Friday, December 19, 2014

BES Sexual Harassment and Discrimination Policy

The posts here often discuss conceptual issues, ideas and empirical insights, and opportunities for learning and communication that can promote the science, education, and community engagement of the Baltimore Ecosystem Study.  This post is a little different, but it points to an equally important ingredient for success of a collaborative, productive, and engaged project: the avoidance of sexual harassment and discrimination.  Given that diversity of various sorts, including the kinds mentioned in the policy, is important for the success of science, education, and application, a policy that is aimed at protecting the participants in BES from sexual harassment is also important.

Why are we promulgating a policy now?  A growing body of research has documented that sexual harassment, assault, and rape are unfortunately a part of the field research experience.  Action is necessary on the part of individuals and institutions to change the culture and the reality behind this sad situation.  Here's a news article that gives some background:

The Project Management Committee was stimulated to go on record with an anti-harassment policy for BES.  All participants in BES, from young students to senior leaders deserve a comfortable, open, and non-discriminatory work environment -- whether it's in the classroom, the lab, the field, or the office.  This means that everybody involved BES --whether officially paid by BES funds or not --must understand what sexual harassment is in order to avoid engaging in harassing behaviors, and to be able to seek recourse if it does occur.

It is important for all to understand that intent is not the definition of harassing behavior -- effect is.  Unintentional harassment is still harassment.  The policy gives examples of things that can be perceived as harassment, and which must therefore be avoided.

Here is the entire text of the policy:


The Baltimore Ecosystem Study (BES) LTER is committed to providing a constructive research environment that is free of harassment and that supports individual dignity and respect.

Accordingly, BES advocates a strict policy prohibiting sexual harassment and discrimination because of race, color, creed, gender, national origin, age, physical or mental disability, sexual orientation, military service, or any other classification protected by Federal, State or local law. Such conduct will not be tolerated and is prohibited.

Sexual harassment includes, but is not limited to, the following:

1.   Unwelcome sexual advances; requests for sexual favors; and all other verbal, visual or physical conduct of a sexual nature based on gender, especially where:
a.   submission to such conduct is made explicitly or implicitly a term or condition of involvement in BES;
b.   submission to or rejection of such conduct is used as the basis for decisions affecting an individual’s involvement in BES; or
c.    such conduct has the purpose or effect of interfering with an individual’s work performance or creating an intimidating, hostile or offensive research environment.

2.   Offensive comments, jokes, drawings, pictures or cartoons, innuendoes, and other sexually oriented statements, whether verbal or written.

Similarly, any of the following conduct may involve unlawful harassment or discrimination because of race, color, creed, gender, national origin, age, physical or mental disability, sexual orientation, military service or any other classification protected by Federal, State or local law:

1.   Verbal conduct such as epithets, derogatory comments, slurs, jokes or comments;
2.   Visual conduct such as derogatory poster, photography , cartoons, drawing or gestures,
3.   Physical conduct such as unwanted touching, blocking normal movement, or inappropriate physical gestures;
4.   Retaliation for having objected to reported or threatened to report harassing conduct.

If a person believes that he or she is being harassed or discriminated against because of his or her sex, race, disability, ancestry or other protected classification, such person should follow the policy of their home institution for reporting such conduct. 

--------End of Policy--------------------

This policy will be posted in the BES office and lab, and on the website.  Participants in BES should also consult the anti-harassment policies of each of their employers, and further details may appear there.  In addition, specific institutions provide channels for grievance and recourse.

Please take the need to understand and avoid sexual harassment seriously.  Also take seriously the desire of the leadership of BES to be helpful in facilitating appropriate recourse by the legally responsible institutions if any harassment does occur as a part of BES activities and work. 

Monday, October 20, 2014

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.

Wednesday, October 15, 2014

Baltimore and Beijing: A Learning Expedition to China

Famously Rampant Urbanization

This last summer, I had the pleasure of being hosted as a Visiting International Professor by the Research Center for Eco-Environmental Sciences in Beijing.  This center is part of the Chinese Academy of Sciences, and is the home of the State Key Laboratory of Urban and Regional Ecology.  My goal in spending three months in China was to learn about its form, magnitude, and rate of urbanization. The speed and novelty of urban growth in China are exceptional.  Although some countries have faster annual percent rates of conversion of population from rural to urban, none has a greater absolute number of participants in the process.  Nor do other countries rival China in the extent of the creation of new cities virtually from scratch across broad regions.  It is a perfect place to help put our work in Baltimore in a larger perspective.  In addition, researchers in China are excited and very well prepared to share their new knowledge about urbanization with the rest of the world.

China has for thousands of years been a largely agricultural
country.  The establishment of the People’s Republic saw the proportion of rural residents in the solid majority.  Although Chinese cities boast histories reaching back thousands of years, they were mostly distinct settlements, often retaining ancient defensive walls and sharing key aspects of their city plans.  However, starting from the late 1970s, with the establishment of new policies, the growth of its cities, and the transformation of its population from predominantly rural to mainly city-dwelling, took off.

Chinese urbanization is more than simply the growth of established cities, however.  The idea of urban agglomerations, more recently conceptually deepened in terms of urban megaregions, was one that originated to capture the extraordinary spatial scope of urban change in China and elsewhere in Asia.  There are 23 planned megaregions or urban agglomerations in China (Fang 2011).

Twenty-three existing and planned urban megaregions in China (Fang 2011)

Urban megaregions require understanding urban change in an inclusive way, as something that embraces old city cores, new neighborhoods, novel extensions within large urban administrative units, the engulfing of ancient villages by dense and often high-rise urban fabric, the replacement of agricultural villages by mixed industrial settlements, the demolition of villages and their replacement by superblocks of gated high-rise condos or apartment buildings, and even some modest development of villas, or what we in the U.S. would call single-family houses with yards. 

The richness of the kinds of change and the spatial mosaics produced are novel and not well researched at this time.  Chinese urban ecologists recognize a pressing need to understand the environmental implications of this long list of transformations.

Shifting Policy Landscape

Coming from the United States, I had the impression that China’s strong central government would make urban policy easy to understand, and would also make rational urban plans the norm.  What I learned however, was the existence of a complex, multi-level and multi-sector process of urban change.  In addition, I learned of a fluid policy landscape.  For example, until late July of this year, urban residents had to be registered.  This excluded many people who wished to migrate from the countryside from full participation in urban life and its amenities.  Children of unregistered residents were not permitted to attend public schools. Furthermore, unregistered rural migrants were often crowded into less-than ideal rental units. 

In July 2014 the central government announcemed that this policy, labeled hukou, would apply differently depending on the size cities.  Although the intent is to more evenly spread urbanization across the spectrum of cities, there may well be an pulse in migration to cities as a result.  The social and ecological consequences will be not only interesting, but very likely potent.

The revision of the hukou policy is situated within a larger trajectory of policy evolution in China.  The previous central government policy prioritized industrial development.  The term “development” is used all over the world and is the stuff of headlines and political slogans.  However, it strikes me that most uses in the public discourse in China and elsewhere are rather vague and loaded.  In the past, given the evidence on the ground (and in the heavy, polluted air!) development in China suggested an industrial pathway, and China’s prowess as a maker for the world has been rightly recognized as a result.  But the term development, again based on my personal observations of the culture of consumption that has saturated the big cities with global brands, automobiles with foreign name plates, familiar fast food restaurants, and multi-story shopping malls, also implies a growing emphasis on the provision and acquisition of luxury goods.  The urbanization policy now driving demographic and spatial change in cities, suburbs, with its implications for villages and rural life, shifts emphasis to domestic consumption as a driver for development.

Of course industrially based economic activities and infrastructure will continue to be built and operated in China.  But the new emphasis on urbanization intertwines with a new national policy on the environment.  How these two strands will be reconciled and whether there are the desired environmental – and human well being – outcomes, remains to be seen. 

Chinese urban ecologists are concerned to be part of the dialogue, and many ecological leaders are well placed to help urban planners and municipal authorities to improve the ecological processes and services within their jurisdictions.  I did, however, see evidence of some shortfalls in linking ecological and urbanization processes.

Shortcomings in Contemporary Urbanization

One problem is the sheer speed of urban development.  An interesting and salubrious institution in many large Chinese cities is the city planning museum or planning exhibition hall.  I visited three of these: Beijing, Tianjin, and Shanghai.  In some cases, a glance at the current iteration of the city regional plan was jarring in its dissonance with the facts on the ground.  Much of the greenspace promised by the current plan for Beijing had already disappeared under roads and buildings.  An aspect of the plan that was clearly successful was the protection of the mountain districts in the extensive megacity administrative boundaries of Beijing. These lands were well preserved under the rubric of protecting the air and watersheds on which the city depends, although as a plant ecologist I was interested to know how much impact the transplantation of large, mature trees from the forests into new city and urban developments affected the source stands. 

Tianjin’s urban plan seemed to have clearer bioecological content, and establishing boundaries to protect sensitive forests, lakes, seacoast, and rivers was a part of the plan.  Lands were set aside for parks for urban residents as well, and restoration of wetlands formerly devoted to agriculture in the city boundaries was called for.  The ecological rationale for such conservation and restoration was well laid out in Tianjin’s exhibition hall.

Another issue is the predominance of an economically driven real estate industry, a social institution not unknown in the capitalist west, of course.  My na├»ve view of the communitarian nature of the Chinese state did not prepare me for the news about the power and efficiency of the private real estate juggernaut in China.

The final shortcoming was the nature of many eco-cities.  As an ecologist and an urbanist who thinks that sustainability is a reasonable strategy for visualizing multi-dimensional improvements in urban social-ecological systems, I had high hopes for the eco-city idea.  However, eco-city developments seem to emphasize a rather narrow suite of strategies, such as engineering efficiencies, multimodal transportation and density, improved onsite stormwater management structures, supplementation of energy sources with renewables, such as wind.  They also have generous street tree plantings and green courtyards in the high-rise residential blocks.  However, the eco-city developments, which were conspicuous in the impressive city models in the planning exhibitions, and evident on the ground in many places, had significant lapses in my view.  I highlight several below.

The rich diversity of commercial opportunities scattered throughout the older urban neighborhoods and even in larger villages, were relegated to centralized shopping malls in the eco-cities.  Three was little to invite residents to interact on the street, and although the individual residential clusters apparently provide recreational amenities behinds their gates, the life on the street seemed depauperate.  This seems to violate one of the tenets of functional urbanism, and was a great disappointment to see so often.  Altogether, the utility of the sustainability concept, which calls for the joint attention to ecological integrity, social functionality and equity, and economic vitality, seems to be poorly realized in much of the urban growth that I saw in China.

Visualizing Urbanization: Opportunities for Enhancement

China also offers insights into the visualization of urban change, a problem that is widely shared.  The process of land conversion and of remaking existing cities is so striking that it is frequently and compellingly represented by a few contrasting colors on GIS maps.  Derived from aerial imagery, such maps represent core urban zones in red, agricultural areas in yellow, and forest and grassland in shades of green.  Because the shifts over five or ten years are so great, such color contrasts over time tell a powerful story.  
Change of land covers in Beijing from 1984 through 2010. Red is
developed urban land.  Copyright
Prof. Weiqi Zhou.  Do not duplicate without permission. 

But such coarse classification of urban lands – red blob mapping -- neglects much of the subtlety of urban form.  This is due to both the frequent use of coarse spatial resolutions on the order of 10s of meters, as well as to the fact that these classifications are blind to the rich array of ways in which people actually use different patches.  And here I do not mean use in the sense of simple zones like commercial, industrial, or transportation areas.  Nor does even recognizing the height of buildings reveal key social and ecological relationships that different spatially recognized patches might possess.  There is a great opportunity in China to break down the land covers within urban and urbanizing areas into more specific categories, while recognizing the three dimensional structures of patches.  This approach is one that was pioneered in Baltimore, and I look forward to exploring it with Prof. Weiqi Zhou and other colleagues in China.  The detailed spatial heterogeneity of city regions is a key dimension along which ecological and social understanding have been demonstrated to advance. 

This sort of theoretical perspective on cities also matches very well with the concerns and practices of urban designers, including architects, landscape architects, planners, as well as sociologists concerned with the patchiness of human institutions and social arrangements.  Once more subtle land cover maps are available for Chinese urban regions, the opportunity will arise to understand the social structures, norms and policies, governance arrangements, and of course, the bioecological patterns and processes that exist in those heterogeneous structural mosaics.  The power of fine scale, highly conceptually resolved land classifications in Chinese cities and their rampantly changing urban regions has hardly been tapped.

The Reach of Urbanization

The impact of urbanization in China – or anywhere for that matter -- is not something that is confined to cities and their expanding fringes.  Rather, the growth of cities in China touches even distant villages and rural areas.  Indeed, the national urbanization policies mentioned earlier in this essay guarantee that the link between urban and rural changes will be strong. 

One thing that I explored with Prof Weiqi Zhou and members of his laboratory, was how the continuum of urbanity can be used to advance the understanding of the regional nature of China’s urbanization. 

The continuum of urbanity identifies four dimensions along which the structures and processes of urban change play out: Livelihood, lifestyle, spatial connections including local, regional, and global, and the social and biophysical nature of specific places.  The continuum of urbanity is a conceptual ordering of the shift between urban and rural influences and processes (Boone et al. 2014).  It is not necessarily a literal transect on the ground, but rather the idea applies to various scales and can be used to understand the effects of urbanization at local, regional, and global spatial scales.

The four components of the continuum of urbanity examine 1) how people support themselves and whether and how they participate in formal and informal economies, 2) the nature and expression of their social identities and the implications of social identity for consumption and symbolic decisions, 3) the spatial scope of influences and material connections, including long-distance linkages or tele-connections, and finally 4) the interaction of the other three dimensions with the biological, physical, cultural, and social environments of specific places.  Such specificity of place can apply to very local or to broader areas.  In describing the interaction with place, it is important that sometimes features of the bio-geo-cultural environment act as constraints on the other three dimensions of the continuum of urbanity, and sometimes the environment is in fact changed by the processes represented by the other dimensions.

Urban district rising on recently converted agricultural land
between Beijing and Tianjin.
It is clear that the continuum of urbanity plays out in China in many ways.  The connections between cities and villages are diverse and impactful.  Some villages are swallowed up into expanding cities, with consequent changes in livelihood and lifestyle.  Some villages continue to exist, but become sites of industrial production as factories excluded from polluted cities relocate to rural areas, while some are converted to tourist economies, for example.  In other cases, villages are bought out and the land converted to high-rise, gated apartment blocks with the associated transportation infrastructure.  

And the continuum of urbanity does not stop at China’s borders.  As the official policies to generate a more urban, domestic consumer-based society move forward, a rising middle class demands more meat, for example, which alters land use and livelihoods as far away as Australia and the Americas.  Pig farming, migration of fruit bats to cities, and shifts in bat-borne disease risk are outcomes of the continuum of urbanity that spans from China to Australia. 

The continuum of urbanity represents a useful way to organize research on the extensive effects of urban development in China.  It can focus on fine scale heterogeneity within cities, as called for above, or it can expose the continental and global effects of urbanization.  The mutual relationships of urban regions linked in a global system are eliciting greater attention in the world of economics, and ecology will change at both ends of any urban teleconnections.

An Urban Ecological Future

The changes in China’s urban realm, and its megaregional, continental, and global reach are vast research frontiers.  To summarize what I learned in China:

1. There is great need for describing, modeling, and working with spatial heterogeneity at refined conceptual resolutions and at various spatial grains.

2. Social phenomena and dynamics need to be better connected with ecological and physical data and representations of urban change.

3. The connections between both former and persistent-but-altered rural zones and villages with cities are an open research task.

4. Addressing the shortcomings of some “eco-city” approaches, and applying sustainability as a linked set of social, environmental, and economic goals are important challenges.

The richness, speed, and nature of Chinese urbanization are a useful intellectual foil to the specific history and trajectory of urban change in Baltimore.  China defines at least one extreme of the conceptual space that all urban social-ecological research and application occupy.  Opportunities for comparison and for collaboration are great.


My trip to China was supported by an International Visiting
Professorship from the Chinese Academy of Sciences.  My hosts were Prof. Weiqi Zhou and Prof. Zhiyun Ouyang of the State Key Laboratory of Urban and Regional Ecology of the Research Center for Eco-Environmental Sciences.  The graduate students and faculty in Prof. Zhou’s lab were indispensable guides and warm friends, and I am indebted to them all for many kindnesses, including compensating for my attempts to apply New York rules for jaywalking in an inappropriate cultural context.  I know a lot more about urbanism and urban ecology now than I did when I landed in Beijing.  They also taught me how to make dumplings.


Bai, X., P. Shi, and Y. Liu. 2014. Realizing China's urban dream. Nature 509:158-160.

Boone, C. G., C. L. Redman, H. Blanco, D. Haase, J. Koch, S. Lwasa, H. Nagendra, S. Pauleit, S. T. A. Pickett, K. C. Seto, and M. Yokohari. 2014. Reconceptualizing land for sustainable urbanity. Pages 313-330 in K. C. Seto and A. Reenberg, editors. Rethinking urban land use in a global era. MIT Press, Cambridge.

Fang C. 2011. New structure and new trend of formation and development of urban agglomeration in China, Scientia Geographica Sinica, 31, 1025-1034 (In Chinese with abstract in English).

Hall, P. 2009. Looking Backward, Looking Forward: The City Region of the Mid-21st Century. Regional Studies 43:803-817.

Plowright, R. K., H. E. Field, C. Smith, A. Divljan, C. Palmer, G. Tabor, P. Daszak, and J. E. Foley. 2008. Reproduction and nutritional stress are risk factors for Hendra virus infection in little red flying foxes (Pteropus scapulatus). Proceedings of the Royal Society B-Biological Sciences 275:861-869.

Plowright, R. K., P. Foley, H. E. Field, A. P. Dobson, J. E. Foley, P. Eby, and P. Daszak. 2011. Urban habituation, ecological connectivity and epidemic dampening: the emergence of Hendra virus from flying foxes (Pteropus spp.). Proceedings of the Royal Society B-Biological Sciences 278:3703-3712.

Thursday, September 18, 2014

BES Book of the Year, 2014-2015: Gottdiener and Hutchinson, The New Urban Sociology

The previous Book of the Year focused on bio-ecological theory.  Because BES is a social-ecological research and education endeavor, the Project Management Committee agreed that this year our book should focus on social theory.  An ideal book to help all of us in the project who are not social scientsts is Mark Gottdiener and Ray Hutchinson's book, The New Urban Sociology, 4th Edition, published in 2010.  Some of us have profited by reading earlier editions of this book, which combines social processes and social heterogeneity thinking.  Hence, it is an excellent social mirror for our originally biological and geophysical spatial approach summarized by patch dynamics and the nested watershed concept.  They label their approach, “socio-spatial,” but those of you in the social sciences should not jump to the conclusion that this book is a resurrection of the discredited aspects of the Chicago School, or that it is an exercise in environmental determinism. 
Because BES is a social-ecological research and education project, the Project Management Committee agreed that this year should focus on social theory.

The book is written as a text book and therefore will be an accessible (but not condescending) introduction for biophysical scientists and educators in BES.  Hopefully, it will also provide fodder for our social science members to weigh in with their own insights and experience on the concepts, cases, and controversies the book discusses. 

The book comprises 14 Chapters that address the foundational theories in urban sociology and the contemporary issues and controversies about the topic.  The chapter titles are as follows:

1. The New Urban Sociology.  Including topics such as urban regions, megacities, and articulation of the socio-spatial approach.

2. The Origins of Urban Life.  The long history of urbanization through capitalist industrialization.

3. The Rise of Urban Sociology.  Here are the field’s founding giants, whose  theories continue to echo in current controversies and applications: Simmel, Wirth, the Chicago School and the rise of human ecology.

4. Contemporary Urban Sociology.  Theories and applications of political ecology, class conflict, capital accumulation, real estate, and urban culture.

5. Urbanization in the United States.  Our national urban history, through the rise of the post-war metropolis.

6. Suburbanization, Globalization, and the Emergence of the Urban Region.  This chapter includes deindustrialization, uneven development, suburbs and beyond, multi-nucleated regions.

7. People and Lifestyles in the Metropolis: Urban and Suburban Culture.  Class differentiation and space, gender, revitalization, and migration are topics.

8. Minority Settlement Patterns, Neighborhoods, and Communities.  Neighborhood dynamics, new forms of community, and interaction without proximity.

9. Metropolitan Problems: Racism, Poverty, Crime, Housing, and Fiscal Crisis.  The socio-spatial approach to social problems, income inequality, affordable housing, and service problems are additional topics beyond those in the subtitle of the chapter.

10. Urbanization in the Developed Nations.  This chapter compares and contrasts urban processes in Western and Eastern Europe and Japan vis a vis the US.

11. Globalization and Urbanization in the Developing World.  Changing perspectives on urbanization, the demographic transition, primate cities, shantytowns, and informal economies are discussed here.

12. Metropolitan Planning and Environmental Issues.  Sprawl, the sociology of land use planning, trends in planning are covered.

13. Metropolitan Social Policy.  Topics include the “tragedy of the commons,” uneven development, privitism, and social justice.

14. The Future of Urban Sociology.  Understanding the new urban world features here.

These topics are all helpful in understanding the social side of the Baltimore equation, as well as for understanding the national and international context in which Baltimore fits.  The changing nature of the global network of urban areas is a crucial ingredient in this understanding.

Each chapter ends with a list of key concepts, important names, and discussion questions.
The book is published in paperback by Westview Press.  The authors chose this publisher to be able to produce a book that was more affordable than the average university textbook.  You can order it from your local bookstore, or your favorite online source.  Used ones go for the mid 20 USD, and new for a little less than 50 USD.  It is also available as an e-book from some sources.  Those of you at colleges and universities might request that your library obtain a copy and put it on reserve.  The OCLC website – – can tell you whether local libraries have the book.

We will be planning a series of webinars to discuss various chapters or topics in the book.  If you want to be alerted to these, contact the BES Project Facilitator, Holly Beyar at beyarh at caryinstitute dot org.

Wednesday, September 17, 2014

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.


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.

Thursday, May 22, 2014

Collecting Data is the Most Abstract Thing You Can Do.

I borrowed that statement from Tim Allen, Professor Emeritus at the University of Wisconsin.  Tim is a colleague of long standing, and I think he’s one of the best thinkers in ecology.  His books on hierarchy and complexity repay detailed attention.  So why does he say that data collection is so abstract, and what does this have to do with urban long-term ecological research?

At first glance, collecting data seems like a pretty concrete activity, like going to work at the bank, or cutting the grass.  To collect data, you pull on your boots, spray tick repellent on your pants cuffs, and head out the door.  Or you fire up the computer and download the latest census data or a remotely sensed image from the National Agricultural Imagery Program.

But the concreteness is only an illusion.  Of course, there is the obvious abstraction of a statistical design.  Spatial and temporal arrangement of samples, the statistical models that will be used to detect any difference among samples are pretty well in mind as you pull on those boots, or following out footwear metaphor, boot up the computer. 

Erica Tauzer preparing to sample a vacant lot in Baltimore.
Lurking behind the statistical abstraction implied by data, are deeper theoretical and conceptual structures.  Data are as much conceptual as they are empirical.  What kinds of questions does girding for battle with data raise about the conceptual realm?  This is an important area of consideration during BES’s Year of Theory.

Data are first of all, framed.  They are collected within in a specified spatial extent, and represent a specified spatial grain size or temporal window.  The spatial or temporal interval between samples is also a kind of framing.  It is no mistake that the term “framework” is so important in discussions of theory.  That term acknowledges that framing, and specifying the relationships of data in the frame, are key tasks for theory.  In other words, framing specifies the scope and spatial and temporal texture of the area of interest.  The framing tells what the data are "for" or "against."

Data collected are relevant to some model, and that model needs to be specified.  Models indicate the entities or processes of concern, how they are related, what the expected dynamics are, and what the potential outcomes are.  Models thus fill in the details of the working of the system within its specified frame.  Often, multiple models are employed to understand a system, as models work best when they have very specific scopes.  Consequently, complementary models that cover different scopes of the pattern or process of interest must be employed.

Data usually rely on some theoretical structure to determine what measurements are appropriate.   Measurement of temperature as a scientific variable would be useless without the theory of heat to explain what processes temperature can affect.  Further biological models, like that of Q10, expressing the relationship of endothermic versus exothermic metabolism to external temperature add richness to the role of temperature data. 

Theories are also key to comparison.  For example, in Baltimore bird biodiversity has been found to relate to vegetation in neighborhoods and nearby parks, while in Phoenix, bird diversity has been found to relate to wealth of neighborhood residents.  At first these seem to imply perhaps contradictory theories.  However, underwriting both relationships is the response of bird communities to vegetation structure.  It turns out that the social and historical drivers of the bird-vegetation relationship differ between the two cities.  A deeper theoretical structure is implied by the initial incongruity between the data of the two cities.

Another example emerges from the watershed approach used in BES.  Why do we measure the things we do in streams?  The watershed approach frames material fluxes as integrated by water within the boundaries of a catchment.  In BES, as in any urban system, piped water input, and the rerouting of water within the watershed in drains and storm sewers are model details that are required.  So the concreteness of data collection assumes the existence of infrastructure within the watershed.  Of course, it also assumes a patch structure that may influence the processing of materials – their transformation or transport – in the watershed.  Finally, the relevant theory suggests that limiting nutrients will be retained in by the biological processes in the watershed, while those that are not limiting will be passed through at levels reflecting their input and the flow resistance within the watershed.  The chemical forms, sizes of particles, and role in organismal metabolism are all details that determine how a material will behave.  In ecosystems outside of urban areas, these last ideas may be combined in the principle of ecosystem retention.  This emerging theory of urban watershed function explains the different behaviors of materials viewed as contaminants, pollutants by virtue of their excessive concentration, and indicators of human activity.

The frameworks of scientific theories are often depicted as nested hierarchies.  The most general form of content of a theory must contain more specific subtheories or models to translate their abstractions into measurables.  Likewise, even those translating theories and models may need to be further specified for very particular times and places.  Hence, the theories in between the most general and the most specific are of great importance.  They are called “midlevel theories” and are the locus of much interdisciplinary and integrative work.  The models of greatest detail may not translate well across disciplines, while the theories at their most general may offer only metaphorical encouragement for integration across disciplines.  Being attuned to different levels of abstraction is important in managing and linking different kinds of data.

Metacity theory provides an example of nested theories in urban ecology.  The most general level of the metacity states the phenomenon of interest: spatially heterogeneous and changing mosaics of urban systems.  This calls for three more specific kinds of theory: those that deal with the landscape mosaics in which fluxes acn be modeled, those that deal with the choices that people, institutions, and organisms make about where to locate or move in the urban compelx, and finally those that portray the combined outcomes of fluxes and cjoices.  Each of these three mid level theories would be supported by still more specific models.  For example, the flux mosaic might include models of human migration, biogeochemical nutrient flows, energy apportionment, and traffic.  Each of the other mid level theories could similarly be subdivided into more specific models.

Each set of data, and each relationship between one kind of data and another, calls for a statement of the framing assumptions, the model structures, and the more inclusive or general theoretical relationships.  Sorting this out, and articulating these relationships for all our supposedly concrete data sets, is a task for the BES Year of Theory.

Allen, T. F. H. and T. W. Hoekstra. 1992. Toward a unified ecology. Columbia University Press, New York.

Ahl, V. and T. F. H. Allen. 1996. Hierarchy theory: a vision, vocabulary, and epistemology. Columbia University Press, New York.

Pickett, S. T. A., J. Kolasa, and C. Jones. 2007. Ecological understanding: the nature of theory and the theory of nature. 2nd edition. Academic Press, Boston.

Saturday, May 3, 2014

What's An Urban Long-Term Ecological Research Project To Do?

When in 1997 the National Science Foundation (NSF) requested proposals for up to two urban Long-Term Ecological sites to join the network of wild and production ecosystems that had been studied up to that point, it had both long-standing and new goals in mind.  These goals emerged from two main conditions.

Landscape ecologist M.L. Cadenasso, architect Phanat Xanamane, and landscape architect Victoria Marshall (L-R) work on the "periodic table" of urban land covers for Baltimore using the HERCULES methodology.
First, there was the need to understand ecological systems over the long term.  Since 1980, Long-Term Ecological Research “sites,” as they are still most often called, had been funded to conduct research in specific places over the long term.  This was a reaction to the fact that most scientific ecological studies funded before then had been of short duration, generally 1 to 3 years.  That situation limited ecological understanding because many ecological processes take many years or even decades to play out.  Succession, natural disturbance, the accumulation or loss of nutrients, the change in soil and climate, or the effects of colonization of a new species, for example, are processes that require long times to occur, and thus, similarly long times to evaluate.  Of course, simulation modeling can take existing data and, making careful assumptions about dynamics, make reasonable projections through time.  But at some point the validity of such projections is most securely evaluated against real data.  In 1997, the network of 18 sites included such extremes as moist deciduous forest, and a northern hardwoods mountain transect-- both in the eastern US -- temperate coniferous forest in the Pacific Northwest, coastal sites, a high alpine site, a forest and a tundra site in Alaska, a tropical forest, desert grassland, shrub desert, short grass prairie, an agricultural site, northern and southern lakes, and so on.  (See for the complete roster and history of sites.)  The urban sites would add a new kind of ecosystem in which long-term changes were undoubtedly important, to the existing roster of LTER sites.

The second goal was to add sites that explicitly examined the role of people as components of the ecosystems to be studied.  Except for the agricultural site in Michigan, usually people were not thought to be of great significance to the structure and functioning of LTER sites.  But beginning in the early 1980s, when more and more ecologists began to look seriously at the history and distant connections of their sites, the conclusion became clear, that people – both present and absent – could no longer be ignored in understanding the ecology of North America.  So NSF acted on this second goal in choosing a focus on systems where people and their actions could never be ignored – urban ecosystems.

The final goal, according to the 1997 Request for Proposals, was “to enhance the interdisciplinary breadth of the Long-Term Ecological Research (LTER) Network.”  Obviously, to understand urban areas as ecosystems, the skills, talents, theories, and methodologies of experts in various social sciences would have to be integrated with the familiar work of biological ecologists and the physical scientists they were used to working with.  Urban ecological research would necessarily be interdisciplinary.  Not only the technical expertise of social and economic scientists would be required, but also their experience in dealing with social structures and human institutions would be needed for working in urban systems.  It turned out in Baltimore that we also recognized the need to borrow their “social capital” and trust built up over decades of working with communities, organizations, and governments in the Baltimore region.

Putting all this together resulted in seven explicit goals that an urban LTER would have to satisfy.  Five were required of all LTER sites, and had been in place since 1980:

·        Primary Production: pattern and control of primary production,
·        Population Studies: spatial and temporal distribution of populations selected to represent trophic structure,
·        Movement of Organic Matter: pattern and control of organic matter accumulation in surface layers and sediments,
·        Movement of Inorganic Matter: patterns of inorganic inputs and movements of nutrients through soils, groundwater, and surface waters, and
·        Disturbance: patterns and frequency of disturbance to the research site.

But in addition, urban LTERs would have to deal with:

·        Land Use and Land Cover Change: examine the human impact on land use and land-cover change in urban systems and relate these effects to ecosystem dynamics,

·        Human-Environment Interactions: monitor the effects of human-environmental interactions in urban systems, develop appropriate tools (such as GIS) for data collection and analysis of socio-economic and ecosystem data, and develop integrated approaches to linking human and natural systems in an urban ecosystem environment, and

·        School Systems: integrate research with local K-12 educational systems.
The seven core urban LTER action areas and the BES long-term data or programs that contribute to each one.  The five core research areas identified with the origin of the LTER Network in 1980 are shown in brown, and the additional core activities defined in the 1997 NSF call for urban LTER proposals are shown in blue-grey.

So it turns out that the Urban LTERs, our Baltimore Ecosystem Study and the Central Arizona-Phoenix LTER have seven core areas of accomplishment. These seven core requirements can be considered the charter of the Urban LTERs.  Integration of social and biophysical approaches to understand the feedbacks in urban ecosystems as complex, spatially heterogeneous mosaics, is thus a multidimensional pursuit in satisfying the founding charter.  

Monday, April 7, 2014

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.

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. (  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.