JASSS Paper Accepted

This week one of the papers I have been working on as a result of my PhD research has been accepted for publication in the Journal of Artificial Societies and Social Simulation (JASSS). The paper, written with Raúl Romero-Calcerrada, John Wainwright and George Perry, describes the agent-based model of agricultural land-use decision-making we constructed to represent SPA 56 in Madrid, Spain. We then present results from our use of the model to examine the importance of land tenure and land use on future land cover and the potential consequences for wildfire risk. The abstract is below, and I’ll post again here when the paper is published and online.

An Agent-Based Model of Mediterranean Agricultural Land-Use/Cover Change for examining Wildfire Risk

James D. A. Millington, Raúl Romero-Calcerrada, John Wainwright, George L.W. Perry
(Forthcoming) Journal of Artificial Societies and Social Simulation

Humans have a long history of activity in Mediterranean Basin landscapes. Spatial heterogeneity in these landscapes hinders our understanding about the impacts of changes in human activity on ecological processes, such as wildfire. Use of spatially-explicit models that simulate processes at fine scales should aid the investigation of spatial patterns at the broader, landscape scale. Here, we present an agent-based model of agricultural land-use decision-making to examine the importance of land tenure and land use on future land cover. The model considers two ‘types’ of land-use decision-making agent with differing perspectives; ‘commercial’ agents that are perfectly economically rational, and ‘traditional’ agents that represent part-time or ‘traditional’ farmers that manage their land because of its cultural, rather than economic, value. The structure of the model is described and results are presented for various scenarios of initial landscape configuration. Land use/cover maps produced by the model are used to examine how wildfire risk changes for each scenario. Results indicate land tenure configuration influences trajectories of land use change. However, simulations for various initial land-use configurations and compositions converge to similar states when land-tenure structure is held constant. For the scenarios considered, mean wildfire risk increases relative to the observed landscape. Increases in wildfire risk are not spatially uniform however, varying according to the composition and configuration of land use types. These unexpected spatial variations in wildfire risk highlight the advantages of using a spatially-explicit ABM/LUCC.

April 2008 Conference Posters

Final preparations are underway for the US-IALE Symposium in Madison, WI, next week. I’ve finished the poster that we’ll be presenting there on the progress we’re making withour ecological-economic forest landscape model. We’ve also been putting the finishing touches on our posters for the wildfire session at EGU in Vienna (which Raul will be attending and presenting our posters at). Links to .pdf versions of the posters are below. Thoughts and photos from Madison and Chicago (where I’ll be stopping off for a couple of days on the way home) on my return.

An Ecological-Economic Model for Sustainable Forest Management: Modeling Deer Distributions from Local & Landscape Characteristics
J.D.A. Millington, J.P. LeBouton, M.B. Walters, K.R. Hall, M.S. Matonis, E.J. Laurent, F. Lupi, S. Chen, J. Liu

An Integrated Socio-Ecological Simulation Model of Succession-Disturbance Dynamics in a Mediterranean Landscape
J.D.A. Millington, J. Wainwright, G.L.W. Perry, R. Romero-Calcerrada, & B.D. Malamud

Spatial modelling of the influence of human activity on wildfire ignition risk in a Mediterranean landscape
R. Romero-Calcerrada, F. Barrio-Parra, J.D.A. Millington, C.J. Novillo

Tackling Amazonian Rainforest Deforestation

This week’s edition of Nature devotes an editorial, a special report and an interview to the subject of tropical rainforests and their deforestation. The articles highlight both the proximate causes and underlying driving forces of tropical deforestation, and the importance of human activity as an agent of change (via fire for example), in these socio-ecological systems.

The editorial considers the economics of rainforest destruction, with regards to global carbon emissions. It suggests that deforestation must be integrated into international carbon markets, to reward those countries that have been able to control the removal of forest land (such as India and Costa Rica). Appropriate accounting of tropical rainforest carbon budgets is required however, and the authors point to the importance of carbon budget modelling and the monitoring of (via satellite imagery for example) change in rainforest areas over large spatial extents. Putting an economic price on ‘ecosystem services’ is key to this issue, and the editorial concludes:

One of the oddly positive effects of global warming is that it has given the world the opportunity to build a more comprehensive and inclusive economic model by forcing all of us to grapple with our impact on the natural environment. We are entering a phase in which new ideas can be developed, tested, refined and rejected as necessary. If we find just one that can beat the conventional economic measure of gross domestic product, and can quantify some of the basic services provided by rainforests and other natural ecosystems, it will more than pay for itself.

The special report focuses on the efforts of the Brazilian government to curb the rate of deforestation in the their Amazonian forests. The Brazilian police force is blockading roads, conducting aerial surveys and inspecting agricultural and logging operations, to monitor human activities on the ground. Brazilian scientists meanwhile are monitoring the situation from space, and have developed methodologies and techniques that are leading the way globally in the remote monitoring of forests. The Brazilian government is a keen advocate of the sort of economic approaches to the issues of rainforest destruction highlighted in the editorial outlined above, and sees this rigorous monitoring as key to be able to show how much carbon they can save by preventing deforestation.

Halting the removal of forest cannot simply be left to carbon trading alone, however, and local initiatives need to be pursued. To ensure the forest’s existence is sustainable, local communities need to be able make money for themselves without chopping down the trees – if they can do this it will be their in their interests NOT to remove forest. But developing this incentive has not been straightforward. For example, some researchers have have suggested that as commodity prices for crops such as soya beans have increased (possibly due to increased demand for corn-based ethanol in the US) deforestation has increased as a result. Although the price of soya beans may be a contributing factor to rainforest removal, Ruth DeFries (who will be visiting CSIS and MSU next week as part of the Rachel Carson Distinguished Lecture Series) suggests that it is not the main driver. Morton et al. found that during for the period 2001-04, conversion of forest to agriculture peaked in 2003. This situation makes it clear that there are both proximate causes and underlying driving forces of tropical deforestation. The Nature special report suggests:

If the international community is serious about tackling deforestation, it will probably need to use a hybrid approach: helping national governments such as Brazil to fund traditional policies for enforcement and monitoring and enabling communities to experiment with a market-based approach.

But how long do policy-makers have to discuss this and get these measures in place? One set of research suggests 55% of the Amazon rainforest could be removed over the next two decades, and the complexity of the rainforest system means that a ‘tipping point’ (i.e., an abrupt transition) beyond which the system might not recover (i.e., reforestation would not be possible). The Nature interview with Carlos Nobre highlights this issue – the interactions of climate change with soil moisture and the potential for fire indicate that the there is risk of rapid ‘savannization’ in the eastern to southeastern Amazon as the regional climate changes. When asked what the next big question scientists need to address in the Amazon is, Nobre replies that the role of human-caused fire will be key:

Fire is such a radical transformation in a tropical forest ecosystem that biodiversity loss is accelerated tremendously — by orders of magnitude. If you just do selective logging and let the area recover naturally, perhaps in 20–30 years only a botanist will be able to tell that a forest has been logged. If you have a sequence of vegetation fires going through that area, forget it. It won’t recover any more.

As I’ve previously discussed, considering the feedbacks and interactions between systems is important when examining landscape vulnerabilities to fire. Along with colleagues I have examined the potential effects of changing human activity on wildfire regimes in Spain (recently we had this paper published in Ecosystems and you can see more wildfire work here). However, the integrated study of socio-economic and ecological systems is still very much in its infancy. And the processes of landscape change in the northern Mediterranean Basin and the Amazonian rainforest are very different; practically inverse (increases in forest in the former and decreases in the latter). As always, plenty more work needs to be done on these subjects, and with the potential presence of ‘tipping points’, now is an important time to be doing it.

Landscape Ecology paper In Press

We were informed this week that the paper I have been working on with Raul Romero Calcerrada and other colleagues at Universidad Rey Juan Carlos has been accepted by Landscape Ecology. I’ve copied the abstract below. It should be out later in 2008, but email me if you want a pre-print.

Currently I’m working on two paper with colleagues describing the construction and initial results of the model I constructed during my PhD research. We’re also submitting abstracts to the European Geophysics Union General Assembly 2008 on this and work related to the Landscape Ecology paper.

The abstract submitted with colleagues at CSIS has been accepted for poster presentation at the US-IALE meeting in Madison in April. Should be a good meeting. Also, the doi for Perry and Millington (2008) in PPEES now works.

Tomorrow I’m heading back to Europe for a couple of weeks. I have my PhD graduation ceremony next week (maybe I’ll post some photos of me looking scholarly/awkward in my academic dress/get-up), a couple days snowboarding in the Swiss Alps, and a couple of days working with Bruce Malamud at King’s following up on the work we published on US wildfire regimes in PNAS. Should be a fun couple of weeks!

GIS analysis of spatial patterns of wildfire human-caused ignition risk in the SW of Madrid (Central Spain) (In Press) Landscape Ecology

Raul Romero Calcerrada; Carlos J. Novillo Camacho; James DA Millington; Inmaculada Gomez-Jimenez

Abstract: The majority of wildfires in Spain are caused by human activities. However, much wildfire research has focused on the biological and physical aspects of wildfire, with comparatively less attention given to the importance of socio-economic factors. With recent changes in human activity and settlement patterns in many parts of Spain, potentially contributing to the increases in wildfire occurrence recently observed, the need to consider human activity in models of wildfire risk for this region are apparent. Here we use a method from Bayesian statistics, the Weights of Evidence (WofE) model, to examine the causal factors of wildfires in the south west of the Madrid region for two differently defined wildfire seasons. We also produce predictive maps of wildfire risk. Our results show that spatial patterns of wildfire ignition are strongly associated with human access to the natural landscape, with proximity to urban areas and roads found to be the most important causal factors. We suggest these characteristics and recent socio-economic trends in Spain may be producing landscapes and wildfire ignition risk characteristics that are increasingly similar to Mediterranean regions with historically stronger economies, such as California, where the urban-wildland interface is large and recreation in forested areas is high. We also find that the WofE model is useful for estimating future wildfire risk. We suggest the methods presented here will be useful to optimize time,
human resources and fire management funds in areas where urbanization is increasing the urban-forest interface and where human activity is an important cause of wildfire ignition.

Update 06/02/08: This paper is now online here and here.

Seeing the Wood for the Trees: Pattern-Oriented Modelling

A while back I wrote about the potentially misplaced preoccupation with statistical power in species distribution models. Our attempts at drawing out some relationships between our deer distribution data and descriptors of land cover is proving taxing – the relationships evident at a more coarse spatial resolution (e.g. county level) than we are considering aren’t found in our stand-level data. As a result we moving toward taking a modelling approach that is driven less by our empirical data and more by inferences based on multiple information sources. Particularly I’m drawn toward emphasising an approach I first encountered in my undergraduate landscape ecology class taught by George Perry – ‘Pattern-Oriented Modelling‘.

A prime example of the POM approach is its use to model the spread of rabies through central Europe. The rabies virus has been observed to spread in a wave-like manner, carried by foxes. Grimm et al. (1996) describe how they developed a cellular automate-type model that considers cells (of fox territory) to be in either a healthy, infected or empty state. Through an iterative model development process, their model was gradually refined (i.e. its assumptions and parameters modified) by comparing model results with empirical patterns.

The idea underpinning this iterative POM approach is

“… if we decide to use a pattern for model construction because we believe this pattern contains information about essential structures and processes, we have to provide a model structure which in principle allows the pattern observed to emerge Whether it does emerge depends on the hypotheses we have built into the model.”

This approach has been found particularly useful for the development of ‘bottom-up’ agent-based models. Often understanding of the fine-scale processes driving broad-scale system dynamics and patterns is poor, making it difficult to both structure and parameterise mechanistic models. However, whilst the logical fallacy of affirming the consequent remains, if a model of low-level interactions is able to reproduce higher-level patterns, we can be confident that our model is a better representation of the system mechanics than one that doesn’t. Furthermore, the more patterns at different scales that the model reproduces, the mode confident we can be in it. Thus, in POM

“multiple patterns observed in real systems at different hierarchical levels and scales are used systematically to optimize model complexity and to reduce uncertainty.”Grimm et al. (2005)

Grimm and Berger outline the general protocol of a pattern-oriented modelling approach (whilst reminding us that there is no standard recipe for model development):

  1. Formulate the question or problem
  2. Assemble hypotheses about essential processes and structures
  3. Assemble (observed) patterns
  4. Choose state variables, parameters and structures
  5. Construct the model
  6. Analyse, test and revise the model
  7. Use patterns for parameterisation
  8. Search for independent predictions

Several iterations of this process will be required to refine the model. In initial iterations, steps 2 and 4 may need to be largely inferential if the state of knowledge about the system is poor. However, by moving iteratively back through these steps, and in particular exploiting steps 6 and 7 to inform us about model performance relative to system behaviour, we can improve our knowledge about the system whilst simultaneously ensuring our model recreates observed patterns. For example, during the development of the landscape fire-succession model in my PhD, I compared the landscape-level model results of different sets of (unknown) flammability probabilities (parameters) of each vegetation type required by the model with empirically observed wildfire regime behaviour. By modifying parameters for individual vegetation types I was able to reproduce the appropriate wildfire frequency-area distribution for Mediterranean-type environments that had previously been found (I’m currently writing this up for publications – more soon).

But what does this all have to do with our model of the relationship between deer browse and timber harvest in Michigan’s Upper Pensinsula? Well, right now I think we’re at steps 2,3 and 4 (all at the same time). As our deer and land cover relationships are weak at the stand-level (which is the level we are considering so that we can integrate the model with an economic module), I am currently developing hypotheses (i.e. assumptions) about the structure of the system from previous research on different specific aspects of similar systems. Furthermore, we’re continuing to look for spatial patterns in both vegetation and deer distribution so that we can compare the results of our hypothetical model.

For example, one thing I’m struggling with right now is is how to establish the probability of which individual trees (or saplings) will be removed from a stand due to a given level of deer browse (which in turn is dependent upon a deer density). This is not something that has been explicitly studied (and would be very difficult to study at the landscape level). Therefore we need to parameterise this process in order for the model to function. We should be able to do this by comparing several different parameterisations to empirically observed patterns such as spatial configuration of forest types classified by age class or age/species distributions at the stand-level. That’s the idea anyway – we’ll see how it goes over the next months…

In the meantime, next week I head back to the study area for the first stage of our seedling experiment. We’re planting seedlings now across a gradient of browse and site conditions with the intention of returning in the spring to see what has been browsed and count deer pellets. This should improve our understanding of the link between pellet counts and browse pressure and provide us with some more empirical patterns which we can use in our ongoing model development.

Call for Abstracts: Wildfires session at EGU 2008

As in previous years, I’m a co-convener of the Wildfires session at the 2008 European Geophysics Union General Assembly (along with Rosa Lasaponara, Luciano Telesca and Don McKenzie). We hope this year’s session will be as successful as ever, and are expecting the best papers presented to compose a special issue of Ecological Modelling. The call for abstracts is now open (copied below). Abstracts should be submitted at the conference website. Important deadlines are:

Abstract Submission: 14 January 2008
Financial Applications 07 December 2007
Pre-registration: 31 March 2008

Subject: Call for Abstracts: Wildfires session at EGU 2008

5 November 2007

Dear Colleagues [Apologies for cross-posting],

The European Geosciences Union (EGU) General Assembly 2008 is to be help from 13-18 April 2008 in Vienna, Austria. We invite you to participate in the session ‘Spatial and temporal patterns of wildfires: models, theory, and reality’ (NH8.4/BG2.16 – co-organized by the Natural Hazards & Biogeosciences divisions).

Session description:
Wildfires are the result of a large variety and number of interacting components, producing patterns that vary significantly both spatially and temporally. This session will examine models, theory, and empirical studies in wildfire research. We encourage submissions in any one or combination of these three main areas, and envision bringing together wildfire hazard managers, applied researchers, and theoreticians. Posters are also very much encouraged, as we plan to have both lively
oral and poster sessions.

The best papers will be considered for publication in a Special Issue of Ecological Modelling

ABSTRACT DEADLINE: 14 January 2008
Web site for submission: http://meetings.copernicus.org/egu2008/

Please note that the deadline for financial applications is 07 December 2007, and for pre-registration is 31 March 2008. We look forward to seeing you in Vienna. Please forward this message also to your colleagues.

With best regards,

Lasaponara, R. (Convener)
Telesca, L.; McKenzie, D.; Millington, J. (Co-conveners)

Lasaponara Rosa, PhD
Research on Remote Sensing and Signal Processing
lasaponara at imaa.cnr.it

Luciano Telesca
Research on geoscience and Signal Processing
luciano.telesca at imaa.cnr.it

Don McKenzie
Research Ecologist
Pacific WIldland Fire Sciences Lab
US Forest Service

Affiliate Professor
College of Forest Resources
CSES Climate Impacts Group
University of Washington

dmck at u.washington.edu
donaldmckenzie at fs.fed.us

James D.A. Millington, PhD
Research Associate
Center for Systems Integration and Sustainability
Michigan State University
jmil at msu.edu

W1: http://csis.msu.edu
W2: http://www.landscapemodelling.net

An Integrated Fire Research Framework

Integrated, multi- and inter-disciplinary studies are becoming increasingly demanded and required to understand the consequences of human activity on the natural environment. In a recent paper, Sandra Lavorel and colleagues highlight the importance of considering the feedbacks and interactions between several systems when examining landscape vulnerabilities to fire. They present a framework for integrated fire research that considers the fire regime as the central subsystem (FR in the figure below) and two feedback loops, the first with consequences for atmospheric and biochemical systems (F1) and the second that represents ecosystems services and human activity (F2). It is this second feedback loop in their framework that my research focuses.

To adequately quantify the fire-related vulnerability of different regions of the world the authors suggest that a better understanding of the relative contributions of climate, vegetation and human activity to the fire regime is required. For example, they suggest that an examination of the statistical relationships between spatio-temporal patterns evident in wildfire regimes and data on ecosystem structure, land use and other socio-economic factors. We made a very similar point in our PNAS paper and hope to continue to use the exponent (Beta) of the power-law frequency-area relationship that is evident in many model and empirical wildfire regimes to examine these interactions. One statistical relationship that might be investigated is between Beta and the level of forest fragmentations, thought to be a factor confounding research on the effects of fire suppression of wildfire regimes.

But the effects of landscape fragmentation can also be examined in a more mechanistic fashion using dynamic simulation models. Lavorel et al. mention the impacts of agricultural abandonment on the connectivity of fuels in Mediterranean landscapes which are attributed, in conjunction with a drier than average climate, to the exceptionally large fires that burned there during the 1990s. My PhD research examined the impacts of agricultural land abandonment on wildfire regimes in central Spain. I’m currently working on writing this work up for publication, but I plan on continuing to develop the model to more explicitly represent the F2 feedbacks loop shown in the figure above.

The potential socio-economic consequences of changing fire regimes are an area with a lot of room to improve our understanding. For example, some regions of the world, such as the Canadian boreal forest, are transitioning from a net sink for carbon to a net source (due to emission during burning). If carbon sinks are considered in future emission trading systems, regions such as are losing a potential future economic commodity. Lavorel et al. also discuss the interesting subject of potential land conflict due to mismatches in the time scales between land planning and fire occurrence. In Indonesia for example, years which burn large areas force re-allocation of land development plans by local government. Often however the processes of developing these plans is not fast enough to forestall the exploitation by local residents of the new land available for occupation and use.

The need for increased research in this area is highlighted by the case studies for Alaskan and African savannah ecosystems presented by Lavorel et al. Whilst discussion of the wildfire regime and atmospheric/biochemical feedbacks can be discussed in detail, poor understanding of the ecosystem services/human activity feedbacks prevents such detailed discussion.

The framework Lavorel et al. present is a very useful way to conceptualise and plan for future research in this field. They suggest (p.47-48) that “Assessments of vulnerability of land systems to fire demand regional studies that use a systemic approach that focuses on the feedback loops described here” and “… will require engaging a collection of multiscale and interdisciplinary regional studies”. In many respects, I expect my future work to contribute to this framework, particularly with regards the human activity (F2) feedback loop.

Fire Danger Very High Across Michigan – Aug 2007

Currently on the MDNR homepage:

“Increasing drought conditions across Michigan have increased the fire danger to very high. Department of Natural Resources wildfire officials are asking outdoor enthusiasts to use caution with outdoor fires.”

Over the weekend erratic winds have fanned a fire to greater than 12,000 acres in the UP, just north of Tahquamenon Falls State Park. More here.

Update – 4th January 2008
On 29th August 2007 Michigan DNR reported the Sleeper Lake fire was 95% contained and at ~18,000 acres was the third largest fire in Michigan history.

Modeling Disturbance Spatially using the FVS

We plan to use the Forest Vegetation Simulator (FVS), developed by the USFS over the previous couple of decades, in our ecological-economic model of a managed forest landscape. This week I’ve been thinking a lot about how best to link a representation of white-tailed deer browse with the FVS.

Two good examples I’ve found of the modelling of forest disturbance using FVS are the Fire and Fuels Extension (FFE) developed at the USFS Rocky Mountain Research Station in collaboration with other parties, and the Westwide Pine Beetle Model developed by the Forest Health Technology Enterprise Team (FHTET).

The Fire and Fuels Extension to the Forest Vegetation Simulator (FFE-FVS) links the existing FVS, models that represent fire and fire-effects, and fuel dynamics and crowning submodels. The overall model is currently calibrated for northern Idaho, western Montana, and northeastern Washington. More details on the FFE-FVS can be found here, where you can also download this video about the extension:

The Westwide Pine Beetle Model simulates impacts of mountain beetle (Dendroctonus ponderosae Hokpins), western pine beetle (D. brevicomis Leconte), and Ips species for which western pines are a host. The model simulates the movement of beetles between the forest stands in the landscape using the Parallel Processor Extension (PPE) to represent multiple forest stands in FVS.

A recent paper by Ager and colleagues in Landscape and Urban Planning presents work that links both the FFE and the WPBM to FVS using the PPE:

We simulated management scenarios with and without thinning over 60 years, coupled with a mountain pine beetle outbreak (at 30 years) to examine how thinning might affect bark beetle impacts, potential fire behavior, and their interactions on a 16,000-ha landscape in northeastern Oregon. We employed the Forest Vegetation Simulator, along with sub-models including the Parallel Processing Extension, Fire and Fuels Extension, and Westwide Pine Beetle Model (WPBM). We also compared responses to treatment scenarios of two bark beetle-caused tree mortality susceptibility rating systems. As hypothesized, thinning treatments led to substantial reduction in potential wildfire severity over time. However, contrary to expectations, the WPBM predicted higher bark beetle-caused mortality from an outbreak in thinned versus unthinned scenarios. Likewise, susceptibility ratings were also higher for thinned stands. Thinning treatments favored retention of early seral species such as ponderosa pine, leading to increases in proportion and average diameter of host trees. Increased surface fuel loadings and incidence of potential crown fire behavior were predicted post-outbreak; however, these effects on potential wildfire behavior were minor relative to effects of thinning. We discuss apparent inconsistencies between simulation outputs and literature, and identify improvements needed in the modeling framework to better address bark beetle-wildfire interactions.

Whilst I’m still in the early stages of working out how our model will all fit together, it seems like an approach that takes a similar approach will be suitable for our purposes. We’ll need to develop a model that is able to represent the spatial distribution of the deer population across the landscape and that can specify the impact of those deer densities on the vegetation for given age-height classes (for each veg species). This model would likely then be linked with FVS via the the PPE. So concurrently over the next few months I’m going to be working on developing a model of deer density and browse impacts, coding this model into a structure that will link with FVS-PPE, and acquiring and developing data for model initialization.

Ager, A.A., McMahan, A., Hayes, J.L. and Smith, E.L. (2007) Modeling the effects of thinning on bark beetle impacts and wildfire potential in the Blue Mountains of eastern Oregon Landscape and Urban Planning 80:3 p.301-311

Daniel Botkin’s Renegade Blog

Daniel Botkin, eminent Ecologist and author of Discordant Harmonies, has recently started a blog called Reflections of a renegade naturalist. Two recent posts caught my eye.

The days of Smokey Bear, an enduring American icon of wildland management and its efforts to communicate with the public, are apparently numbered. Whilst his message about taking precautions against starting wildfires remains necessary, the underlying ethos of forest (and environmental) management has changed. Once, ecologists’ theoretical foundation was the ‘balance of nature’ and the presence of equilibrium and stability within ecosystems. But over the past three decades this perception has dramatically shifted and now ‘change is natural’ would be a more apt motto. Ecosystems are dynamic. Disturbance, such a wildfire, is now seen as an inherent and necessary component of many landscapes to ensure ecosystem health. This shift in thinking is evident on the Smokey website, with sections discussing the use of prescribed fire, fire’s role in ecosystem function, and the potential pitfalls of excluding fire entirely. George Perry has written an excellent review of these shifts in ecological understanding.

So what about Smokey Bear? His message about taking precautions in wilderness areas still remain of course. But with this new ecological ethos in mind, Botkin was asked for suggestions for a new management mascot. He came up with Morph the Moose. I haven’t seen anything about Morph previously, and a quick Google search currently only throws up 7 hits, so we’ll have to watch out for Morph wandering around with his new message soon.

The second post that got my eye is related to the evaluation of the forest growth model JABOWA that Botkin developed. JABOWA is an individual-based model that considers the establishment, growth and senescence of individual trees. In 1991 JABOWA was used to forecast how potential global warming would influence the Kirtland’s warbler, an endangered species that nests only in Michigan. Botkin and his colleagues forecast that by 2015 the Jack pine habitat of the warbler would decline significantly with detrimental consequences for the warbler. On his blog he suggests that matching this prediction with contemporary observations will be an ideal test to validate the predictions of the JABOWA model. Given my previous discussion about ‘affirming the consequent’ (i.e. deeming a model a true representation of reality if its predictions match observed reality, and false if it does not) it’s good to see Botkin does not suggest a valid prediction indicates the validity of the model itself. We’re advised us to stay tuned for the results. Given the subject matter and quality of the articles on the new renegade blog I certainly will.