Complex Systems Lab

Research

In our laboratory we apply the theory of ecological complexity and the methods of ecological informatics to resolve theoretical and practical research questions related to environmental management, conservation and monitoring in marine, coastal and terrestrial systems. Our work is highly multidisciplinary and involves extensive collaboration with other scientists in university, industry and governmental sectors.

Most of our projects involve modelling and/or data analysis. Since we develop novel approaches, we program our own code in MATLAB, C or some other language. Students who do not have previous programming experience are trained in the tools necessary to accomplish their project. Our multidisciplinary team of geographers, biologists, engineers and physicists provides the perfect environment for the exchange of ideas and expertise between the disciplines.

What is ecological complexity?

Current research projects

Development of a multi-agent model to facilitate the integrated management of human activities in the Saguenay-St. Lawrence Marine Park and Marine Protected Area in Quebec
NSERC strategic project in collaboration with Parks Canada, Fisheries and Oceans Canada, le Groupe de recherche et d'éducation sur les mammifères marins (GREMM), l'École de Technologie Supérieure (Montréal) and the University of Calgary.

The objective of this project was to develop an agent-based model to simulate the movement of marine traffic (whale watching vessels, commercial shipping traffic, pleasure craft, kayaks, etc.) and marine mammals in the Saguenay-St. Lawrence Marine Park and the proposed adjacent Marine Protected Area in order to investigate the effects of different management scenarios on spatiotemporal patterns of traffic circulation and whale-vessel encounters. We are currently applying the model to answer a broad range of management questions for the estuary in collaboration with government and industry partners. Cristiane A. Martins (Ph.D. student), Clément Chion (Ph.D. student), Philippe Lamontagne (M.Sc. student) and Samuel Turgeon (M.Sc. student) have contributed to this project.

Modelling and scenario building to inform better forest management practices in woodland caribou habitat
This project, in collaboration with Université Laval and industrial partners, is funded by an NSERC Collaborative Research and Development Grant.

The overall objective of this project is to study how structural changes in the landscape caused by forest harvesting and management affect the dynamics of large mammal populations in the boreal forest of Québec. To study this question, we are developing an individual-based model of interactions between the woodland caribou (Rangifer tarandus caribou), wolf (Canis lupus), moose (Alces alces) and their habitat for a study area situated in the Côte Nord region of Québec. The model will serve as a decision support tool with which forest managers can explore the effects of different forest management strategies (e.g., locations and sizes of cut blocks and protected areas, rotation periods, locations of access roads, etc.) in order to ensure that viable populations of woodland caribou, whose survival is largely determined by interactions with its main predator, the wolf, are maintained. The project will therefore enhance our understanding of both the direct and indirect effects of human activities on the woodland caribou that arise from complex interactions between multiple species and their environment. The project is being carried out by Guilluame Latombe (PhD student) and Kristel Lucas (MSc student) in collaboration with Daniel Fortin (Biology, U. Laval).

Using complexity as an ecological indicator for environmental monitoring in marine and terrestrial habitats
Project funded by an NSERC discovery grant awarded to L. Parrott

One of the key challenges in complexity science is the development of appropriate measures of complexity. A number of projects in our lab are focused on the modification of existing techniques, or the development of new methods, for the characterisation of complexity in ecological data. For example, Francis Meloche (M.Sc. student) has applied a series of information-based measures to time series from different Boreal ecosystems. A recent article (Parrott, 2005) describes a new mesure that can be used to describe the complexity of spatiotemporal data. As a follow-up to this article, members of the lab have developed a new suite of tools suitable for the analysis of spatiotemporal data in ecology (Parrott, 2010; Parrott et al., 2008). We have applied these meaures to a wide range of data, including underwater images of coral reefs and repeat photography series taken in the forest understory, and found a good correlation between habitat complexity and specific diversity.

Climate-vegetation interactions in the Canadian Boreal Region: Effects of land-use scenarios on environmental goods and services in the context of climate change
Project funded by NSERC grants awarded to L. Parrott & N. Ramunkutty (McGill U.) and NSERC and McGill University scholarships awarded to J.S. Landry

The overall scientific question of this project is to quantify how different land use scenarios could impact the internal dynamics of the Canadian boreal forest and its relationship with climate. Land use scenarios are internally consistent descriptions of plausible futures and their implications for land use. The project will include three objectives. First, develop different scenarios of current and plausible future land use activities including traditional forestry, tree plantations for biofuels, agriculture, and protected areas. Second, use a process-based ecosystem model to simulate the interactions of land use with natural disturbances (fires, insects) and logging. The impacts on climate will be evaluated through the contributions to carbon fluxes, modified albedo, and modified evapotranspiration. Third, assess the trade-offs between different land use activities in the boreal forest, and optimize the spatial localization of land use to manage the trade-offs. Carbon capture, biophysical impact on climate, contribution to biofuels production, as well as timber and agricultural production, will be the main objectives of the optimization process. This project should improve the understanding of the consequences of different land use activities in the Canadian boreal region and lead to the identification of possible pathways to manage the trade-offs between the different environmental goods and services provided by this important ecosystem. This project is being carried out by Jean-Sébastien Landry (PhD student), in collaboration with Navin Ramankutty (Geography, McGill University).

Modelling hydrological processes and stream salamander population dynamics on Covey Hill, QC: Perspectives for habitat conservation in the context of climate change
Project funded by the OURANOS consortium (PACC-26) in collaboration with the Ministry for Natural Resources and Fauna (MRNF) and the Ministry for Sustainable Development, Environment and Parks (MDDEP). Researchers: Marie Larocque (UQAM), Lael Parrott (U. Montréal), David Green (Redpath Museum, McGill U.), Martin Lavoie (U. Laval), Stéphanie Pellerin (U. Montréal-IRBV)

The overall objective of this project is to use ecological and hydrological modeling to recommend conservation strategies to promote resilience of the ecosystem of Covey Hill in the presence of climate change. The hill is home to the mountain dusky salamander (threatened) and the spring salamander (a rare species). The specific objectives are 1) to develop a groundwater flow model reflecting recent climate variability as well as key periods of paleoclimate conditions to quantify the current dynamics of salamander habitats, 2) simulate the dynamics of recent populations of salamanders, 3) to quantify changes in hydrological conditions and salamander populations in response to climate change and 4) to recommend measures for land conservation to mitigate the impacts of climate change on hydrology and salamander habitat of Covey Hill. This project will provide concrete recommendations to the MNRF and MDDEP for conservation in the region of Covey Hill in order to protect salamander populations. Philippe Girard (postdoctoral fellow) is currently working on this project, in collaboration with other team members at UQAM and U. Laval.

Some of our past research projects:

Modelling dynamical ecological networks

An ecosystem can be represented as a network in which each node represents a species or a resource in the environment. Links in the network represent the strength of the interactions (which can be a positive, negative or null value) between nodes. Equations describing the nature of these interactions and their effects on the abundance of each species or resource can be used to simulate the overall dynamics of the network. Two doctoral students in the lab (Élise Larose-Filotas and Pascal Côté) have developed novel methods of modelling the dynamics of ecological networks in a spatial context and have applied their models to the study of species co-evolution and community assembly. This project is being carried out in collaboration with Martin Grant (Physics, McGill University) and Per Rikvold (Physics, University of Florida).

SFMN GeoSearch: The Sustainable Forestry Management Network Geographic Searchable Database

This project in ecological informatics consisted of building a forestry-oriented data sharing and vizualisation system for the Sustainable Forestry Management Network (SFMN), a pan-Canada scientific network of about 180 researchers. The system allows members of the network to post, visualise (geographically or not), share and discuss field data with as much ease as possible, permitting better communication of data and results among researchers. The project was financed by the SFMN, and was undertaken in collaboration with Jeffrey Cardille (Géographie, UdeM). Click here to go to the GeoSearch project web site.

The WIST model

Much of our simulation work has been based on the model WIST (Weather driven, Individual-based, Spatially explicit, Terrestrial ecosystem model) which is still under continued development by members of the research team. WIST is a generally configurable, multi-species ecosystem model that demonstrates spatiotemporal self-organisation and other complex dynamical features in simulated systems. We have applied WIST to the study of the relationship between complexity (spatial, temporal and structural) and disturbance frequency in ecosystems and to study the factors contributing to successful colonisation of invasive species in a community. For more information on the WIST model, click here.

Individual-based forest stand modelling with TRAGIC++

This project on individual-based forest stand modelling with the model TRAGIC++ (Tree Response to Acidification in Groundwater Catchments) was undertaken in collaboration with the ecological modelling research team at the University of Bayreuth, Germany and the Norwegian Forest Research Institute (Skogforsk, As, Norway). Our work was focused on the characterisation of spatial structure in simulated and natural stands arising from inter-tree competition. More about TRAGIC can be found at the University of Bayreuth web site.

Relationship between complexity and ecological integrity in forest ecosystems

Raphaël Proulx, PhD student, demonstrated that measures of complexity applied to images of forest scenes can serve as ecological indicators, appropriately capturing the state and dynamics of forest habitat. He has also demonstrated the effects of changing scale on measures of spatial complexity. This work is has been published in Ecological Complexity and Ecological Indicators.

Structural complexity: The Mont St. Hilaire food web project

The study of food web structure is one way to gain insight into the structural complexity of an ecosystem. In this project, started in 2002, we applied measures based on the analysis of complex networks to the study of the food web of Mont St. Hilaire. This food web, which contains 906 taxonomic species, was constructed by members of our lab and is amongst the most highly resolved food webs reported in the literature. Our work was published in the Bulletin of Mathematical Biology. For more information, consult the project web site.

Relating complexity and ecological diversity

Raphaël Proulx, doctoral student in the lab, used repeat digital photography to explore the link between the structural complexity of an ecosystem and its diversity. This project involved taking photographs as well as vegetation censuses on Mont St. Hilaire over 2 growing seasons. Véronique Tremblay, NSERC undergraduate bursary student, assisted with fieldwork and image analysis. The work is published in the journal Ecological Indicators.