Uncertainty analysis of least-cost modeling for designing wildlife linkages

Paul Beier, Daniel R. Majka, Shawn L. Newell

Research output: Contribution to journalArticle

115 Citations (Scopus)

Abstract

Least-cost models for focal species are widely used to design wildlife corridors. To evaluate the least-cost modeling approach used to develop 15 linkage designs in southern California, USA, we assessed robustness of the largest and least constrained linkage. Species experts parameterized models for eight species with weights for four habitat factors (land cover, topographic position, elevation, road density) and resistance values for each class within a factor (e.g., each class of land cover). Each model produced a proposed corridor for that species. We examined the extent to which uncertainty in factor weights and class resistance values affected two key conservation-relevant outputs, namely, the location and modeled resistance to movement of each proposed corridor. To do so, we compared the proposed corridor to 13 alternative corridors created with parameter sets that spanned the plausible ranges of biological uncertainty in these parameters. Models for five species were highly robust (mean overlap 88%, little or no increase in resistance). Although the proposed corridors for the other three focal species overlapped as little as 0% (mean 58%) of the alternative corridors, resistance in the proposed corridors for these three species was rarely higher than resistance in the alternative corridors (mean difference was 0.025 on a scale of 1-10; worst difference was 0.39). As long as the model had the correct rank order of resistance values and factor weights, our results suggest that the predicted corridor is robust to uncertainty. The three carnivore focal species, alone or in combination, were not effective umbrellas for the other focal species. The carnivore corridors failed to overlap the predicted corridors of most other focal species and provided relatively high resistance for the other focal species (mean increase of 2.7 resistance units). Least-cost modelers should conduct uncertainty analysis so that decision-makers can appreciate the potential impact of model uncertainty on conservation decisions. Our approach to uncertainty analysis (which can be called a worst-case scenario approach) is appropriate for complex models in which distribution of the input parameters cannot be specified.

Original languageEnglish (US)
Pages (from-to)2067-2077
Number of pages11
JournalEcological Applications
Volume19
Issue number8
DOIs
StatePublished - Dec 2009

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uncertainty analysis
cost
modeling
carnivore
wildlife
corridor
land cover
road

Keywords

  • Connectivity
  • Conservation planning
  • Focal species
  • Least-cost modeling
  • Permeability
  • Umbrella species
  • Uncertainty analysis
  • Wildland linkage
  • Wildlife corridor

ASJC Scopus subject areas

  • Ecology

Cite this

Uncertainty analysis of least-cost modeling for designing wildlife linkages. / Beier, Paul; Majka, Daniel R.; Newell, Shawn L.

In: Ecological Applications, Vol. 19, No. 8, 12.2009, p. 2067-2077.

Research output: Contribution to journalArticle

Beier, Paul ; Majka, Daniel R. ; Newell, Shawn L. / Uncertainty analysis of least-cost modeling for designing wildlife linkages. In: Ecological Applications. 2009 ; Vol. 19, No. 8. pp. 2067-2077.
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