Impact of enclosure on some of vital ecosystem attributes in El-Bayadh region, North-West Algerien steppe

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Research Paper 15/06/2022
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Impact of enclosure on some of vital ecosystem attributes in El-Bayadh region, North-West Algerien steppe

Salemkour Nora, Chaib Warda, Bettiche Farida, Fadlaoui Haroun
J. Bio. Env. Sci.20( 6), 28-44, June 2022.
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Abstract

Protection of degraded rangelands is widely considered to be the most effective and practical way to conserve plant diversity and maintain ecosystem composition and structure, for this purpose we carried out this study in the region of El-Bayadh, located in North–West Algerien steppe, aiming at assessing the effect of the enclosure technique on plant cover structure and productivity, in both enclosure (protected) and grazed rangelands. Several vital ecosystem attributes such as diversity, richness, total plant cover, perennial plant cover, annual plant cover, soil surface elements cover and pastoral value were compared between enclosure and grazed areas. The findings revealed considerable positive effects of protection on the scored parameters. However, the results emphasized a negative effect of enclosure on vegetation dynamics. This was observed by the occurrence of crusts on the soil surface which may constitute an obstacle to water infiltration and seeds germination, for this we suggest that this parameter be retained for the opening of these aminaged rangelands (enclosure) for grazing.

VIEWS 70

Abdallah F, Noumi Z, Touzard B, Ouled Belgacem A. Chaieb M. 2008. The influence of Acacia tortilis (Forssk.) subsp. raddiana (Savi) and livestock grazing on grass species composition, yield and soil nutrients in arid environments of south Tunisia. Flora 203, 116-125.

Acherkouk M, Maâtougui A, Aziz El Houmaizi M. 2012. Etude de l’impact d’une mise en repos pastoral dans les pâturages steppiques de l’Oriental du Maroc sur la restauration de la végétation. Sécheresse 23, 102-112. doi : 10.1684/sec.2012.0340.

Aguiar MR, Sala OE. 1997. Seed distribution constrains the dynamics of the Patagonian steppe. Ecology 78(1), 93-100.

Aidoud A, Le Floc’h E, Le Houérou HN. 2006. Les steppes arides du nord de l’Afrique. Sécheresse 17, 19-30.

Aidoud A, Nedjraoui D, Djebaili S, Poissonet J. 1983. Évaluation des ressources pastorales dans les Hautes-Plaines steppiques du Sud-Oranais : productivité et valeur pastorales des parcours. Mém. Soc. Hist. Nat. Afr. Nord, Nov. Sér 13, 33-46.

Aidoud A, Touffet J. 1996. La régression de l’Alfa (Stipa tenacissima L.), graminée pérenne, un indicateur de désertification des steppes algériennes. Sécheresse 3, 187-193.

Aidoud A. 1989. Les écosystèmes pâturés des hautes plaines Algéro-oranaises. Fonctionnement, évaluation, et évolution des ressources végétales. Thèse doct. État, Université des Sciences et Technologies H. Boumediène, Alger.

Alyemeni MN, Zayed KM. 1999. Ecology of some plant communities along Riyadh AI-Thumamah Road, Saudi Arabia. Saudi J. Bio. Sci 6(1), 11-25.

Amghar F, Forey E, Margerie P, Langlois E, Brouri L, Kadi-Hanifi H. 2012. Grazing exclosure and plantation: A synchronic study of two restoration techniques improving plant community and soil properties in arid degraded steppes (ALGERIA). Rev. Ecol. Terre et Vie 67(3), 257-269.

Amghar F. 2002. Contribution à l’étude de la biodiversité de quelques formations de dégradation en Algérie. Master 2 thesis, Univ. Sci. Technol. H. Boumediene 166p.

Amiraslani F, Dragovich D. 2011. Combating des ertification in Iran over the last 50 years: an overview of changing approaches. J. Envir. Manag 92, 1-13.

Archer S, Smeins FE. 1991. Ecosystem-level processes. In: Heitschmidt RK, Stuth JW, editors. Grazing management: an ecological perspective. Portland, OR: Timber Press 109-139.

Aronson J, Floret C, Le Floc’h E, Ovalle C, Pontanier R. 1995. Restauration et réhabilitation des écosystèmes dégradés en zone arides et semi-arides. Le vocabulàre et concept. In l’homme peut il refaire ce qu’il a défait ?., Ed. Pontanier R., M’hiri A., Akromi N., Aronson J., Le Floc’h E. Paris 11-29.

Aronson J, Le Floc’h E. 1995. Vital landscape attributes: Missing tools for restoration ecology. Rest. Ecology 4(4), 377-387.

Ayyad M, El-Kadi HF. 1982. Effect of protection and controlled grazing on the vegetation of a Mediterranean ecosystem in Northern Egypt. Vegetation 42, 129-139.

Bakoglu A, Bagci E, Erkovan HI, Koc A, Kocak A. 2009. Seed stocks of grazed and ungrazed rangelands on the Palandoken Mountains of Eastern Anatolia. J Food Agric. Environ 7, 674-678.

Benaradj A. 2009. Exclosure and biological recovery paths in the steppe region Naâma: dissemination and multiplication of some species steppe. Memory Magisterium, Faculty of Natural Science and Life, University of Mascara 229p.

Bencherif S. 2011. L’élevage pastoral et la céréaliculture dans la steppe algérienne. Évolution et possibilités de développement. Thèse Doct, Agro Paris Tech, Paris.

Berkat O. 1986. Population structure, dynamics and regerenation of Artemisia herba alba Asso. Thèse de doctorat en sciences agronomiques. Inst. Agronomique et vétérinaire Hassan II, Rabat 166p.

Borselli L, Biancedani R, Giordani C, Carnicelli S, Ferrari GA. 1996 a. Effect of gypsum on seedling emergence in a kaolinitic crusting soil. Soil Technology 9, 71-81.

Borselli L, Carnicelli S, Ferrari GA, Paglia M, Lucamante G. 1996b. Effects of gypsum on hydrological, mechanical and porosity properties of a kaolinitic crusting soil. Soil Technology 9, 39-54.

Bourahla A, Guittonneau G. 1978. Nouvelles possibilités de régénération des nappes alfatières en liaison avec la lutte contre la désertification. Bull. Inst. Écol. Appl. Orléans 1, 19-40.

Briske DD. 1991. Developmental morphology and physiology of grasses. In: Heitschmidt RK, Stuth JW, editors. Grazing management: an ecological perspective. Portland, OR: Timber Press 85-108.

Callaway R, Tyler C. 1999. Facilitation in rangelands: Direct and indirect effects. In: Proc. The VI th International Rangeland Congress, People and rangelands: building the future. Townsville, Australia 1, 197-202.

Cavalcanti EAH, Larrazabal MEL. 2004. Macrozooplâncton da Zona Econômica Exclusiva do Nordeste do Brasil (segunda expedição oceanográfica – REVIZEE/NE II) com ênfase em Copepoda (Crustacea). Rev. Bras. Zool 21(3), 467-475.

Champness SS, Morris K. 1948. The population of buried variable seeds in relation to contrasting pasture and soil types. J Ecol 36, 149-173.

Daget P, Poissonet J. 1971. Une méthode d’analyse phytoécologique des prairies. Ann. Agron 22, 5-41.

Daget P, Poissonet J. 1972. Un procédé d’estimation de la valeur pastorale des pâturages. Fourrages 49, 31-39.

Daget P. 1980. Sur les types biologiques botaniques en tant que stratégies adaptatives (Cas des thérophytes), in : Actes du Colloque d’Ecologie théorique, E.N.S., Paris 89-114.

Deiri W. 1990. Contribution à l’étude phytoécologique et la potentialité pastorale en Syrie aride. Thèse Doct., Montpellier 210p.

Djebaili S. 1978. Recherches phytoécologiques et phytosociologiques sur la végétation des Hautes Plaines steppiques et de l’Atlas Saharien algériens. Thèse Doct., Université des Sciences et Techniques du Languedoc, Montpellier 229p.

El Gharbaoui A, El Yamani A, El Maghraoui A, Boutouba R, Alaoui M, Kabak A. 1996. Projet de développement des parcours et de l’élevage dans l’Oriental : Stratégie de développement des terrains de parcours. Terre et Vie 24.

El Nrabti K. 1989. Contribution à l’étude de la germination de Stipa tenacissima L. stock du sol en semence et suivie des plantules selon les microsites. Thèse de 3éme cycle. E.N.A. de Meknès 167p.

Emberger L. 1939. Overview of Morocco on vegetation. Comments card phytosociological of Morocco 1/500000. Veroff. Geobot. Inst. Rübel in Zürich. Memory. Sc Nat. Morocco. I.S.C., Rabat 40-157.

Eweg HPA, Van Lammeren R, Deurloo H, Woldu Z. 1998. Analysing degradation and rehabilitation for sustainable land management in the highlands of Ethiopia. Land Degrad. Dev 9, 529-542.

Ferchichi A, Abdelkebir S. 2003. Impact de la mise en défens sur la régénération et la richesse floristique des parcours en milieu aride tunisien. Sécheresse 3, 181-7.

Fleischner TL. 1994. Ecological costs of livestock grazing in western North-America. Conserv. Biol 8, 629-644.

Floret C, Pontanier R. 1982. L’aridité en Tunisie présaharienne. Climat, sol, végétation et aménagement. Travaux et documents de l’ORSTOM, n°150, Paris 544p.

Floret C. 1981. The effects of protection on steppic vegetation in the Mediterranean aride zone of southern Tunisia. Vegetatio 46, 117-129.

Floret CH. 1988. Methods of measure of pastoral vegetation. Pastoralism and development. CIHEAM, Montpellier Cedex pp. 95.

Gallacher D, Hill J. 2006. Effects of camel grazing on the ecology of small perennial plants in the Dubai (UAE) inland desert”, Journal of Arid Environments 66(4), 738-750.

Gamoun M. 2014. Grazing intensity effects on the vegetation in desert rangelands of Southern Tunisia. J. Arid Land 6(3), 324-333.

Ghollasimood S, Amousi, Mahmoodi A. 2014. Evaluation of plant diversity indices and the biomass of Pistacia atlantica under drought stress in grazing and enclosed area (case study: Tag-e Ahmad Shahi, Nehbandan, Iran). Journal of Biodiversity and Environmental Sciences (JBES) 5(2), 276-285.

Gonzalez-Polo M, Austin AT. 2009. Spatial heterogeneity provides organic matter refuges for soil microbial activity in the Patagonian steppe, Argentina. Soil Biol. Biochem. 41, 348-1351.

Gounot M. 1961. Les méthodes d’inventaires de la végétation, Bull. Serv. Carte phytogéogr., Série B. Carte des groupements végétaux. CNRS. Tome VI 1, 7-73.

Hachmi A, El Alaoui-Faris FE, Acherkouk M, Mahy H. 2015. Parcours arides du Maroc : restauration par mise en repos, plantations pastorales et conservation de l’eau et du sol. Geo-Eco-Trop 39(2), 185-204.

Hai R, Weibing D, Jun W, Yu Zuoyue Y, Qinfeng G. 2007. Natural restoration of degraded range and ecosystem in Heshan hilly land. Acta Ecologica Sinica 27, 3593-3600.

Hanke W, Böhner J, Dreber N, Jürgens N, Schmiedel U, Wesuls D. 2014. The impact of livestock grazing on plant diversity: An analysis across dryland ecosystems and scales in Southern Africa. Ecological Applications 24, 1188-1203.

Hassani N, Asghari HR, Frid AS, Nurberdief M. 2008. Impacts of overgrazing in a long term traditional grazing ecosystem on vegetation around watering points in a semi-arid rangeland of North-Eastern Iran. Pakistan Journal of Biological Sciences 11, 1733-1737.

Hiernaux P, Bielders CL, Valentin C, Bationo A, Fernandez-Rivera S. 1999 Effects of livestock grazing on physical and chemical properties of sandy soils in Sahelian rangelands. J. Arid Environ 41, 231-245.

Holling CS. 1973. Resilience and stability of ecological systems. Annu. Rev. Ecol. Evol. Syst 41, 1-23.

Hosseini S, Safaian N, Shokri M, Ghorbani J, Imani A. 2013. Diversity and frequency of wildlife in association with different ranges condition on the Bijar protected, Western Iran. Journal of Biodiversity and Ecological Sciences 3(3), 137-143.

Hu A, Zhang J, Chen X, Chang S, Hou F. 2019. Winter Grazing and Rainfall Synergistically Affect Soil Seed Bank in Semiarid Area, Rangeland Ecology & Management 72, 160-167.

Jacobo EJ, Rodríguez AM, Bartoloni N, Deregibus VA. 2006. Rotational grazing effects on rangeland vegetation at a farm scale. Rangeland Ecology and Management 59(3), 249-257.

Jauffret S. 2001. Validation et comparaison de divers indicateurs des changements à long terme dans les écosystèmes méditerranéens arides. Application au suivi de la désertification dans le Sud tunisien. PhD, Faculté des Sciences et Techniques de St Jérôme, Univ. Aix-Marseille III, France 365 p.

Khalid F, Benabdeli K, Morsli B. 2015. Impact de la mise en défens sur la lutte contre la désertification dans les parcours steppiques: Cas de la région de Naâma (Sud-Ouest Algérien). Rev. Ecol. Terre et Vie 70, 1-16.

Kibret M. 2008. Enclosure as a Viable Option for Rehabilitation of Degraded Lands and Biodiversity Conservation: the Case of Kallu Wereda, Southern Wello. MSc Thesis. Addis Ababa University, Addis Ababa, Ethiopia.

Koc A, Gullap MK, Erkovan HI. 2013. The soil seed bank pattern in highland rangelands of eastern anatolian region of turkey under different grazing systems Turkish Journal of Field Crops 18(1), 109-117.

Lavado RS, Sierra JO, Hashimoto PN 1996. Impact of grazing on soil nutrients in a Pampean grassland. J. Range Manag 49, 452-457.

Le Floc’h E. 2001. Biodiversité et gestion pastorale en zones arides et semi-arides méditerranéennes du Nord de l’Afrique. Bocconea 13, 223-237.

Le Houérou HN, Ionesco T. 1973. Appétibilité des espèces végétales de la Tunisie steppique. Doc. Trav. Proj. FAO / Tun./71/525, 68p.

Le Houérou HN, Servoz H, Shawesh O, Telahique T. 1983. Evaluation of development potentials of existing range projects in Western Libya. Technical Paper, n° 52, UNTF/LIB 18. Tripoli; Rome: Agricultural Research Center; Food and Agriculture Organization (FAO) 125p.

Le Houérou HN. 1969. La végétation de la Tunisie steppique. Ann. Inst. Natl. Agron. Tunis, 42, 1-624.

Le Houérou HN. 1977. Biological recovery versus desertisation. Econ.Geogr 53, 413-420.

Le Houérou HN. 1985. La régénération des steppes algériennes. Rapport de mission, de consultation et d’évaluation. Alger : ministère de l’Agriculture 19p.

Le Houérou HN. 1992. An overview of vegetation and land degradation in world arid lands. Pp 127-163 in: h.e. Dregne (ed.). Degradation and restoration of arid lands. International Center for Arid and semi-arid Land Stu- dies, Texas Tech. Univ., Lubbock.

Louhaichi M, Salkini AK, Petersen SL. 2009. Effect of small ruminant grazing on the plant community characteristics of Semi-Arid Mediterranean ecosystems. Int. J. Agric. Biol 11, 681-689.

Merdas S, Menad A, Mostephaoui T, Sakaa B. 2017. Plant community structure and diversity under grazing gradient in arid Mediterranean steppe of Algeria. J. Mater. Environ. Sci 8(12), 4329-4338.

Meyer SE, Garcia-Moya E. 1989. Plant community patterns and soil moisture regime in gypsum grasslands of north central Mexico. J. Arid Environ 16, 147-155.

Miaojun Ma, Scott L. Collins ZR, Guozhen D. 2021. Soil Seed Banks, Alternative Stable State Theory, and Ecosystem Resilience. BioScience 71(7), 697-707.

Mikola J, Yeates GW, Barker GM, Wardle DA, Bonner KI. 2001. Effects of defoliation intensity on soil food-web properties in an experimental grassland community. Oikos 92, 333-343.

Milton SJ, Dean WRJ, Du Plessis MA, Siegfried WR. 1994. A conceptual model of arid rangeland degradation. Bioscience 44, 70-76.

Msika B, El Harizi K, Bourbouze A, Lazarev G. 1997. Projet de développement de l’élevage et des parcours de l’Oriental. Rome; Montpellier : Fonds international de développement agricole (FIDA); Centre International de Hautes études agronomiques et méditerranéennes-Institut agronomique méditerranéen de Montpellier (CiheamIAMM) Réseau Parcours.

Myers N, Mittermeier RA, Mittermeier CG, Da Fonseca GAB, Kent J. 2000. Biodiversity Hotspots for Conservation Priorities. Nature 403, 853-858.

N’zala D, Nongamani A, Moutsambote JM, Mapangui A. 1997. Diversité floristique dans les monocultures d’eucalyptus et de pin au Congo. Cahier agriculture 6(3), 196-74.

Nedjraoui D, Bédrani S. 2008. La désertification dans les steppes algériennes : causes, impacts et actions de lutte. Vertigo 8, revue électronique: https://vertigo.revues.org/5375.

Noy-Meir I, Gutman M, Kaplan Y. 1989. Responses of Mediterranean grassland plants to grazing and protection. Journal of Ecology 77, 290-310.

Olff H, Ritchie ME. 1998. Effects of herbivores on grassland plant diversity. Rev. Tree 13, 261-265.

Ouled Belgacem A, Neffati M, Papanastasis V, Chaieb M. 2006b. Effects of seed age and seeding depth on growth of Stipa lagascae R. and sch. seedlings, Journal of Arid Environments Vol 65, 682-687.

Ouled Belgacem A, Tarhouni M, Louhaichi M. 2013. Effect of protection on plant community dynamics in the Mediterranean arid zone of southern Tunisia: a case study from Bouhedma national park. Land Degrad. Dev 24(1), 57-62.

Ouled dhaou S, Abdallah F, Ouled belgacem A, Chaieb M. 2010. The protection effects on floristic diversity in a North African pseudo-savanna. Pak. J. Bot 42(3), 1501-1510.

Ozenda P. 1977. Flore et végétation du Sahara, 2éme édition, CNRS., Paris 622p.

Peco B, Ortega M, Levassor C. 1998. Similarity between seed bank and vegetation in Mediterranean grassland: a predictive model. J. Veget. Sci 9, 815-828.

Pei SF, Fu H, Chen YM, Li JB. 2004. Influence of Z. xanthoxylum shrubs on soil fertility in enclosure and grazing conditions. J. Desert Research 24(6), 763-767.

Pielou EC. 1966. The measures of diversity in different types of biological collections. J. Theor. Biol 13, 131-144.

Pouget M. 1980. Les relations sol – végétation dans les steppes Sud-Algéroises. Trav. Doc. ORSTOM 116, 1-555.

Prieto LH, Bertiiler MB, Carrera AL, Olivera NL. 2011. Soil enzyme and microbial activities in a grazing ecosystem of Patagonian Monte, Argentina Geoderma 162, 281-287.

Quézel P, Santa S. 1962-1963. Nouvelle flore de l’Algérie et des régions désertiques méridionales, vol. 1-2. CNRS, Paris 1170p.

Quézel P. 1978. Analysis of the flora of mediterranean and saharian Africa. Ann. Mo. Bot. Gard 65, 479-534.

Salemkour N, Aidoud A, Chalabi K, Chefrour A. 2016. Evaluation des effets du contrôle de pâturage dans des parcours steppiques arides en Algérie. Revue d’écologie (Terre Vie) 71(2), 178-191.

Salemkour N, Benchouk K, Nouasria D, Kherief Nacereddine S. Belhamra M. 2013. Effets de la mise en repos sur les caractéristiques floristiques et pastorale des parcours steppiques de la région de Laghouat (Algérie). Journal Algérien des Régions Arides 12, 103-114.

Salemkour N, Fadlaoui H, Benchouk-Chalabi K, Hamou K. 2017. Effect of two restoration techniques on: plant and soil surface cover and pastoral value in steppic Algerian rangelands. International Journal Of Current Research 9(05), 50923-50928.

Sasaki T, Ohkuro T, Jamsran U, Takeuchi K. 2012. Changes in the herbage nutritive value and yield associated with thresh old responses of vegetation to grazing in Mongolian rangelands. Grass Forage Sci 67, 446-455.

Savory A, Parsons SD. 1980. The Savory grazing method. Rangelands 2, 234-237.

Schlesinger WH, Reynolds JF, Cunningham GL, Huenneke LF, Jarrell WM, Virginia RA, Whitford WG. 1990. Biological feedbacks in global desertification. Science 247, 1043-1048.

Selemani IS, Eik LO, Holand Ø, Ådnøy T, Mtengeti E. Mushi D. 2013. The effects of a deferred grazing system on rangeland vegetation in a north-western, semi-arid region of Tanzania African. J. Range & Forage Sci 30, 141-148.

Shaltout KH, El Halawany EF, El Kady HF, 1996. Consequences of protection from grazing on diversity and abundance of the coastl lowland vegetation in Eastern Saudi Arabia. Biodiv. Conserv 5, 27-36.

Sidi Mohamed YO, Neffati M, Henchi B. 2002. Study of the effect of the vegetation management mode on its dynamics in pre-Saharan Tunisia: the case of the national park of Sidi Toui and its surroundings. Sécheresse 13, 195-203.

Sidi Mohamed YO, Neffati M, Henchi B. 2004. Evolution des indices de diversité spécifique en Tunisie présaharienne sous l’effet de la mise en défens : cas des observatoires de Sidi Toui et de Oued Dekouk. In : Ferchichi A. (comp.), Ferchichi A. (collab.). Réhabilitation des pâturages et des parcours en milieux méditerranéens. Zaragoza: CIHEAM. Options Méditerranéennes 62, 477-480.

Slimani H, Aidoud A, Roze F. 2010. 30 Years of protection and monitoring of a steppic rangeland undergoing desertification. J. Arid Envir 74, 685-691.

Slimani H, Aidoud A, Roze F. 2010. 30 Years of protection and monitoring of a steppic rangeland undergoing desertification. J. Arid Envir 74, 685-691.

SPSS. 2009. Statistical Package for the Social Sciences (SPSS) for Windows (Version 17.0). SPSS, Chicago.

Sternberg M, Gutman M, Perevolotsky A, Kigel J. 2003. Effects of grazing on soil seed bank dynamics: An approach with functional groups. J. Veget. Sci 14, 375-386.

Sternberg M, Gutman M, Perevolotsky A, Ungar D, Kigel J. 2000. Vegetation response to grazing management in a Mediterranean herbaceous community: a functional group approach. J. Appl. Ecol 37, 1-15.

Su YZ, Zhao HL, Zhang TH, Zhao XY. 2004. Soil properties following cultivation and non­grazing of a semiarid sandy grassland in northern China. Soil Tillage Research 75, 27-­36.

Tarhouni M, Ben Salem F, Ouled Belgacem A, Henchi B, Neffati M. 2007b. Variation of flora richness according to the grazing gradient around watering points in pre-Saharan Tunisia, Sécheresse 18, 234-239.

Tarhouni M, Ouled Belgacem A, Neffati M, Henchi B. 2006. Validation de quelques attributs structuraux de l’écosystème sous l’effet de la sécheresse saisonnière et la pression animale autour de points d’eau en zone aride tunisienne. Belgian J Bot 139, 188-202.

Tarhouni M, Ouled Belgacem A, Neffati M, Henchi B. 2007a. Qualification of rangeland degradation using plant life history strategies around watering points in southern Tunisia. Pakistan J Biol Sci 10, 1229-1235.

Tarhouni M. 2008. Indicateurs de biodiversité et dynamique du couvert végétal naturel aux voisinages de trois points d’eau en zone aride tunisienne : cas des parcours collectifs d’El-Ouara. Thèse de doctorat. Université Tunis El Manar 168p. + annexes.

Tastad A, Jasra AW, Salkini AK, Battikha N, Louhaichi M. 2010. Ecological status of protected and unprotected rangelands in Syria: Monitoring the impact of grazing on rangeland vegetation dynamics in three climatological zones. J. Agr. Sci 47(2), 89-98.

Todd SW, Hoffman MT. 2009. A fence line in time demonstrates grazing-induced vegetation shifts and dynamics in the semiarid Succulent Karoo. Ecological Applications 19, 1897-1908.

Todd SW. 2006. Gradients in vegetation cover, structure and species richness of Nama-Karoo shrublands in relation to distance from livestock watering points. Journal of Applied Ecology 43, 293-304.

Tongway DJ, Ludwig JA, Whitford WG, 1989. Mulga log mounds: fertile patches in the semi-arid woodlands of eastern Australia. Australian Journal of Ecology 14, 263-268.

Valentin C. 1983. Effets du pâturage et du piétinement sur la dégradation des sols autour des points d’eau artificiels en région sahélienne (Ferlo, Nord Sénégal). A.C.C. Lutte contre l’aridité en milieu tropical, DGRST., ORSTOM.

Van de Koppel J, Rietkerk M. 2000. Herbivore regulation and irreversible vegetation change in semi-arid grazing systems. Oikos 90, 253-260.

Wallace A, Wallace, GA. 1986 a. Effects of soil conditioners on emergence and growth of tomato, cotton and lettuce seedlings. Soil Science 141, 313-316.

Wissel C. 1984. A universal law of the characteristic return time near thresholds. Oecologia 65, 101-107.

Yates CJ, Norton DA, Hobbs RJ. 2000. Grazing effects on plant cover, soil and microclimate in fragmented woodlands in south-western Australia: implications for restoration. Austr. Ecol 25, 36-47.

Yong–Zhong S, Yu–Lin L, Jian–Yuan C. Wen–Zhi Z. 2005. Influences of continuous grazing and livestock exclusion on soil properties in a degraded sandy grassland, inner Mongolia, northern China. Catena 59, 267-278.

Zhang J, Zhao H, Zhang T, Zhao X, Drake S. 2005. Community succession along a chronosequence of vegetation restoration on sand dunes in Horqin Sandy Land. J. Arid Environ 62(4), 555-566.

Zhao HL, Zhao XY, Zhou RL, Zhang TH, Drake S. 2005. Desertification processes due to heavy grazing in sandy rangeland, Inner Mongolia. J. of Arid Environments 62, 309-319.