An interactive simulation model of urban ecosystem and its implementation

An interactive simulation model is established based on the methodology of 'sensitivity model' (SM) during the cooperative research process between the founders of SM and the authors. And the conceptual framework of SM is developed into the interactively qualitative and quantitative simulation model presented in this paper, which makes it possible to break down a complex urban ecosystem into simple and visual quantitative or qualitative relationships between the factors. By studying the dynamic responses of the system to the changes of the inputs and parameters of the model, future trends in urban development can be predicted and strategies formulated. The whole process is realized on micro-computer in the course of man-computer interaction. Its potential use is shown in a case of Tianjin City.

Review of urban ecosystem services from 2010 to 2020:An analysis based on CiteSpace

This paper systematically combs 416 literature on urban ecosystem services (UES) in China and other countries from 2010 to 2020,and carefully interprets the abstracts of 383 effective literature.According to the classification method of the research perspectives of ecosystem services proposed by Luederitz C,the literature is divided into six categories:ecology,governance,methods / tools / guidelines,social networking,economy and planning,and Excel and CiteSpace software were used for data statistical analysis and visual processing.The research shows that:in terms of research perspectives,foreign researches are evenly distributed in six categories:ecology,governance,methods / tools / guidelines,social networking,economy and planning,while domestic research perspectives are relatively concentrated in three categories:economy,governance,methods / tools / guidelines,and the proportion of economic category is particularly significant.In terms of research contents,there are more studies on climate governance,decision-making mechanism and method innovation abroad,while there are more studies on the measurement of carbon sequestration and oxygen releasing,the evaluation of ecological security pattern and the quantitative evaluation of UES’s economic value in China,and there are less studies on institutional organization structure and policy tools,innovative methods of UES’s value evaluation,the potential role of UES on some social phenomena,the relationship between UES and residents’ behavior and perception.

A fine-scale assessment of the ecosystem service-disservice dichotomy in the context of urban ecosystems affected by alien plant invasions

Background: Natural resources within and around urban landscapes are under increasing pressure from ongoing urbanisation, and management efforts aimed at ensuring the sustainable provision of ecosystem services(ES) are an important response. Given the limited resources available for assessing urban ES in many cities, practical approaches for integrating ES in decision-making process are needed.Methods: We apply remote sensing techniques(integrating LiDAR data with high-resolution multispectral imagery)and combined these with supplementary spatial data to develop a replicable approach for assessing the role of urban vegetation(including invasive alien plants) in providing ES and ecosystem disservices(EDS). We identify areas denoting potential management trade-offs based on the spatial distribution of ES and EDS using a local-scale case study in the city of Cape Town, South Africa. Situated within a global biodiversity hotspot, Cape Town must contend with widespread invasions of alien plants(especially trees and shrubs) along with complex socio-political challenges. This represents a useful system to examine the challenges in managing ES and EDS in the context of urban plant invasions.Results: Areas of high ES provision(for example carbon sequestration, shade and visual amenity) are characterized by the presence of large trees. However, many of these areas also result in numerous EDS due to invasions of alien trees and shrubs – particularly along rivers, in wetlands and along the urban edge where tall alien trees have established and spread into the natural vegetation(for example increased water consumption, increased fire risk and reduced soil quality). This suggests significant trade-offs regarding the management of species and the ES and EDS they provide.Conclusions: The approach applied here can be used to provide recommendations and to guide city planners and managers to fine-tune management interventions at local scales to maximise the provision of ES.

Sustainability analysis of the urban ecosystem in Guangzhou City based on information entropy between 2004 and 2010

The urban ecosystem possesses dissipating structures that can absorb substances and energy from the external environment and export products and wastes to maintain order within the system. Given these circumstances, this paper analyzed the ability of the urban ecosystem in Guangzhou City to sustain development from the perspective of entropy. The research was carried out in three steps. First, an evaluation index system that considers the ability of the urban ecosystem for sustainable development was formed based on the struc- tures and functions of the urban ecosystem and the change in the entropy of the urban so- cioeconomic ecosystem. Second, the sustainable development ability assessment model for the urban ecosystem was built using information entropy. Last, by combining the time series variation of the evaluation indicators with the entropy weights, this paper analyzed the influ- ence of the combined factors on the sustainable development ability of the urban ecosystem in Guangzhou and suggested some measures to promote the sustainable development of the urban ecosystem in Guangzhou. The conclusions of this study can be summarized as follows： （1） The urban ecosystem has developed in an orderly and healthy direction, with effective control over the urban environmental pollution problems in Guangzhou between 2004 and 2010. （2） The sustainable development ability of the urban ecosystem had been on an up- ward trend in Guangzhou during the study period. The ability of the natural urban ecosystem to support the urban socioeconomic ecosystem increased continuously, and the improved ecoenvironment enhanced the harmony and vitality of the urban ecosystem in Guangzhou.

Urban Ecosystem Prediction and Comprehensive Evaluation Ideology

In the light of the study of domestic and foreign ur-ban ecosystem,this article puts forward a set of ideological systemsfor the forecast,evaluation and tactic,and conducts initial primaryexploration of its forecast and evaluation methods.

Understanding the drivers of woody plant diversity in urban parks in a snow climate city of China

Urban parks are an important part of urban ecosystems and play an important role in biodiversity conservation.However,it is still unclear how park characteristics aff ect plant diversity which could hinder the conservation of urban biodiversity due to the ineff ective design of urban parks.The diversity of woody plants in 33 parks of Changchun,China,was measured with plot measurements and linked with urban park characteristics(e.g.,size and age of the park)to uncover the relationship between them.The results show that urban woody plant species were abundant,with 98 species belonging to 51 genera and 26 families in the snow climate city of Changchun.The variation in woody plant diversity was largely explained by internal patch characteristics(e.g.,size,age,shape),and external factors surrounding the park(e.g.,land use type and socioeconomic level)accounted for only 16.0%in our study.For internal patch characteristics,older urban parks with larger areas demonstrated a richer level of plant diversity and increased nonlinearly with increasing park area.The threshold size signifi cantly aff ecting plant diversity variation was approximately 30 ha.Plant diversity had positive linear relationships with the ages of urban parks,supporting the legacy eff ect.In addition,woody plant diversity nonlinearly decreased with increasing park shape index,which suggested that the plant diversity could also be increased by optimizing the park shape.Regarding the external factors surrounding parks,the spatial distribution of woody plant diversity varied greatly from the urban center to the suburbs.House prices around the park had positive linear relationships with woody plant diversity in parks,supporting the luxury eff ect.However,building and road proportions,and green space proportion had no relationship with plant diversity in parks.This study can provide a robust reference for enriching plant diversity in urban parks,thus improving the development of urban sustainable cities.

Seasonal co-occurrence patterns of bacteria and eukaryotic phytoplankton and the ecological response in urban aquatic ecosystem

Microorganisms play a key role in aquatic ecosystems.Recent studies show that keystone taxa in microbial community could change the community structure and function.However,most previous studies focus on abundant taxa but neglected low abundant ones.To clarify the seasonal variation of bacterial and microalgal communities and understand their synergistic adaptation to diff erent environmental factors,we studied the bacterial and eukaryotic phytoplankton communities in Fenhe River that runs through Taiyuan City,central China,and their seasonal co-occurrence patterns using 16S and 18S rDNA sequencing.Results indicate that positive interaction of eukaryotic phytoplankton network was more active than negative one except winter,indicating that the cooperation(symbiotic phenomenon in which phytoplankton are interdependent and mutually benefi cial)among them could improve the adaption of microbial community to the local environmental changes and maintain the stability of microbial network.The main genera that identifi ed as keystone taxa in bacterial network were Salinivibrio and Sphingopyxis of Proteobacteria and they could respond to the variation of nitrite and make use of it,while those that identifi ed as keystone taxa in eukaryotic phytoplankton network were Pseudoschroederia and Nannochloris,and they were more susceptible to nitrate and phosphate.Mychonastes and Cryptomonas were closely related to water temperature.However,the loss of the co-occurrence by environmental factor changes aff ected the stability of network structure.This study provided a reference for analyzing relationship between bacteria and eukaryotic phytoplankton and revealing potential importance of keystone taxa in similar ecological domains in carbon,nitrogen,and phosphorus dynamics.

An Assessment of Ecosystem Services of Urban Green Spaces Based on i-Tree

Ecosystem services of urban green spaces play an important role in the sustainable development of the urban ecosystem. How to quantify the ecological benefits of urban green spaces and evaluate their ecological services is a hot topic in related fields. Currently, with the advancement of science and technology, the assessment method has been developed from the traditional ones such as the Council of Tree and Landscape Appraisers(CTLA) method, afforestation cost method, and carbon tax method to CITYgreen and i-Tree. The latter two models have been widely used in countries of Europe and America, while the use of i-Tree has not been promoted in China. In this paper, i-Tree Eco(UFORE) was selected for research, and its application in the assessment of the ecosystem services of urban green spaces, including energy saving, air quality improvement, interception of rainwater, and aesthetic benefits, were analyzed. This study aims to provide a theoretical and scientific basis for the introduction and localization of i-Tree, as well as its generalization in the assessment of forest ecosystem services domestically.

Integrating ecosystem services evaluation and landscape pattern analysis into urban planning based on scenario prediction and regression model

Urban planning has become a widely concern for minimizing the negative effects of urban expansion on terrestrial ecosystems. We developed an interdisciplinary modeling framework to evaluate the effectiveness and shortcomings of urban expansion management strategies. A three-step method was applied to Yinchuan Plain in the northwestern of China, including(1)analyzing the relationship between landscape pattern and ecosystem service values through mathematical statistics;(2) predicting landscape pattern and ecosystem services change under different scenarios based on cellular automaton model(SLEUTH-3r model); and(3) designing and validating optimized scenario through integrating historical analysis experiments and future multi-comparison suggestions. Results have suggested that landscape composition and configuration can significantly affect regional ecosystem service values, especially the connectivity and shape of landscape. Compact urban growth policy and medium environment protection policy are the appropriate setting for urban expansion plan. Optimization validation of the combined designed scenario implied the reliability of this method. Our results highlighted the significance of integrating application of landscape pattern analysis, ecosystem service value evaluation,model simulation and multi-scenario prediction in urban planning.

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.

Towards an integrative approach to evaluate the environmental ecosystem services provided by urban forest

As a Nature-Based Solution,urban forests deliver a number of environmental ecosystem services(EESs).To quantify these EESs,well-defined,reliable,quantifiable and stable indicators are needed.With literature analysis and expert knowledge gathered within COST Action FP1204 GreenInUrbs,we proposed a classification of urban forest EESs into three categories:(A)regulation of air,water,soil and climate;(B)provisioning of habitat quality;and(C)provisioning of other goods and services.Each category is divided into EES types:(a)amelioration of air quality;restoration of soil and water;amelioration of the microclimate;removal of CO2 from the air;(b)provision of habitat for biodiversity;support for resilient urban ecosystems;provision of genetic diversity;and(c)provision of energy and nutrients;provision of grey infrastructure resilience.Each EES type provides one or more benefits.For each of these 12 benefits,we propose a set of indicators to be used when analyzing the impacts on the identified EESs.Around half of the 36 indicators are relevant to more than one single benefit,which highlights complex interrelationships.The indicators of wider applicability are tree and stand characteristics,followed by leaf physical traits and tree species composition.This knowledge is needed for the optimization of the EESs delivered by urban forests,now and in the future.

Relationship between Urban Floristic Diversity and Ecosystem Services in the Moukonzi-Ngouaka Neighbourhood in Brazzaville, Congo

The relationship between ecosystem services and urban phytodiversity is being studied in the Moukonzi-Ngouaka district of Brazzaville. Urban forestry, a source of well-being for the inhabitants, is associated with socio-cultural foundations. The surveys concern flora, ethnobotany, socio-economics and personal interviews. The 60.30% naturalized flora is heterogeneous and closely correlated with traditional knowledge. The Guineo-Congolese endemic element groups are 39.27% of the taxa, of which 3.27% are native to Brazzaville. Ethnobotany recognizes 48.36% ornamental taxa;28.36% food taxa;and 35.27% medicinal taxa. Some multiple-use plants are involved in more than one field. The supply service, a food and phytotherapeutic source, provides the vegetative and generative organs. Of the 52.31% of recognized taxa, 33.45% essentially provide leaves and 18.50% fruits. The main obsession of plant introduction being 1) food and phytotherapeutic, and 2) aesthetic, obscures other ecosystem services such as fuelwood and income, provided by NTFPs, pillars of poverty alleviation.

Evaluating Structural and Temporal Factors Affecting Supply of Ecosystem Benefits in a University Urban Environment in South Carolina, USA

Sustainable urban forest management is still an evolving concept, particularly as it pertains to a sustainable supply of ecosystem benefits and management planning. Urban forestry maintains a greater human dimension component than traditional timber-oriented rural forestry because urban trees grow in city centers and neighborhoods, supplying critical ecosystem benefits to the population centers. The overall goal of this study was to evaluate the relationship of urban forest stand structure and its temporal dynamics with the sustainable supply of ecosystem benefits in university environments. Individual tree data were collected from a completed inventory, while the i-Tree Eco model was used to generate ecosystem benefits data from the Clemson urban forest. The cumulative-benefits supply curve had an inverted J-shaped curve, but the average supply curve had a negative slope against the species richness. Likewise, individual tree variables total height, DBH, leaf area, and crown height strongly correlated with the total ecosystem services supply. Based on the temporal supply trends, the study area trees were broadly segmented into three groups: establishment, growth, and legacy, with 65%, 31%, and 4% frequency distribution, respectively. Urban forest managers need to identify forest management goals and preferred ecosystem benefits among the urban communities to guide the required forest structure and dynamics to ensure a sustainable and functioning urban forest.

Landscape pattern and its effect on ecosystem functions in Seoul Metropolitan area:Urban ecology on distribution of the naturalized plant species

During land transformation process in the human history, naturalized plants were introduced to several land use patterns by the different ways of plant itself. Including some naturalized plants that had been contribute to land restoration, many naturalized plants have been invaded to original habitat or landscape for native plants. Once the plants were colonized, they extend their area and population size. Urban developed areas often give an important role of source habitat for naturalized plants and expanding their population size. In recent, this situation is appearing as one of environmental problems about the urban landscape management controlling the naturalized plants that invaded in the developed area and conserving the native vegetation. This paper is focusing on relationships between distribution of habitat of naturalized plants and landscape patch in urban area in Seoul. Gangdong-Gu, one of the administrative areas in Seoul was selected for this study. We examined the recent land use change using LANDSAT TM data and spreading of the representative naturalized plants (Robinia pseudoacacia and Eupatorium rugosum) by Seoul Biotope Mapping Project and field survey in 1999. As a result, these two species were often occurred in the same habitat and distributed in forest edge disturbed by man. Their distribution patterns were related to landscape indices (patch size and shape) in the forest edge.

北京市主城区高分辨率的城市水碳通量模拟研究

城市化通过影响地表蒸散发(ET)过程改变了区域水热平衡等水文和生态过程,进而改变了陆地生态系统的结构与功能。为科学评估城市水碳过程,基于哨兵二号卫星数据的植被信息,估算了2016—2021年逐月北京市主城区10 m×10 m空间分辨率的植被指数,进一步结合PT-JPLim四源蒸散发模型、InVEST模型以及解析型生态系统水分利用效率(WUE)模型,模拟了2016—2021年北京市主城区10 m×10 m空间分辨率的蒸散发、蒸散发分量(植被蒸腾E t、土壤蒸发E b、截留蒸发E i和不透水面蒸发E u)、总初级生产力(GPP)、碳储量以及WUE的月值,并分析了其相关关系。植被指数较大值集中在西部山区,其次为北京市的公园区域,归一化植被指数NDVI最大值为0.65。主城区多年平均蒸散发量为497 mm,ET随着叶面积植被指数LAI和增强植被指数EVI的增加而增加。2016—2021年期间,NDVI、LAI和EVI分别以每年0.0048、0.016 m^(2)·m-2和0.0047的速度增加。区域平均E t为141.51 mm,E i为50.77 mm,E b为272 mm,不透水面上的E u ET为18.2%。碳储量较高的区域主要分布在西部山区,该区域海拔相对较高,植被覆盖率较高,总碳储量密度高值超过5 t hm^(2)。研究区GPP的平均值为2.7 g·m^(-2)·d^(-1),多年平均WUE为0.63 g·mm^(-1)。WUE和E t ET呈显著负相关(R=-0.44,p<0.001),WUE随GPP的增加呈现显著的上升趋势。精细化的城市水碳模拟能够为海绵城市的建设和评估提供理论基础,对“双碳”目标的实现具有重要意义。

Floral Diversity Status in Urban Coastal Wetland &Associated Coastal Ecosystems of Crow Island Mattakkuliya, Sri Lanka

Colombo is the capital of Sri Lanka and the only wetland city in South Asia under the Ramsar Convention. Crow Island Beach Park and associated coastal area belong to the Colombo urban coastal wetland ecosystems. Crow Island wetland contributes diverse habitats for numerous flora and fauna species. The present study was conducted to assess the status of floral diversity in the Crow Island Beach Park and associated coastal ecosystem during the months of August to October 2021. Study area is divided in to three sites (A, B, C). Line transects method and field observations were used in the study. This coastal wetland consists of mosaic of five major vegetation types: Herbaceous, tree, shrub, creeper, grass and other than that marine algae namely Chaetomorpha antennina, Rhizoclonium africanum, Ulva compressa belonging to chlorophyta (green algae) and Grateloupia lithophila belonging to rhodophyta (red algae) were found in the study area. A total number of 102 flora species belonging to 50 families were recorded from the study area. There were two true mangrove species and 16 mangrove associated species in the study sites. Out of the 102 plant species 46 were recognized and documented as plants with medicinal values. Shannon-Wiener diversity indexes for mangrove and mangrove associated species were recorded as 2.378, 2.304 and 1.676 in site A, B and C respectively. Simpson’s diversity index for mangrove and mangrove associated species was recorded as 0.889, 0.874 and 0.735 respectively in site A, B and C and Jaccard index of similarity between three study sites showed high values ranging from 41% to 69% for mangrove and mangrove associated species.

城市蔓延对生态系统服务流的影响研究进展及对长江流域的启示

全面梳理城市蔓延对生态系统服务流的影响研究现状,有利于促进区域社会经济可持续发展。综述了城市蔓延对生态系统服务流的影响研究,结果表明:城市蔓延对生态系统服务流的影响研究仍处于起步阶段。城市蔓延通过载体传递和流动路径两方面改变了生态系统服务流的流量、流速和流向,导致生态系统服务流总量的减少和空间异质性的增加;城市蔓延的单项指标变化、城市蔓延的尺度以及城市蔓延的多情景模拟是探索城市蔓延对生态系统服务流影响过程的主要切入点;城市蔓延过程中引起的生态系统服务流扩散效应主要源于土地利用类型的变化和人类居住模式的改变。已有研究在一定程度上解释了城市蔓延对生态系统服务流的影响,但在揭示影响机理、剖析影响过程、评估影响效应以及探索生态系统服务流合理分配以促进城市可持续发展等方面的研究还存在较大空白。在此前提下,未来应基于“机理揭示-影响模拟-效应评估”的研究思路,建立长江流域城市蔓延对生态系统服务流影响研究框架,探索长江流域城市可持续发展与生态系统服务流的合理分配方案,实现长江流域生态保护与社会发展的协同共进。