Floristic Indices and ion content of Some Medicinal Plants along Sand Dunes Altitude in Cholistan Desert of Pakistan
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Abstract
The present study was conducted to explore the nutrient ions status, their uptake ratio and floristic indices of some medicinal plants of Cholistan desert of Pakistan from Drawar fort area. Vegetations on sand dunes of approximately equal size were evaluated with three replications. In soil of zone 1 (top of dune), maximum frequency (100) of Caligonum polygonoides and minimum (33.34) of Salsola imbricata and Capparis decidua were recorded. In soil of zone 2, maximum frequency (100) of Caligonum polygonoides while minimum (33.33) of Calotropis procera while in zone 3, 100% frequency of lonely species Symbopogon jawarancusa was observed. In soil of zone 1, maximum concentrations were of sodium (Na), bicarbonate (HCO3), nitrogen ((N) and organic matter (OM) while in soil of zone 2, EC, pH, phosphorus (P) and potassium (K) were maximum. Leaf K and Na were the highest (27.10mg/g) and (118.36mg/g) respectively in Prosopis cineraria. Leaf P was the highest (0.42mg/g) in Prosopis cineraria also. Maximum stem Na (333.00mg/g) was in Salsola imbricata. In flowers, highest P (0.42mg/g) was found in flower of Salsola imbricata.
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Ghulam Yasin, Iqra Anwer, Aqsa Ahmad, Adeela Altaf, Shahzadi Saima, & Asma Kanwal. (2021). Floristic Indices and ion content of Some Medicinal Plants along Sand Dunes Altitude in Cholistan Desert of Pakistan. Sindh University Research Journal - SURJ (Science Series), 53(04). https://doi.org/10.26692/surj.v53i04.4219
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References
References
[1]Farns worth, N.R.(1990).The role of ethno pharma ecology in drug development.Ciba Found Symposium,154:2–11.
[2] Farnsworth, N.R.(1994).Ethnopharmacology and drug development. CibaFound Symposium,185:42–51.
[3] Solecki, R.andI.V.Shanidar. (1975). A Neanderthalflowerburialinnorthern Iraq. Science,190:880–881.
[4]Munzer, U.,M.Sarfraz, H.Ullah., M.U.Khan., M.Kanwal.(2021).Ethnomedicinal UsesofDifferentPlantsfortheTreatmentof AsthmainPakistan.BiomedicalJournalof ScienceandTechnologyResearch.36.BJSTR. MS.ID.005917
[5]SadiaA.,H.I.Ahmad,A.Jabbar,M.M.Tolba,S.AbouZid, N.Irm,F.Zulfiqar,M.Z.Iqbal,S. AhmadandZ.Aslam.(2021).UseofMedicinal PlantsforRespiratoryDiseasesinBahawalpur,Pakistan. BiomedicalResearchInternational.5578914.doi:10.1155/2021/5578914
[6]ShoaibG.,G.M.Shah,N.Shad,Y.Dogan,Z.Siddique,A.H.Shah,M.Farooq,K.R.Khan,A. Nedelcheva.(2020).Traditionalpracticesofthe ethnoveterinaryplantsintheKaghanValley, WesternHimalayas-Pakistan.RevistaBiologia Tropica.69:1–11.
[7] Wickens,G.E.(1998).Ecophysiology of economic plants in arid and semi-arid lands. Berlin: Springer.
[8] Lambers, H.; F.S. Chapin and T.L. Pons. (1998). Plant physiological ecology. New York, etc.:Springer.[9]Rachmilevitch,S.,M.D.Costaand B.Huang.(2006).Physiological and Biochemical Indicators for Stress Tolerance. In Bingru Huang(Ed.),Plant-Environment Interactions (3rded., pp. 321–355).New York:CRC Press, ISBN978-1-4200-1934-6.
[10] Akbar,G.,T.N.Khanand M.Arshad.(1996).Cholistan desert, Pakistan. Rangelands, 18:124-128.
[11] Akbar, G.andM.Arshad.(2000).developing sustainable strategies for Cholistan desert: opportunitiesandperspectives.ScienceVision 5:77-85
[12]Arshad,M.,M.Y.Ashraf,M.AhmadandF.Zaman.(2007).Morpho-genetic variability potentialofCenchrusciliarusL.,fromCholistan desert,Pakistan.PakistanJournalofBotany,39:1481-1488.[13]Arshad,M.,G.AkbarandS.Rashid.(2003).Wealth ofmedicinal plantsofCholistan desert,Pakistan:Conservational strategies. HamdaradMedicus,105:25-34.
[14]Ali,S.I.andM.Qaiser.(Eds)(1993–2011).Flora ofPakistan.Department ofBotany,University ofKarachi,Pakistan.Nos.194–218.
[15]Jain,S.K.(1995).AManualofEthnobotany,2ndEdition.ScientificPublishers,Jodhpur.
[16]Khan,S.S.(1993).Ethnomedicinalstudieson plantsofBhopaldistrict ofM.P,Ph.D.Thesis, BarkatullahUniversity,Bhopal.
[17] Jackson,M. L. 1967.Soilchemicalanalysis.NewDelhi:PrenticeHallofIndia.
[18] Duncan, D.B. (1955). Multiple Range andMultipleF-Test.Biometrics,11:1-42.
[19]Sperry,J.S.andU.G. Hacke.(2002).Desert shrubwaterrelationswithrespect tosoil characteristics andplantfunctionaltype. FunctionalEcology,16(3):367-378.
[20]Youssef,A.M.andM.A.Al-Fredan.(2008).Community compositionofmajorvegetations inthecoastalareaofAl-Uqair,SaudiArabiain responsetoecological variations. Journalof BiologicalScience,8(4):713-721.
[21] Glenn, E., R. Pfister, J.I. Brown., T.L.ThompsonandJ.W.O'leary.(1996).NaandK accumulation andsalttoleranceof Atriplexcanescens (Chenopodiaceae) genotypes.AmericanJournal of Botany, 83(8):997-1005
[22]Youssef,A.M.(2009). Salttolerance mechanisms insomehalophytesfromSaudi ArabiaandEgypt.Research Journalof AgricultureandBiologicalSciences,5(3):191-206.
[23]Farghali, K.A.(1998).Somephysiological adaptation infivedesertperennials:seasonal changesinionicandmetabolicsolutes.BulletinfacultyofScience,UniversityofAssiut,27:25-39.
[24]Wang X.Q.,J.Jiang,J.Q.Lei.(2004) Relationship betweenephemeralplants distributionandsoilmoistureonlongitudinal dunesurfaceinGur-bantunggut Desert. ChineseJournal of AppliedEcology,15(4):556–560.
[25] Gorham, J. (1990). Salt tolerance in the Triticeae: Ion discrimination in Rye and Triticale. Journal of Experimental Botany, 41(5):609–614.
[26] Khan,M.A.,I.A.UngarandA.M.Showalter. (2000).Effectsofsalinity ongrowth,water relationsandionaccumulation ofthe subtropical perennialhalophyte,Atriplex griffithiivar.stocksii.AnnalsofBotany,85(2):225-232.
[27] Brant,A.N.andH.Y.H.Chen.(2015).Patterns andmechanisms ofnutrientresorptionin plants.CriticalReviewinPlantScience.34,471–486.
[28] Yang, Y., B.R. Liu and S.S. An.(2018).Ecologicalstoichiometryinleaves,roots,litters andsoilamongdifferentplantcommunitiesin adesertifiedregionofNorthernChina.Catena166,328–338.
[29] Arshad,M.andG.Akbar.(2002). Benchmark ofplantcommunities ofCholistandesert. PakistanJournalofBiologicalScience,5:1110-1113.
[30]Cragg,G.M.;D.J.Newman andS.S.Yang. (2006). Naturalproductextractsofplantand marineoriginhavingantileukemia potential: theNCIexperience. JournalofNatural Products,69:488–498.
[31] Vinton,M.A.andI.C.Burke.(1995).Interactions betweenindividualplantspecies andsoilnutrient statusinshortgrasssteppe. Ecology,76:1116–1133.
[32]Hook, P.B.,I.C. Burke andW.R.Lanenroth. (1991).Heterogeneity insoilNandC associatedwithindividual plantsandopenings inNorthAmericanshortgrasssteppe.Plantand Soil,138:247–256.
[33] Schlesinger,W.H., J.F. Reynoldsand G.L.Cunningham.(1990).Biologicalfeedbacksin globaldesertification.Science,47:1043–1048.
[34]Schlesinger, W.H.,J.A,Raikes,A.E.Hartley andA.F.Cross.(1996).onthespatialpatternof soilnutrientsindesertecosystems.Ecology,77:364–374.
[35]Whitford,W.G.,J.AndersonandP.M.Rice. (1997).Stemflow contributiontothe‘fertile island’effectincreosotebush,Larreatridentata. JournalofAridEnvironments,35:451–457.
[36]Noy-Meir, I.(1973).Desertecosystems: environmentandproducers.AnnualReviewof EcologyandSystematics,4:25–51.
[37] Austin, A.T., L. Yahdjian, J.M. Stark, J.Belnap,A.Poporato,U.Norton,D.A.Ravetta andS.M.Schaeffer. (2004). Waterpulsesand biogeochemical cyclesinaridandsemiarid ecosystems.Oecologia,141(2):221–235.
[38]Guerrero-Campo,J.,F.Alberto,J.Hodgson,
J.M.Garcia-Ruiz,G.Montserrat-Marti.(1999).
Plantcommunity patternsinagypsumareaof NESpain:I.Interactions withtopographic factors andsoilerosion. JournalofArid Environments,41:401–410
[39]Li,J.R,G.S.Okin,I.AlvarezL,etal.(2008).Effects ofwinderosiononthespatial heterogeneity ofsoilnutrientsintwodesert grasslandcommunities.Biogeochemistry,88:73–88.
[40]Zuo,X.A.,H.L.Zhao,X.Y. ZhaoX.Y,etal (2008).Spatialpatternandheterogeneityofsoil properties insanddunesundergrazingand restoration inHorqinSandyLand,Northern China,SoilandTillageResearch,99:202–212.
[41]Wezel,A.,J.L.RajotandC.Herbrig,(2000).Influenceofshrubsonsoilcharacteristics and theirfunctioninSahelianagro-ecosystemsinsemi-aridNiger.JournalofAridEnvironments,44:383–398.
[42]Dhillion, S.S.(1999).Environmental heterogeneity, animaldisturbances,microsite character-istics,andseedlingestablishmentina Quercushavardii community.Restoration Ecology,7:399–406.
[43]Valiente-Banuet,A.andE.Ezcurra.(1991).Shadeasacauseoftheassociationbetweenthe cactusNeobuxbaumiatetetzo andthenurse plantMimosaluisanaintheTehuacan Valley, Mexico.JournalofEcology,79:961–971.
[44] Parsons, A.J., A.D. Abrahams and J.R.Simanton.(1992).Microtopographyandsoil-surfacematerials onsemi-aridpiedmont hillslopes, southernArizona.JournalofArid Environments,22:107–115.
[45]Dunkerly,D.(2000).Hydrologic effectsof drylandshrubs, defining thespatial extentof modified soilwateruptakeratesatan Australian desertsite.JournalofArid Environments,45:159–172.
[46] Caldwell,M.M.and J.H. Richards.(1989).Hydraulic lift,watereffluxfromupperroots improveseffectivenessofwateruptakebydeep roots.Oecologia,79:1–5.
[47] Garner, W. and Y. Steinberger. (1989). Aproposed mechanism for the formation of‘fertileislands’inthedesertecosystem.JournalofAridEnvironments,16:257–262.[48]Romney,E.M.,A.Wallace,H.KaazandV.Q.Hale.(1980). theroleofshrubs on redistributionofmineralnutrientsinsoilinthe Mojave Desert.GreatBasin Naturalist Memoirs,4:124–133.
[49] Moorhead, D.L., F.M. Fisher and W.G.Whitford. (1988).Coverofspringannualson nitrogen richkangarroratmounds ina Chihuahuan Desertgrassland.American MidlandNaturalist,120:443–447.
[50] Hochstrasser, T., G. Kroel-Dulay, D.P.C.PetersandJ.R.Gosz.(2002).Vegetationand climatecharacteristics ofaridandsemi-arid grasslandsinNorthAmericaandtheirbiome transitionzone.JournalofAridEnvironments,51:55–78.
[51]Lauenroth, W.K.,O.E.Sala,D.P.Coffinand T.B.Kirchner.(1994). Theimportance ofsoil waterintherecruitmentofBoutelouagracilisin theshortgrasssteppe.EcologicalApplications,4:741–749.[52]Smith,S.D.,R.K.Monson andJ.E.Anderson. (1997).Physiological Ecology ofNorth American DesertPlants.Berlin:Springer-Verlag.286pp.
[53]Aguiar,M.R.andO.ESala.(1999). Patch structure, dynamics andimplications forthe functioning ofaridecosystems.Trendsin EcologyandEvolution,14:273–277.
[54] Tielborger, K. and R. Kadmon. (1997).Relationships betweenshrubsandannual communities inasandydesertecosystem,a three-yearstudy.PlantEcology,130:191–201.
[55] Walker, L.R., D.B. Thompson and F.H.Landau.(2000).Experimentalmanipulationsof fertileislandsandnurseplanteffects inthe MojaveDesert,USA.WesternNorthAmerican Naturalist,61:25–35.[56]Nielson,R.P.(1993).Transient ecotone response toclimatic change: someconceptual andmodelling approaches.Ecological Applications,3:385-395.
[1]Farns worth, N.R.(1990).The role of ethno pharma ecology in drug development.Ciba Found Symposium,154:2–11.
[2] Farnsworth, N.R.(1994).Ethnopharmacology and drug development. CibaFound Symposium,185:42–51.
[3] Solecki, R.andI.V.Shanidar. (1975). A Neanderthalflowerburialinnorthern Iraq. Science,190:880–881.
[4]Munzer, U.,M.Sarfraz, H.Ullah., M.U.Khan., M.Kanwal.(2021).Ethnomedicinal UsesofDifferentPlantsfortheTreatmentof AsthmainPakistan.BiomedicalJournalof ScienceandTechnologyResearch.36.BJSTR. MS.ID.005917
[5]SadiaA.,H.I.Ahmad,A.Jabbar,M.M.Tolba,S.AbouZid, N.Irm,F.Zulfiqar,M.Z.Iqbal,S. AhmadandZ.Aslam.(2021).UseofMedicinal PlantsforRespiratoryDiseasesinBahawalpur,Pakistan. BiomedicalResearchInternational.5578914.doi:10.1155/2021/5578914
[6]ShoaibG.,G.M.Shah,N.Shad,Y.Dogan,Z.Siddique,A.H.Shah,M.Farooq,K.R.Khan,A. Nedelcheva.(2020).Traditionalpracticesofthe ethnoveterinaryplantsintheKaghanValley, WesternHimalayas-Pakistan.RevistaBiologia Tropica.69:1–11.
[7] Wickens,G.E.(1998).Ecophysiology of economic plants in arid and semi-arid lands. Berlin: Springer.
[8] Lambers, H.; F.S. Chapin and T.L. Pons. (1998). Plant physiological ecology. New York, etc.:Springer.[9]Rachmilevitch,S.,M.D.Costaand B.Huang.(2006).Physiological and Biochemical Indicators for Stress Tolerance. In Bingru Huang(Ed.),Plant-Environment Interactions (3rded., pp. 321–355).New York:CRC Press, ISBN978-1-4200-1934-6.
[10] Akbar,G.,T.N.Khanand M.Arshad.(1996).Cholistan desert, Pakistan. Rangelands, 18:124-128.
[11] Akbar, G.andM.Arshad.(2000).developing sustainable strategies for Cholistan desert: opportunitiesandperspectives.ScienceVision 5:77-85
[12]Arshad,M.,M.Y.Ashraf,M.AhmadandF.Zaman.(2007).Morpho-genetic variability potentialofCenchrusciliarusL.,fromCholistan desert,Pakistan.PakistanJournalofBotany,39:1481-1488.[13]Arshad,M.,G.AkbarandS.Rashid.(2003).Wealth ofmedicinal plantsofCholistan desert,Pakistan:Conservational strategies. HamdaradMedicus,105:25-34.
[14]Ali,S.I.andM.Qaiser.(Eds)(1993–2011).Flora ofPakistan.Department ofBotany,University ofKarachi,Pakistan.Nos.194–218.
[15]Jain,S.K.(1995).AManualofEthnobotany,2ndEdition.ScientificPublishers,Jodhpur.
[16]Khan,S.S.(1993).Ethnomedicinalstudieson plantsofBhopaldistrict ofM.P,Ph.D.Thesis, BarkatullahUniversity,Bhopal.
[17] Jackson,M. L. 1967.Soilchemicalanalysis.NewDelhi:PrenticeHallofIndia.
[18] Duncan, D.B. (1955). Multiple Range andMultipleF-Test.Biometrics,11:1-42.
[19]Sperry,J.S.andU.G. Hacke.(2002).Desert shrubwaterrelationswithrespect tosoil characteristics andplantfunctionaltype. FunctionalEcology,16(3):367-378.
[20]Youssef,A.M.andM.A.Al-Fredan.(2008).Community compositionofmajorvegetations inthecoastalareaofAl-Uqair,SaudiArabiain responsetoecological variations. Journalof BiologicalScience,8(4):713-721.
[21] Glenn, E., R. Pfister, J.I. Brown., T.L.ThompsonandJ.W.O'leary.(1996).NaandK accumulation andsalttoleranceof Atriplexcanescens (Chenopodiaceae) genotypes.AmericanJournal of Botany, 83(8):997-1005
[22]Youssef,A.M.(2009). Salttolerance mechanisms insomehalophytesfromSaudi ArabiaandEgypt.Research Journalof AgricultureandBiologicalSciences,5(3):191-206.
[23]Farghali, K.A.(1998).Somephysiological adaptation infivedesertperennials:seasonal changesinionicandmetabolicsolutes.BulletinfacultyofScience,UniversityofAssiut,27:25-39.
[24]Wang X.Q.,J.Jiang,J.Q.Lei.(2004) Relationship betweenephemeralplants distributionandsoilmoistureonlongitudinal dunesurfaceinGur-bantunggut Desert. ChineseJournal of AppliedEcology,15(4):556–560.
[25] Gorham, J. (1990). Salt tolerance in the Triticeae: Ion discrimination in Rye and Triticale. Journal of Experimental Botany, 41(5):609–614.
[26] Khan,M.A.,I.A.UngarandA.M.Showalter. (2000).Effectsofsalinity ongrowth,water relationsandionaccumulation ofthe subtropical perennialhalophyte,Atriplex griffithiivar.stocksii.AnnalsofBotany,85(2):225-232.
[27] Brant,A.N.andH.Y.H.Chen.(2015).Patterns andmechanisms ofnutrientresorptionin plants.CriticalReviewinPlantScience.34,471–486.
[28] Yang, Y., B.R. Liu and S.S. An.(2018).Ecologicalstoichiometryinleaves,roots,litters andsoilamongdifferentplantcommunitiesin adesertifiedregionofNorthernChina.Catena166,328–338.
[29] Arshad,M.andG.Akbar.(2002). Benchmark ofplantcommunities ofCholistandesert. PakistanJournalofBiologicalScience,5:1110-1113.
[30]Cragg,G.M.;D.J.Newman andS.S.Yang. (2006). Naturalproductextractsofplantand marineoriginhavingantileukemia potential: theNCIexperience. JournalofNatural Products,69:488–498.
[31] Vinton,M.A.andI.C.Burke.(1995).Interactions betweenindividualplantspecies andsoilnutrient statusinshortgrasssteppe. Ecology,76:1116–1133.
[32]Hook, P.B.,I.C. Burke andW.R.Lanenroth. (1991).Heterogeneity insoilNandC associatedwithindividual plantsandopenings inNorthAmericanshortgrasssteppe.Plantand Soil,138:247–256.
[33] Schlesinger,W.H., J.F. Reynoldsand G.L.Cunningham.(1990).Biologicalfeedbacksin globaldesertification.Science,47:1043–1048.
[34]Schlesinger, W.H.,J.A,Raikes,A.E.Hartley andA.F.Cross.(1996).onthespatialpatternof soilnutrientsindesertecosystems.Ecology,77:364–374.
[35]Whitford,W.G.,J.AndersonandP.M.Rice. (1997).Stemflow contributiontothe‘fertile island’effectincreosotebush,Larreatridentata. JournalofAridEnvironments,35:451–457.
[36]Noy-Meir, I.(1973).Desertecosystems: environmentandproducers.AnnualReviewof EcologyandSystematics,4:25–51.
[37] Austin, A.T., L. Yahdjian, J.M. Stark, J.Belnap,A.Poporato,U.Norton,D.A.Ravetta andS.M.Schaeffer. (2004). Waterpulsesand biogeochemical cyclesinaridandsemiarid ecosystems.Oecologia,141(2):221–235.
[38]Guerrero-Campo,J.,F.Alberto,J.Hodgson,
J.M.Garcia-Ruiz,G.Montserrat-Marti.(1999).
Plantcommunity patternsinagypsumareaof NESpain:I.Interactions withtopographic factors andsoilerosion. JournalofArid Environments,41:401–410
[39]Li,J.R,G.S.Okin,I.AlvarezL,etal.(2008).Effects ofwinderosiononthespatial heterogeneity ofsoilnutrientsintwodesert grasslandcommunities.Biogeochemistry,88:73–88.
[40]Zuo,X.A.,H.L.Zhao,X.Y. ZhaoX.Y,etal (2008).Spatialpatternandheterogeneityofsoil properties insanddunesundergrazingand restoration inHorqinSandyLand,Northern China,SoilandTillageResearch,99:202–212.
[41]Wezel,A.,J.L.RajotandC.Herbrig,(2000).Influenceofshrubsonsoilcharacteristics and theirfunctioninSahelianagro-ecosystemsinsemi-aridNiger.JournalofAridEnvironments,44:383–398.
[42]Dhillion, S.S.(1999).Environmental heterogeneity, animaldisturbances,microsite character-istics,andseedlingestablishmentina Quercushavardii community.Restoration Ecology,7:399–406.
[43]Valiente-Banuet,A.andE.Ezcurra.(1991).Shadeasacauseoftheassociationbetweenthe cactusNeobuxbaumiatetetzo andthenurse plantMimosaluisanaintheTehuacan Valley, Mexico.JournalofEcology,79:961–971.
[44] Parsons, A.J., A.D. Abrahams and J.R.Simanton.(1992).Microtopographyandsoil-surfacematerials onsemi-aridpiedmont hillslopes, southernArizona.JournalofArid Environments,22:107–115.
[45]Dunkerly,D.(2000).Hydrologic effectsof drylandshrubs, defining thespatial extentof modified soilwateruptakeratesatan Australian desertsite.JournalofArid Environments,45:159–172.
[46] Caldwell,M.M.and J.H. Richards.(1989).Hydraulic lift,watereffluxfromupperroots improveseffectivenessofwateruptakebydeep roots.Oecologia,79:1–5.
[47] Garner, W. and Y. Steinberger. (1989). Aproposed mechanism for the formation of‘fertileislands’inthedesertecosystem.JournalofAridEnvironments,16:257–262.[48]Romney,E.M.,A.Wallace,H.KaazandV.Q.Hale.(1980). theroleofshrubs on redistributionofmineralnutrientsinsoilinthe Mojave Desert.GreatBasin Naturalist Memoirs,4:124–133.
[49] Moorhead, D.L., F.M. Fisher and W.G.Whitford. (1988).Coverofspringannualson nitrogen richkangarroratmounds ina Chihuahuan Desertgrassland.American MidlandNaturalist,120:443–447.
[50] Hochstrasser, T., G. Kroel-Dulay, D.P.C.PetersandJ.R.Gosz.(2002).Vegetationand climatecharacteristics ofaridandsemi-arid grasslandsinNorthAmericaandtheirbiome transitionzone.JournalofAridEnvironments,51:55–78.
[51]Lauenroth, W.K.,O.E.Sala,D.P.Coffinand T.B.Kirchner.(1994). Theimportance ofsoil waterintherecruitmentofBoutelouagracilisin theshortgrasssteppe.EcologicalApplications,4:741–749.[52]Smith,S.D.,R.K.Monson andJ.E.Anderson. (1997).Physiological Ecology ofNorth American DesertPlants.Berlin:Springer-Verlag.286pp.
[53]Aguiar,M.R.andO.ESala.(1999). Patch structure, dynamics andimplications forthe functioning ofaridecosystems.Trendsin EcologyandEvolution,14:273–277.
[54] Tielborger, K. and R. Kadmon. (1997).Relationships betweenshrubsandannual communities inasandydesertecosystem,a three-yearstudy.PlantEcology,130:191–201.
[55] Walker, L.R., D.B. Thompson and F.H.Landau.(2000).Experimentalmanipulationsof fertileislandsandnurseplanteffects inthe MojaveDesert,USA.WesternNorthAmerican Naturalist,61:25–35.[56]Nielson,R.P.(1993).Transient ecotone response toclimatic change: someconceptual andmodelling approaches.Ecological Applications,3:385-395.