Jeffrey A. Cardille

Monitoring Canada’s forests. Part 2: National forest fragmentation and pattern

Canada is one of the world’s largest nations, with a land area of nearly one billion hectares. This vast area is home to a number of unique ecosystems, comprised of different climate, land cover, topography, and disturbance characteristics. Depiction of forest composition, based on satellite-derived land cover, is a common means to characterize and identify trends in forest conditions and land use. Forest pattern analyses that consider the size, distribution, and connectivity of forest patches can provide insights to land use, habitat, and biodiversity. In this communication, we present the pattern characteristics of Canada’s forests as determined by the Earth Observation for Sustainable Development of Forests (EOSD) product, a new land cover classification of the forested area of Canada. The EOSD product (EOSD LC 2000) represents conditions circa the year 2000, mapping each 25 m × 25 m pixel into one of 23 categories. We used the EOSD data to assess forest patterns nationally at four spatial extents: level 1, 13 000 km2 (corresponding to the area of a single 1:250 000 scale National Topographic System (NTS) map sheet); level 2, 800 km2 (corresponding to the area of a single 1:50 000 scale NTS map sheet); level 3, 1 km2; and level 4, 1 ha. For levels 1–3, a total of 95 landscape pattern metrics were calculated; for the 1 ha units, a subset of eight metrics were calculated. The results of this analysis indicate that Canada’s forest pattern varies by ecozone, with some ecozones characterized by large areas of contiguous forest (i.e., Boreal Shield, Atlantic Maritime, and Montane Cordillera), while other ecozones have less forest and are characterized by large numbers of small forest patches, reflecting the complex mosaic of land cover types present (Taiga Shield, Taiga Cordillera). Trends for the subset of metrics used to characterize national conditions are relatively consistent across levels 1-3. Level 4 metrics, where the analysis extent is 1 ha, are well-suited to regional or local analyses. As the first regional assessments of the patterns contained in the EOSD LC 2000, these measures of Canada’s forest landscape patterns add value to the national land cover baseline.

From the redwood forest to the Gulf Stream waters: human signature nearly ubiquitous in representative US landscapes

What landscapes best represent the land uses and land covers (LU/LC) of the continental United States? Would the set include a cornfield? A forest? A backyard? Combining principles of landscape ecology and computer science, we identified a small set of “exemplar landscapes”, representing distinct LU/LC pattern types of the conterminous US. We first partitioned the 1992 US National Land Cover Dataset into 193 705 landscapes, and quantified patterns with standard measures of LU/LC composition and configuration. Using the values to estimate similarity of LU/LC patterns between landscapes, we applied an algorithm developed to find representatives in large sets. In the resulting 17-member set of exemplar landscapes, patterns created and managed by human activity are by far the most evident features. This set of representatives summarizes the nations LU/LC, demonstrating the degree to which human-influenced patterns dominate: aggregations of rectangular fields, farmlands within cleared forests, shrublands/past...

Applying Circuit Theory for Corridor Expansion and Management at Regional Scales: Tiling, Pinch Points, and Omnidirectional Connectivity

Connectivity models are useful tools that improve the ability of researchers and managers to plan land use for conservation and preservation. Most connectivity models function in a point-to-point or patch-to-patch fashion, limiting their use for assessing connectivity over very large areas. In large or highly fragmented systems, there may be so many habitat patches of interest that assessing connectivity among all possible combinations is prohibitive. To overcome these conceptual and practical limitations, we hypothesized that minor adaptation of the Circuitscape model can allow the creation of omnidirectional connectivity maps illustrating flow paths and variations in the ease of travel across a large study area. We tested this hypothesis in a 24,300 km2 study area centered on the Montérégie region near Montréal, Québec. We executed the circuit model in overlapping tiles covering the study region. Current was passed across the surface of each tile in orthogonal directions, and then the tiles were reassembled to create directional and omnidirectional maps of connectivity. The resulting mosaics provide a continuous view of connectivity in the entire study area at the full original resolution. We quantified differences between mosaics created using different tile and buffer sizes and developed a measure of the prominence of seams in mosaics formed with this approach. The mosaics clearly show variations in current flow driven by subtle aspects of landscape composition and configuration. Shown prominently in mosaics are pinch points, narrow corridors where organisms appear to be required to traverse when moving through the landscape. Using modest computational resources, these continuous, fine-scale maps of nearly unlimited size allow the identification of movement paths and barriers that affect connectivity. This effort develops a powerful new application of circuit models by pinpointing areas of importance for conservation, broadening the potential for addressing intriguing questions about resource use, animal distribution, and movement.

Representative Landscapes in the Forested Area of Canada

Canada is a large nation with forested ecosystems that occupy over 60% of the national land base, and knowledge of the patterns of Canada’s land cover is important to proper environmental management of this vast resource. To this end, a circa 2000 Landsat-derived land cover map of the forested ecosystems of Canada has created a new window into understanding the composition and configuration of land cover patterns in forested Canada. Strategies for summarizing such large expanses of land cover are increasingly important, as land managers work to study and preserve distinctive areas, as well as to identify representative examples of current land-cover and land-use assemblages. Meanwhile, the development of extremely efficient clustering algorithms has become increasingly important in the world of computer science, in which billions of pieces of information on the internet are continually sifted for meaning for a vast variety of applications. One recently developed clustering algorithm quickly groups large numbers of items of any type in a given data set while simultaneously selecting a representative—or “exemplar”—from each cluster. In this context, the availability of both advanced data processing methods and a nationally available set of landscape metrics presents an opportunity to identify sets of representative landscapes to better understand landscape pattern, variation, and distribution across the forested area of Canada. In this research, we first identify and provide context for a small, interpretable set of exemplar landscapes that objectively represent land cover in each of Canada’s ten forested ecozones. Then, we demonstrate how this approach can be used to identify flagship and satellite long-term study areas inside and outside protected areas in the province of Ontario. These applications aid our understanding of Canada’s forest while augmenting its management toolbox, and may signal a broad range of applications for this versatile approach.

Multipurpose habitat networks for short-range and long-range connectivity: a new method combining graph and circuit connectivity

Summary Biodiversity conservation in landscapes undergoing climate and land-use changes requires designing multipurpose habitat networks that connect the movements of organisms at multiple spatial scales. Short-range connectivity within habitat networks provides organisms access to spatially distributed resources, reduces local extinctions and increases recolonization of habitat fragments. Long-range connectivity across habitat networks facilitates annual migrations and climate-driven range shifts. We present a method for identifying a multipurpose network of forest patches that promotes both short- and long-range connectivity. Our method uses both graph-theoretic analyses that quantify network connectedness and circuit-based analyses that quantify network traversability as the basis for identifying spatial conservation priorities on the landscape. We illustrate our approach in the agroecosystem, bordered by the Laurentian and Appalachian mountain ranges, that surrounds the metropolis of Montreal, Canada. We established forest conservation priorities for the ovenbird, a Neotropical migrant, sensitive to habitat fragmentation that breeds in our study area. All connectivity analyses were based on the same empirically informed resistance surface for ovenbird, but habitat pixels that facilitated short- and long-range connectivity requirements had low spatial correlation. The trade-off between connectivity requirements in the final ranking of conservation priorities showed a pattern of diminishing returns such that beyond a threshold, additional conservation of long-range connectivity had decreased effectiveness on the conservation of short-range connectivity. Highest conservation priority was assigned to a series of stepping stone forest patches across the study area that promote traversability between the bordering mountain ranges and to a collection of small forest fragments scattered throughout the study area that provide connectivity within the agroecosystem. Landscape connectivity is important for the ecology and genetics of populations threatened by climate change and habitat fragmentation. Our method has been illustrated as a means to conserve two critical dimensions of connectivity for a single species, but it is designed to incorporate a variety of connectivity requirements for many species. Our approach can be tailored to local, regional and continental conservation initiatives to protect essential species movements that will allow biodiversity to persist in a changing climate.

Remote sensing of lake CDOM using noncontemporaneous field data

There are perhaps millions of lakes in Canada, and remote sensing is a crucial tool for making regional estimates of carbon stocks. Estimation using existing platforms has been hampered by both spatial and spectral resolution, but a new generation of sensors promises greatly improved image quality with broad-scale repeat coverage. Nearly all remote sensing studies in aquatic environments include carefully coordinated field campaigns with satellite overpasses, but this greatly limits the number of lakes that can be used in model development. We explored the opportunities and limits for combining high-quality Advanced Land Imager imagery with legacy lake samples to estimate colored dissolved organic matter (CDOM), a lake characteristic of high value in constructing lake carbon budgets. The passage of time produces somewhat greater scatter than in the standard model with timed field campaign, but there is no indication of a bias toward an incorrect model when using field samples from a variety of dates. Because many thousands of older field samples exist for Canadian lakes, existing limnological databases hold considerable value for estimating CDOM from satellite with sensors of sufficient radiometric depth and signal quality. This study reveals a substantial opportunity for creating and refining estimates of fundamental lake parameters in one of the worlds great storehouses of aquatic carbon.

Agent-based land-use models and farming games on the social web—Fertile ground for a collaborative future?

Abstract Each day, millions of people from all walks of life use agent-based simulation models of land use. Preparing land, finding seeds, tending crops, responding to the lands needs—across the planet, human players simulate many of the same choices faced by the worlds real-life farmers. These millions, though using simulation models, do not pursue their agricultural goals for an academic purpose. Rather, driven by human curiosity and the desire to connect to others, they are playing computer games with names like “Farmville”, “Happy Farm”, and “Farm Town.” Using the rapidly emerging social media framework, these are among the most popular games devised in all of human history. Meanwhile, academics labour to schedule playing sessions for their carefully crafted real-world land-use simulation models. What if these two worlds could be combined, with millions of people acting as agents in academically informative land-use models? This paper compares the characteristics of the worlds most popular social media farming games to agent-based agricultural land use models produced in academia. We describe how the multiplayer aspect of social media games can inform and improve existing scientific models, and propose a framework for merging these technologies to create “massively multi-player land use models”, or MMLUMs. Such models require no significant technical breakthroughs, but rather a reconception of the representation of space and of player management that already is present in academic models. Accessed by millions through social media, such hybrid academic/gaming models could quickly make significant contributions to scientific understanding of agricultural land use dynamics. More broadly, a functioning MMLUM game, even if only moderately successful by online gaming standards, could help researchers from many fields address a very wide host of vital questions about Earths future.

ASSESSING LAND SUITABILITY FOR RESIDENTIAL DEVELOPMENT IN PERMAFROST REGIONS: A MULTI-CRITERIA APPROACH TO LAND-USE PLANNING IN NORTHERN QUEBEC, CANADA

Northern Quebec (Nunavik) presents an important intersection between population growth and climate change. The Inuit population of Nunavik has the fastest growth rate in any region of Canada. Land-use planning is an urgent and pressing need for northern communities built on permafrost, where there are considerable risks to development in areas where permafrost may thaw. As northern communities work to adapt to climate changes, they will be in great need of confident recommendations about locations of future development projects. This paper presents a case-study of the community of Tasiujaq and assesses the probability of thaw settlement of the surface, a process seriously affecting infrastructure stability. A method is developed for quantifying uncertainty in the resulting map, expressed as a function of judgmentbased uncertainty in the various factors that can influence eventual map quality. The best estimate of vulnerability and of the confidence in that estimate can be expressed in a single, simple map that allows an analyst to convey both of these vital aspects of the assessment process.

SFMN GeoSearch: An interactive approach to the visualization and exchange of point-based ecological data

Abstract Recent advances in computer networks and information technologies have created exciting new possibilities for sharing and analyzing scientific research data. Although individual datasets can be studied efficiently, many scientists are still largely limited to considering data collected by themselves, their students, or closely affiliated research groups. Increasingly widespread high-speed network connections and the existence of large, coordinated research programs suggest the potential for scientists to access and learn from data from outside their immediate research circle. We are developing a web-based application that facilitates the sharing of scientific data within a research network using the now-common “virtual globe” in combination with advanced visualization methods designed for geographically distributed scientific data. Two major components of the system enable the rapid assessment of geographically distributed scientific data: a database built from information submitted by network members, and a module featuring novel and sophisticated geographic data visualization techniques. By enabling scientists to share results with each other and view their shared data through a common virtual-globe interface, the system provides a new platform for important meta-analyses and the analysis of broad-scale patterns. Here we present the design and capabilities of the SFMN GeoSearch platform for the Sustainable Forest Management Network, a pan-Canadian network of forest researchers who have accumulated data for more than a decade. Through the development and dissemination of this new tool, we hope to help scientists, students, and the general public to understand the depth and breadth of scientific data across potentially large areas.

Forest Connectivity Regions of Canada Using Circuit Theory and Image Analysis.

Ecological processes are increasingly well understood over smaller areas, yet information regarding interconnections and the hierarchical nature of ecosystems remains less studied and understood. Information on connectivity over large areas with high resolution source information provides for both local detail and regional context. The emerging capacity to apply circuit theory to create maps of omnidirectional connectivity provides an opportunity for improved and quantitative depictions of forest connectivity, supporting the formation and testing of hypotheses about the density of animal movement, ecosystem structure, and related links to natural and anthropogenic forces. In this research, our goal was to delineate regions where connectivity regimes are similar across the boreal region of Canada using new quantitative analyses for characterizing connectivity over large areas (e.g., millions of hectares). Utilizing the Earth Observation for Sustainable Development of forests (EOSD) circa 2000 Landsat-derived land-cover map, we created and analyzed a national-scale map of omnidirectional forest connectivity at 25m resolution over 10000 tiles of 625 km2 each, spanning the forested regions of Canada. Using image recognition software to detect corridors, pinch points, and barriers to movements at multiple spatial scales in each tile, we developed a simple measure of the structural complexity of connectivity patterns in omnidirectional connectivity maps. We then mapped the Circuitscape resistance distance measure and used it in conjunction with the complexity data to study connectivity characteristics in each forested ecozone. Ecozone boundaries masked substantial systematic patterns in connectivity characteristics that are uncovered using a new classification of connectivity patterns that revealed six clear groups of forest connectivity patterns found in Canada. The resulting maps allow exploration of omnidirectional forest connectivity patterns at full resolution while permitting quantitative analyses of connectivity over broad areas, informing modeling, planning and monitoring efforts.