Modeling urban landscape dynamics: A case study in Phoenix,USA

Urbanization has profoundly transformed many landscapes throughout the world, and the ecological consequences of this transformation are yet to be fully understood. To understand the ecology of urban systems, it is necessary to quantify the spatial and temporal patterns of urbanization, which often requires dynamic modeling and spatial analysis. In this paper, we describe an urban growth model, the Phoenix Urban Growth Model (PHX-UGM), illustrate a series of model calibration and evaluation methods, and present scenario-based simulation analyses of the future development patterns of the Phoenix metropolitan region. PHX-UGM is a spatially explicit urban landscape model and is a modified version of the Human-Induced Land Transformations (HILT) model originally developed for the San Francisco Bay Area. Using land use and other data collected for the Phoenix area, existing growth rules were selectively modified and new rules were added to help examine key ecological and social factors. We used multiple methods and a multi-scale approach for model calibration and evaluation. The results of the different evaluation methods showed that the model performed reasonably well at a certain range of spatial resolutions (120–480 m). When fine-scale data are available and when landscape structural details are desirable, the 120-m grain size should be used. However, at finer levels the noise and uncertainty in input data and the exponentially increased computational requirements would considerably reduce the usefulness and accuracy of the model. At the other extreme, model projections with too coarse a spatial resolution would be of little use at the local and regional scales. A series of scenario analyses suggest that the Metropolitan Phoenix area will soon be densely populated demographically and highly fragmented ecologically unless dramatic actions are to be taken soon to significantly slow down the population growth. Also, there will be an urban morphological threshold over which drastic changes in certain aspects of landscape pattern occur. Specifically, the scenarios indicate that, as large patches of open lands (including protected lands, parks and available desert lands) begin to break up, patch diversity declines due partly to the loss of agricultural lands, and the overall landscape shape complexity also decreases because of the predominance of urban lands. It seems that reaching such a threshold can be delayed, but not avoided, if the population in the Phoenix metropolitan region continues to grow. PHX-UGM can be used as a tool for exploring the outcome of different urban planning strategies, and the methods illustrated in this paper can be used for evaluating other urban models.     

城市景观设计与城市生态平衡关系研究

城市规划是城市发展的战略、纲领和管理城市的依据。按照深入贯彻落实科学发展观的要求,现代城市规划更加注重城市生态的内涵,包括生态城市规划、生态城市设计和生态城市建设。生态城市设计是以真实地实现城市生态化目标,较好地体现不同城市拥有的城市生态环境、城市文化、城市形象和城市风格为基本出发点和归结点。城市景观设计与城市产业设计、城市住区设计一起,构成生态城市设计的三大基本设计方面。本文主要是从城市景观设计方面来探究与城市生态平衡的关系,发挥和提升城市景观设计在规划、设计、建设和管理生态城市中的功能性作用。     

A conceptual framework for the study of human ecosystems in urban areas

The need for integrated concepts, capable of satisfying natural and social scientists and supporting integrated research, motivates a conceptual framework for understanding the role of humans in ecosystems. The question is how to add humans to the ecological models used to understand urban ecosystems. The ecosystem concept can serve as the basis, but specific social attributes of humans and their institutions must be added. Learning and feedback between the human and natural components of urban ecosystems are key attributes of the integrated model. Parallels with familiar ecological approaches can help in understanding the ecology of urban ecosystems. These include the role of spatial heterogeneity and organizational hierarchies in both the social and natural components of urban ecosystems. Although urban watersheds are commonly highly altered, the watershed approach can serve as a spatial basis for organizing comparative studies of ecosystems exhibiting differing degrees of urbanization. The watershed concept can also spatially organize the hierarchically scaled linkages by which the integrated human ecosystem model can be applied. The study of urban ecosystems is a relatively new field, and the questions suggested by the integrated framework can be used to frame ecosystem research in and associated with urban and metropolitan areas.     

Terrestrial vertebrates in urban ecosystems: developing hypotheses for the Gwynns Falls Watershed in Baltimore,Maryland

We review the literature on terrestrial vertebrates in urban and urbanizing areas in terms of the new paradigm in ecology that focuses on the origin, spatial pattern, and current influences of habitat patches. Studies of terrestrial vertebrates have documented differences in species composition along an urban-rural gradient and have identified some of the key land use features associated with these differences. We use information from a database developed for the Gwynns Falls Watershed in Baltimore City and County, Maryland to demonstrate how a study of forest-dependent breeding birds could be used to identify mechanisms that account for differences in the bird communities of forest patches in urban areas, and to provide useful information to planners and managers involved in wildlife conservation and management.     

The effects of landscape cover on surface soils in a low density residential neighborhood in Baltimore,Maryland

Previous studies at the scale of a city have shown that surface soil nutrients, pH, and soil organic matter (SOM) can vary by land cover, land use, and management. This study was conducted in Baltimore County, Maryland, to quantify the differences in characteristics of soil in a residential neighborhood and adjacent forest patch sampling at a fine scale. The first objective was to compare soil characteristics in a residential neighborhood among ecotope types of forest, lawn, and planting beds that were underlain by the same parent material and thus only differed in plant cover. Another objective was to examine differences in soil properties of lawn soils that differed in age by 10 years. The final objective was to quantify the variation of these residential and forest soils. Composite soil samples from the surface to a depth of 5 cm were taken from planting beds and lawns from 50 residences and an adjacent forest patch. Results showed that the forest soil had 30 % more SOM and was more acidic than lawn soil. Conversely, Mg, P, K, and Ca were 47 to 67 % lower in forest compared to lawn soils even though both soils developed from similar parent materials. For the residential lawns, the older development had significantly higher concentration of soil P. There was also a difference between front and back lawns where front lawns had 26 and 10 % higher concentrations of Ca and Mg, respectively, and a higher pH than the back lawns. Finally, the variation of soil characteristics of all areas sampled, from lowest to highest was pH < SOM < K < Mg < Ca < P. Results of this study suggest that anthropogenic factors appear to overwhelm natural soil forming factors in suburban residential areas in the Baltimore metropolitan area and these differences appear to increase with time.     

Approaches to the study of urban ecosystems: The case of Central Arizona—Phoenix

CAP LTER focuses on an arid-land ecosystem profoundly influenced, even defined, by the presence and activities of humans and is one of only two LTER sites that specifically studies the ecology of an urban system. In this large-scale project, biological, physical, and social scientists are working together to study the structure and function of the urban ecosystem, to assess the effects of urban development on surrounding agricultural and desert lands, and to study the relationship and feedbacks between human decisions and ecological processes.Our interdisciplinary investigations into the relationship between land-use decisions and ecological consequences in the rapidly growing urban environment of Phoenix are of broad relevance for the study of social ecological systems and cites in particular. Refinements in our conceptual model of social ecological systems focuses our attention on recognizing the scales and periodicities of ecological and human phenomena, understanding the means and impacts of human control of variability in space and time, and finally an evaluation of the resilience of various aspects of socio-ecological systems especially their vulnerabilities and their potential for adaptive learning.     

Urban ecosystem management and change during the past millennium: a case study from New York City

Changes in a deciduous forest and salt marsh ecosystem, Hunter Island, New York City, are related to management over the past millennium. Sequential methods, fossil pollen analysis, map and aerial photography series, and vegetation resampling were performed to supplement the historical and archaeological records. The enhanced ecosystem management history provides an expanded context to examine management planning alternatives.Siwanoy native Americans utilized Hunter Island to provide fuel, land for corn planting, and living space through cutting forests in at least the northeast portion of the island. The fossil pollen record indicates that about the time of site abandonment, the Siwanoy planted the forest opening with hickory. Dutch colonial settlers protected forest in the area, but later the island's forest was cut for the British Navy during the American Revolution. John Hunter created a gentleman's farm on the island beginning in 1812.The New York City Parks Department purchased Hunter Island in 1888 and permitted social agencies to clear trees for recreation during the next 46 years. The chestnut blight eliminated American chestnut from the forest in 1908, and at the same time a hickory bark beetle infestation decimated the hickory population. A survey in 1934 showed that the northeast portion of the Island contained a forest, dominated by oak and yellow poplar, and a field. The island became a day-use picnic site in 1943, and for this purpose all the woody plants with stems less than 10 cm in diameter were removed.Aerial photography demonstrated a trend of forest replacing field over the past century. A resurvey of the northeast section of the island in 1988 revealed that oak and yellow popular remained dominant in the old forest, and the field became a hickory and sassafras stand. The hickory dominance, which is typical of Hunter Island, is unusual for New York City forests and could be related to native American plantings over 700 years ago. The management plan for Hunter Island is focused on preservation of the field and forest legacy of the recent recreation period. Instead of preserving an environmental patchwork common in New York City parks, an alternative management focus could enhance the hickory forest component to represent the former native American cultural setting.     

Ecological consequences of fragmentation and deforestation in an urban landscape: a case study

Landscape change is an ongoing process even within established urban landscapes. Yet, analyses of fragmentation and deforestation have focused primarily on the conversion of non-urban to urban landscapes in rural landscapes and ignored urban landscapes. To determine the ecological effects of continued urbanization in urban landscapes, tree-covered patches were mapped in the Gwynns Falls watershed (17158.6?ha) in Maryland for 1994 and 1999 to document fragmentation, deforestation, and reforestation. The watershed was divided into lower (urban core), middle (older suburbs), and upper (recent suburbs) subsections. Over the entire watershed a net of 264.5 of 4855.5?ha of tree-covered patches were converted to urban land use??125 new tree-covered patches were added through fragmentation, 4 were added through reforestation, 43 were lost through deforestation, and 7 were combined with an adjacent patch. In addition, 180 patches were reduced in size. In the urban core, deforestation continued with conversion to commercial land use. Because of the lack of vegetation, commercial land uses are problematic for both species conservation and derived ecosystem benefits. In the lower subsection, shape complexity increased for tree-covered patches less than 10?ha. Changes in shape resulted from canopy expansion, planted materials, and reforestation of vacant sites. In the middle and upper subsections, the shape index value for tree-covered patches decreased, indicating simplification. Density analyses of the subsections showed no change with respect to patch densities but pointed out the importance of small patches (??5?ha) as ??stepping stone?? to link large patches (e.g., >100?ha). Using an urban forest effect model, we estimated, for the entire watershed, total carbon loss and pollution removal, from 1994 to 1999, to be 14,235,889.2?kg and 13,011.4?kg, respectively due to urban land-use conversions.     

Suitability of biodiversity-area and biodiversity-perimeter relationships in ecology: a case study of urban ecosystems

Urban areas are probably the most fragmented environments with respect to the presence of semi-natural habitats and shape of these habitats may be significantly affected by urbanization. Patch perimeter in landscape or habitat studies is much less popular to study than patch area. The studied sites were situated in the industrial city of Pardubice, which is one of the ten largest cities in the Czech Republic with nearly 100,000 inhabitants. In total, 40 grasslands were studied within a circular area of 314 km². Butterflies and beetles with diurnal activity were studied during timed survey walks. A Simultaneous autoregressive model was used for test of the effect of biodiversity-area and biodiversity-perimeter relationships and for exclusion of potential bias caused by spatial autocorrelation. The models including patch perimeter performed better than those using patch area in explaining species richness, abundance and diversity of investigated organisms and were less influenced by spatial autocorrelation. The main conclusion and recommendation of the present study is that researchers should pay more attention to the possible influence of the patch perimeter as a potential predictor or co-predictor for landscape and habitat studies – especially in urban areas, where the negative effects of fragmentation might be much higher than in rural or more natural landscapes. Performing preliminary tests on comparisons between area and perimeter is highly recommended.     

城市复合生态系统理论在崇明生态岛建设中的应用

为落实上海对崇明岛的总体规划及崇明岛的发展定位,按照现代生态文明理念和建设世界级、现代化的生态岛标准,首要任务是贯彻执行崇明岛生态保护、恢复和重建工程,规范崇明生态岛的建设行为。崇明生态岛建设纲要已于2010年初正式出台,城市复合生态系统理论、可持续发展理念以及科学化咨询方法在崇明生态岛建设纲要及其制定过程中得到了充分体现和灵活应用。     

Notes on the evolution and organization of the urban ecosystem

The continual spread of human settlements over the world’s surface has transformed the natural environment on a global scale. Human’s intervention has changed primary ecosystems (protoecosystems or euecosystems) into anthropoecosystems. The spread of urban ecosystems, cultivated surfaces (agroecosystems), and various areas differentiated by their level of anthropization has facilitated the progressive reduction of euecosystems. The evolution of urban areas over the course of history with transformations of cities and surrounding territory, has created very complex mosaics. A proper study of the city, drawing together historical, cultural, social, and other factors, as well as abiotic ones (urban climate, soil, water, air), requires appropriate, uniform terminology for expressing the complex relationships existing among these factors. We therefore propose that the city (or metropolis) be considered as a set of ecosystems, a “synecosystem”. The entire urban area should be termed a “synbiotope”. It is divided into numerous partial biotopes (macro-, meso- and microbiotopes), the result of modifications wrought through the historical and cultural vicissitudes of the human population. Urban biotopes host not only humans, but also a characteristic vegetable and animal component, the “biosyncoenosis”, formed of numerous plant and animal communities, selected on the basis of the environmental conditions of the individual biotopes, which differ from each other in structure, dynamics, age, and position in the urban space. This terminology should facilitate study of the biotic component and its connection to the urban territory, as well as interpretation of results obtained in the different disciplines in terms of the human population’s quality of life.     

Commodified language in Chinatown: A contextualized approach to linguistic landscape1

In Washington DC's newly gentrified Chinatown, recent commercial establishments, primarily non‐Chinese owned chains, use Chinese‐language signs as design features targeted towards people who neither read nor have ethnic ties to Chinese. Using this neighborhood as a case study, we advocate a contextualized, historicized and spatialized perspective on linguistic landscape which highlights that landscapes are not simply physical spaces but are instead ideologically charged constructions. Drawing from cultural geography and urban studies, we analyze how written language interacts with other features of the built environment to construct commodified urban places. Taking a contextually informed, qualitative approach, we link micro‐level analysis of individual Chinese‐language signs to the specific local socio‐geographic processes of spatial commodification. Such a qualitative approach to linguistic landscape, which emphasizes the importance of sociohistorical context, and which includes analysis of signage use, function, and history, leads to a greater understanding of the larger sociopolitical meanings of linguistic landscapes.     

Regional disparities in bonding and bridging social capital: An empirical study of rural and urban Japan

This article investigates regional social capital development by focusing on disparities in bonding and bridging social capital among rural and urban areas of Japan. Rural–urban differences in social capital in Western contexts have been discussed by many studies. Their main finding is that bonding social capital is richer in rural areas and bridging social capital is richer in urban areas. However, the empirical evidence presented in this article suggests that in Japan both bridging and bonding social capital are richer in rural than urban areas, diverging from traditional thinking about these two types of social capital. This finding suggests that urbanization and depopulation in rural areas of Japan have led to changes in people's behavior and their demand for social networks, promoting the development of bridging social capital in rural areas.     

Forest ethnography: An approach to study the environmental history and political ecology of urban forests

Urban Ecosystems - A landscape succession paradigm has shaped much of our understanding about the processes of forest emergence and transformation in the United States. Drawing heavily from theory...     

Urban ecosystem management: bringing science and policy together

The U.S. Department of Agriculture has many programs that directly affect urban ecosystems, and many more, such as the collection, interpretation, and dissemination of natural resource data, that affect rural and urban areas alike. The policy challenge is to bring the vast scientific resources of the Department to the urban decision maker in an effective manner. This requires teamwork on the part of federal agencies, which can be greatly improved by innovative programs such as the Urban Resources Partnership. In spite of the progress being made, there are many challenges and opportunities ahead as national policymakers seek to bring science and policy together in ways that assist local leaders and citizens in improving environmental quality and the quality of life in urban and suburban areas.     

The ideology of social problems: gambling, a case study

Un problème social représente la géneralisation d'une déviation sérieuse par rapport au comportement normatif et comprend des aspects tant objectifs que subjectifs; c'est-à-dire, d'une part, des actes de transgression objectivement vérifiables et, d'autre part, la consience répandue quant à la nature et aux conséquences indésirables de ces comportements. Selon ces critères, le jeu d'argent est généralement considéré - par l'opinion professionnelle non moins que par la non-professionnelle - comme un problème social sésrieux. Un examen de la situation du jeu d'argent mene a la conclusion qu'il n'est pas un problème social et qu'une telle désignation ne répond pas à une analyse critique mais plutôt à un certain ensemble de croyances - une idéologie La conception publique du jeu est analogue à celle que l'on se fait d'autres phénomènes sociaux qui sont de la meme façon dévalues au plan moral. Les aspects problématiques de plusieurs tels phenomenes, surtout dans la ‘societé de masse,’ sont examinés brièvement dans le texte. Dans tous les cas, les données empiriques indiquent clairement que de telles activités constituent une adaptation sociale rationnelle de la part de groupes qui sont généralement des objets de stigmatisation. A social problem is understood to imply a generalized serious departure from normatively sanctioned behaviour, comprising objective as well as subjective aspects; the former manifest by means of objectively verifiable acts of transgression, and the latter consisting of a widespread awareness of the undesirable nature and consequences of the relevant conduct. On these criteria, gambling is by general assent - professional no less than lay - considered to qualify as a serious social problem. Examining the rightful status of gambling as a social problem, this paper concludes such designation does not stand up to critical analysis but derives from a particular set of beliefs - an ideology. The public concept of gambling is analogous to the view taken of other social phenomena, similarly morally devalued. The problematic aspects of several such phenomena, especially of ‘mass society,’ are briefly examined in the present paper. In all instances, empirical evidence clearly suggests such activities constitute socially adaptive rational behaviour for such social groups as generally find themselves the principal targets for stigmatization.     

Hurricane driven changes in vegetation structure and ecosystem services in tropical urban yards: a study case in San Juan,Puerto Rico

Urban forests are valuable spaces for species conservation, protection of local biodiversity and provision of ecosystem services. However, they are also vulnerable to the impact of extreme climate events like hurricanes. Understanding how urban forests are responding to hurricane disturbances is crucial to improve their design, management, and resilience. Here we analyzed pre-and post-hurricane vegetation surveys in 52 residential yards in San Juan to assess urban forest responses after Hurricanes Irma and María impacted Puerto Rico in 2017. We used these surveys to compare vegetation structure and composition (including species-specific mortality and damage rates) and to quantify changes in the ecosystem services provided by these yards. We found that hurricane disturbances significantly altered the structure but not the composition of yard vegetation. We detected a 27% reduction and 31% mortality of standing stems, and a significant reduction in plants health. Yard species composition was dominated by non-native species and this trend did not change with hurricane disturbance. Changes in vegetation structure translated into substantial reductions in ecosystem services. Food provision, an important service provided by a large proportion of yards before the hurricane, reported the highest reduction (41.9%) while carbon storage was the service that changed the least (9%). Our combined results emphasize the key role played by residential yards providing ecosystem services in tropical cities and call for further efforts to manage private and public urban forests in ways that may ensure their resilience to mitigate extreme climate events, provide multiple ecosystem services, and promote long-term urban sustainability.

     

Gender,domestic space,and urban upgrading: a case study from Amman

The author discusses an urban upgrading project in the Wadi and Jabal areas of central Amman. These two areas, home to Palestinian refugees from the 1948 and 1967 exoduses, are among the most congested and poor in the central city. The Wadi borders a refugee camp and the Jabal is surrounded by low-income neighborhoods. Through the upgrading project, the state asserted control over every facet of women's lives, addressing most aspects of private and public life in the targeted communities. Women responded in a rally around the notions of domesticity and femininity, effectively managing public agencies and personnel in such a manner that the project was eventually turned to their advantage. Sections consider women in the domestic environment, relationships between women across households, the urban upgrading project, planning to restructure social relations, blurring the private and the public, and women's responses.     

Connecting local environmental knowledge and land use practices: A human ecosystem approach to urbanization in West Georgia

Issues of urban sprawl and migration of exurban residents into the surrounding countryside of metropolitan areas have generated considerable debate across the US. These debates often revolve around the ecological footprint of urban areas and the erosion of quality of life indicators associated with rapid expansion of urban and residential areas. Although there has been much research done on the environmental and socioeconomic impacts of urbanization, little attention has been given to cultural impacts. This paper focuses specifically on the role of local environmental knowledge as an important resource in human ecosystems, and looks at the implications of environmental knowledge loss associated with urbanization and its related demographic changes. We compared environmental knowledge among rural, urban, and developing watersheds in western Georgia, and also look at relationships between local environmental knowledge and variables such as gender, education, income, and participation in outdoor recreational activities. We then explored how variations in environmental knowledge affected land use practices at the household level. The mean knowledge scores of residents in all three classifications of rural watersheds were higher than those living in developing and urban watersheds. We found residents of managed pine watersheds possessed the highest mean scores (p = 0.006), while urban watershed residents were the lowest. We also found that local environmental knowledge was influenced by active participation in outdoor recreation, with active bird-watchers having the highest environmental knowledge scores. However, we found less influence of factors such as education and income on environmental knowledge. We also found a clear connection between local environmental knowledge and land management practices. Timber owners scored higher than non-timber owners (p = 0.099), and landowners who constructed streamside management zones (SMZs) scored higher than those who did not (p = 0.034).