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The driving ideas at the backdrop of the current discussion of urbanization, sprawl and sustainability is the notion that urbanization is associated with low-density sprawl (Duany and Talen 2002; Sushinsky et al. 2013) and that sprawl reduces the amount of open spaces, fragments open spaces (Forman 1995, p. 418) and as a result adversely affects biodiversity (Fahrig 2001; Fahrig 2003; Alberti 2005; Donnelly and Marzluff 2006; Groom et al. 2006; Theobald et al. 2012). It is far from certain that these notions describe precisely the extant reality. While sprawl does reduce the amount of open space within boundaries of cities and does cause fragmentation, it does not necessarily reduce biodiversity. In some cities, the fragmented patches of open spaces remain interconnected allowing living spaces for plants and animals. Indeed, some view polycentric urban expansion as an opportunity to possible amelioration of declining biodiversity (Czamanski et al. 2008).

There is a growing public interest in the impact of urbanization on sustainability and in government actions to mitigate associated adverse repercussions on biodiversity. While much effort is being devoted to fashion policies, the relevant discourse and consequent policy prescriptions are broad, often vague and obscured by stylized facts and excessively broad conceptions of the relevant phenomena.

It is the purpose of the proposed book to shed light on the obscure and to place the discussion on a solid scientific basis. The contributors to this volume are an active group of scholars that span various disciplines, utilize advanced methods and make use of the vast, spatially detailed data that has become available in recent years. Their work models the relevant phenomena precisely and provides a basis for carefully fashioned alternate policies.

The major objectives of the proposed book are to:

  • Describe conceptual models of the interactions among the three main types of land-uses: urban, agricultural and natural.

  • Characterize the dynamics of city-agriculture-nature interfaces.

  • Illustrate the conceptual models by means of case studies so as to reveal the particular forces and interactions that govern the respective interface dynamics.

  • Develop and introduce land-use policies, planning measures and land-use planning tools to promote the sustainability of boundary areas.

  • Assess the relationship between different taxa of species and the structure of the urban landscape.

The significance of these studies should be understood in the context of the growing urbanization of the world. In the middle of the second decade of the twenty-first century, over 50 % of the world’s population is living in cities. This is remarkable since the process of urbanization that brought this about started in earnest less than 200 years ago. At that time, the number of people living in cities was only about 2 %. By 1900, the number of urbanites grew to 12 % (United Nations Population Division 2002). In other words, the last 100 years witnessed a huge human migration into cities. The slow clustering of people into small settlements during early biblical times, into villages and towns some 3,000 years ago and eventually into cities some 200 years ago has given rise now to a veritable flood. While forecasts of the world’s future urban population are marred by many difficulties, including differences among countries in the definition of cities and urban areas as well as in forecasting methods, the United Nations has prepared such forecasts. Of the more than 2.2 billion in the world’s population that will be added until the year 2030, some 95 % will live in cities (Cohen 2003). The world’s population and economic activities are increasingly concentrated in space.

Scholarly interest in the uneven geographic evolution of the world’s population and of economic activities started with von Thunen, also almost two centuries ago (Thünen 1826). It has been growing slowly, but steadily, ever since. A major impetus for this was the early work of the late Walter Isard (1956). But the scientific interest in urban phenomena peaked during the last decade of the twentieth century and the first years of the twenty-first century. An outburst of new models aiming to explain the births of cities and the dynamic processes governing their evolution, and the uneven geographic distribution of economic activities in general, started with a 1991 paper and culminated in the award of the Nobel Prize in economics to Paul Krugman in 2008 (Krugman 1991). Until Krugman the neoclassical explanations for the location of cities and increasing spatial concentration of activities and people was anchored in local resource endowments, the so-called first-nature. Cities formed where there were resources creating a competitive edge. Since Krugman, the emphasis shifted to explanations anchored in the relative locations of economic agents, the so-called second-nature.

While we are quite sophisticated in our modeling, the state of our understanding of the relevant phenomena remains far from satisfactory. Much of the existing theoretical infrastructure yields only partial insights concerning obvious and well-documented urban phenomena. Perhaps this is not surprising. The history of science is filled with examples of theories that despite insurmountable evidence to the contrary were and are believed to be true. Sometimes the untrue, maintained, theories do not have a worthy replacement. Facts that do not accord well with the accepted theory remain perplexing and are a source of embarrassment to some scientists. It is not understood fully why quite often such facts are ignored.Footnote 1 At times, they lead to periods of frantic search for new theories and a new, albeit a partial, explanation is forthcoming. Yet, often the sheer conservatism of the scientific community keeps the accepted and insufficient theory alive and prevents the nascent newcomer theory from taking its legitimate place.

Just as in the case of the spatial concentration of populations, the public discourse concerning nature and the welfare of ecological systems in the midst and at the boundaries of the built areas of cities is colored by unsubstantiated facts, popularly believed to be true, and theories with little empirical evidence to support them. This is particularly true in discussions concerning the resilience of networks of urban open spaces, their dynamics, the character of the ecological systems that populate these areas and forecasts concerning their future.

Scientists, particularly European ones, have begun exploring such issues over 100 years ago. Warren (1871) published a report on the floral composition in the urban parks of London and Kreuzpointner (1876) studied the flora of Munich. While the issues relating to ecological diversity in urban areas have interested researchers for many years, the crux of the questions addressed has changed. With the increasing pressure imposed by human populations on ecosystems in general, and specifically on urban ones, research has expanded from merely descriptive studies, to studies addressing theoretical questions pertaining to eco-urban systems, and progressively towards studies resulting in management and planning recommendations.

While earlier studies were descriptive by nature, towards the end of the twentieth century more attention has been dedicated to the relationship between urban patterns and species diversity. In contrast to expectations and beliefs many studies demonstrate that diversity of certain taxa can be as high, or even higher, within the city boundaries compared to surrounding natural areas (McKinney 2008). While from an accounting point of view this might be good news, this may not necessarily be the case from an ecological perspectives, as some of these species were artificially introduced by people. This is particularly true for flora species, as home gardens and city parks contribute many species to the urban species pool. This effect, however, cascades up the trophic levels as insects and vertebrates are attracted the heterogeneity and diversity of habitats generated within the urban landscape. Even predator abundance seems to be higher within the city, but the species which seem to be the mostly highly affected by urban development are the large bodied carnivores and birds of prey (Fischer et al. 2012).

Acknowledging the biological diversity in cities, and increasing awareness of them being in peril, has led to many initiatives that further map diversity patterns, protect them and valuate the importance of functioning ecosystems within the urban landscape. Individual cities, including New York City, Rio de Janeiro, Cape Town, Chicago, Melbourne, Jerusalem, countries, including Singapore, Portugal, the United Kingdom, Israel and others, and the United Nations have all set out to map the diversity and evaluate the ecological and economic importance of these systems. Thus, on the one hand, cities are growing and urban areas continue to sprawl, resulting in conversion of open spaces and agricultural lands into built environments, increasing pollution loads and potentially threatening the existence of species. On the other hand, awareness of importance of biodiversity and ecosystem function within the urban landscape have led to a better understanding of the services they provide and to different to mindful planning and growth of urban areas. For example, it has been demonstrated that urban open areas serve to filter air pollution, buffer and drain storm water, reduce noise, regulate micro-climate, provide recreational areas which benefit human welfare, and can serve as habitats for endangered species, as in the case of New York City and the Peregrine Falcon (Bolund and Hunhammar 1999; Kiviat and Johnson 2013).

Despite the growing availability of very detailed data and the shrinking cost of obtaining and managing them, there has been relatively little effort to date to expose and to map out a detailed picture of the relevant reality. The common theories are not confronted rigorously with empirical evidence. Yet, just like in the case of urban spatial dynamics, here as well there is already massive factual evidence that does not accord well with some of the accepted theories. In this volume, we seek to present evidence that cannot be ignored and point out theoretical constructs that should be abandoned. We propose and analyze dynamic processes that conform well to the evidence and can serve as a basis for productive management of the built and the natural environments.

A very good example of the incongruence of theory and facts is the most popular and most quoted model of urban spatial structure. It views cities as monocentric cones (Alonso 1964). Although the model is static, it implies that over time cities grow from the center outwards. As a result of natural increase of population and of immigration, the competition for accessibility leads to an outward expansion of the built areas. The implied wave of expansion is presumed not to leave any open spaces. Ecological systems and biodiversity are presumed to be jeopardized and that many species will not be able to survive. This is contrary to empirical evidence. It is enough to examine the available detailed footprints of built areas in a variety of cities to realize that open spaces are abundant and that even in compact cities there are open spaces that support the continued existence of species and communities (Sandstrom et al. 2006; Young et al. 2009).

At the broadest level, the lack of agreement between theories and evidence is due to the inconsistency of the spatial and temporal resolution at which the theoretical and empirical analyses are carried out. Theories generally refer to reality in broad-brush fashion and refer to crude, stylized facts. Almost exclusively the scholarly literature concerning cities and their environments are based on the behavior of typical agents and per capita, or per unit, indicators that focus on that which is common to various places and masks that which is particular to them. The use of such metrics misleads us to think that various phenomena display linear relationships to size and that there exist average dynamics common to all places. In reality, these robust macro relationships are the result of non-linear interactions in the underlying micro dynamic processes and local emergent processes. They display sub-linear and super-linear relationships (Bettencourt et. al. 2010). The focus on macro relationships at a crude spatial and temporal resolution does not allow us to identify the particularities of processes in the individual city and ecological system. There is a growing body of empirical evidence that suggests that spatial dynamics reflect scaling laws and are place-specific (Benguigui et al. 2000; Benguigui and Czamanski 2004). Empirical evidence is increasingly very detailed with great geographical and temporal coverage.

At the most common resolution, theories are not only too general to accommodate facts, most of the theoretical infrastructure is static. Reality is viewed by means of a single, or several, still pictures and accompanying story that attempts to bridge the gap. Rarely are we presented with a fully developed story that accounts for a video-like stream of pictures of social and natural processes. Such dynamic pictures reveal nonlinear evolutions of the built and natural systems and surprising twists and turns in their interactions. Indeed, these are complex systems of many intertwined organizational levels starting from microstructures and ending with macrostructures. They are historically dependent and at times they display emergent properties and self-organization.Footnote 2

There are myriad of obstacles on the way to satisfying theories of the dynamic interactions of cities and nature. Perhaps the most formidable of these stems from the complex nature of the dynamic processes that needs to be considered. There is a huge variance in the characteristic time of the various elements that comprise the urban and natural systems. The dynamic processes take place in different time frames. During certain periods, the processes are fast and during other periods, they are slow. For example, were we to depict the life cycle of the processes of several such systems by means of logistic functions, along the time axis, the incidence of accelerating part of the curves and the saturations will not coincide. While one of the processes is accelerating, another is slowing down.

The chapters in this book touch on various aspects of the above issues. They combine empirical field studies, including field observations, analysis of remote sensing and GIS data, and high-resolution urban and regional models for getting a deep insight into the land pattern on the city-agriculture-nature interfaces and on the human abilities to plan and manage these evolving socio-ecological systems.

Koomen and Dekkers explore the potential of geospatial analysis to characterise land-use dynamics in the urban fringe and in particular focus on the impact of land-use policies in steering these developments. They formalize the open space preservation policies in the Netherlands, simulate the potential implications of proposed policy changes and investigate at what extent the policies are effective in limiting urbanization of the areas restricted for development.

Hatna and Bakker employ a set of digitized historical land-cover maps in order to compare the spatial distribution of cropland, pasture, and nature surrounding cities in the Netherlands over a long time period – 1900, 1960 and 1990. While they find general stability in the land cover around cities, the growth in the amount of croplands near the perimeter of cities in 1900, was weakened by the middle of the century and almost completely ceased by 1990.

The chpater by Marceau, Wang, and Wijesekara describes the application of two cellular automata (CA) designed at two spatial scales to investigate the land-use dynamics occurring respectively in the whole watershed and in the eastern portion of the watershed, immediately adjacent to the City of Calgary. The first model is at a spatial resolution of 60 m. It provides information about alternative spatial distributions of urban areas that can occur according to spatial constraints imposed on land development. The second model is at a resolution of 5 m. It is a patch-based model. The models were used to simulate land development scenarios over a period of 20–30 years. The analyses reveal how land consumption can be considerably diminished by encouraging the protection of sensitive areas and increasing the density of existing and new urban residential areas.

Miguel Serra and Paulo Pinho investigate formation of suburban street networks at the urban fringe by studying Oporto dynamics over a period of 55 years. Their scrupulous high-resolution study employs space syntax approach identifies individual development operations and structural evolution of the entire street networks through simple topological parameters. The chapter demonstrates essential influence of the local developments on the developing network and offers a view of the bottom-up regulation of the street network development that can be translated in planning procedures.

The chapter by Matthies et al. compares between two urban landscapes, Hannover and Haifa, in an attempt to identify the factors driving vegetation diversity patterns within the open space patches s of the cities. Patch sizes and distances from the urban border were used as explanatory variables to predict species richness, native species richness and the proportion of native species within a patch. In spite of the fact that cities are located in different geographical and climatic areas, in both urban landscapes only patch size was found to be a significant factor dictating total species richness and native species richness.

The chapter by Runfola, Polsky, Giner, Pontius Jr., and Nicolson provides a study of the growth of lawns in the United States. Because lawns are maintained through fertilization and watering they present risks for water use and quality, nutrient cycling, urban climate regimes, and even human health. The associated ecological ramifications, such as habitat fragmentation, water quality and availability may be far-reaching. The authors produce a high resolution (0.5 m) land-cover classification to quantify existing lawn extent for the year 2005 in the Plum Island Ecosystem (PIE), a collection of 26 suburban towns northeast of Boston, MA, USA. They then use this dataset in conjunction with the GEOMOD land-change model to project lawn extent for the year 2030.

The chapter by Felsenstein, Lichter, Ashbel and Grinberger present a high-resolution model of the land use-land cover dynamics at the urban fringe that focuses on the reciprocal dependencies between the land cover and land use. They employ historical data on the land use and land cover in Tel Aviv metropolitan during last two decades, and explicitly simulate dynamics on the metropolitan fringe as dependent on the rate of population growth and land demand to the year 2023. When coupled with an appropriate biodiversity model, the land use-land cover model could be extended to forecasting the environmental stress of metropolitan expansion.

Insarov’s and Insarova’s chapter considers the effect of urbanization on lichens and vegetation. It focuses on the main processes taking place in urban lichens and plants at the level of organism, community and ecosystem, and the ecological services they provide. Species richness and composition, community and ecological processes, growth, anatomical, morphological traits and physiological processes under urbanization stress are discussed. Various ecological services provided by urban vegetation, which include: air quality improvement and abatement of noise, among other, are described. A number of case studies from various cities around, which assessed changes of urban lichen communities, are reported. The importance of lichens as monitors of temporal and spatial trends in the state of urban biota under air pollution stress is detailed, and implications for city planning and management are provided.