Polarization in (post)nomadic resource use in Eastern Morocco: insights using a multi-agent simulation model
Tóm tắt
Mobile pastoralist strategies have evolved over centuries and are well adjusted to the variable climatic conditions of semi-arid regions. However, economic, social, and climatic changes, as well as technical advancements such as truck transportation, have increasingly affected the livelihood of pastoralist households in recent decades. An increase in inequality has been observed between wealthy pastoralists with large herds and impoverished households that are experiencing decreasing herd sizes on the High Plateau in Eastern Morocco, for example. In addition, whereas wealthy pastoralists possess the financial means to use trucks to transport their herds across large distances, the impoverished households are mainly limited to ranges they can travel by foot. This phenomenon can be described as polarization: the emergence of two distinct socio-economic groups with respect to household livestock and monetary resources. The reasons that have led to this polarization, however, are not well understood at present. In this study, we present a multi-agent simulation model to examine the economic, ecological, climatic, and demographic factors driving this polarization. The model captures the feedbacks between pastoralist households, their herds, and the pastures that they use in a common property grazing system. Using this model, we are able to show that heterogeneities in household assets (livestock and monetary resources) are only one cause of polarization. Changes in ecological conditions and the impact of climate and demographic change can also cause polarization, even if households are completely homogeneous in their characteristics.
Tài liệu tham khảo
Adriansen HK (1997) The development of nomadic pastoralism in Africa. Dissertation, Institute of Geography, University of Copenhagen
Bonabeau E (2002) Agent-based modeling: methods and techniques for simulating human systems. Proc Natl Acad Sci U S A 99(Suppl 3):7280–7287. https://doi.org/10.1073/pnas.082080899
Bourbouze A, Ben Saad A, Chiche J, Jaubert R (2009) Managing collective land and rangelands. In: Hervieu B (ed) Mediterra 2009: Rethinking rural development in the Mediterranean, Presses de Sciences, pp. 233–260
Breuer I (2007) Livelihood security and mobility in the high atlas mountains. In: Gertel J, Breuer I (ed) Pastoral Morocco. Globalizing scapes of mobility and insecurity, Dr. Ludwig Reichert Verlag, pp. 165–180
Breuer I, Kreuer D (2011) Market spaces in a globalising periphery: livestock trade, borders, and liberalisation in Eastern Morocco. In: Le Heron R, Gertel J (eds) Economic spaces of pastoral production and commodity systems: markets and livelihoods. Ashgate Publishing, Farnham
Dominguez P, Bourbouze A, Demay S, Genin D, Kosoy N (2012) Diverse ecological, economic and socio-cultural values of a traditional common natural resource management system in the Moroccan High Atlas: the Ait Ikiss Tagdalts. Environ Value 21(3):277–296. https://doi.org/10.3197/096327112X13400390125939
Dressler G, Müller B, Frank K (2012) Mobility—a Panacea for Pastoralism? an ecological-economic modelling approach. Proceedings of the iEMSs Fifth Biennial Meeting: International Congress on Environmental Modelling and Software (iEMSs 2012). International Environmental Modelling and Software Society, Leipzig, Germany
Esteban J-M, Ray D (1994) On the measurement of polarization. Econometrica 4:819–851
Fernández-Giménez M (2000) The role of Mongolian nomadic pastoralists’ ecological knowledge in rangeland management. Ecol Appl 10(5):1318–1326. https://doi.org/10.1890/1051-0761(2000)010[1318:TROMNP]2.0.CO;2
Foster JE, Wolfson MC (2010) Polarization and the decline of the middle class: Canada and the U.S. J Econ Inequal 8:247–273. https://doi.org/10.1007/s10888-009-9122-7
Fratkin E (2005) A comparative approach to transition and social change among livestock pastoralists in East Africa and Central Asia. Senri Ethnological Studies 69:15–29
Heffernan C, Rushton J (2000) Restocking: a critical evaluation. Nomadic Peoples 4(1):110–124. https://doi.org/10.3167/082279400782310700
Hirschman A (1964) The paternity of an index. Am Econ Rev 54(5):761. http://www.jstor.org/stable/1818582
Hogg R (1986) The new pastoralism: poverty and dependency in Northern Kenya. Africa 56:319–333. http://www.jstor.org/stable/1160687
Homann S, Rischkowsky B, Steinbach J, Kirk M, Mathias E (2008) Towards endogenous livestock development: Borana pastoralists’ responses to environmental and institutional changes. Hum Ecol 36(4):503–520. https://doi.org/10.1007/s10745-008-9180-7
Krätli S, Huelsebusch C, Brooks S, Kaufmann B (2013) Pastoralism: a critical asset for food security under global climate change. Anim Front 3(1):42–50. https://doi.org/10.2527/af.2013-0007
Kreuer D (2011) Land use negotiation in Eastern Morocco. Nomadic Peoples 15(1):54–69. https://doi.org/10.3167/np.2011.150103
Lamprey RH, Reid RS (2004) Expansion of human settlement in Kenya’s Maasai Mara: what future for pastoralism and wildlife? J Biogeogr 31(6):997–1032. https://doi.org/10.1111/j.1365-2699.2004.01062.x
Little PD (1985) Social differentiation and pastoralist sedentarization in Northern Kenya. Africa 55:243–261. http://www.jstor.org/stable/1160579
Mahdi M (2007) Pastoralism and institutional change in the oriental. In: Gertel J, Breuer I (ed) Pastoral Morocco. Globalizing scapes of mobility and insecurity. Dr. Ludwig Reichert Verlag
Martin R, Müller B, Linstädter A, Frank K (2014) How much climate change can pastoral livelihoods tolerate? Modelling rangeland use and evaluating risk. Glob Environ Chang 24:183–192. https://doi.org/10.1016/j.gloenvcha.2013.09.009
Martin R, Linstädter A, Frank K, Müller B (2016) Livelihood security in face of drought—assessing the vulnerability of pastoral households. Environ Model Softw 75:414–423. https://doi.org/10.1016/j.envsoft.2014.10.012
Milner-Gulland EJ, Kerven C, Behnke R, Wright IA, Smailov A (2006) A multi-agent system model of pastoralist behaviour in Kazakhstan. Ecol Complex 3:23–36. https://doi.org/10.1016/j.ecocom.2005.05.004
Müller B, Bohn F, Dressler G, Groeneveld J, Klassert C, Martin R, Schlüter M, Schulze J, Weise H, Schwarz N (2013) Describing human decisions in agent-based models—ODD+D, an extension of the ODD protocol. Environ Model Softw 48:37–48. https://doi.org/10.1016/j.envsoft.2013.06.003
Müller B, Schulze J, Kreuer D, Linstädter A, Frank K (2015) How to avoid unsustainable side effects of managing climate risk in drylands—the supplementary feeding controversy. Agric Syst 139:153–165. https://doi.org/10.1016/j.agsy.2015.07.001
Niamir-Fuller M, Turner MD (1999) A review of recent literature on pastoralism and transhumance in Africa. In: M Niamir-Fuller (ed) Managing mobility in African rangelands: the legitimization of transhumance, Intermediate Technology/FAO, pp. 18–46
Okayasu T, Okuro T, Jamsran U, Takeuchi K (2010) An intrinsic mechanism for the coexistence of different survival strategies within mobile pastoralist communities. Agric Syst 103(4):180–186. https://doi.org/10.1016/j.agsy.2009.12.006
Paeth H, Born K, Girmes R, Podzun R, Jacob D (2009) Regional climate change in tropical and northern Africa due to greenhouse forcing and land use changes. J Clim 22:114–132. https://doi.org/10.1175/2008JCLI2390.1
Quaas M, Baumgärtner S, Becker C, Frank K, Müller B (2007) Uncertainty and sustainability in the management of semi-arid rangelands. Ecol Econ 62(2):251–266. https://doi.org/10.1016/j.ecolecon.2006.03.028
Rachik H (2000) Comment rester nomade. Afrique Orient, p. 175
Rachik H (2009) Les nomades et l’argent. In: Bonte P, Elloumi M, Guillaume H, Mahdi M (ed) Développement rural, environnement et enjeux territoriaux. Regards croisés Oriental marocain et Sud-Est tunisien. Tunis, Cérès Éditions, pp 79–89
Rasch S, Heckelei T, Oomen R, Naumann C (2016) Cooperation and collapse in a communal livestock production SES model—a case from South Africa. Environ Model Softw 75:402–413. https://doi.org/10.1016/j.envsoft.2014.12.008
Ruttan L, Borgerhoff Mulder M (1999) Are East African pastoralists truly conservationists? Curr Anthropol 40(5):621–652. https://doi.org/10.1086/300086
Schwartz HJ (2006) Ecological and economic consequences of reduced mobility in pastoral livestock production systems. In: Fratkin E, Roth EA (eds) As pastoralists settle: social, health, and economic consequences of the pastoral sedentarization in Marsabit District, Kenya. Springer Science & Business Media. https://doi.org/10.1007/b107561
Seppelt R, Müller F, Schröder B, Volk M (2009) Challenges of simulating complex environmental systems at the landscape scale: a controversial dialogue between two cups of espresso. Ecol Model 220(24):3481–348. https://doi.org/10.1016/j.ecolmodel.2009.09.009
Toth R (2015) Traps and thresholds in pastoralist mobility. Am J Agric Econ 97(1):315–332. https://doi.org/10.1093/ajae/aau064
Walks A (2013) Income inequality and polarization in Canada’s cities: an examination and new form of measurement. Research Paper 227, Cities Centre, University of Toronto
Werner J (2006) Nomades entre marginalisation, entreprenariat et conflits: Stratégies des éleveurs mobiles du sud du Maroc face aux bouleversements du contexte pastoral et aux impératifs d’un développement durable. In: Boland H, Hoffmann V, Nagel UJ (eds) Kommunikation und Beratung, Vol. 70. Margraf Publishers
Zurell D, Berger U, Cabral J, Jeltsch F, Meynard C, Munkemüller T, Nehrbass N, Pagel J, Reineking B, Schröder B, Grimm V (2010) The virtual ecologist approach: simulating data and observers. Oikos 119(4):622–635. https://doi.org/10.1111/j.1600-0706.2009.18284.x