, Volume 10, Issue 3, pp 448–461

Spatial Graphs: Principles and Applications for Habitat Connectivity

  • Andrew Fall
  • Marie-Josée Fortin
  • Micheline Manseau
  • Dan O’Brien

DOI: 10.1007/s10021-007-9038-7

Cite this article as:
Fall, A., Fortin, MJ., Manseau, M. et al. Ecosystems (2007) 10: 448. doi:10.1007/s10021-007-9038-7


Well-founded methods to assess habitat connectivity are essential to inform land management decisions that include conservation and restoration goals. Indeed, to be able to develop a conservation plan that maintains animal movement through a fragmented landscape, spatial locations of habitat and paths among them need to be represented. Graph-based approaches have been proposed to determine paths among habitats at various scales and dispersal movement distances, and balance data requirements with information content. Conventional graphs, however, do not explicitly maintain geographic reference, reducing communication capacity and utility of other geo-spatial information. We present spatial graphs as a unifying theory for applying graph-based methods in a geographic context. Spatial graphs integrate a geometric reference system that ties patches and paths to specific spatial locations and spatial dimensions. Arguably, the complete graph, with paths between every pair of patches, may be one of the most relevant graphs from an ecosystem perspective, but it poses challenges to compute, process and visualize. We developed Minimum Planar Graphs as a spatial generalization of Delaunay triangulations to provide a reasonable approximation of complete graphs that facilitates visualization and comprehension of the network of connections across landscapes. If, as some authors have suggested, the minimum spanning tree identifies the connectivity “backbone” of a landscape, then the Minimum Planar Graph identifies the connectivity “network”. We applied spatial graphs, and in particular the Minimum Planar Graph, to analyze woodland caribou habitat in Manitoba, Canada to support the establishment of a national park.

Key words

landscape modelingwoodland cariboupatchVoronoiDelaunay triangulationleast-cost path

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Andrew Fall
    • 1
    • 5
  • Marie-Josée Fortin
    • 2
  • Micheline Manseau
    • 3
  • Dan O’Brien
    • 4
  1. 1.School of Resource and Environmental ManagementSimon Fraser UniversityBurnabyCanada
  2. 2.Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoCanada
  3. 3.Parks CanadaWinnipegCanada
  4. 4.Cortex ConsultantsVictoriaCanada
  5. 5.VictoriaCanada