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Using network theory to prioritize management in a desert bighorn sheep metapopulation

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Abstract

Connectivity models using empirically-derived landscape resistance maps can predict potential linkages among fragmented animal and plant populations. However, such models have rarely been used to guide systematic decision-making, such as identifying the most important habitat patches and dispersal corridors to protect or restore in order to maximize regional connectivity. Combining resistance models with network theory offers one means of prioritizing management for connectivity, and we applied this approach to a metapopulation of desert bighorn sheep (Ovis canadensis nelsoni) in the Mojave Desert of the southwestern United States. We used a genetic-based landscape resistance model to construct network models of genetic connectivity (potential for gene flow) and demographic connectivity (potential for colonization of empty habitat patches), which may differ because of sex-biased dispersal in bighorn sheep. We identified high-priority habitat patches and corridors and found that the type of connectivity and the network metric used to quantify connectivity had substantial effects on prioritization results, although some features ranked highly across all combinations. Rankings were also sensitive to our empirically-derived estimates of maximum effective dispersal distance, highlighting the importance of this often-ignored parameter. Patch-based analogs of our network metrics predicted both neutral and mitochondrial genetic diversity of 25 populations within the study area. This study demonstrates that network theory can enhance the utility of landscape resistance models as tools for conservation, but it is critical to consider the implications of sex-biased dispersal, the biological relevance of network metrics, and the uncertainty associated with dispersal range and behavior when using this approach.

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References

  • Adriaensen F, Chardon JP, De Blust G, Swinnen E, Villalba S, Gulinck H, Matthysen E (2003) The application of ‘least-cost’ modelling as a functional landscape model. Landsc Urban Plan 64(4):233–247

    Article  Google Scholar 

  • Albert EM, Fortuna MA, Godoy JA, Bascompte J (2013) Assessing the robustness of networks of spatial genetic variation. Ecol Lett 16:86–93

    Article  PubMed  Google Scholar 

  • Bleich VC, Wehausen JD, Ramey RR II, Rechel JL (1996) Metapopulation theory and mountain sheep: implications for conservation. In: McCullough DR (ed) Metapopulations and wildlife conservation. Island Pres, Covelo

    Google Scholar 

  • Chardon J, Adriaensen F, Matthysen E (2003) Incorporating landscape elements into a connectivity measure: a case study for the Speckled wood butterfly (Pararge aegeria L.). Landscape Ecol 18(6):561–573

    Article  Google Scholar 

  • Chetkiewicz C-LB, Boyce MS (2009) Use of resource selection functions to identify conservation corridors. J Appl Ecol 46(5):1036–1047

    Article  Google Scholar 

  • Crooks KR, Sanjayan MA (2006) Connectivity conservation. Cambridge University Press, Cambridge

    Book  Google Scholar 

  • Cushman SA, McKelvey KS, Hayden J, Schwartz MK (2006) Gene flow in complex landscapes: testing multiple hypotheses with causal modeling. Am Nat 168(4):486–499

    Article  PubMed  Google Scholar 

  • Cushman SA, Chase M, Griffin C (2010) Mapping landscape resistance to identify corridors and barriers for elephant movement in southern Africa. In: Cushman SA, Huettmann F (eds) Spatial complexity, informatics, and wildlife conservation. Springer, Tachikawa, pp 349–367

    Chapter  Google Scholar 

  • Dijkstra EW (1959) A note on two problems in connexion with graphs. Numer Math 1(1):269–271

    Article  Google Scholar 

  • Dyer RJ, Nason JD (2004) Population graphs: the graph theoretic shape of genetic structure. Mol Ecol 13(7):1713–1727

    Article  PubMed  Google Scholar 

  • Epps CW, McCullough DR, Wehausen JD, Bleich VC, Rechel JL (2004) Effects of climate change on population persistence of desert-dwelling mountain sheep in California. Conserv Biol 18(1):102–113

    Article  Google Scholar 

  • Epps CW, Palsbøll PJ, Wehausen JD, Roderick GK, Ramey RR, McCullough DR (2005) Highways block gene flow and cause a rapid decline in genetic diversity of desert bighorn sheep. Ecol Lett 8(10):1029–1038

    Article  Google Scholar 

  • Epps CW, Palsbøll PJ, Wehausen JD, Roderick GK, McCullough DR (2006) Elevation and connectivity define genetic refugia for mountain sheep as climate warms. Mol Ecol 15(14):4295–4302

    Article  PubMed  Google Scholar 

  • Epps CW, Wehausen JD, Bleich VC, Torres SG, Brashares JS (2007) Optimizing dispersal and corridor models using landscape genetics. J Appl Ecol 44(4):714–724

    Article  Google Scholar 

  • Epps CW, Wehausen JD, Palsbøll PJ, McCullough DR (2010) Using genetic tools to track desert bighorn sheep colonizations. J Wildl Manag 74(3):522–531

    Article  Google Scholar 

  • Epps CW, Wasser SK, Keim JL, Mutayoba BM, Brashares JS (2013) Quantifying past and present connectivity illuminates a rapidly changing landscape for the African elephant. Mol Ecol 22(6):1574–1588

    Google Scholar 

  • Fortuna MA, Gómez-Rodríguez C, Bascompte J (2006) Spatial network structure and amphibian persistence in stochastic environments. Proc R Soc B 273(1592):1429–1434

    Article  PubMed Central  PubMed  Google Scholar 

  • Frankham R (2005) Genetics and extinction. Biol Conserv 126(2):131–140

    Article  Google Scholar 

  • Garroway CJ, Bowman J, Carr D, Wilson PJ (2008) Applications of graph theory to landscape genetics. Evol Appl 1(4):620–630

    PubMed Central  Google Scholar 

  • Graves TA, Beier P, Royle JA (2013) Current approaches using genetic distances produce poor estimates of landscape resistance to interindividual dispersal. Mol Ecol 22(15):3888–3903

    Article  PubMed  Google Scholar 

  • Guillot G, Rousset F (2013) Dismantling the Mantel tests. Methods Ecol Evol 4(4):336–344

    Article  Google Scholar 

  • Hanski I (1994) A practical model of metapopulation dynamics. J Anim Ecol 63(1):151–162

    Article  Google Scholar 

  • Holsinger KE, Weir BS (2009) Genetics in geographically structured populations: defining, estimating and interpreting FST. Nat Rev Genet 10(9):639–650

    Article  PubMed  CAS  Google Scholar 

  • Hoyle M, James M (2005) Global warming, human population pressure, and viability of the world’s smallest butterfly. Conserv Biol 19(4):1113–1124

    Article  Google Scholar 

  • Jordán F, Báldi A, Orci KM, Rácz I, Varga Z (2003) Characterizing the importance of habitat patches and corridors in maintaining the landscape connectivity of a Pholidoptera transsylvanica (Orthoptera) metapopulation. Landscape Ecol 18(1):83–92

    Article  Google Scholar 

  • Krausman PR, Sandoval AV, Etchberger RC (1999) Natural history of desert bighorn sheep. In: Valdez R, Krausman PR (eds) Mountain Sheep of North America. University of Arizona Press, Tucson

    Google Scholar 

  • Laita A, Kotiaho J, Mönkkönen M (2011) Graph-theoretic connectivity measures: what do they tell us about connectivity? Landscape Ecol 26(7):951–967

    Article  Google Scholar 

  • Levins R (1969) Some demographic and genetic consequences of environmental heterogeneity for biological control. Bull ESA 15(3):237–240

    Google Scholar 

  • Lookingbill TR, Gardner RH, Ferrari JR, Keller CE (2010) Combining a dispersal model with network theory to assess habitat connectivity. Ecol Appl 20(2):427–441

    Article  PubMed  Google Scholar 

  • Lovich JE, Ennen JR (2011) Wildlife conservation and solar energy development in the desert southwest, United States. BioScience 61(12):982–992

    Article  Google Scholar 

  • McRae BH, Beier P (2007) Circuit theory predicts gene flow in plant and animal populations. Proc Natl Acad Sci 104(50):19885–19890

    Article  PubMed Central  PubMed  Google Scholar 

  • McRae BH, Dickson BG, Keitt TH, Shah VB (2008) Using circuit theory to model connectivity in ecology, evolution, and conservation. Ecology 89(10):2712–2724

    Article  PubMed  Google Scholar 

  • McRae BH, Hall SA, Beier P, Theobald DM (2012) Where to restore ecological connectivity? Detecting barriers and quantifying restoration benefits. PLoS One 7(12):e52604

    Google Scholar 

  • Mills L (2007) Conservation of wildlife populations: demography, genetics, and management. Blackwell Publishing, Malden

    Google Scholar 

  • Minor ES, Urban DL (2007) Graph theory as a proxy for spatially explicit population models in conservation planning. Ecol Appl 17(6):1771–1782

    Article  PubMed  Google Scholar 

  • Moilanen A (2011) On the limitations of graph-theoretic connectivity in spatial ecology and conservation. J Appl Ecol 48(6):1543–1547

    Article  Google Scholar 

  • Moilanen A, Smith Andrew T, Hanski I (1998) Long-term dynamics in a metapopulation of the American pika. Am Nat 152(4):530–542

    Article  PubMed  CAS  Google Scholar 

  • Opsahl T, Agneessens F, Skvoretz J (2010) Node centrality in weighted networks: generalizing degree and shortest paths. Social Netw 32(3):245–251

    Article  Google Scholar 

  • Parks SA, McKelvey KS, Schwartz MK (2012) Effects of weighting schemes on the identification of wildlife corridors generated with least-cost methods. Conserv Biol 27:145–154

    Article  PubMed  Google Scholar 

  • Pascual-Hortal L, Saura S (2006) Comparison and development of new graph-based landscape connectivity indices: towards the prioritization of habitat patches and corridors for conservation. Landscape Ecol 21(7):959–967

    Article  Google Scholar 

  • Perez-Espona S, Perez-Barberia FJ, McLeod JE, Jiggins CD, Gordon IJ, Pemberton JM (2008) Landscape features affect gene flow of Scottish Highland red deer (Cervus elaphus). Mol Ecol 17(4):981–996

    Article  PubMed  CAS  Google Scholar 

  • Reed DH, Frankham R (2003) Correlation between fitness and genetic diversity. Conserv Biol 17(1):230–237

    Article  Google Scholar 

  • Rozenfeld AF, Arnaud-Haond S, Hernández-García E, Eguíluz VM, Serrão EA, Duarte CM (2008) Network analysis identifies weak and strong links in a metapopulation system. Proc Natl Acad Sci 105(48):18824–18829

    Article  PubMed Central  PubMed  Google Scholar 

  • Sawyer SC, Epps CW, Brashares JS (2011) Placing linkages among fragmented habitats: do least-cost models reflect how animals use landscapes? J Appl Ecol 48(3):668–678

    Article  Google Scholar 

  • Spear SF, Balkenhol N, Fortin M-J, McRae BH, Scribner KIM (2010) Use of resistance surfaces for landscape genetic studies: considerations for parameterization and analysis. Mol Ecol 19(17):3576–3591

    Article  PubMed  Google Scholar 

  • Theobald DM, Reed SE, Fields K, Soulé M (2012) Connecting natural landscapes using a landscape permeability model to prioritize conservation activities in the United States. Conserv Lett 5(2):123–133

    Article  Google Scholar 

  • Torres SG, Bleich VC, Wehausen JD (1994) Status of bighorn sheep in California, 1993. Desert Bighorn Council Trans 38:17–28

    Google Scholar 

  • Urban DL, Minor ES, Treml EA, Schick RS (2009) Graph models of habitat mosaics. Ecol Lett 12(3):260–273

    Article  PubMed  Google Scholar 

  • Wasserman TN, Cushman SA, Littell JS, Shirk AJ, Landguth EL (2012) Population connectivity and genetic diversity of American marten (Martes americana) in the United States northern Rocky Mountains in a climate change context. Conserv Genet 14(2):529–541

    Google Scholar 

  • Wehausen JD (1999) Rapid extinction of mountain sheep populations revisited. Conserv Biol 13(2):378–384

    Article  Google Scholar 

  • Whitlock MC, McCauley DE (1999) Indirect measures of gene flow and migration: FST ≠ 1/(4Nm + 1). Heredity 82(2):117–125

    Google Scholar 

  • Zeller K, McGarigal K, Whiteley A (2012) Estimating landscape resistance to movement: a review. Landscape Ecol 27(6):777–797

    Article  Google Scholar 

Download references

Acknowledgments

Funding for this research was provided by the National Park Service Climate Change Response Program and Oregon State University. We thank David Theobald and two anonymous reviewers for comments that greatly improved the manuscript.

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Authors and Affiliations

  1. Department of Fisheries and Wildlife, Oregon State University, 104 Nash Hall, Corvallis, OR, 97331, USA

    Tyler G. Creech & Clinton W. Epps

  2. National Park Service, Biological Resource Management Division, 1201 Oak Ridge Drive, Fort Collins, CO, 80525, USA

    Ryan J. Monello

  3. White Mountain Research Station, University of California, 3000 E. Line Street, Bishop, CA, 93514, USA

    John D. Wehausen

Authors
  1. Tyler G. Creech
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  2. Clinton W. Epps
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  3. Ryan J. Monello
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  4. John D. Wehausen
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Correspondence to Tyler G. Creech.

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Creech, T.G., Epps, C.W., Monello, R.J. et al. Using network theory to prioritize management in a desert bighorn sheep metapopulation. Landscape Ecol 29, 605–619 (2014). https://doi.org/10.1007/s10980-014-0016-0

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