Spatial Feedbacks (Love it or Hate it?)

I was hoping to make my first blog post of the year about the latest paper to come out of my work in Michigan. The paper is entitled, Filling the gap: A compositional gap regeneration model for managed northern hardwood forests and is forthcoming in Ecological Modelling. Unfortunately, despite being accepted for publication by the editors some time before Christmas, the manuscript seems to have got lost in the production system and has been delayed. If all goes to plan the paper will be out in time for February’s blog post. Instead, today I’ll highlight some other recent activities.

Between Christmas and New Year I took a bit of time to finish off a paper I was invited to submit to a special issue of Ecology and Society. The special issue will be entitled, Exploring Feedbacks in Coupled Human and Natural Systems (CHANS) and will bring together multiple different approaches for accounting for feedbacks in CHANS modelling and applications. The CHANS research framework emphasizes the importance of reciprocal human-nature interactions and the need for holistic study of humans and nature. Feedback loops can be formed in CHANS when information about one system component produces a change in a second component, which in turn provides information which produces a change in the original component.

Feedbacks loops between human and natural components of coupled systems are a primary reason that humans and nature must be investigated together to properly understand their temporal dynamics. However, as a geographer I’m also interested in the role space plays in system dynamics. It seems that there haven’t been any broad overviews or analyses of spatial feedbacks for CHANS, so I set out to produce one with the goal of improving understanding about the issue.

After a couple of drafts with very useful comments from the editors of the special issue and colleagues George Perry and David O’Sullivan, I arrived at a manuscript entitled, Three types of spatial feedback loop in coupled human and natural systems. As the title suggests, after identifying some of the key characteristics of feedbacks, I conceptualize and describe three types of spatial feedback loop. These three types address the areal growth of system entities, the importance of transport costs across space, and how spatial patterns can create feedback loops with spatial spread processes.

I won’t go into the details of these now as the manuscript is still under peer review (I think it’s a bit of a Marmite manuscript – they’ll either love it or hate it). However, I will highlight some of the simple spatial simulation models I used to help me conceptualize the feedbacks and which should be useful to help readers do the same (along with the real world examples I used). You can play with the simulation models yourself as they are freely available online. Download the models and their source code for use with NetLogo from, or use them online without downloading NetLogo from I think these simple spatial simulations should be far more helpful for understanding spatio-temporal dynamics – inherent to spatial feedbacks – than the figures I present in the paper (like that below). See what you think. We’ll find out whether the  reviewers love it or hate it in a month or two.

Since the New Year, I’ve spent most of my time working on undergraduate modules I’ll be teaching later this term. In particular, I’m developing a new module named Spatial Data and Mapping for the Principles of Geographical Inquiry course. In the module I’ll introduce students to some of the methods, tools and technologies available to collect and present spatial data. These include GPS and remote sensing (e.g., orthophotos) on the collection side and EDINA Digimap and ArcMap on the presentation side of things. Alongside lectures, there will be plenty of opportunity for students to use these tools as they will collect their own data from London’s Southbank which they will then use to create a digital map. It’s the first time running the module so there may be some teething issues, but hopefully the students will find it interesting and useful for their future studies.

I’m also teaching a PhD-level short course for the KISS-DTC entitled, Social Simulation. The course will provide an introduction to the use of computer simulation methods – notably agent-based modelling – for questions germane to social scientists. I won’t go into detail on that now, maybe in future.

Finally, I’ll just highlight some new urlists I’ve been making as resources for myself and students (and maybe you?). Urlist is a collaboration tool to collect, organize and share lists of links which I’ve found quite handy. I’ve started lists on Open Data (freely available for analysis), Spatial Data and Geodata resources and tools, and Valuation of Ecosystem Services. The Open Data list is collaborative so anyone can contribute relevant links – if you know good Open Data sources online that aren’t listed there please feel free to add!

Catching up on 2012

This blog has been seriously neglected over the last six months, so there’s a lot of catching up to do here.

There’s lots of conferences and papers to list, but first I should highlight the slight difference in look of this blog and the entire website. I recently decided I was going to switch to Google sites to host and move this blog from WordPress to Blogger (for multiple reasons I won’t go into here). The website is lacking many of the pages from its previous guise and the NetLogo models have been moved to I’m continuing to add the old (and maybe some new) content to the website but that’s likely to be a slow process (particularly given how long it’s taken me to get to write this post!). The link structure of the blog pages has changed – I think I’ve managed to change most links but there may still be some that are broken (if you find any please let me know). Many of the images are also currently missing – I’ll get to re-inserting those sometime…

I’ve managed to get to quite a few conferences this year in the US, UK and Germany.A particular highlight was getting to see my old PhD advisor George Perry in the US. George was on sabbatical at Harvard Forest and he invited me to the forest to give a seminar. It was also great to attend the 4th USFS FVS conference in Fort Collins, CO and to be one of the only four or so international attendees. There’s a list below of all the conference presentations I gave with links to the conference websites.

I’ve also been working hard to get a few papers published. The paper I’ve been working on with George and David O’Sullivan on the narrative properties of generative simulation models (i.e., agent-based models and the like) has now been accepted and is in press at Geoforum. Two papers I have been working on related to my work in Michigan have also been accepted, subject to corrections, by Ecological Modelling. The papers are closely linked, with one describing the northern hardwood forest gap regeneration model we developed and the second showing how that model can be used in the integrated model to examine trade-offs and synergies in managing for both timber and deer in the forests. The current (provisional) citations for the three papers are below. When all are available online and in print I’ll post again here with the abstracts and links to the full text (and likely tweet the links before I blog!)

I’m still working on lots of other things, including a paper on the school choice modelling I have been doing, and another paper for a special issue in Ecology and Society on feedbacks in Coupled Human and Natural Systems. I’m also preparing some exciting (I hope) new classes for the students at King’s, including a field day at Heartwood Forest and a class on GPS and mapping. More details on that to come in the future too I’m sure!

Millington, J.D.A., O’Sullivan, D., Perry, G.L.W. (in press) Model histories: Narrative explanation in generative simulation modelling Geoforum
[Online] [Geoforum]

Millington, J.D.A., Walters, M.B., Matonis, M.S. and Liu, J. (accepted) Modelling for forest management synergies and trade-offs: Tree regeneration, timber and deer; research manuscript accepted, subject to corrections, by Ecological Modelling
[Ecological Modelling]

Millington, J.D.A., Walters, M.B., Matonis, M.S. and Liu, J. (accepted) Filling the gap: A compositional gap regeneration model for managed northern hardwood forests; research manuscript accepted, subject to corrections, by Ecological Modelling
[Ecological Modelling]

Millington, J.D.A., Walters, M.B., Matonis, M.S., Liu, J. Trade-offs in long-term forest ecosystem management: Timber, birds and deer Presented at: 19th ialeUK conference, Edinburgh, UK, September 2012

Millington, J.D.A. Using social psychology theory for modelling farmer decision-making Presented at: 6th International Congress on Environmental Modelling and Software, Leipzig, Germany, July 2012
[iEMSs 2012]

Millington, J.D.A., O’Sullivan, D., Perry, G.L.W. Narrative explanation of agent decision-making Presented at: 6th International Congress on Environmental Modelling and Software, Leipzig, Germany, July 2012
[iEMSs 2012]

Millington, J.D.A., Walters, M.B., Matonis, M.S., Liu, J. Investigating Combined Long-Term Effects of Variable Tree Regeneration and Timber Management on Forest Wildlife and Timber Production Using FVS Presented at: Fourth Forest Vegetation Simulator (FVS) Conference, Fort Collins, Colorado, April 2012
[FVS 2012]

Millington, J.D.A. Agricultural Landscape Change: Using social psychology theory in agent-based models of land-use change Presented at: US-IALE Symposium, Newport, Rhode Island, April 2012
[US-IALE 2012]

Millington, J.D.A., Walters, M.B., Matonis, M.S., Liu, J. Regeneration for Sustainability: Coordinating Long-term Forest Ecosystem Management for Timber Production and Wildlife Habitat Presented at: US-IALE Symposium, Newport, Rhode Island, April 2012
[US-IALE 2012]

Launching effective interdisciplinary human-environment research

After a while bouncing around various outlets, the paper that emerged from the CHANS Workshop at US-IALE 2009 in Snowbird has been published. Presented as a meeting review in the ESA Bulletin, Research on Coupled Human and Natural Systems (CHANS): Approach, Challenges, and Strategies discusses what the CHANS approach is and what the current challenges and strategies in this field are. For example, we suggest the following are the keys to launching effective CHANS research projects:

Identify the goals and final products of the project

  • Goals and products could include answers to scientific questions, hypothesis testing, a simulation model or decision-support tool, policy or management recommendations, or education.
  • Identify and articulate analysis boundaries and scales of interest: spatially, temporally, and in terms of physical processes.
  • A preliminary conceptual model may help initiate discussion among potential collaborators; the conceptual model need not be correct in what it is illustrating, but rather serve to “break the ice” and generate discussion.

Build a team around the identified goals and products

  • Identify project manager(s) and submanagers, where the submanagers may be discipline specific and responsible for a particular component of the project.
  • It may also be beneficial to assign to one person responsibility for overseeing and maintaining the project timeline. It might be advantageous for this person not to be a manager or submanager to minimize potential conflicts.
  • Once the team is together, reexamine the initial goals and final products.

Methods necessary to accomplish project goals and products should now be developed.

  • It is important to recognize that the final products may change in response to the project team’s vision and analysis. Team members must be prepared to be flexible, to reevaluate the project’s conceptual framework and methods as a partnership matures.
  • Potential challenges of complexity and uncertainty should be discussed at this point; where in the project may they later manifest themselves? How may they be overcome?
  • Each team member should be recognized as “a tool in a toolbox,” each providing a unique contribution that works in tandem with the other tools (e.g., the compass and ruler) to build the entire project.

We conclude; “The CHANS approach is emerging from its infancy, characterized by the use of rudimentary language skills in describing deeply complex systems. With proper support, it stands to contribute to a better understanding of the multifaceted interactions between human and natural systems, and thus inform societal choices in pursuit of sustainability.”

Leverhulme Early Career Fellowship

Around the time I wrote this blog about the National Assessment of UK Forestry and Climate Change Steering Group report I was thinking about writing a proposal to the Leverhulme Trust for an Early Career Fellowship. I found out recently that my proposal was successful and so from January 2011 I will be back at King’s College, London!

The Leverhulme Trust makes awards in support of research and education with special emphasis on original and significant research that aims to remove barriers between traditional disciplines. Their Early Career Fellowships are awarded across all disciplines and in 2010 approximately 70 were expected to be awarded to individuals to hold at universities in the UK. Given the emphasis on original, significant and cross-disciplinary research made by the Trust I looked for something that matched my research skills in coupled human and natural systems modelling but that pushed work in that area in a new direction. I thought back to the ideas about model narratives I have previously explored with David O’Sullivan and George Perry (but have not worked on since then) and Bill Cronon’s plenary address at the Royal Geographical Society in 2006 on the need for ‘sustainable narratives’. With that in mind, and given the UK Forestry and Climate change report I had been reading, I decided to make a pitch for a project that would explore how narratives from the use of models could help individuals identify how local actions transcend scales to mitigate global climate change in the context of the anticipated woodland planting that will be ongoing in the UK in future years. It proved to be a successful pitch!

I’m sure I will blog plenty more about the project in the future, so for now I will just leave you with the proposal rationale (below). I’m looking forward to getting to work on this when I get back to London, but before that there’s plenty more things to get done on the Michigan forest landscape ecological-economic modelling.

Model narratives for climate change mitigation
The abstract, vast, and systemic narratives that dominate the issue of global climate change do little to illustrate to individuals and groups how their actions might contribute to mitigate the effects of what is often framed as a global problem (Cronon 2006). Ways to improve the ability of individuals and groups to identify how their local actions transcend scales to mitigate global climate change are needed. In this research I will explore how narratives produced from computer simulation models that represent individuals’ actions can provide people with insights into how their behaviour affects system properties at a larger scale. Although the narrative properties of simulation models have been highlighted (O’Sullivan 2004), the use of models to develop localised narratives of climate change which emphasise individual agency has yet to be explored. Confronting individuals with these narratives will also help researchers reveal important underlying, and possibly implicitly held, assumptions that influence choices and behaviour.

This research will address the following general questions:

  • How can computer simulation models be better used to reveal to individuals how their local actions can contribute to global environmental issues such as Climate Change Mitigation (CCM)?
  • What are the narrative properties of simulation models and how can they be exploited to help individuals find meaning about their actions as they relate to global climate change?
  • By using simulation tools to spur reflection what can we learn about the factors influencing individuals’ choices and behaviour with regards CCM options?

Answering these questions will require a uniquely interdisciplinary research approach that spans the physical sciences, social sciences and humanities. Such ground-breaking, boundary-crossing work is necessary if we are to re-connect the physical sciences with the publics they intend to benefit and find solutions to large-scale and pressing environmental problems. For example, one of the key findings from a recent report by the National Assessment of UK Forestry and Climate Change Steering Group (Read et al. 2009) was that “[t]he extent to which the potential for additional [greenhouse gas] emissions abatement through tree planting is realized … will be determined in large part by economic forces and society’s attitudes rather than by scientific and technical issues alone” (p.xvii). The report also argued the need “to better understand and consider the role of different influences affecting choices and behaviour. Without the appropriate emotional, cultural or psychological disposition, information will make no difference.” (p.210). Narratives based on scientific understanding which portray how individuals can make a difference to large-scale, diffuse environmental issues will be important for fostering such a disposition. Simulation models – quantitative representations of reality which provide a means to logically examine how high-level and large-scale patterns are generated by lower-level and smaller-scale processes and events – have the potential to contribute to the construction of these narratives.

Social Network Analysis

As I mentioned in a tweet earlier this week, Prof. Ken Frank was ‘visiting’ CSIS this week. Ken studies organizational change and innovation using, amongst other methods, Social Network Analysis (SNA). SNA examines how the structure of ties between people affects individuals’ behaviour, at how social network structure and composition influences the social norms of a group, and how resources (for example, of information) flow through a social network. This week Ken organised a couple of seminars on the use of SNA to investigate natural resource decision-making (for example, in small-scale fisheries) and I joined a workshop he ran on how we actually go about doing SNA, learning about software like p2 and KliqueFinder. Ken showed us the two main models; the selection model and the influence model. The former addresses network formation and examines individuals’ networks and how they chose it. The latter examines how individuals are influenced by the people in their network and the consequences for their behaviour. As an example of how SNA might be used, take a look at this executive summary [pdf] of the thesis of a recent graduate students from MSU Fisheries and Wildlife.

On Friday, after having been introduced through the week to what SNA is, I got to chat with Ken about how it might relate to the agricultural decision-making modelling I did during my PhD. In my agent-based model I used a spatial neighbourhood rule to represent the influence of social norms (i.e. whether a farmer is ‘traditional’ or ‘commercial’ in my categories). However, the social network of farmers is not solely determined by spatial relationshps – farmers have kinship ties and might meet other individuals at the market or in the local cerveceria. We discussed how I might be able to use SNA to better represent the influences of other farmers on an indiviuals’ decision-making in my model. I don’t have the network data needed to do this right now but it’s something to think about for the future.

If I’d been more aware of SNA previously I may have incorporated some discussion of it into the book chapter I re-wrote recently for Environmental Modelling. In that chapter I focused on the increasing importance of behavioural economics for investigating and modelling the relationships between human activity and the environment. SNA is certainy something to add to the toolbox and seems to be on the rise in natural resources research. Something else I missed whilst working on re-writing that that chapter was the importance of behavioural economics to David Cameron‘s ‘Big Society’ idea. He seems to be aware of the lessons we’ve started learning from things like social network analysis and behavioural economics – now he’s in charge maybe we’ll start seeing some direct application of those lessons to UK public policy.

US-IALE 2010 Preparation

Next week is the Twenty-fifth Anniversary Symposium of the US chapter of the International Association of Landscape Ecology (US-IALE). I’ll be in attendance in Athens, Georgia and am currently working on my presentation, entitled Ecological-economic modeling for sustainable forest management (scheduled for Thursday 8th, 2.20pm in room T/U). In the context of our larger modelling project I’ll present work we’ve published, stuff we’re still working on, and the initial results from putting it all together.

Several symposia have been organised and I plan to be at those that consider landscape ecology and wildfires, bioenergy and land-use change, and climate change and landscape connectivity. Particularly interesting should be Don McKenzie’s presentations on ecosystem energetics and scaling laws in the wildfire symposium and Paul Opdam’s presentations on Natura 2000 and the role of landscape ecology in the climate change symposium. Two of the plenary addresses I’d like to catch are Collapse and Sustainability: Lessons from History (Joseph A Tainter) and Linking Renaissance Ecologists with Citizen Scientists to Advanced Scientific Research and Literacy (Carol Brewer).

As usual CSIS has a strong presence at US-IALE this year with seven presentations, including the insights of Jack Liu and Wu Yang into the challenges and opportunities for landscape ecology and conservation in coupled human natural research, the analysis by Andres Vina and Xiaodong Chen of the potential conservation benefits that might be offset by natural disasters, Mao-Ning Tuanmu’s work on Giant Panda habitat and the work by Pete Esselman and Dana Infante on the National Assessment of the Status of Fish Habitat. The full list of CSIS presentations is below.

It’s shaping up to be a good couple of days! I’ll try to tweet and blog some thoughts as they arise during the conference and maybe reflect on things afterwards also.

CSIS Presentations at US-IALE 2010
6th April
Are conservation benefits offset by natural disasters? — The case of the May 12, 2008 Wenchuan Earthquake. Andrés Viña, Xiaodong Chen, Wei Liu, et al.

Coupling human and natural systems: Challenges and opportunities for landscape ecologists. Jianguo Liu

The spatial framework and results of the initial National Assessment of the Status of Fish Habitat. Peter C Esselman, Dana M Infante, et al.

7th April
Effects of human-environment relationships on the spatiotemporal dynamics of giant panda habitat. Mao-Ning Tuanmu, Wei Liu, Andrés Viña, et al.

8th April
Ecological-economic modeling for sustainable forest management. James D A Millington, Michael B Walters, Megan S Matonis, et al.

Mechanisms for effective conservation in coupled human-natural systems. Wu Yang, Wei Liu, Mao-Ning Tuanmu, et al.

Patterns and drivers of reforestation: A case study in the Qinling Mountains, China. Yu Li, Andrés Viña, Jianguo Liu

The Omnivores’ Trifecta: A feast of ideas

This week I went to a seminar presented by Dr Richard Bawden of the Systemic Development Institute, Australia. This was the first event in MSU’s “conversation about our food future”. It turned out to be much more interesting than I had hoped; Bawden is an engaging and charismatic speaker who presented a thoughtful perspective on what he termed ‘The Omnivores’ Trifecta’: Agriculture, Food and Health and the Systemic Relationships between them. He covered a hearty spread of ideas, so I’ll recap his most interesting points in bite-sized pieces:

i) Bawden suggested that Agriculture, Food and Health (A-F-H) when considered separately are not a system. But by understanding each as a discourse (i.e. as a subject for “formal discussion of debate”) they become viewed in a systemic perspective.

ii) At the intersection of these three subjects are four very important (sub-)discourses which Bawden termed the “engagement discourse subsystem”. These are: business, lay citizens, governance, and experts.

iii) Bawden proposed that it is the profound differences in episteme (worldview) between these discourse ‘subsystems’ that are at the heart of the majority of the conflicts across the A-F-H system and the environment in which it is situated.

iv) These epistemic differences are so profound as to be polemic. Bawden bemoaned this fact and highlighted that “Dialectic yields to Polemic“. He emphasised that dialectics are the only way forward to forge a world in common and that polemics prevent deliberation, debate and kill democracy.

v) To illustrate these points Bawden used the case of Australian agriculture since the mid-20th century. He described this case as being characteristic of many messy, wicked problems and argued that reductionist science alone was insufficient to bring resolution (and hence is why he founded the Systemic Development Institute). During this argument he quoted Beck but questioned whether we have reached second modernity. Bawden argued that the “culture of technical control” still prevails within current modernist society has an episteme that privileges fact over value, analysis over synthesis, individualism over communalism, teaching over learning and productionism over sustainablism.

vi) On these last two dichotomies, Bawden suggested that the question of what is to be sustained (and therefore what sustainability is) is a moral question not a technical one.

vii) He proposed that higher education is about learning differently not learning more; the ability to look the world and make sense of it for oneself (and then take action in response) is what characterises a good education. Awareness of the presence of different worldviews is key to this ability. Furthermore, Bawden argued that the complete learner will be prepared to enter a form of learning that the academy is currently unable to provide because it is too reductionist. This learning would require critical reflection of one’s own worldview, as Jack Mezirow has proposed.

viii) Bawden then presented the diagram that synthesises his message (see below). This diagram describes the “integrated process of the critical learning system” and shows how perceiving, understanding, planning and acting are connected within our rational experience of the world and how they are linked to the intuitive facets of learning.

Quite the feast of ideas eh? I’m still digesting them and might be for a while. But the key message I take away from this is a post-normal one; in learning about human-environment interactions and to solve current wicked problems, inter-epistemic as well as inter-disciplinary work will be needed. Although different scientific disciplines such as ecology, biology, and chemistry have different terminology and conventions, they share a worldview – the one that favours facts over values and aims to subsume empirical observations into universal laws and theories. Other worldviews are available. Inter-epistemic human-environment study would seek to cross the boundaries between worldviews, recognize that reductionist science is only one way to understand the world and is unlikely provide complete answers to wicked problems, and emphasise dialectics over polemics.

Global Change Blog

This week I discovered a new blog that looks worth following for anyone interested in human-environment interactions, sustainability, or CHANS. The Global Change blog intends to explore big questions about society and environmental change, such as:

  • How do personal choices and values play a role in this conversation?
  • What do the natural sciences have to say about the way our world is changing?
  • What do the social sciences and humanities have to say about the ways that the social and the cultural intersect with questions surrounding environment?
  • How can we address environmental and social challenges at the same time?
  • How is environmentalism changing in response to these pressures?
  • What’s the role of higher education in facilitating sustainability and environmental literacy?

So far the blog has posted a mix of thoughtful original writing (for example on reasons why people don’t engage climate change) and brief highlights of other work. Hope they keep it coming!

Interdisciplinarity, Sustainability and Critical Realism

I have a new paper to add to my collection of favourites. Hidden in the somewhat obscure Journal of Critical Realism it touches on several issues that I often find myself thinking about and studying: Interdisciplinarity, Ecology and Scientific Theory.

Karl Høyer and Petter Naess also have plenty to say about sustainability, planning and decision-making and, although they use the case of sustainable urban development, much of what they discuss is relevant to broader issues in the study of coupled human and natural systems. Their perspective resonates with my own.

For example, they outline some of the differences between studying open and closed systems (interestingly with reference to some Nordic writers I have not previously encountered);

… The principle of repetitiveness is crucial in these kinds of [reductionist] science [e.g. atomic physics, chemistry] and their related technologies. But such repetitiveness only takes place in closed systems manipulated by humans, as in laboratories. We will never find it in nature, as strongly emphasised by both Kvaløy and Hägerstrand within the Nordic school. In nature there are always open, complex systems, continuously changing with time. This understanding is in line with key tenets of critical realism. Many of our most serious ecological problems can be explained this way: technologies, their products and substances, developed and tested in closed systems under artificial conditions that generate the illusion of generalised repetitiveness, are released in the real nature of open systems and non-existing repetitiveness. We are always taken by surprise when we experience new, unexpected ecological effects. But this ought not to be surprising at all; under these conditions such effects will necessarily turn up all the time.

At the same time, developing strategies for a sustainable future relies heavily on the possibility of predicting the consequences of alternative solutions with at least some degree of precision. Arguably, a number of socio-technical systems, such as the spatial structures of cities and their relationships with social life and human activities, make up ‘pseudo-closed’ systems where the scope for prediction of outcomes of a proposed intervention is clearly lower than in the closed systems of the experiments of the natural sciences, but nevertheless higher than in entirely open systems. Anticipation of consequences, which is indispensable in planning, is therefore possible and recommendable, although fallible.

The main point of their paper, however, is the important role critical realism [see also] might play as a platform for interdisciplinary research. Although Høyer and Naess do highlight some of the more political reasons for scientific and academic disciplinarity, their main points are philosophical;

…the barriers to interdisciplinary integration may also result from metatheoretical positions explicitly excluding certain types of knowledge and methods necessary for a multidimensional analysis of sustainability policies, or even rejecting the existence of some types of impacts and/or the entities causing these impacts.

These philosophical (metatheoretical) barriers include staunchly positivist and strong social constructionist perspectives;

According to a positivist view, social science research should emulate research within the natural sciences as much as possible. Knowledge based on research where the observations do not lend themselves to mathematical measurement and analysis will then typically be considered less valid and perhaps be dismissed as merely subjective opinions. Needless to say, such a view hardly encourages natural scientists to integrate knowledge based on qualitative social research or from the humanities. Researchers adhering to an empiricist/naive realist metatheory will also tend to dismiss claims of causality in cases where the causal powers do not manifest themselves in strong and regular patterns of events – although such strong regularities are rare in social life.

On the other hand, a strong social constructionist position implies a collapsing of the existence of social objects to the participating agents’ conception or understanding of these objects. …strong social constructionism would typically limit the scope to the cultural processes through which certain phenomena come to be perceived as environmental problems, and neglecting the underlying structural mechanisms creating these phenomena as well as their impacts on the physical environment. At best, strong social constructionism is ambivalent as to whether we can know anything at all about reality beyond the discourses. Such ‘empty realism’, typical of dominant strands of postmodern thought, implies that truth is being completely relativised to discourses on the surface of reality, with the result that one must a priori give up saying anything about what exists outside these discourses. At worst, strong social constructionism may pave the way for the purely idealist view that there is no such reality.

At opposite ends of the positivist-relativist spectrum neither of these perspectives seem to be the most useful for interdisciplinary research. Something that sits between these two extremes – critical realism – might be more useful [I can’t do this next section justice in an abridged version – and this is the main point of the article – so here it is in its entirety];

The above-mentioned examples of shortcomings of reductionist metatheories do not imply that research based on these paradigms is necessarily without value. However, reductionist paradigms tend to function as straitjackets preventing researchers from taking into consideration phenomena and factors of influence not compatible with or ignored in their metatheory. In practice, researchers have often deviated from the limitations prescribed by their espoused metatheoretical positions. Usually, such deviations have tended to improve research rather than the opposite.

However, for interdisciplinary research, there is an obvious need for a more inclusive metatheoretical platform. According to Bhaskar and Danermark, critical realism provides such a platform, as it is ontologically characterised doubly by inclusiveness greater than competing metatheories: it is maximally inclusive in terms of allowing causal powers at different levels of reality to be empirically investigated; and it is maximally inclusive in terms of accommodating insights of other meta-theoretical positions while avoiding their drawbacks.

Arguably, many of the ecologists and ecophilosophers referred to earlier in this paper have implicitly based their work on the same basic assumptions as critical realism. Some critical realist thinkers have also addressed ecological and environmental problems explicitly. Notably, Ted Benton and Peter Dickens have demonstrated the need for an epistemology that recognises social mediation of knowledge but also the social and material dimensions of environmental problems, and how the absence of an interdisciplinary perspective hinders essential understanding of nature/society relationships.

According to critical realism, concrete things or events in open systems must normally be explained ‘in terms of a multiplicity of mechanisms, potentially of radically different kinds (and potentially demarcating the site of distinct disciplines) corresponding to different levels or aspects of reality’. As can be seen from the above, the objects involved in explanations of the (un)sustainability of urban development belong partially to the natural sciences, partially to the social sciences, and are partially of a normative or ethical character. They also belong to different geographical or organisational scales. Thus, similar to (and arguably to an even higher extent than) what Bhaskar and Danermark state about disability research, events and processes influencing the sustainability of urban development must be understood in terms of physical, biological, socioeconomic, cultural and normative kinds of mechanisms, types of contexts and characteristic effects.

According to Bhaskar, social life must be seen in the depiction of human nature as ‘four-planar social being’, which implies that every social event must be understood in terms of four dialectically interdependent planes: (a) material transactions with nature, (b) social interaction between agents, (c) social structure proper, and (d) the stratification of embodied personalities of agents. All these categories of impacts should be addressed in research on sustainable urban development. Impacts along the first dimension, category (a), typically include consequences of urban development for the physical environment. Consequences in terms of changing location of activities and changing travel- ling patterns are examples of impacts within category (b). But this category also includes the social interaction between agents leading to changes in, among others, the spatial and social structures of cities. Relevant mechanisms at the level of social structure proper (category [c]) might include, for exam- ple, impacts of housing market conditions on residential development projects and consequences of residential development projects for the overall urban structure. The stratified personalities of agents (category [d]) include both influences of agents on society and the physical environment and influences of society and the physical environment on the agents. The latter sub-category includes physical impacts of urban development, such as unwholesome noise and air pollution, but also impacts of the way urban planning and decision- making processes are organised, for example, in terms of effects on people’s self esteem, values, opportunities for personal growth and their motivation for participating in democratic processes. The influence of discourses on the population’s beliefs about the changes necessary to bring about sustainable development and the conditions for implementing such changes also belongs to this sub-category. The sub-category of influences of agents on society and the physical environment includes the exercise of power by individual and corporate agents, their participation in political debates, their contribution to knowledge, and their practices in terms of, for example, type and location of residence, mobility, lifestyles more generally, and so on.

Regarding issues of urban sustainability, the categories (a)–(d) are highly interrelated. If this is the case, we are facing what Bhaskar and Danermark characterise as a ‘laminated’ system, in which case explanations involving mechanisms at several or all of these levels could be termed ‘laminated expla- nations’. In such situations, monodisciplinary empirical studies taking into consideration only those factors of influence ‘belonging’ to the researcher’s own discipline run a serious risk of misinterpreting these influences. Examples of such misinterpretations are analyses where increasing car travel in cities is explained purely in terms of prevailing attitudes and lifestyles, addressing neither political-economic structures contributing to consumerism and car-oriented attitudes, nor spatial-structural patterns creating increased needs for individual motorised travel.

Moreover, the different strata of reality and their related mechanisms (that is, physical, biological, socio-economic, cultural and normative kinds of mechanisms) involved in urban development cannot be understood only in terms of categories (a)–(d) above. They are also situated in macroscopic (or overlying) and less macroscopic (or underlying) kinds of structures or mechanisms. For research into sustainable urban development issues, such scale-awareness is crucial. Much of the disagreement between proponents of the ‘green’ and the ‘compact’ models of environmentally sustainable urban development can probably be attributed to their focus on problems and challenges at different geographical scales: whereas the ‘compact city’ model has focused in particular on the impacts of urban development on the surrounding environment (ranging from the nearest countryside to the global level), proponents of the ‘green city’ model have mainly been concerned about the environment within the city itself. A truly environmentally sustainable urban development would require an integration of elements both from the former ‘city within the ecology’ and the latter ‘ecology within the city’ approaches. Similarly, analyses of social aspects of sustainable development need to include both local and global effects, and combine an understanding of practices within particular groups with an analysis of how different measures and traits of development affect the distribution of benefits and burdens across groups.

Acknowledging that reality consists of different strata, that multiple causes are usually influencing events and situations in open systems, and that a pluralism of research methods is recommended as long as they take the ontological status of the research object into due consideration, critical realism appears to be particularly well suited as a metatheoretical platform for interdisciplinary research. This applies not least to research into urban sustainability issues where, as has been illustrated above, other metatheoretical positions tend to limit the scope of analysis in such a way that sub-optimal policies within a particular aspect of sustainability are encouraged at the cost of policies addressing the challenges of sustainable urban development in a comprehensive way.

In conclusion; critical realism can play a very important role as an underlabourer of interdisciplinarity, with its maximal inclusiveness both in terms of allowing causal powers at different levels of reality to be empirically investigated and in terms of accommodating insights of other meta-theoretical positions while avoiding their drawbacks

I’m going to have to spend some time thinking about this but there seems to be plenty to get ones teeth into here with regards the study of coupled human and natural systems and the use of agent-based modelling approaches. For example, agent-based modelling seems to offer a means to represent Bhaskar‘s four planes but there are plenty of questions about how to do this appropriately. I also need to think more carefully about how these four planes are manifested in the systems I study. Generally however, it seems that critical realism offers a useful foundation from which to build interdisciplinary studies of the interaction of humans and their environment for the exploration of potential pathways to ensure sustainable landscapes.

Høyer, K.G and Naess, P. 2008 Interdisciplinarity, ecology and scientific theory: The case of sustainable urban development Journal of Critical Realism 7(2) 179-207 doi: 10.1558/jocr.v7i2.179

CHANS-Net at AAG 2010

Details of plans for CHANS-Net activities at the 2010 annual meeting of the Association of American Geographers (AAG) in Washington, D.C. have been posted.

Presentations and a workshop are expected to synthesise across CHANS research projects, potentially leading to publication. The CHANS-Net website also indicates there are opportunities for junior scholars to receive financial assistance.

Deadline for abstract submission to the AAG meeting is 28th October 2009 (submissions to the CHANS events are due by 20th October).