Article

Article name BROWN BEAR (URSUS ARCTOS) ECOLOGICAL NICHE AND HABITAT SUITABILITY MODELING IN THE SOUTHERN TAIGA SUBZONE USING THE METHOD OF GNESFA
Authors

Sergey S. Ogurtsov, Researcher of the Central Forest State Nature Biosphere Reserve; Russia (172521, Tver region, Nelidovo district, Zapovednyi settlement); e-mail: etundra@mail.ru

Reference to article

Ogurtsov S.S. 2020. Brown bear (Ursus arctos) ecological niche and habitat suitability modeling in the southern taiga subzone using the method of GNESFA. Nature Conservation Research 5(3): 86–113. https://dx.doi.org/10.24189/ncr.2020.034

Electronic supplement. The used ecological-geographical variables and distribution of weights for GNESFA models (Link).

Section Research articles
DOI https://dx.doi.org/10.24189/ncr.2020.034
Abstract

The article presents the results of ecological niche and habitat suitability modelling of Ursus arctos, performed in the Central Forest State Nature Reserve and its buffer zone (Tver region, Russia), using the GNESFA factor analysis method. Briefly discussed are the basic rules for performing such a study, approaches and modelling techniques. The ecological niche was modelled using FANTER, ENFA and MADIFA. The habitat suitability was modelled using Mahalanobis distances analysis. As ecogeographical variables, vegetation indices, morphometric characteristics of the relief, proximity rasters and types of landscape cover were used. The presence points of the species were recorded on permanent routes using a GPS navigator during 2008–2018. As a final result, six models with a different combination of input data (presence points and environmental variables) were selected. As a set of independent test data, we used U. arctos' presence points recorded by the forest rangers and research staff. The scenarios of the influence of utilisation weights on presence points and multicollinearity on variables are separately modelled. The global marginality of the best model was 1.17, while the tolerance was 0.69. The distance to anthropogenic food sources, the NDVI and the projective cover of grasslands made the highest contribution along the marginality axis. In the first three axes of specialisation, coniferous forests, Sphagnum pine (Pinus sylvestris) forests, and the distance to the rivers made the largest contribution. AUC values ranged from 0.66 to 0.73. Values of the continuous Boyce index were from 0.85 to 0.93. The area of the partially violated buffer zone turned out to be more suitable for U. arctos than the inner area of the Central Forest State Nature Reserve. Utilisation weights and the number of ecogeographical variables had a significant impact on the results of all analyses.

Keywords

biotope, Brown bear, Carnivora, ENFA, GIS, HSM, MADIFA, Mahalanobis distances, spatial modelling, Ursidae

Artice information

Received: 05.04.2020. Revised: 19.06.2020. Accepted: 12.07.2020.

The full text of the article
References

Andryuschenko A.Yu., Zhukov A.V. 2016. Scale-dependent effects in structure of the wintering ecological niche of the Mute Swan during wintering in the Gulf of Sivash. Biological Bulletin of Bogdan Khmelnitskiy Melitopol State Pedagogical University 6(3): 234–247. [In Russian]
Austin M. 2007. Species distribution models and ecological theory: a critical assessment and some possible new approaches. Ecological Modelling 200(1–2): 1–19. DOI: 10.1016/j.ecolmodel.2006.07.005
Basille M., Calenge C., Marboutin É., Andersen R., Gaillard J.-M. 2008. Assessing habitat selection using multivariate statistics: some refinements of the ecological-niche factor analysis. Ecological Modelling 211(1–2): 233–240. DOI: 10.1016/j.ecolmodel.2007.09.006
Boyce M.S., Vernier P.R., Nielsen S.E., Schmiegelow F.K.A. 2002. Evaluating resource selection functions. Ecological Modelling 157(2–3): 281–300. DOI: 10.1016/S0304-3800(02)00200-4
Braunisch V., Bollmann K., Graf R.F., Hirzel A.H. 2008. Living on the edge – Modelling habitat suitability for species at the edge of their fundamental niche. Ecological Modelling 214(2–4): 153–167. DOI: 10.1016/j.ecolmodel.2008.02.001
Broennimann O. 2018. Package «ecospat», version 3.0. Spatial Ecology Miscellaneous Methods. 107 p.
Brotons L., Thuiller W., Araujo M.B., Hirzel A.H. 2004. Presence-absence versus presence-only modelling methods for predicting bird habitat suitability. Ecography 27(4): 437–448. DOI: 10.1111/j.0906-7590.2004.03764.x
Browning D., Beaupré S., Duncan L. 2005. Using partitioned Mahalanobis D2(K) to formulate a GIS-based model of timber rattlesnake hibernacula. Journal of Wildlife Management 69(1): 33–44. DOI: 10.2193/0022-541X(2005)069<0033:UPMDTF>2.0.CO;2
Calenge C. 2011. Exploratory analysis of the habitat selection by the wildlife in R: the «adehabitatHS» package. 60 p.
Calenge C. 2020. Package «adehabitatHS», version 0.3.15. Analysis of Habitat Selection by Animals. 67 p.
Calenge C., Basille M. 2008. A general framework for the statistical exploration of the ecological niche. Journal of Theoretical Biology 252(4): 674–685. DOI: 10.1016/j.jtbi.2008.02.036
Calenge C., Darmon G., Basille M., Loison A., Jullien J.-M. 2008. The factorial decomposition of the Mahalanobis distances in habitat selection studies. Ecology 89(2): 555–566. DOI: 10.1890/06-1750.1
Carretero M.A., Sillero N. 2016. Evaluating how species niche modelling is affected by partial distributions with an empirical case. Acta Oecologica 77: 207–216. DOI: 10.1016/j.actao.2016.08.014
Caruso N., Guerisoli M., Luengos Vidal E.M., Castillo D., Casanave E.B., Lucherini M. 2015. Modelling the ecological niche of an endangered population of Puma concolor: First application of the GNESFA method to an elusive carnivore. Ecological Modelling 297: 11–19. DOI: 10.1016/j.ecolmodel.2014.11.004
Cayuela L. 2004. Habitat evaluation for the Iberian wolf Canis lupus in Picos de Europa National Park, Spain. Applied Geography 24(3): 199–215. DOI: 10.1016/j.apgeog.2004.04.003
Chefaoui R.M., Hortal J., Lobo J.M. 2005. Potential distribution modelling, niche characterization and conservation status assessment using GIS tools: a case study of Iberian Copris species. Biological Conservation 122(2): 327–338. DOI: 10.1016/j.biocon.2004.08.005
Cherednichenko O., Gorik V., Borodulina V. 2016. Herb vegetation diversity in the north of Central Forest Reserve (Tver` province, Russia). In: 25th Meeting of European Vegetation Survey. Book of Abstracts. Italy, Roma: Sapienza University. P. 26.
Clark J., Dunn J., Smith K. 1993. A multivariate model of female black bear habitat use for a geographic information system. Journal of Wildlife Management 57(3): 519–526. DOI: 10.2307/3809276
Corsi F., Dupré E., Boitani L. 1999. A large scale model of wolf distribution in Italy for conservation planning. Conservation Biology 13(1): 150–159. DOI: 10.1046/j.1523-1739.1999.97269.x
De Angelo C., Paviolo A., Di Bitetti M. 2011. Differential impact of landscape transformation on pumas (Puma concolor) and jaguars (Panthera onca) in the Upper Paraná Atlantic Forest. Diversity and Distributions 17(3): 422–436. DOI: 10.1111/j.1472-4642.2011.00746.x
Demidov A.A., Kobets A.S., Gritsan Yu.I., Zhukov A.V. 2013. Spatial agricultural ecology and soil recultivation. Dnepropetrovsk: A.L. Svidler Press. 560 p. [In Russian]
Dettki H., Löfstrand R., Edenius L. 2003. Modeling habitat suitability for moose in coastal northern Sweden: empirical vs. process-oriented approaches. Ambio 32(8): 549–556. DOI: 10.1639/0044-7447(2003)032[0549:MHSFMI]2.0.CO;2
Dormann C.F., Elith J., Bacher S., Buchmann C., Carl G., Car­ré G., García Marquéz J.R., Gruber B., Lafourcade B., Leitão P.J., Münkemüller T., McClean C., Osborne P.E., Reineking B., Schröder B., Skidmore A.K., Zurell D., Lautenbach S. 2013. Collinearity: a review of methods to deal with it and a simulation study evaluating their per­formance. Ecography 36(1): 27–46. DOI: 10.1111/j.1600- 0587.2012.07348.x
Dray S., Chessel D., Thioulouse J. 2003. Co-inertia analysis and the linking of ecological data tables. Ecology 84(11): 3078–3089. DOI: 10.1890/03-0178
Elith J., Graham C.H., Anderson P.R., Dudík M., Ferrier S., Guisan A., Hijmans R.J., Huettmann F., Leathwick J.R., Lehmann A., Li J., Lohmann L.G., Loiselle B.A., Manion G., Moritz C., Nakamura M., Nakazawa Y., Overton J.McC.M., Townsend Peterson A., Phillips S.J., Richardson K., Scachetti-Pereira R.K., Schapire R.E., Soberón J., Williams S., Wisz M.S., Zimmermann N.E. 2006. Novel methods improve prediction of species' distributions from occurrence data. Ecography 29(2): 129–151. DOI: 10.1111/j.2006.0906-7590.04596.x
Falcucci A., Ciucci P., Maiorano L., Gentile L., Boitani L. 2009. Assessing habitat quality for conservation using an integrated occurrence-mortality model. Journal of Applied Ecology 46(3): 600–609. DOI: 10.1111/j.1365-2664.2009.01634.x
Farber O., Kadmon R. 2003. Assessment of alternative approaches for bioclimatic modeling with special emphasis on the Mahalanobis distance. Ecological Modelling 160(1–2): 115–130. DOI: 10.1016/S0304-3800(02)00327-7
Fonderflick J., Azam C., Brochier C., Cosson E., Quékenborn D. 2015. Testing the relevance of using spatial modeling to predict foraging habitat suitability around bat maternity: a case study in Mediterranean landscape. Biological Conservation 192: 120–129. DOI: 10.1016/j.biocon.2015.09.012
Gallego D., Cánovas F., Esteve M.A., Galían J. 2004. Descriptive biogeography of Tomicus (Coleoptera: Scolytidae) species in Spain. Journal of Biogeography 31(12): 2011–2024. DOI: 10.1111/j.1365-2699.2004.01131.x
Galparsoro I., Borja Á., Bald J., Liria P., Chust G. 2009. Predicting suitable habitat for the European lobster (Homarus gammarus), on the Basque continental shelf (Bay of Biscay), using Ecological-Niche Factor Analysis. Ecological Modelling 220(4): 556–567. DOI: 10.1016/j.ecolmodel.2008.11.003
Guisan A., Thuiller W., Zimmermann N.E. 2017. Habitat suitability and distribution models. Cambridge: Cambridge University Press. 462 p.
Guisan A., Zimmermann N.E. 2000. Predictive habitat distribution models in ecology. Ecological Modelling 135(2–3): 147–186. DOI: 10.1016/S0304-3800(00)00354-9
Halstead B.J., Wylie G.D., Casazza M.L. 2010. Habitat Suitability and Conservation of the Giant Gartersnake (Thamnophis gigas) in the Sacramento Valley of California. Copeia 4: 591–599. DOI: 10.1643/CE-09-199
Hanley J.A., McNeil B.J. 1982. The meaning and use of the area under a receiver operating characteristic (ROC) curve. Radiology 143(1): 29–36. DOI: 10.1148/radiology.143.1.7063747
Hemery L., Galton-Fenzi B., Améziane N., Riddle M., Rintoul S., Beaman R., Post A., Eléaume M. 2011. Predicting habitat preferences for Anthometrina adriani (Echinodermata) on the East Antarctic continental shelf. Marine Ecology Progress Series 441: 105–116. DOI: 10.3354/meps09330
Hirzel A.H., Hausser J., Chessel D., Perrin N. 2002. Ecological-niche factor analysis: how to compute habitat-suitability maps without absence data? Ecology 83(7): 2027–2036. DOI: 10.1890/0012-9658(2002)083[2027:ENFAHT]2.0.CO;2
Hirzel A.H., Posse B., Oggier P.A., Crettenand Y., Glenz C., Arlettaz R. 2004a. Ecological requirements of reintroduced species and the implications for release policy: the case of the bearded vulture. Journal of Applied Ecology 41(6): 1103–1116. DOI: 10.1111/j.0021-8901.2004.00980.x
Hirzel A.H., Hausser J., Perrin N. 2004b. Biomapper 3.1. Division of Conservation Biology. Bern: University of Bern. Available from http://www.unil.ch/biomapper
Hirzel A.H., Le Lay G., Helfer V., Randin C., Guisan A. 2006. Evaluating the ability of habitat suitability models to predict species presences. Ecological Modelling 199(2): 142–152. DOI: 10.1016/j.ecolmodel.2006.05.017
Hirzel A.H., Le Lay G. 2008. Habitat suitability modelling and niche theory. Journal of Applied Ecology 45(5): 1372–1381. DOI: 10.1111/j.1365-2664.2008.01524.x
Hutchinson G.E. 1957. Concluding remarks. Cold Spring Harbour Symposium on Quantitative Biology 22: 415–427. DOI: 10.1101/SQB.1957.022.01.039
Isachenko T.I. 1980. South taiga forests. In: Vegetation of the European part of the USSR. Leningrad: Nauka. P. 93–96. [In Russian]
Jackson D.A. 1993. Stopping rules in principal components analysis: a comparison of heuristical and statistical approaches. Ecology 74(8): 2204–2214. DOI: 10.2307/1939574
Kassambara A., Mundt F. 2020. Package «factoextra», version 1.0.7. Extract and Visualize the Results of Multivariate Data Analyses. 84 p.
Keitt T. 2015. Package «colorRamps», version 2.3. Builds color tables. 9 p.
Knick S., Dyer D. 1997. Distribution of black-tailed jackrabbit habitat determined by GIS in southwestern Idaho. Journal of Wildlife Management 61(1): 75–85. DOI: 10.2307/3802416
Lobo J.M, Jiménez-Valverde A., Hortal J. 2010. The uncertain nature of absences and their importance in species distribution modelling. Ecography 33(1): 103–114. DOI: 10.1111/j.1600-0587.2009.06039.x
Manly B.F., McDonald L.L., Thomas D.L., MacDonald T.L., Erickson W.P. 2002. Resource selection by animals. Statistical design and analysis for field studies. London: Kluwer Academic Publisher. 222 p. DOI: 10.1007/0-306-48151-0
Martin J., Revilla E., Quenette P.-Y., Naves J., Allainé D., Swenson J.E. 2012. Brown bear habitat suitability in the Pyrenees: transferability across sites and linking scales to make the most of scarce data. Journal of Applied Ecology 49(3): 621–631. DOI: 10.1111/j.1365-2664.2012.02139.x
Mertzanis G., Kallimanis A.S., Kanellopoulos N., Sgardelis S.P., Tragos A., Aravidis I. 2008. Brown bear (Ursus arctos L.) habitat use patterns in two regions of northern Pindos, Greece – management implications. Journal of Natural History 42(5–8): 301–315. DOI: 10.1080/00222930701835175
Mestre F.M., Ferreira J.P., Mira A. 2007. Modelling the distribution of the european polecat Mustela putorius in a Mediterranean agricultural landscape. Revue d Écologie (Terre Vie) 62(1): 35–47.
Milanesi P. 2014. Landscape ecology and genetics of the wolf in Italy. PhD Thesis. Bologna: Università di Bologna. 126 p.
Milanesi P., Caniglia R., Fabbri E., Galaverni M., Meriggi A., Randi E. 2015. Non-invasive genetic sampling to predict wolf distribution and habitat suitability in the Northern Italian Apennines: implications for livestock depredation risk. European Journal of Wildlife Research 61(5): 681–689. DOI: 10.1007/s10344-015-0942-4
Nawaz M.A., Martin J., Swenson J.E. 2014. Identifying key habitats to conserve the threatened brown bear in the Himalaya. Biological Conservation 170: 198–206. DOI: 10.1016/j.biocon.2013.12.031
Nazeri M., Kumar L., Jusoff K., Bahaman A.R. 2014. Modeling the potential distribution of sun bear in Krau wildlife reserve, Malaysia. Ecological Informatics 20: 27–32. DOI: 10.1016/j.ecoinf.2014.01.006
Neupane D., Kwon Y., Risch T.S., Williams A.C., Johnson R.L. 2019. Habitat use by Asian elephants: Context matters. Global Ecology and Conservation 17: e00570. DOI: 10.1016/j.gecco.2019.e00570
Nielsen S.E., Boyce M.S., Stenhouse G.B. 2004. Grizzly bears and forestry: I. Selection of clearcuts by grizzly bears in west-central Alberta, Canada. Forest Ecology and Management 199(1): 51–65. DOI: 10.1016/j.foreco.2004.04.015
Ogurtsov S.S. 2016. Brown bear habitat suitability modelling based on remote sensing data. In: Theriofauna of Russia and adjacent areas. Moscow: KMK Scientific Press Ltd. P. 294. [In Russian]
Ogurtsov S.S. 2018. The Diet of the Brown Bear (Ursus arctos) in the Central Forest Nature Reserve (West-European Russia), Based on Scat Analysis Data. Biology Bulletin 45(9): 1039–1054. DOI: 10.1134/S1062359018090145
Ogurtsov S.S. 2019. Brown bear (Ursus arctos) habitat suitability and distribution modelling in the southern taiga subzone using the method of maximum entropy. Nature Conservation Research 4(4): 34–64. DOI: 10.24189/ncr.2019.061 [In Russian]
Peterson A.T., Soberόn J., Pearson R.G., Anderson R.P., Martínez-Meyer E., Nakamura M., Araújo M.B. 2011. Ecological Niches and Geographic Distributions. Princeton and Oxford: Princeton University Press. 329 p.
Pettorelli N., Hilborn A., Broekhuis F., Durant S.M. 2009. Exploring habitat use by cheetahs using ecological niche factor analysis. Journal of Zoology 277(2): 141–148. DOI: 10.1111/j.1469-7998.2008.00522.x
Phillips S.J., Anderson R.P., Schapire R.E. 2006. Maximum entropy modeling of species geographic distributions. Ecological Modelling 190(3–4): 231–259. DOI: 10.1016/j.ecolmodel.2005.03.026
Posilico M., Meriggi A., Pagnin E., Lovari S., Russo L. 2004. A habitat model for brown bear conservation and land use planning in the central Apennines. Biological Conservation 118(2): 141–150. DOI: 10.1016/j.biocon.2003.07.017
Préau С., Trochet A., Bertrand R., Isselin-Nondedeu F. 2018. Modeling Potential distributions of three european amphibian species comparing ENFA and MaxEnt. Herpetological Conservation and Biology 13(1): 91–104.
Puzachenko Yu.G., Kozlov D.N. 2007. Geomorphological history of the development of the territory of the Central Forest State Nature Reserve. Proceedings of the Central Forest State Nature Reserve 4: 125–159. [In Russian]
Qi D., Hu Y., Gu X., Li M., Wei F. 2009. Ecological niche modeling of the sympatric giant and red pandas on a mountain-range scale. Biodiversity and Conservation 18(8): 2127–2141. DOI: 10.1007/s10531-009-9577-7
R Development Core Team. 2020. R: a language and envi­ronment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing. Available from http://www.R-project.org
Reutter B.A., Helfer V., Hirzel A.H., Vogel P. 2003. Modelling habitat-suitability using museum collections: an example with three sympatric Apodemus species from the Alps. Journal of Biogeography 30(4): 581–590. DOI: 10.1046/j.1365-2699.2003.00855.x
Rinnan D.S., Lawler J. 2019. Climate-niche factor analysis: a spatial approach to quantifying species vulnerability to climate change. Ecography 42(9): 1494–1503. DOI: 10.1111/ecog.03937
Rinnan D.S. 2020. Package «CENFA», version 1.1.0. Climate and Ecological Niche Factor Analysis. 36 p.
Robin X., Turck N., Hainard A., Tiberti N., Lisacek F., Sanchez J.-C., Müller M., Siegert S., Doering M. 2020. Package «pROC», version 1.16.2. Display and Analyze ROC Curves. 95 p.
Rotenberry J.T., Preston K.L., Knick S.T. 2006. GIS-based niche modeling for mapping species' habitat. Ecology 87(6): 1458–1464. DOI: 10.1890/0012-9658(2006)87[1458:GNMFMS]2.0.CO;2
Santos X., Brito J.C., Sillero N., Pleguezuelos J.M., Llorente G., Fahd S., Parellada X. 2006. Inferring habitat-suitability areas with ecological modelling techniques and GIS: A contribution to assess the conservation status of Vipera latastei. Biological Conservation 130(3): 416–425. DOI: 10.1016/j.biocon.2006.01.003
Sattler T., Bontadina F., Hirzel A.H., Arlettaz R. 2007. Ecological niche modelling of two cryptic bat species calls for a reassessment of their conservation status. Journal of Applied Ecology 44(6): 1188–1199. DOI: 10.1111/j.1365-2664.2007.01328.x
Silva L.D., Costa H., Azevedo E., Medeiros V., Alves M., Elias R.B., Silva L. 2017. Modelling native and invasive woody species: a comparison of ENFA and MaxEnt applied to the Azorean forest. In: A. Pinto, D. Zilberman (Eds.): Modeling, Dynamics, Optimization and Bioeconomics II. DGS 2014. Vol. 195. P. 415–444. DOI: 10.1007/978-3-319-55236-1_20
Strubbe D., Matthysen E. 2008. Predicting the potential distribution of invasive ring-necked parakeets Psittacula krameri in northern Belgium using an ecological niche modelling approach. Biological Invasions 11(3): 497–513. DOI: 10.1007/s10530-008-9266-6
Thiebot J.-B., Lescroël A., Pinaud D., Trathan P.N., Bost C.-A. 2011. Larger foraging range but similar habitat selection in non-breeding versus breeding sub-Antarctic penguins. Antarctic Science 23(2): 117–126. DOI: 10.1017/S0954102010000957
Thioulouse J., Chessel D. 1992. A method for reciprocal scaling of species tolerance and sample diversity. Ecology 73(2): 670–680. DOI: 10.2307/1940773
Traill L.W., Bigalke R.C. 2007. A presence-only habitat suitability model for large grazing African ungulates and its utility for wildlife management. African Journal of Ecology 45(3): 347–354. DOI: 10.1111/j.1365-2028.2006.00717.x
Tsoar A., Allouche O., Steinitz O., Rotem D., Kadmon R. 2007. A comparative evaluation of presence-only methods for modelling species distribution. Diversity and Distribution 13(4): 397–405. DOI: 10.1111/j.1472-4642.2007.00346.x
Unger D.E., Fei S., Maehr D.S. 2008. Ecological niche factor analysis to determine habitat suitability of a recolonizing carnivore. In: Proceedings of the 6th Southern Forestry and Natural Resources GIS Conference. Athens, GA: University of Georgia. P. 237–250.
Valle M., Borja Á., Chust G., Galparsoro I., Garmendia J.M. 2011. Modelling suitable estuarine habitats for Zostera noltii, using Ecological Niche Factor Analysis and Bathymetric LiDAR. Estuarine Coastal and Shelf Science 94(2): 144–154. DOI: 10.1016/j.ecss.2011.05.031
Xuezhi W., Weihua X., Zhiyun O., Jianguo L., Yi X., Youping C., Lianjun Z., Junzhong H. 2008. Application of ecological-niche factor analysis in habitat assessment of giant pandas. Acta Ecologica Sinica 28(2): 821–828. DOI: 10.1016/S1872-2032(08)60030-X
Zajec P., Zimmermann F., Roth H.U., Breitenmoser U. 2005. The return of the Brown bear to Switzerland – Suitable habitat distribution, corridors and potential conflicts. KORA Bericht 28: 1–31.
Zaniewski A.E., Lehmann A., Overton J.McC. 2002. Predicting species spatial distributions using presence-only data: a case study of native New Zealand ferns. Ecological Modelling 157(2–3): 261280. DOI: 10.1016/S0304-3800(02)00199-0
Zheltukhin A.S., Puzachenko Y.G., Kotlov I.P., Shironiya I.I., Sandlerskiy R.B. 2016. Spatial-temporal dynamics of the pine marten (Martes martes L.), mountain hare (Lepus timidus L.) and red squirrel (Sciurus vulgaris L.) trail activity in the European southern taiga. Zhurnal Obshchei Biologii 77(4): 262–283. [In Russian]
Zimaroeva A.A., Zhukov A.V., Ponomarenko A.L., Matsyura A. 2015. Ecological niche modelling of Fringilla coelebs Linnaeus, 1758 (common chaffinch) using GIS tools. Romanian Journal of Biology – Zoology 60(2): 135–146.
Zimmermann F. 2004. Conservation of the Eurasian lynx (Lynx lynx) in a Fragmented Landscape Habitat Models, Dispersal and Potential Distribution. PhD Thesis. Lausanne: University of Lausanne. 193 p.