Posted on 2007-09-07

The Tyranny of Power?

The past week or two I’ve been wrestling with the data we have on white-tailed deer density and vegetation in Michigan’s Upper Peninsula in an attempt to find some solid statistical relationships that we might use in our ecological-economic simulation model. However, I seem to be encountering similar issues to previous researchers, notably (as Weisberg and Bugmann put it) “the weak signal-to noise ratio that is characteristic of ungulate-vegetation systems”, that “multiple factors need to be considered, if we are to develop a useful, predictive understanding of ungulate-vegetation relationships”, and that “ungulate-vegetation interactions need to be better understood over multiple scales”.

Hobbs suggests that one of the problems slowing species distribution research is a preoccupation with statistical power that he calls “the tyranny of power”. This tyranny arises, he suggests, because traditional statistical methods that are powerful at smaller scales become less useful at larger extents. There are at least three reasons for this including,

small things are more amenable to study by traditional methods than large things
variability increases with scale (extent)
potential for bias increases with scale (extent)

“The implication of the tyranny of power is that many of the traditionally sanctioned techniques for ecological investigation are simply not appropriate at large-scales… This means that inferences at large-scales are likely to require research designs that bear little resemblance to the approaches many of us learned in graduate school.” Hobbs p.230

However, this tyranny may simply be because, as Fortin and Dale point out, “most study areas contain more than one ecological process that can act at different spatial and temporal scales”. That is, the processes are non-stationary in time and space. Leaving time aside for now, spatial non-stationarity has already been found to be present in our study area with regards the processes we’re considering. For example, Shi and colleagues found that Geographically Weighted Regression (GWR) models are better at predicting white-tailed deer densities than an ordinary least-squares regression model for the entirety of our study area.

Hobbs’ argument suggests that it’s often useful analyse ecological data from large regions by partitioning them into smaller, more spatially homogenous areas. The idea is that these smaller patches are more likely to be governed by the same ecological process. But how should these smaller regions be selected? A commonly used geographical division is the ecoregion. Ecoregions divide land into areas of similar characteristics such as climate, soils, vegetation and topography. For our study area we’ve found that relationships between deer densities and predictor variables do indeed vary by Albert’s ecoregions. But we think that there might be more useful ways to divide our study area that take into account variables that are commonly believed to strongly influence spatial deer distributions. In Michigan’s UP the prime example is the large snow fall is received each winter and which hinders deer movement and foraging.

We’re beginning to examine how GWR and spatial boundary analysis might be used to delineate these areas (at different scales) in the hope of refining our understanding about the interaction of deer and vegetation across our large (400,000 ha) landscape. In turn we should be able to better quantify some of these relationships for use in our model.

Posted on 2007-08-27

The Role for Landscape Ecology in Poverty Relief

In the latest issue of Landscape Ecology, Louis Iverson suggests landscape ecologists have a role in poverty relief. Reviewing Sachs‘ The End of Poverty: Economic Possibilities for our Time, Iverson believes the book ‘should motivate additional research and implementation of principles within landscape ecology into this critical arena’ and argues that landscape ecologists‘can provide expertise to efficiently use funds to the greatest value and to research sustainable, integrated pathways to development’. After discussing several aspects of the current state of the global poverty problem (poverty statistics, water scarcity, Millennium Development Goals, environmental constraints on development), Iverson suggests landscape ecologists can contribute to these issues by;

Modelling the impacts and possible mitigation of climate change on water and agricultural production, especially in the most vulnerable zones with high levels of extreme poverty

Creating innovative, landscape-level systems for efficient water use, agricultural production, and infrastructure in the zones of extreme poverty

Working towards sustainable management of ecosystems, especially fragile ecosystems, that are deteriorating due to human pressures

Assisting in planning for urban growth that also sustains agriculture productivity using appropriate water, soil, and food management systems

Building models of low-cost but sustainable means of protection against natural or technological disasters, especially storms, floods, and droughts (climate-related disasters)

Designing infrastructure and energy improvements in developing countries with maximum positive human impact and minimum negative environmental impact

Working to better understand the diseases of the poor and spatial and temporal relationships of these diseases

Working to understand how over-consumption and excessive wealth contributes to environmental degradation and poverty elsewhere in the global landscape, and propose/model remedial solutions

Developing partnerships with ecologists, economists, landscape architects, wildlife managers, and land managers in developing countries that make a difference

Seeking out students from poor countries who can provide direct linkages to projects back in their home countries

Assisting in land-use and urban planning efforts where practical and feasible, focusing on improving conditions for slum dwellers

Working to help influence decision-makers to realize that investments toward the goals outlined above are well spent and the right thing to do

More inspiration, if it were needed, to continue this field of research…

Posted on 2007-08-23

infidelity offsetting

This is Genius. Nice one boys.

Posted on 2007-08-05

The Wilderness Ideal

One evening whilst sitting on a deck overlooking a tranquil lake in the wilds of the UP’s northern hardwood forests, I began reading William Cronon’s contributions to the volume he edited himself; Uncommon Ground. The book has been around for a decade and more but it is only recently that I came across a copy in a secondhand book store. It seems apt that I considered what it had to say about the ‘social construction’ of nature in a setting of the type that has long intrigued me. Maybe the view of a landscape which confronted me is another of the reasons I am doing what I am right now. I have had pictures of these large wilderness landscapes on the walls of my mind, and elsewhere, for a while.

Cronon examines “the trouble with wilderness” with reference to the Edenic ideal that underlay it from the beginning. Wordsworth and Thoreau were in bewildered or lost awe of the sublime landscapes they travelled, but by the time John Muir came to the Sierra Nevada the landscape was an ecstasy. Whilst Adam and Eve may have been driven from the garden out into the wilderness, the myth was now ‘the mountain as cathedral’ and sacred wilderness was a place to worship God’s natural world. Furthermore, as the American frontier diminished with time and technology,

“wilderness came to embody the national frontier myth, standing for the wild freedom of America’s past and and seeming to represent a highly attractive natural alternative to the ugly artificiality of modern civilization. … Ever since the nineteenth century, celebrating wilderness has been an activity mainly for well-to-do city folks. Country people generally know far too much about working the land to regard unworked land as their ideal.” (p.78)

Cronon suggests that there is a paradox at the heart of the Wilderness ideal, this conception that true nature must also be wild and that humans must set aside areas of the world for it to remain pristine. As Cronon puts it, this paradox is that “The place where we are is the place where nature is not”. Taking this logic to its extreme results in the need for humans to kill themselves in order to preserve the natural world;

“The absurdity of this proposition flows from the underlying dualism it expresses. … The tautology gives us no way out: if wild nature is the only thing worth saving, and if our mere presence destroys it, then the sole solution to our own unnaturalness, the only way to protect sacred wilderness from profane humanity, would seem to be suicide. It is not a proposition that seems likely to produce very positive or practical results.” (p.83)

I’ll say. But Cronon is not saying that protected wilderness areas are themselves undesirable things, of course not. His point is about the idea of Wilderness. As a response he suggests that rather than thinking of nature as ‘out there’, we need to learn how to bring the wonder we feel when in the wilderness closer to home. We need to abandon the idea of the tree in the garden as artificial and the tree in the wilderness as natural. If we see both trees as natural, as wild, then we will be able to see nature and wildness everywhere; in the fields of the countryside, between the cracks in the city pavement, and even in our own cells.

“If wildness can stop being (just) out there and start being (also) in here, if it can start being as humane as it is natural, then perhaps we can get on with the unending task of struggling to live rightly in the world – not just in the garden, not just in the wilderness, but in the home that encompasses both” (p.90)

Sitting on that deck looking out over the lake it was clear that landscapes such as the one I was in aren’t the idealised, pristine, wilderness that they may be portrayed as in books, photographs and travel brochures. Just as in studying its nature I have come to understand a little better the uncertainties of the scientific method that is supposed to bring facts and truth, so I think have come to better understand the place of human needs within these ‘wild’ landscapes. As naive as it is to think that science might offer the absolute truth (it can’t, but it is still the best game in town to understand the world around us), thinking humans are inseparable from nature seems equally foolish.

In the introduction to a book on natural resource economics (which has mysteriously vanished from my bookshelf), an author describes a similar situation. As a young man he wanted to study the environment in order that he might save it from destructive hands of humans. But in time he came to realise this was unrealistic and that better would be to study the means by which humans use the ‘natural world’ to harvest and produce the resources we need to live. Economics is concerned with the means by which we allocate, and create value from, resources. Just as it is important to understand how ‘nature’ works, it is also important to understand how a world in which humans are a natural component works, and how it can continue to function indefinitely.

Landscape Ecology and Ecological Economics have grown out of this understanding. Whilst theories and models about the natural world independent of humans remain necessary, increasingly important are theories and models that consider the interaction between the social, economic and biophysical components of the natural world. These tools might help us get on with the task of living sustainably in the place which humans should naturally call home.

Buy on Amazon

Posted on 2007-07-27

Usefulness of Spatial Landscape Models

Turner et al.’s discussion about the usefulness of spatial models in land management is now a bit of a classic (written in 1995) but it had also been a while since I read it. Re-reading it after coming back from a trip to our study area, many of the paper’s points resonated with what people (many of them natural resource managers) I met with were saying.

Turner et al. suggest that (p.13) “Models that integrate ecological and economic components so that the models can be used to explore both sets of consequences simultaneously are even more valuable [than ecological alone]”. This is the driving rationale for our research project. As it was succinctly put by one potential landowner in the study area, models of this kind will contribute to the development of plans that are based on an ecological approach but backed up with economic justification.

Given the hierarchical nature of landscape ecological processes and the importance of human activity on those processes, Turner et al. highlight (p.15) that “Land ownership has a large impact on management decisions, and a useful contribution of spatially explicit models is the ability to explore the effects of management by various owners within a mosaic of public and private lands.” With a range land owners, including the state and private industrial companies, the UP study area is in this position and the model we are developing will be able to directly consider the impacts of different land owner management strategies for the landscape as a wider region. Thus, one of the driving questions of the research is “how should timber be harvested across space and time in multiple land ownerships to ensure a sustainable landscape?”

One of the most striking things I was told on my trip was that the most useful thing our model would be able to do for land managers would be if it could get people to sit down together to come up with a coherent, sustainable management plan. Again, the links with Turner et al. are clear (p.15); “Communication between land managers and ecologists remains an important challenge, and spatially explicit models have the potential to create a common working framework.”

However, not only is the communication and collaboration side of the research a challenge, but so too is the technical side of things. Turner et al. highlight the issue of data quality; the model will only be as good as the data used and the accurate up-to-date spatial data bases required are expensive to produce. Furthermore, the quality of the data will determine the modeller’s ability to parameterizes the model at a given spatial resolution and extent. I’m currently reviewing the data that has been collected over the past few years by the research group at CSIS regarding the interactions between deer density, tree regeneration and bid habitat, but also the data managed and made available by Michigan’s Department of Natural Resources. Producing an accurate representation of deer population dynamics and movement across the landscape is certainly going to be a challenge. Next, the relationships between deer browse pressure and vegetation regeneration need to be specified and parameterized. The estimates of deer population and location can then be combined with these relationships to dynamically represent the interactions across space.

Once the model is up and running we will be able to examine spatial scenarios of forest management to assess both ecological and economic sustainability. For example, with regard to the appropriate location of mesic confer regeneration “…increasing the [mesic confer] component is expected to increase the number of individuals of conifer-associated bird species. And over time reduce productivity of the summer deer range and expand areas potentially suitable for deer during winter, resulting in a smaller deer herd dispersed over a larger wintering area (Doepker et al, 2001) in turn resulting in less browsing pressure in WUP forests. The eventual size, configuration, contiguousness and/or juxtaposition of restored habitats to existing or historical mesic conifer habitats and winter deer-yards on non-MDNR lands (public and private) may affect the success of these outcomes” (DNR 2004). Right now this confer regeneration is not going well and areas of maple forest are increasing.

Economically, the model should be able to show how different harvest rotations and management plans by private industrial land owners can ensure the most productive use of their land whilst ensuring both ecological and economic sustainability of the landscape. And not only for single landowners. The model should be useful to examine how actions of neighbouring land under differing ownership can work in concert. For example, if the private industrial goal is intensive harvest, maybe the primary objective of the state should be to ensure conifer cover. But the question then is what are the spatial implications of this? Is there any point in confer regeneration (which provides thermal cover for deer in the winter) if the distance between state and corporate land is large and deer cannot move from thermal cover to find food?

These are the sorts of questions and challenges to which spatial landscape models can be applied, and which we are aiming to tackle. Right now though, it’s time to concentrate on the technical development of the model and the representation of the spatio-temporal deer-vegetation interactions.

Reference
Turner, M.G., Arthaud, G.J., Engstrom, R.T, Hejl, S.J., Liu, J., Loeb, S. & McKelvey, K. (1995) Usefulness of Spatially Explicit Population Models in Land Management Ecological Applications, 5:1 12-16.

Posted on 2007-07-13

Ecological Approach, Economic Justification

This last week I have been touring around our study area and its wider landscape setting in Michigan’s Upper Peninsula. As well as spending a couple of days in the forest ‘helping out’ with some empirical fieldwork being done by MSc student Megan Metonis on the relationship between northern hardwood forest regeneration, timber harvest gap size, and deer browse, I’ve been talking with local managers from the Department of Natural Resources and other management stakeholders.

Whilst I’ll write more about my trip once I’m back at MSU, one of the key things the DNR indicated they would hope our modelling project might achieve is the improved collaboration of multiple land owners and stakeholders, each with their own priorities and expectations, to build the beginnings of a long-term forestry management plan. Such long-term planning has been virtually non-existent in the past, but it was interesting to see an article in a UP newspaper describing the meeting of corporate land owners, natural resource managers and university academics to discuss future land use, ownership and economic trends. This meeting gives me some hope that improved collaboration for forestry management in this area isn’t impossible. If this is the case, as one potential future land owner suggested, the use of the model we’re developing could help develop plans that are based on an ecological approach but backed up with economic justification.

Posted on 2007-06-24

Alternative Model Assessment Criteria

Given the discussion in the previous posts regarding the nature of socio-ecological systems, equifinality and relativism in environmental modelling, how should we go about assessing the worth and performance of our simulation models of human-environment systems?

Simulation models are tangible manifestations of a modellers’ ‘mental model’ of the structure of the system being examined. Socio-Ecological Simulation Models (SESMs) may be thought of as logical and factual arguments made by a modeller, based on their mental model. If the model assumptions hold, these arguments should provide a cogent and persuasive indication of how system states may change under different scenarios of environmental, economic and social conditions. However, the resulting simulation model, based upon a logical and factually coherent mental model, is unlikely to be validated on these two criteria (logic and fact) alone.

First, the problems of equifinality suggest that there are multiple logical model structures that could be implemented for any particular system. Second, accurate mimetic reproduction of an empirical system state by a model may be the most persuasive form of the factual proof of a model in many eyes, but the dangers of affirming the consequent make it impossible to prove temporal predictions in models of open systems are truly accurate. Simulation models may be based on facts about empirical systems, but their results cannot be taken as facts about the modelled empirical system.

Thus, some other criteria alongside the logical and factual criteria will be useful to evaluate or validate a SESM. A third and fourth criteria, for environmental simulation models that consider the interaction of social and ecological systems at least, are available by specifically considering the user(s) of a model and its output. These criteria are closely linked.

My third proposed criterion is the establishment of user trust in the model. Trust is used here in the sense of ‘confidence in the model’. If a person using a model or its results does not trust the model it will likely not be deemed fit for its intended purpose. If confidence is lacking in the model or its results, confidence will consequently be lacking in any knowledge derived, decision made, or policy recommended based upon the model. Thus, the use of trust as a criterion for validation is a form of ‘social validation’, ensuring that user(s) agree the model is a legitimate representation of the system.

The fourth criteria by which a model might achieve legitimacy and receive a favourable evaluation (i.e. be validated), is the provision of some form of utility to the user. This utility will be termed ‘practical adequacy’. If a model is not trusted then it will not be practically adequate for its purpose. However, regardless of trust, if the model is not able to address the problems or questions set by the user then the model is equally practically inadequate.

The addition of these two criteria, centred on the model user rather than the model itself, suggests a shift away from falsification and deduction as model validation techniques, toward more reflexive approaches. The shift in emphasis is away from establishing the truth and mimetic accuracy of a model and toward ensuring trust and practical adequacy. By considering trust and practical adequacy, validation becomes an exercise in model evaluation and reclaims its more appropriate meaning of ‘establising a model’s legitimacy’.

From his observation of experimental physicists and work on the ‘experimenter’s regress’, Collins has arrived at the view that there is no distinction between epistemological criteria and social forces to resolve a scientific dispute. The position outlined previously seems to imply a similar situation for models of open, middle-numbered systems where modellers are required to resort to social criteria to justify their models due the inability to do so convincingly epistemologically. This is not necessarily an idea that many natural scientists will sit comfortably with. However, the shift away from truth and mimetic accuracy should not necessarily be something modellers would object to.

First, all modellers know that their models are not true, exact replications of reality. A model is an approximation of reality – there is no need to create a model system if experimentation on the existing empirical system is possible. Furthermore, accepting the results of a model are not ‘true’ (i.e. in the sense that they are perfect predictions of the future) in no way requires the model be built on incorrect logic or facts. As Hesse notes in criticism of Collins, whilst the resolution of scientific disputes might result from a social decision that is not forced by the facts, “it does not follow that social decision has nothing to do with objective fact”.

Second, regardless of truth and mimetic accuracy, modellers have several options to build trust and ensure practical adequacy scientifically. Ensuring models are logically coherent and not factually invalid (i.e. criteria one and two) will already have come some way to make a scientific case. Furthermore, the traditions of scientific methodological and theoretical simplicity and elegance can be observed, and the important unifying potential across theories and between disciplines that modelling offers can be emphasised. Thus, regardless of the failures of epistemological methods for justifying them, socio-ecological and other environmental simulation models must be built upon solid logical and factual foundations;

“The postmodern world may be a nightmare for … normal science (Kuhn 1962), but science still deserves to be privileged, because it is still the best game in town. … [Scientists] need to continue to be meticulous and quantitative. But more than this, we need scientific models that can inform policy and action at the larger scales that matter. Simple questions with one right answer cannot deliver on that front. The myth of science approaching singular truth is no longer tenable, if science is to be useful in the coming age.”
(Allen et al. p.484)

Post-normal science highlights the importance of finding alternative ways for science to engage with both the problems faced in the contemporary world and the people living in that world. As they have been defined here, SESMs will inherently address questions that will be of concern to more than just scientists, including problems of the ‘risk society’. From a modelling perspective, a post-normal science approach highlights the need to build trust in the eyes of non-scientists such that understanding is fostered.

Further, it emphasises the need for SESMs to be practically adequate such that good decisions can be made promptly. It also implies that the manner in which a ‘normal’ scientist will go about assessing the trustworthiness or practical adequacy of a model (such as the methods described above) will differ markedly from that of a non-scientist. For example, scientific model users will often, but not always, have also been the person to develop and construct the model. In such a case the model will be constructed to ensure the model is practically adequate to address their particular scientific problems and questions.

When the model is to be used by other parties the issue of ensuring practical adequacy will not be so straight-forward, and particularly so when the user is a non-scientist. In such situations, the modeller needs to ask the question ‘practically adequate for what’? The inhabitants of the study areas investigated will have a vested interest in the processes being examined and will themselves have questions that could be addressed by the model. In all probability many of these questions will be ones that the modeller themselves has not considered or, if they have, may not have considered relevant. Further, the questions asked by local stakeholders may be non-scientific – or at least may be questions that environmental scientists are not used to attempting to answer.

The use and improvements in technical approaches (such a spatial error matrices from pixel-by-pixel model assessment) will remain useful and necessary in the future. Here however, I have emphasised potential alternative methods for model validation (assessment) might be useful to utilise the additional information and knowledge which is available from those actors driving change in a socio-ecological system. In other words, there is information within the system of study that is not utilised for model assessment by simply comparing observed and predicted system states. This information is present in the form of local stakeholders’ knowledge and experience.

Posted on 2007-06-09

let’s go nuts!

Let’s go Lansing Lugnuts that is. Last night I went to my first Minor League Baseball game. I’ve been to a couple of Major League games before, but on a nice summers’ evening it was about time to find out more about what goes on in the lower echelons of the game that has always intrigued me. When I was about 8 my uncle brought me back a Red Socks baseball and pennant from a business trip. Maybe that got it started. One of my favourite writers Stephen Jay Gould was a huge baseball fan and used the apparent extinction of the .400 batting average as an adroit metaphor in one of his books to discount the idea of evolutionary progress with humans at the pinnacle in. And of course there are the parallels with cricket.

The lower levels of professional sport rarely get heard above the din and clamour for the biggest and best teams. The FA Premiership is now the richest football league in the world and followed avidly by many fans around the world. Its transition from a league with a reputation of violence and hooliganism to one of the most marketable sporting brands in the world has come via a change in attitude and facilities. I have a vivid memory from one of my first trips to a Bristol City game in the late 1980’s (again, I must have been about 8 – I hasten to add City are not, unfortunately, in the Premiership). I needed to use a bathroom so Dad took me to the ‘Gents’ where I was confronted simply by a 10 foot wall painted black with a gutter of urine running along the bottom. The smell was ‘colourful’ as was the language around me. It was intense to say the least. How this experience has effected me later personal development I can only guess – Mum certainly didn’t approve of me going along. But the violent and abusive behaviour that once embodied watching the game is no longer tolerated and the terraces have been replaced by more manageable and comfortable rows of covered seating (and more hygienic toilets).

Apparently a similar change has occurred in the minor leagues of baseball. In the game programme was a piece about the rise in popularity of Minor League games. Season attendances in every season since 2000 have been placed in the top 10 since the leagues began and in 2006 the current record was set at 41.7 million fans. That’s more than the NBA, and more than the NFL and NHL combined, each year. Fifth Third Field in Dayton Ohio has sold out every game since it opened in 2000. But the continuing growth has come since the 1990’s and a similar attitude toward the game as has changed football in the UK. And the programme article described a lady faced by a similar toilet experience as my childhood one – it’s certainly not like that now. The emphasis has shifted toward entertainment and whilst the minor league game hasn’t changed, the crowds have. In family-friendly America this means kids. And lots of ’em.

So whilst the high pitched screaming wasn’t so good for my ears, the $9 seat in the third row along the first base line was good for my wallet and got me close to those 90 mph pitches. I have got to say though, even with my uneducated eye, the quality of play wasn’t quite up there with, say, the SF Giants. The Lugnuts gave up 4 runs in the first inning and it wasn’t looking good. But then South Bend gave up 5 in the second and from there on we cruised to victory (8-5). Highlights from ‘the game’ for me included a Lugnuts batter snapping his bat over his knee (golfer style) after he struck out with the bases loaded, and the genius sack race ‘run’ by some ‘hefty’ women from the crowd between 8th and 9th innings. I was less impressed that they wouldn’t refill my plastic beer glass when buying a second and that I HAD to have a new one. Grrr…

Regardless of the quality of play it was a good night. And seemingly the growth of Minor League Baseball is good for the cities in which the teams are located. Oldsmobile Park is leading the much needed regeneration of the waterfront area of downtown Lansing. After the game, the fireworks reflected in the windows of the old Ottawa Power Station (above) that has lain empty for over a decade. Regeneration is needed in Michigan of all places in the States, where the decline of the American auto industry has hit hard. With manufacturing in sharp decline the state and the city need to turn to alternative industries for income and regeneration. The dollars spent in the stadium are now helping to boost the local economy, and give this part of town something to build around for the future. So, let’s go nuts!

Posted on 2007-06-05

Initial Michigan UP Ecological Economic Modelling Webpage

We now have a very basic webpage online, (very) briefly outlining the Michigan UP Ecological-Economic Modeling project. This is just so that we have an online presence for now – in time we will develop this into a much more comprehensive document detailing the model, its construction and use. Hopefully, at some point in the future we’ll also mount a version of the model online. I’ll keep you posted on the online development of the project.

Direction not Destination

Blog by James Millington, PhD

Tag: Economic