The Invisible in the City

Much that happens in cities -- urban areas more broadly -- is not obvious to the naked eye or to casual observation.  The invisible things in urban social-ecological systems represent four key dimensions: social processes and their legacies; the built and technological structures and infrastructures; ecological structures and processes; and influences and events that arrive from a distance.  These ordinarily invisible features of urban systems can become visible when something goes awry, or when some long-forgotten decision rears its head as a legacy shaping current conditions or options.  The invisible becomes visible when something "breaks" or is unexplainable based only on current or local conditions.

 

Social Invisibility

Social legacies take myriad forms.  This blog has presented several examples, from the clashing street grids in Baltimore arising from orientation to different shorelines around a complex harbor, to the mortgage redlining that mirrors the concentrated abandonment in city neighborhoods. 

The "break" of the clashing grids is revealed in several layers of attempts to knit the city's traffic flow more seamlessly.  The disjunction between the north-south grid of the Mount Vernon neighborhood and the north-west to southeast orientation of the Madison neighborhood reflect differences between the orthogonal north-south/east-west orientation of the monument-studded downtown grid, and the more organic flow following the old market road on the high ground of the divide between the Gwynns Falls and Jones Falls watersheds, which trends northwestward.  

The 1890 map of Baltimore City, showing the multiple, incongruent street grids.

The break of redlining is actually part of a longer-term and persistent system of racial, ethnic, and class segregation that has characterized Baltimore since at least the demise of post-Civil War Reconstruction and the rise of Jim Crow laws, customs, and conventions.  Given that the primary source of wealth of most Americans is investment in a house, the denial of mortgage security put the residents of neighborhoods judged by the federal Home Owners Loan Corporation to be less than mortgage worthy at a significant and lasting disadvantage in the accumulation of wealth.  Other local ripples of this situation extend to property tax revenue flow, educational resources, and through a complex cascade to access to such things as gainful employment in a post-industrial economy and grocers purveying fresh vegetables.

The 1930s redlining map of Baltimore city, with green, yellow, and red overlays indicating high, medium, and low mortgage desirability based on factors such as race, national origin, and housing stock.

Infrastructural Invisibility

Much built infrastructure is literally out of sight.  Fresh water and gas mains are buried beneath streets and sidewalks, as are sanitary sewers and storm drains.  The drainage infrastructure exemplifies the complexity of build infrastructure.  In row house neighborhoods in old Baltimore, the stormwater drainage system extends from roofs sloping from the street sides of houses toward the back yards, with downspouts draining into alley gutters, which conveyed water to storm drain catch basins in the streets.  So the infrastructure was not just the pipes, but also the roofs, downspouts, gutters, and then the buried drain pipes.  Many of the underground stormwater pipes were, in actuality, buried and piped streams.  The breakage of this stormwater system is seen in the collapse of roofs of long abandoned houses, and the puddling of rainwater in cellar holes and elsewhere where debris collects or obstructs the flow of rain water. 

Water main break at Gay and Lombard Streets.

Other forms of breakage are the common leaks that unintentionally connect the remaining surface streams, the sanitary sewers, and the storm drains.  The pressurized drinking water system also leaks, adding flow to streams and the two sewer systems, and in some cases adding an avoidable burden to sanitary treatment facilities.  

 

Invisible Ecology

Perhaps the least visible component of urban systems is the ecological structures and processes they contain.  Of course, the large green spaces in cities, suburbia, and exurbs are obvious.  Signature parks, golf courses, cemeteries, and the green campuses of private and public institutions are often recognized as ecosystems, a designation that clearly acknowledges their ecological content, and facilitates their inclusion in designs and plans.  However, such large and often socially valued properties are not the only venues for biophysical processes in urban systems.  Yards, volunteer vegetation along fencelines, slivers of lightly managed areas along rights-of-way also contribute to the ecological processes.  Hidden riparian strips behind shopping malls, or at the backs of factories, or transportation corridors can also be seen as ecosystems.  Clearly, there are many ecological processes that occur in these sites: nutrients are cycling, carbon is being processed, decomposition of organic matter is under way. 

However, these quintessential ecological processes are also occurring in urban soils, in surface streams, and in largely ignored wetlands.  Biodiversity -- native and introduced birds, medium sized mammals, and an impressive complement of microbes -- are active throughout the urban system.  Some of these help retain potentially polluting nutrient compounds, sequester some of the climate-changing carbon that economic processes release, help control disease agents, or simply give pleasure to urban residents.  Some of these organisms release contaminating byproducts, and others are themselves disease agents or vectors.  But together they constitute a web of interactions and influences that generate amenities and hazards in urban areas.  Harnessing the positive outputs of urban biota, conserving native biodiversity, and limiting the risks that some organisms pose, requires making them and their interactions visible features of the city.

 

Invisible from a Distance or from the Past

Not all things that influence the social-ecological structure and processes in a given urban area constantly reside or originate within it.  This is especially true of socially-generated influences, which arrive in the form of new migrants at airports, appear as redistribution of financial capital via investment, disinvestment, or personal remittance, or exist as cultural products such as fashion, movies, or music.  Political movements can be seeded from a distance, and opportunities for trade, migration, or commuting determine population densities, economic activities, or cultural vitality.  Social influences, either personified or electronically mediated, are extraordinarily mobile in the globalized, urban world.

A tornado over Baltimore in June 2013

Other, seemingly more concrete effects also arise from outside a given urban area.  Biophysical agents of disturbance, those events that can disrupt the physical structure of a city, often arrive from elsewhere.  Hurricanes, with strong winds, coastal flooding, or torrential inland rains are a familiar example.  So to are storm fronts that unleash snow, ice, or tornados.  Climate change, with the potentials for obvious change in average temperatures, seasonal distributions of heat, cold, wet, and dry, is a prime and increasingly widely appreciated action from outside.  Ironically, the high energy demands of urban systems contribute to these global changes, which come back to haunt, in some form or another, virtually every urban area on the planet.  Notably, many of the changes associated with climate change are already well developed in urban areas.  Heat islands, heat stress, drought, and extreme storm events are phenomena that urban policy makers, managers, and citizens are planning for and adapting to at present.

 

The Invisible as Personal

Given that humans seem to give greatest credence to events and things that they have themselves experienced, it may be that a great deal of what characterizes urban social-ecological-technical systems remains invisible.  The experience of individual persons, or even a nuclear family, is constrained.  Human memory is powerful and poignant, but it is temporally quite limited.

On the scale of a human life span, or the span of two or three generations' memory, many important ecological events can be missed.  Fires in uninhabited chaparral -- shrubland in the mediterranean climates of the American west -- may recur about once every 70 years on average.  A single generation, or even two, may not have seen a big chaparral fire.  Chaparral vegetation is made up of species that are adapted to reproduce after fire.  Indeed, without fire for long periods, other species can replace the chaparral dominants.  Add short human life spans to the fact that the majority of residents in American mediterranean climates are likely to be new arrivals who lack a personal access to multi-generational memory, and the possibility of chaparral fires to be invisible parts of suburbs and exurbs in California or Colorado is enhanced.  Many vegetation types are affected naturally by fire, such as many pine forests in the south and eastern U.S.  Others are affected by periodic catastrophic wind storms, albeit on a time interval of several centuries.  Extreme floods also periodically affect many riverine areas.  However, if people have never experienced such a flood, or if they are lulled into security by a floodwall built to contain the last most catastrophic flood plus a foot or two, the risk is essentially invisible.  In such situations, floods "to worry about" are virtually invisible.

This is a common phenomenon.  Reporting on urban disasters driven by otherwise invisible ecological events often includes this kind of sentiment: "I've lived here all my life, and I have never seen anything like this before."  The "this" can be a wind storm, blizzard, hurricane, huge tornado, or outbreak of some native insect.  Add to this list new invasive pest or disease organisms, intensifying storms due to climate change, shifting and deepening of drought prone pockets, and so on, and the list of the invisible in the city becomes longer still.

The invisible in the city points toward the need for humility -- individual memory often misses rare weather events, social legacies no longer much spoken about, or catastrophic infrastructure failures of the past.  Even family or communal memory seems fallible.  The invisible is a key part of cities and urban systems.  Urban social-ecological-technical research helps to lift the veil.  Maybe the old New Englander suggests how to operationalize humility in the face of the invisible: The question was asked, "Have you lived here all your life?" The droll reply was, "Not yet."  One hopes the answer suggests an openness to the invisible in that lived place.  Seeking the invisible in the city is one of urban ecology's primary tasks.

A Background Reading for the June 2015 Quarterly Project Meeting

Several of us have been working on an essay to describe more fully than an earlier post here, a theory of urban heterogeneity.  That essay is not complete yet, but it is mature enough to share with the BES community for purposed of this meeting.

It is entitled "Dynamic Heterogeneity as a Framework to Promote Ecological Integration and Hypothesis Generation in Urban Systems."  It is not ready for reposting or citation, so just use it for internal BES purposes now.

You can find it on Dropbox at https://www.dropbox.com/s/ur7tynfh8aljtai/A%20Theory%20of%20Urban%20Heterogeneity%20Text%20V12.docx?dl=0

Urban Ecology: Knowing or Making?

Our friend and colleague, Alex Felson, of the Yale School of Architecture and the Yale School of Forestry and Environmental Studies has a unusual perspective on what urban ecology is and does.  Trained as a landscape architect, urban designer and as an ecological scientist, his perspective is quite unusual among urbanists.  You can find information about his work and laboratory here: http://uedlab.yale.edu/

He often argues that urban ecological science is about understanding the city, suburbs and exurbs, as a given.  Science seeks to determine the patterns, mechanisms, processes and dynamics that characterize existing urban ecosystems.  In contrast architects, planners, urban designers, landscape architects, and engineers intend to make the city-suburb-exurban system, in part or in whole, de novo or repurposed.  The big contrast is between knowing and making.

Such a contrast is useful in highlighting the range of stances about the city as a subject.  Alex emphasizes that working with designers – that inclusive community of people who design or change urban systems – forces ecologists to engage in the process of city making.  Bridging the difference between knowing and making is a significant opportunity for ecological scientists.  But there is a variety of ways to accomplish such bridging.

Individual people can be trained and practiced in both ecological research and the theory and practice of urban design (in the broadest sense – architecture, landscape architecture, engineering).  Currently, that is the rare bird.  There are not many people who are trained like that.

Alternatively, people who are trained as designers – the makers -- and those trained in ecological research – can interact through the design process as practiced in architectural firms, municipal planning departments, and sustainability offices.  Ideally, engagement of makers and researchers should be constant through the entire design process, from inception through construction, through assessment of performance of the built project.  Feedbacks between knowing and making should be a constant spiral of interaction and reflection. 

Thinking about designs as experiments, as both envisioned and built projects and as assessments of the performance of the projects, is a real advance (Felson and Pickett 2005, Felson et al. 2013).  This is a method and philosophy that Alex has promoted for a long time.  Makers and knowers can share hats.  Makers must know (as they do via site analysis and observing urbanistic successes and failures), and knowers can be a part of making.  The dichotomy is ultimately a false one.  In addition, monitoring should not be an optional after-the-fact activity, rarely funded or contracted, and thus rarely done.  Rather, knowing and making can be combined in an ongoing, seamless process. 

Urban ecology and urban design can both be improved by the union of knowing and making.  Many ecologists have always been interested in making – conservation, restoration, and management were passions of many of the founders of modern ecology.  For example, Frederic Clements (Clements 1935), the pioneering theorist of plant community dynamics, was deeply exercised by wanting to restore damaged prairie lands.  Other members of the first generation of American ecologists, such as Victor Shelford, were the instigators of such practically motivated organizations as The Nature Conservancy.  Contemporary expressions of the marriage of knowing and making are found in the Ecological Society’s Earth Stewardship Initiative, which calls ecologists to be engaged – along with other disciplines and making professions – in helping to shape sustainable futures (Chapin et al. 2010).

Urban ecology has much to gain from an smoother connection between knowing and making.  It may be time to retire the contrast, at least as a community, if not as individual renaissance-style polymaths.  As the world becomes increasingly urban, making and knowing can’t remain far apart.

Bibliography

Chapin, F. S., S. R. Carpenter, G. P. Kofinas, C. Folke, N. Abel, W. C. Clark, P. Olsson, D. M. S. Smith, B. Walker, O. R. Young, F. Berkes, R. Biggs, J. M. Grove, R. L. Naylor, E. Pinkerton, W. Steffen, and F. J. Swanson. 2010. Ecosystem stewardship: sustainability strategies for a rapidly changing planet. Trends in Ecology & Evolution 25:241-249.

Clements, F. E. 1935. Experimental ecology in the public service. Ecology 16:342-363.

Felson, A. J., M. A. Bradford, and T. M. Terway. 2013. Promoting Earth Stewardship through urban design experiments. Frontiers in Ecology and the Environment 11:362-367.

Felson, A. J. and S. T. A. Pickett. 2005. Designed experiments: new approaches to studying urban ecosystems. Frontiers in Ecology and Environment 3  549-556.

Theory of Urban Heterogeneity

In order to plan for the next phase of BES, we are beginning to consider theoretical frameworks.  Here is the current status of that search.

A Multitude of Urban Theories.  There are many theories relevant to urban ecosystems.  These theories differ in their focus on specific facets of urban structure, function, or dynamics, and in their focus on one or several scales.  Broad urban theories address topics as diverse as the ancient development of cities, the scaling law of benefits and burdens of urban size, urban gradients in megaregional context, urban metabolism and footprint, urban biodiversity, species homogenization and adaptation, political ecology, industrial modernization, and many others.  Urban theories have emerged from disciplines as diverse as sociology, architecture, urban planning, and economics.  This document introduces a candidate theory for BES: a theory of urban heterogeneity.

Jobs of Theory.  There are two main jobs for BES theory: 1) Motivating the hypotheses behind specific research projects within BES; and 2) Clearly linking the diverse specialized activities in BES to a multidisciplinary framework.  In addition, our theory should help organize research and education in the context of Baltimore’s metropolitan shift from a sanitary to a sustainable city and help meet the challenges of climate change.  What theory might the Baltimore Ecosystem Study use to move forward? 

A Candidate Framework.  BES has helped pioneer the social-ecological approach to metropolitan ecosystems and of urban regions consisting of cities, suburbs, exurbs, and rural lands.  This approach recognizes spatial heterogeneity at various scales, ranging from individual parcels to the entire urban region.  Although we have used this perspective, in the form of patch dynamics, from the beginning of BES, important improvements in the understanding of urban systems suggest that we should attempt to articulate a new, inclusive theory of urban spatial heterogeneity.  Advances in understanding the spatial dimensions of biogeophysical and social sciences must be accommodated.  

A newly articulated theory for BES could emerge from an overarching hypothesis: spatial heterogeneity at various scales, and reflecting the key structures and processes in the metropolis, drives social-ecological interactions and dynamics. 

Nested within the overarching hypothesis would be specific subtheories or model domains that specify the different, key structures and processes we deem important in the Baltimore ecosystem.  The choice of the subtheories should build on empirical experience in Baltimore as well as on the broader social and biogeophysical theories our team brings to the table.

The subtheories of urban heterogeneity match the fundamental structure of ecosystems.  We focus on 1) the flux of materials across heterogeneous space, 2) the biotic potential of different patches, with its implications for nutrient retention and ecosystem production in the urban mosaic, and 3) the design and management decisions by human institutional.  These three subtheories can help connect the overarching hypothesis to our specific long-term data, experiments, and syntheses.

The discussions at the steering committee meeting on September 21 should identify key model types, data streams, and the organizing hypotheses in each of these three major urban ecosystem realms.

Does Urbanization Stop?

A lot of effort in urban ecological science around the world is now focused on the process of urbanization.  This is reasonable because the demographic, social, environmental, and economic shifts toward urban in all its forms have become dominant trends for our planet.  The conversion of land from rural or wild landscapes and covers to city and suburb is considered by some to be the essence of urbanization.  

Baltimore (upper right) and
Washington  DC in 1900
(J. O'Neil-Dunne, University of Vermont
Spatial Analysis Lab)

When urbanization is charted – literally mapped – it can be seen as a one way conversion.  Often on such maps, urbanized land is shown as a shade of red, agriculture as yellow, grassland and forest as different shades of green, water as blue, and so on.  Much recent work at the coarse spatial scale shows the color-coded blob of city and suburb spreading across a landscape at the expense of wild, agricultural, or even aquatic covers.  Perhaps the garish colors were chosen to highlight the almost incredible magnitude of urban changes starting about a century ago, and even growing explosively in places like China and India where the trend started more recently.  Some observers fall into a state of panic about the urban when viewing these maps.  Such negative bias about the urban was evident in the “social pathology” approach of the Chicago School of urban sociology, or even longer ago in Thomas Jefferson’s idealization of the agricultural life and the open American frontier exemplified by the Louisiana Purchase.  

Baltimore and Washington, 2001

But whatever the biases and rationales for the colors mapped, the changes are commonly represented as one-way transitions.  Urbanization, like the old-fashioned views of ecological succession, might be considered to be a linear, directional process that has a terminal point.  Such maps do tell a very useful story at the coarse scale.  The comparison of cities and of times, and the planning and management of regions can benefit from the coarse scale mapping of urban entities.

In spite of its value, the coarse mapping approach to urbanization does leave out some important subtleties.  Three big things about the urban realm need to be added: 1) within-urban spatial heterogeneity; 2) the issue of what comes after urban; and 3) the existence of city/suburban/exurban systems as qualities as well as material entities.

Urban Heterogeneity.

Urban is used here inclusively, referring to various kinds of dense, demographically diverse, infrastructurally invested systems and their various human networks and social interactions.  Urban is city, suburb, and exurb together.  It includes locations as different as central business district, leafy suburb, shantytown, strip mall, industrial park at the Interstate exchange, forested park, community gardens, vacant lots, and many more kinds of designed and accidental places. 

Social-biophysical, high conceptual
resolution land cover map (HERCULES)
in metropolitan Baltimore

Sometimes the red blobs of urban maps are shaded to represent commercial, transpiration, residential districts of varying densities.  If the maps are constructed at relatively fine grained spatial resolution, riparian, forest, park, grasslands, brownfields, and the like may be shown.  Depending on the spatial resolution and how land cover classes are defined, infill and edge sprawl development can be shown.  

But cover can be conceptualized in a way to acknowledge that it comprises both biologically-derived ecological components like trees, shrubs, grass, and socially derived components like buildings and pavement.  Human actions stand behind these heterogeneous components through migration, transportation, design, construction, management, demolition, etc.  The HERCULES land cover system reflects this multi-dimensional biological-social heterogeneity (Cadenasso et al. 2007). 

What Comes After Urbanization?

The issue of heterogeneity within coarse-scale representation of urbanized areas points to the second shortcoming of simple conceptions of urbanization.  Once a place is urbanized, it can continue to change.  In other words, the nature of urban fabric and the interactions it is entangled with can continue to change.  In fact, such change is a remarkably common feature of urban systems.  Changes range from the shifts from residential to commercial use along some transportation routes, to wholesale abandonment as population becomes sparser in the inner city, to “scrapeoffs” of older, smaller suburban houses and their replacement by lot-filling McMansions, to conversion of disused industrial structures or warehouses to residences or artistic venues.  Even the vegetation component of urbanized patches can wax and wane as street and yard plantings mature or succumb to storm, pest infestation, or neglect.  The currently growing interest in community gardens and urban farming is another example of mutability within urbanized land covers.  The urban blob is a snare and a delusion, since fine- and medium-scale changes within urban areas continue.

If the conversion of land from agricultural and wild to urban is a step function or a threshold that is not reversible at the coarse scale, still urban processes continue.  Urbanized areas continue to change, sometimes in large ways and sometimes in micro-patches.  Hence, it may be useful to conceive of urbanization in ways like ecologists have come to view community or ecosystem succession.  

Classically, succession was thought to start with a pioneer community established after some large disturbance and to proceed through dominance by higher statured plants while adding layers, and ultimately to end in a stable configuration and composition of species and metabolic processes -- the so-called climax.  Contemporary understanding of succession accepts that “stages” may be skipped or not come in the expected order, that fine or medium scale disturbances may continue to play a role in structuring the community, and that there is rarely anything like a local climax.  Urbanization may be like this – an idiosyncratic trajectory, contingent upon a specific concatenation of human and natural events, and not reaching some stable end point.  Urbanization in the current era may best be thought of as an ongoing urban processes.  In other words, to have been urbanized is not to stop changing.

Some social scientists have similar views.  For example, Gottdiener and Budd (2005:184) state that “Urbanization attempts to chart and understand the rise and fall of great cities.”  In that same article they point to some of the complexities of contemporary urbanization.  The existence of multiple kinds of urban form within the same urban system, the role of industrialization in urbanization, the role of consumption lifestyles, and the regional scope and connectivity of city and suburban settlements.  Marcotullio and Solecki (2011) note that some social and environmental problems blamed on urbanization would be better disaggregated into more distal, fundamental causes, such as affluence, lifestyle, and power relationships rather than a vague, overgeneralized variable such as urbanization.

The City as Quality

Urbanization is often thought of in the environmental sciences and in the planning realm as a physical entity.  This view supports the emphasis on mapping and the colorful sprawl time-series we so often see in writings about urban policy and urban problems.  Marcotullio and Solecki (2013) do a nice job of highlighting the limitations of the approach to cities only or primarily as quantities or physical entities.  Maps of land conversion, drawing of sharp boundaries, and defining the distinctions between urban versus the rural and the wild, for example, are approaches that are reinforced by the view of cities as quantity or entity.  Social phenomena such as human density, concentration, kind of employment (agricultural vs. non-agricultural), and heterogeneity are part of the "entitation" of cities.  So are the physical features such as impervious surfaces, modification of stream networks, transportation and infrastructural grids, commuting radii, installation and management of vegetation, and the concentration of heat, contaminants, and certain resources.  All are mappable quantities.

Certainly cities, suburbs, and exurbs are physical places. 

Night life along the river in Tianjin,
China. A variety of formal and informal
activities represent the quality of an
urban area.

But they are also lived experiences and suites of interactions. These are the qualities of urban systems.  Qualities include such things as institutional arrangements and social norms, reliance upon legal versus familial strictures, connection with distant resources, opportunities, and limits.  Lifestyle and livelihood might be useful short hand for important features of the urban systems as quality.  Of course, there are many economic and social processes that scaffold these lifestyle and livelihood as quality.  Another aspect of quality is sense of place.  Sense of place reflects individual and community-held cognitive maps, the landmarks that people mentally locate themselves and also physically navigate by, the feeling of support or comfort in some locations versus discomfort and fear in others. 

Importantly, although these all reflect quality of the urban, it is possible using various sociological and anthropological methods to measure and compare these reactions to urban as quality.  Many of the features of the human ecosystem framework (Machlis et al.  1999) reflect the qualitative side of Cities/Suburbs/Exurb systems.  Myths and cultural resources, interacting individuals, and the temporal changes of households, communities, and institutions become part of the quality of urban life as well.  These qualitative features are recognized by contemporary social-ecological urban systems theory to be involved in feedbacks with the biophysical processes in urban ecosystems.  Discovering and understanding these linkages between the social qualities and the biophysical quantities remains a key goal of contemporary urban ecological science.

Is There a Better Term?

Urbanization as a term fails us by not connoting the subtleties of internal physical and social heterogeneity, the fact that urban areas never stop changing, and the idea that “cityness” is both physical quantity and social quality.  The processes are multiscalar and continue in various forms, from “the business cycle” to population growth and residential thinning.  If the suffix “-ize” means to become something – in our case to become urban -- what word will stand for the continuing changes, sometimes episodic and sometimes gradual once the urban realm has come into being?  Maybe we can shoehorn “urbanization” into this definition, and beat it into submission.  

Or maybe we can speak instead of “urbaning,” to represent the ongoing changes that old, new, and yet to be born cities, suburbs, and exurbs will be involved in.  Urbaning would mean the condition of being urban and dynamic.  Or since nobody is going to accept such a neologism, maybe we can just be careful with our conceptual, empirical, and theoretical models, and always keep urban quality, urban quantity, and urban change in clear view across scales from a neighborhood to an urban megaregion.

Bibliography

Cadenasso, M. L., S. T. A. Pickett, and K. Schwarz. 2007. Spatial heterogeneity in urban ecosystems: reconceptualizing land cover and a framework for classification. Frontiers in Ecology and Environment 5:80-88.  Concepts and a spatial analysis approach that links socially-generated and biologically-generated sources of spatial heterogeneity at fine scales in urban, suburban, and exurban landscapes

Gottdiener, M. and L. Budd. 2005. Key concepts in urban studies. Sage Publications, London.  A conceptual dictionary of terms about urban studies from the social sciences.  Useful entries on urbanization and urbanism.

Machlis, G. E., J. E. Force, and W. Burch, Jr. 1999. The human ecosystem as an organizing concept in ecosystem management. Pages 21-36 in N. C. Johnson, A. J. Malk, W. T. Sexton, and R. Szary, editors. Ecological stewardship:a common reference for ecosystem management. Elsevier Science Ltd., Oxford.  The Human Ecosystem Framework contains many elements that represent quality of urban areas, as well as those that are physical entities or quantities.

Marcotullio, P. J. and W. Solecki. 2013. What is a city? an essential definition for sustainability. Pages 11-25 in C. G. Boone and M. Fragkias, editors. Urbanization and sustainability: linking urban ecology, environmental justice, and environmental change. Springer, New York.  A clear and compelling assessment of the quantity and quality approaches to cities, and cautions about the neglect of quality in environmental sciences.  An excellent overview of the social controversies behind this continuum.

Simone, A. 2010. City life from Jakarta to Dakar: movements at the crossroads. Routledge, New York.  Discusses the nature of “cityness,” and is thus a nice complement to Marcotullio and Solecki with many examples from the very dynamic urban processes in Africa and South Asia.

Urban Ecology: Stones or Rocks?

Why are there two words for mineral concretions?  And what does that have to do with urban ecology?

I recently visited Newark, NJ to work with BES urban design expert, Brian McGrath.  He lives in an the old industrial neighborhood of “The Ironbound,” and like many such places, there is great dynamism.  Some old buildings are being demolished, restaurants and clubs are being renovated in this place famous for Portuguese food, and the general rust down, fix up of lively urban places is much in evidence.  As we walked to a (strong!) coffee break during an afternoon of writing, I noticed a vacant lot that contained a big, smooth, ovoid boulder next to a yellow backhoe.  The lot sloped gently into the cellar hole of the missing building, and the rock and the backhoe were the only adornments I noticed in the fenced lot.

A Rock in the City

Why did I call it a rock, and not a stone?  This big rock with a grey, smooth surface was a remnant of the last glacial age.  It looked like nothing so much as a huge, water smoothed pebble – the sort of thing you could see on the bottom of a creek.  But this one was about a meter and a half long, and a meter wide.  It looked to be a little flattened, so that it would not roll easily.  Of course this rock was big enough so that it wouldn't roll easily in any event.

My big rock, was in fact a scaled up version of a

The Newark rock. Photo: Victoria Marshall

creek pebble, but the water in which the lonely Ironbound boulder was shaped was the water released by a mile-high mass of ice as it melted.  Such meltwater streams were huge, and they could carry rocks half the size of a first-generation suburban tract house.  Those streams tumbled the big and the small rocks that had been dislodged and trapped as the ice ground across the surface of northern North America some 20,000 years ago.  And this one was a good sized, but not a gigantic representative of glacial grinding followed by years of tumbling down the huge glacially fed precursor of the Passaic River.  The Passaic River is now a pretty respectable stream.  But when the glaciers were melting, it would have been much larger, and been joined to a sibship of other massive streams coursing toward the then distant Atlantic coast.  As the glaciers were exhausted by their own melting, the massive streams shrank and left deposits of mixed, smoothed sediments, pebbles, cobbles, and boulders. 

When I commented on the rock to Brian, he smiled and said that our landscape architect colleague, Victoria Marshall had also commented on the boulder.  Brian's remark went something like “you landscape people notice the same things.” 

Stones in the Country

Then I thought of another architect/ecologist story from some dozen years earlier.  Brian and Victoria were kind enough to include me as an ecological resource person in some of their urban design studios.  On one occasion, we arranged for some of the students to come up to the Cary Institute to work with me and fellow ecologist Mary Cadenasso.  I picked them up at the train station in Poughkeepsie, NY, and drove them the 13 miles on Rte 44 through the Dutchess County suburbs, engulfed agricultural mill towns, and exurban fringe with its regrowing, post-agricultural woods.  We drove down a small hill into the village center of Pleasant Valley, and as we turned the corner heading into town, we were presented with two architectural gems.  One was a two story, Art Deco switching station sitting amid huge power pylons and banks of muscular electrical transformers.  But a bit beyond the buff and black Art Deco treasure was a limestone barn, of much greater age.  The barn was large, had simple lines, just a few windows, a gable roof and the expected huge wooden doors in the side.  

One of the architects exclaimed aloud at the unexpected visual treat.  Now the “landscape” joke here is definitely on me, because I had been driving by that transformer yard for about 12 years before I even noticed the old barn.  Let’s give me a break and say it was because I was the ever cautious driver who always looked at the road.  But in reality, it was that I wasn't tuned into the built in this odd, now suburban site.  I was usually looking at the creek on the other side of the road – was it in flood, or was the water low?  Were there any lanky waterbirds standing by the bank?  Were the big sycamores on the eroding banks still upright?  Were the maple buds on the leafless branches expanding as the days got longer?  That kind of “landscape” ecology stuff.  To claim a little credit, I had actually finally noticed the stone barn a few years before the architecture student exclaimed over an unexpected and complex find.

Art Deco switching station lower left, old stone barn upper center.  Bing.com

Seeing Rocks and Seeing Stones

So there are two contrasts in these stories.  Rocks versus stones, and who sees rocks and who sees stones.  Rocks are generally considered those things out there in, on, and of the ground that are found where the volcanoes, rivers, glaciers, faults, uplift, and erosion left them.  They may have smooth or sharp edges depending on how long and how effectively water and wind have worked them, or whether the work has been dome by freezing and thawing of water in almost imperceptible cracks.

Stones on the other hand are things that have been shaped and arranged by people.  The stone barn was assembled from blocks of limestone quarried from very nearby.  Because many of the early colonial houses in the Hudson Valley are made of limestone, or sometimes roughly worked shale, I should not have been surprised to find an elegant, simple old barn constructed of limestone that could be obtained close by.  But even though limestone tends to fracture in relatively flat planes, there is some work in the quarrying.  And the shale and slate from one of the twisty formations of these rocks in Dutchess County, NY would likely have to undergo some hammer blows to make them fit better in building walls. 

Here's the big difference.  Stones may be found, but more likely worked, and them moved and arranged by people for their purposes.  That’s different from rocks, that just are, though they may be used pretty much as they are found sometimes.  Field walls are more likely an example of “use as found,” of course, since they don’t have to be weather-tight.  So the difference between stones and rocks says something about origin of the mineral conglomeration, the source of the energy shaping them, and whether there is purpose embodied in the shape.

It might be too easy to make a big deal out of an architect seeing buildings – stones; and an ecologist paying attention to other things at the same bend in the road.  Too easy to make a “thing” out of being excited by seeing an unexpected glacial relic a few blocks from the Newark train station.  Does one always have to see rocks OR stones? 

Saxa Loquuntur

Now we are back to urban ecology.  One could say that in the past, when urban ecology as a biological science was just getting started, it was conducted through the filter of seeing rocks in the city.  Looking for those places, processes, and entities that represented the unintentionality of nature motivated a lot of the earliest work by bioecologists in the city.  And it is very important to see this part of urban systems, as Anne Whiston Spirn suggested in her 1984 book, Granite Garden.  Cities work in part because there is natural work going on in and around them.  But her title also tells us that it is proper and necessary to see the built, the designed, the engineered, and the lived in as a part of an expanded view of urban ecology.  One has to see the stones of the city.  

The A. Hoen Lithography and Printing factory.  S. Pickett

But most urbanism in the past has focused only on the stones – the built fabric of cities – and ignored the biological processes that traditional ecology has pointed out to occur even in urban centers.  So it’s not a matter of stones versus rocks, but of a conversation that values both.  The pleasures of the architect joined with the pleasures of the ecologist, and the joys of the social scientist, as well, who help us understand how people live in and make decisions about our gardens of rock and stone.  As the bas reilef shield above the door of the now abandoned A. Hoen & Company lithography and printing shop in East Baltimore tells us, Saxa loquuntur - The stones are speaking to you. (http://www.zigersnead.com/current/blog/post/saxa-loquuntur-stones-and-stories-of-hoen-lithography/09-13-2011/3452/)  So are the rocks.  It’s a language that requires many differently trained ears to hear, and many voices to translate.  That’s today’s urban ecology.

Introducing the BES Urban Lexicon

The members of BES represent a wide variety of disciplines and backgrounds.  Some are educators, some are experts in community engagement, and some are researchers whose interests span from physical to social sciences.  It is no surprise that such a diverse community might use the same words in different ways, or have vocabularies that emerge from different theoretical assumptions and particular practical applications. 

A Tool for Synthesis and Conceptual Integration

In order to promote communication and shared meaning across this heterogeneous intellectual landscape, we introduce a lexicon – a roster of terms and their meanings.  Go here for the lexicon: http://besurbanlexicon.blogspot.com/ .  This list of words was assembled by a call for suggestions from the BES community.  Many different people contributed definitions.

But each definition also includes an example or two, a statement of why the term or idea is important, and some suggestions of additional sources of information on the topic.  Importance can reside in intellectual or practical realms.  Many of our concepts in fact have a dual life – as fundamental idea and as practical

application.  A figure, map, graph, or photograph may also accompany the entries.

How to Find a Term.

The BES Urban Lexicon takes the form of a web log, so the entries appear in the order in which they were posted.  In order to see an alphabetical list of the terms, users should consult the navigation pane to the left hand side of the web page.  Clicking on the term in the navigation pane reveals the entry.

Do You Want to See a New Term In the Lexicon?

If members of the BES community or the readership at large would like to see additional terms defined by us, please send suggestions to our Project Facilitator (beyarh@caryinstitute.org).  We can’t promise that we will find an author for all terms suggested, but we’ll give it a try.  If you are a member of the BES community and wish to define a term, send it to us in an e-mail following the format of terms already posted. 

We hope this collection of ideas and terms appropriate to contemporary urban ecological science is useful.  

A New Book on Urban Ecology

A new book on urban ecology is about to appear.  Three urban ecologists from the University of Quebec in Montreal, Beatrix Beisner, Christian Messier, and Luc-Alain Giraldeau, have compiled an engaging series of essays to share with general readers and students the richness of ecological processes and phenomena in cities, suburbs, and exurbs (CSE).  I was very excited to obtain an advanced copy of this book at a recent meeting on urban biodiversity in Montreal.

The book starts out with a statement that will be uncontroversial to biophysical ecologists and the other researchers who work with them: “Above all else, ecology is a science.  Ecology is not a philosophy or a way of being, and even less is it a panacea to save the planet” (Beisner et al. 2013: 1).  Of course sound ecological knowledge is of extraordinary utility in identifying and solving environmental problems, but this is because of the scientific foundation it provides.  Ethics, philosophy, and action are the tools by which scientific knowledge come to play its key role in personal and social decision making.  In its 147 pages, this book comprises 25 essays that range widely across the ecological principles, processes, and responses relevant to urban systems in the broadest sense.

Readers will come away with an understanding of the fundamental processes of biological production and decomposition as they occur in CSE systems.  The technical vocabulary needed for this understanding is gently introduced, and for the forgetful, a glossary appears at the end of the book.  Each essay includes a few beautiful line drawings and illustrations to engage the reader visually in the topic as well.

Although the titles of the essays do not always alert the professional ecologist to the technical content, rest assured that the conceptual coverage is broad.  Ponds and aquatic organisms, the function of plants and the composition of vegetation, the role of invasive species, evolution and adaptation, population dynamics, pollution, and social ecology are among the many topics exemplified in the essays. 

In addition to understanding some of the key points of ecological knowledge needed to understand and better manage and plan CSE systems, readers will come to appreciate the nature of ecological science itself.  Controversies, conflicting hypotheses, and problematic interpretations are highlighted in some of the essays.  All of the essays include questions, a point to discuss, or an invitation for rigorous observation that can involve readers in the thinking and doing that are the core of science. 

Watch for this little book in 2013, in either paper or e-book formats, as a stimulus for teaching and learning about the inextricable meshing of the ecological in our cities, suburbs, and towns. 

Bibliography

Beisner, B., C. Messier, and L.-A. Giraldeau, editors. 2013. Nature all around us: a guide to urban ecology. University of Chicago Press, Chicago.  (Readers in French will want to look for the publication under the title L’ecologie en ville published by Editions Fide in 2006.)