Landscape Ecology

, Volume 26, Issue 5, pp 723–736 | Cite as

Measuring landscape configuration with normalized metrics

  • Xianli Wang
  • Steven G. Cumming
Research Article


Natural and anthropogenic disturbances on natural landscapes reduce the abundance and alter the spatial arrangement of certain habitat types. Measuring and modeling such alterations, and their biological effects, remains challenging in part because many widely used configuration metrics are correlated with habitat amount. In this paper, we consider the sources of such correlation, and distinguish process or sample-based correlation from functional correlation that may be an artifact of the metrics themselves. Process correlation is not necessarily a serious problem for statistical inference, but functional correlation would be. We propose that functional correlation may be reduced by normalizing metrics by habitat abundance. We illustrate with normalized versions of total core area, mean nearest neighbor distance, and mean shape index, and show informally that the standard versions of these metrics should exhibit functional correlation. We evaluate the normalized metrics on samples of harvested and undisturbed forested landscapes, and on simulated landscapes generated with varying degrees of spatial autocorrelation. Normalization markedly reduced correlations with habitat abundance on natural landscapes, but not on simulated landscapes. The reasons for this appear to be a combination of differing variances in metric values within levels of habitat abundance, and of the precise form of the relationships between habitat abundance and the un-normalized metrics. In all cases, the normalization changes the ordering of landscapes by metric values across levels of habitat abundance. In consequence, normalized and standard metrics cannot both be accurate measures of configuration. We conclude that statistical modeling of ecological response data is needed to finally determine the merits of the normalizations.


Boreal forest Forest harvesting Habitat fragmentation Landscape configuration metrics Landscape dynamics Landscape pattern metrics Mean nearest neighbor distance Mean shape index Normalization Total core area 



This research was conducted to support the regional dynamic modeling initiatives of the Boreal Ecology and Economics Synthesis Team (BEEST), a research group funded by the Sustainable Forest Management Network. We thank BEEST members Grant Hauer, Wictor Adamowicz and Robert Jagodzinski for their support and technical assistance, Dr. Tarmo Remmel from York University for providing landscape simulation software, and Drs. Xinsheng Hu, Petro Bakak, Andreas Hamann, and Dan Mazerolle of the Department of Renewable Resources, University of Alberta, for their valuable suggestions and discussions. We thank the two anonymous reviewers for their thorough review and valuable comments and suggestions, which significantly contributed to improving the quality of this paper.


  1. Andren H (1994) Effects of habitat fragmentation on birds and mammals in landscapes with different proportions of suitable habitat—a review. Oikos 71:355–366CrossRefGoogle Scholar
  2. Bender DJ, Contreras TA, Fahrig L (1998) Habitat loss and population decline: a meta-analysis of the patch size effect. Ecology 79:517–533CrossRefGoogle Scholar
  3. Bender DJ, Tischendorf L, Fahrig L (2003) Using patch isolation metrics to predict animal movement in binary landscapes. Landscape Ecol 18:17–39CrossRefGoogle Scholar
  4. Cumming SG, Armstrong GW (2001) Divided land bases and overlapping forest tenure in Alberta, Canada: assimilation study of the costs of forest policy. For Chron 77:501–508Google Scholar
  5. Cumming SG, Vernier P (2002) Statistical models of landscape pattern metrics, with applications to regional scale dynamic forest simulations. Landscape Ecol 17:433–444CrossRefGoogle Scholar
  6. Cushman SA, McGarigal K, Neel MC (2008) Parsimony in landscape metrics: strength, universality, and consistency. Ecol Indic 8:691–703CrossRefGoogle Scholar
  7. Fahrig L (1997) Relative effects of habitat loss and fragmentation on population extinction. J Wildl Manag 61:603–610CrossRefGoogle Scholar
  8. Fahrig L (2003) Effects of habitat fragmentation on biodiversity. Annu Rev Ecol Evol Syst 34:487–515CrossRefGoogle Scholar
  9. Flather CH, Bevers M (2002) Patchy reaction-diffusion and population abundance: the relative importance of habitat amount and arrangement. Am Nat 159:40–56PubMedCrossRefGoogle Scholar
  10. Fortin MJ, Boots B, Csillag F, Remmel TK (2003) On the role of spatial stochastic models in understanding landscape indices in ecology. Oikos 102:203–212CrossRefGoogle Scholar
  11. Freckleton R (2002) On the misuse of residuals in ecology: regression of residuals vs multiple regression. J Anim Ecol 71:542–545CrossRefGoogle Scholar
  12. Golden DM, Crist TO (2000) Experimental effects of habitat fragmentation on rove beetles and ants: patch area or edge? Oikos 90:525–538CrossRefGoogle Scholar
  13. Gustafson EJ (1998) Quantifying landscape spatial pattern: what is the state of the art? Ecosystems 1:143–156CrossRefGoogle Scholar
  14. Gustafson EJ, Parker GR (1992) Relationships between landcover proportion and indexes of landscape spatial pattern. Landscape Ecol 7:101–110CrossRefGoogle Scholar
  15. Hastie TJ, Tibshirani RJ (1990) Generalized additive models. Chapman and Hall, LondonGoogle Scholar
  16. Hauer G, Cumming S, Schmiegelow F, Adamowicz W, Weber M, Jagodzinski R (2010) Tradeoffs between forestry resource and conservation values under alternate policy regimes: a spatial analysis of the western Canadian boreal plains. Ecol Model 221(21):2590–2603CrossRefGoogle Scholar
  17. Jaeger JAG (2000) Landscape division, splitting index, and effective mesh size: new measures of landscape fragmentation. Landscape Ecol 15:115–130CrossRefGoogle Scholar
  18. Koper N, Schmiegelow FKA, Merrill EH (2007) Residuals cannot distinguish between ecological effects of habitat amount and fragmentation: implications for the debate. Landscape Ecol 22:811–820CrossRefGoogle Scholar
  19. Lee P, Gysbers JD, Stanojevic Z (2006) Canada’s forest landscape fragments: a first approximation. A global forest watch Canada report. Global ForestWatch Canada, Edmonton, AlbertaGoogle Scholar
  20. Li HB, Reynolds JF (1993) A new contagion index to quantify spatial patterns of landscapes. Landscape Ecol 8:155–162CrossRefGoogle Scholar
  21. Li HB, Wu JG (2004) Use and misuse of landscape indices. Landscape Ecol 19:389–399CrossRefGoogle Scholar
  22. Linke J, Franklin SE, Huettmann F, Stenhouse GB (2005) Seismic cutlines, changing landscape metrics and grizzly bear landscape use in Alberta. Landscape Ecol 20:811–826CrossRefGoogle Scholar
  23. McGarigal K, Marks BJ (1995) Fragstats: spatial pattern analysis program for quantifying landscape structure, general technical report PNW-GTR-351. US Forest Service Pacific Northwest Research Station, Portland, Oregon, USAGoogle Scholar
  24. McGarigal K, Cushman SA, Neel MC, Ene E (2002) FRAGSTATS: spatial pattern analysis program for categorical maps. University of Massachusetts, Amherst. Massachusetts, USAGoogle Scholar
  25. Moilanen A, Nieminen M (2002) Simple connectivity measures in spatial ecology. Ecology 83:1131–1145CrossRefGoogle Scholar
  26. Neel MC, McGarigal K, Cushman SA (2004) Behavior of class-level landscape metrics across gradients of class aggregation and area. Landscape Ecol 19:435–455CrossRefGoogle Scholar
  27. O’Neill RV, Krummel JR, Gardner RH, Sugihara G, Jackson B, DeAngelis DL, Milne BT, Turner MG, Zygmunt B, Christensen SW, Dale VH, Graham RL (1988) Indices of landscape ecology. Landscape Ecol 1:153–162CrossRefGoogle Scholar
  28. Pearson SM, Gardner RH (1997) Neutral models: useful tools for understanding landscape patterns. In: Bissonette JA (ed) Wildlife and landscaqpe ecology: effects of pattern and scale. Springer, New York, pp 215–230Google Scholar
  29. R Development Core Team (2006) R: a language and environment for statistical computing, reference index version 2.3.1. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-12-7,
  30. Reed WJ (1998) Determining changes in historical forest fire frequency from a time-since-fire map. J Agric Biol Environ Stat 3:430–450CrossRefGoogle Scholar
  31. Remmel TK, Csillag F (2003) When are two landscape pattern indices significantly different? J Geogr Syst 5(4)331–351Google Scholar
  32. Riitters KH, ONeill RV, Wickham JD, Jones KB (1996) A note on contagion indices for landscape analysis. Landscape Ecol 11:197–202CrossRefGoogle Scholar
  33. Robinson SK, Thompson FR, Donovan TM, Whitehead DR, Faaborg J (1995) Regional forest fragmentation and the nesting success of migratory birds. Science 267:1987–1990PubMedCrossRefGoogle Scholar
  34. Roland J, Keyghobadi N, Fownes S (2000) Alpine Parnassius butterfly dispersal: effects of landscape and population size. Ecology 81:1642–1653Google Scholar
  35. Schneider RR, Federation of Alberta Naturalists, Alberta Centre for Boreal Research (2002) Alternative futures: Alberta’s boreal forest at the crossroads. Federation of Alberta Naturalists, EdmontonGoogle Scholar
  36. Smith AC, Koper N, Francis CM, Fahrig L (2009) Confronting collinearity: comparing methods for disentangling the effects of habitat loss and fragmentation. Landscape Ecol 24:1271–1285CrossRefGoogle Scholar
  37. Sokal RR, Rohlf FJ (1995) Biometry: the principles and practice of statistics in biological research. Freeman, New YorkGoogle Scholar
  38. Trzcinski MK, Fahrig L, Merriam G (1999) Independent effects of forest cover and fragmentation on the distribution of forest breeding birds. Ecol Appl 9:586–593CrossRefGoogle Scholar
  39. Turner MG (2005) Landscape ecology in North America: past, present, and future. Ecology 86:1967–1974CrossRefGoogle Scholar
  40. Vernier PR, Schmiegelow FKA, Hannon SJ, Cumming SG (2008) Generalizability of songbird habitat models in boreal mixedwood forests of Alberta. Ecol Model 211:191–201CrossRefGoogle Scholar
  41. Villard MA, Trzcinski MK, Merriam G (1999) Fragmentation effects on forest birds: relative influence of woodland cover and configuration on landscape occupancy. Conserv Biol 13:774–783CrossRefGoogle Scholar
  42. Wang XL, Cumming SG (2009) Modeling configuration dynamics of harvested forest landscapes in the Canadian boreal plains. Landscape Ecol 24:229–241CrossRefGoogle Scholar
  43. Wang XL, Cumming SG (2010) Configuration dynmamics of boreal forest landscapes under recent fire and harvesting regimes in western Canada. Landscape Ecol 25:1419–1432CrossRefGoogle Scholar
  44. Weaver K, Perera AH (2004) Modelling land cover transitions: a solution to the problem of spatial dependence in data. Landscape Ecol 19:273–289CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.Department of Renewable ResourcesUniversity of AlbertaEdmontonCanada
  2. 2.Département des sciences du bois et de la forêtUniversité LavalQuebecCanada

Personalised recommendations