrate green spaces with non-mortorized system,so as to enhance the comprehensive efficiency of urban linear spaces.

The Implications of Urbanization Processes in Developed Countries for Africa

Urbanization is the inevitable path of national economic development,and the level of urbanization development in most African countries is still low.By analyzing five typical developed countries in the United States,Britain,France,Germany,and Japan,this paper discusses the promoting factors and problems of the rapid urbanization development in their specific years,as well as the experiences and lessons that Africa can learn,so as to prevent Africa from taking the detour in the urbanization process of Western developed countries and promote the balanced regional development of various African countries.

LiMo 2040 Sustainable urban Living and Mobility Concept-Elevator System

How can individual mobility in urban areas be maintained alongside scooters and cargo bikes if conventional vehicles are foreseeably no longer allowed to enter city centers?And how can urban living be combined with individual mobility in a sustainable and socially acceptable way?LiMo-2040 attempts to provide answers to these questions.It follows a holistic approach according to the criteria:As light,as compact and as simple(cost-effective)as possible.Modular e-vehicle concepts(consisting of vehicle cabin and chassis)are known,but have not yet been thought through to their logical conclusion.The LiMo cabin is not only a vehicle cabin,but also a component of a modern high-rise apartment.It therefore requires no parking space and combines urban living and individual mobility sustainably and cost-effectively.If a vehicle is needed,an app can be used to book a chassis that comes along autonomously and waits until the cabin,including its occupants,travels down a sophisticated rail system,docks and autonomously heads for the desired destination.

Sustainable Urban Mobility: (A)Synchrony between Subway Systems

The present study analyses the differences between the subways systems of two cities, Lisbon (Portugal) and Brasília (Brazil), verifying the extent to which their subway systems are spatially integrated with the respective urban fabric-which would promote a better synchrony in terms of economy and sustainability. For interpreting the data, the methodology and tools of the Theory of the Social Logic of Space were used, by means of axial maps, researching the relationship between the constructed and empty (public spaces) areas of the urban structures. Based on the findings, meaningful differences between the subway systems and the configuration of urban spaces were observed, as a product of specific design matrixes. In Lisbon, the mobility associated to the subway seems to be encouraged by the integration of the system with the potential for movement provided by the urban tissue (making the secondary centralities articulated with the subway stations more dynamic). In Brasilia, however, there are several difficulties for such mobility, due to the predominant role of the empty spaces in the city which weakens the gathering potential of such areas, despite the fact that such articulation with secondary centralities is also present there.

Patterns of Interactions of the Complex City System:Emotional Urban Objects as Triggering Agents-A Secondary Publication

This article presents an analysis of the patterns of interactions resulting from the positive and negative emotional events that occur in cities,considering them as complex systems.It explores,from the imaginaries,how certain urban objects can act as emotional agents and how these events affect the urban system as a whole.An adaptive complex systems perspective is used to analyze these patterns.The results show patterns in the processes and dynamics that occur in cities based on the objects that affect the emotions of the people who live there.These patterns depend on the characteristics of the emotional charge of urban objects,but they can be generalized in the following process:(1)immediate reaction by some individuals;(2)emotions are generated at the individual level which begins to generalize,permuting to a collective emotion;(3)a process of reflection is detonated in some individuals from the reading of collective emotions;(4)integration/significance in the community both at the individual and collective level,on the concepts,roles and/or functions that give rise to the process in the system.Therefore,it is clear that emotions play a significant role in the development of cities and these aspects should be considered in the design strategies of all kinds of projects for the city.Future extensions of this work could include a deeper analysis of specific emotional events in urban environments,as well as possible implications for urban policy and decision making.

Effects of Urbanization and Industrialization on Farmland System in Shandong Peninsula

[Objective] The aim was to study the effects of urbanization and industrialization on farmland system in Shandong Peninsula. [Method] In Shandong Peninsula, the effects were studied and analyzed using remote sensing and image interpretation with spatial data analysis and statistic data analysis. [Result] During researching periods in Shandong Peninsula, wasteland area changed from decreasing to increasing; farmland area was declining; orchard and forestry areas were increasing, mainly resulting from political policies and benefits maximization of farmers. Meanwhile, chemical fertilizers and agricultural mechanization are more frequently applied with industrialization and urbanization, leading significant effects on environment, industry and urban. [Conclusion] More policies should be formulated to promote harmonious development of society, economy and environment.

SCENARIOS SIMULATION OF COUPLING SYSTEM BETWEEN URBANIZATION AND ECO-ENVIRONMENT IN JIANGSU PROVINCE BASED ON SYSTEM DYNAMICS MODEL

By means of ISM (Interpretative Structural Modeling) and SD (System Dynamics) methods, this paper made a system dynamics model of urbanization and eco-environment coupling in Jiangsu Province according to the implication and PSR (Pressure State Response) framework of urbanization and eco-environment coupling. Moreover, five typical scenarios during 2000-2015 have been simulated and analyzed based on the time serial statistical data during 1990-2003 in Jiangsu, which indicates: firstly, there are significant differences between the results and the scenarios, and the five coupling models all have comparative advantages and drawbacks; secondly, in terms of the characteristics and regional development disparities of Jiangsu and the general rule of world urbanization process, this paper reveals that only when either population urbanization model or social urbanization model to be correspondingly adopted, the sustainable development among population, economy, urbanization and eco-environment can be realized.

IMPACT OF URBANIZATION ON STRUCTURE AND FUNCTION OF RIVER SYSTEM—Case Study of Shanghai,China

Urbanization can affect the physical process of river growth, modify stream structure and further influence the functions of river system. Shanghai is one of the largest cities in the world, which is located in Changjiang (Yangtze) River Delta in China. Since the 1970s, the whole river system in Shanghai has been planned and managed by the Shanghai Water Authority. The primary management objectives in the last 30 years have been to enhance irrigation and flood-control. By using Horton-Strahler classification and Horton laws as a reference, a novel method of stream classification, in conjunction with the traditional and specially designed indicators, was applied to understanding the structure and functions of the river system in Shanghai. Correlation analysis was used to identify the interrelations among indicators. It was found that the impact of urbanization on the river system was significant although natural laws and physical characteristics marked a super-developed river system. There was an obvious correlation between the degree of urbanization and the abnormal values of some indicators. Urbanization impacts on river system such as branches engineered out, riverbank concreting and low diversity of river style were widely observed. Each indicator had distinct sensibility to urbanization so they could be used to describe different characteristics of urban river system. The function indicators were significantly related to structure indicators. Stream structure, described by fractal dimension and complexity of river system, was as important as water area ratio for maintaining river’s multi-function.

What is the relationship between ecosystem services and urbanization? A case study of the mountainous areas in Southwest China

China is undergoing a rapid urbanization process,and urbanization will have a direct impact on regional ecosystems and affect regional ecosystem services.Considering the mountainous counties in Southwestern China as the research object,this study reveals the spatial clustering characteristics of four typical ecosystem services(food production,soil conservation,water yield and carbon sequestration)as well as the trade-offs and synergies among ecosystem services in different urbanized areas.At the same time,piecewise linear regression is used to determine the threshold of the influence of urbanization on ecosystem services.The results indicate that:1)There are spatial autocorrelations among the four typical ecosystem services;with strong clustering characteristics,the positive correlation types are"clustered"locally;and with significant spatial heterogeneity,the negative correlation types are scattered and mainly appear in the highly urbanized area.2)There are also remarkable differences in the relationship among various ecosystem services in different urbanized areas,and in particular,there are marked trade-offs between food production and carbon sequestration in the moderately urbanized area and the highly urbanized area.However,there are synergies between them in the lowly urbanized area.3)With an increase in the compounded night light index(CNLI),water yield,carbon sequestration,food production and overall ecosystem services values present an increasing-decreasing trend,the soil conservation function value shows a decreasing-increasing trend.The response of water yield,carbon sequestration,food production,and overall ecosystem services to the compounded night light index(CNLI)has a threshold of 1.2642,1.4833,1.3388,1.5146 and 1.2237,respectively.Based on the detected relationships between urbanization and ecosystem services,this study provides a theoretical reference for the selection of urbanization development models in key ecological functional areas.

Investigation of the Interactive,Intimidating Relation Between Urbanization and the Environment in an Arid Area Based on Grey System Theory

Taking the Hexi Corridor in western China as an example, this paper studies the interactive intimate i relation between urbanization and the environment in add areas based on the grey system theory. The results show that the grey relational degree between urbanization and the environment is low in the agriculture-oriented cities, modest in the tourism-oriented cities and great in the industry-oriented cities. The changing trend of coupling degree between urbanization and the environment does not entirely agree with that of urbanization or the environment. It showed fluctuating trends, which reflects the compactness and properties of the different stages of the coupling states between urbanization and the environment. In order to achieve a harmonious development with the environment in add areas, traditional development ideas about urbanization should be revised and more attention should be paid to the effect of restriction of water resources and the ecological environment on the development of the economy and society.