不同放牧強度下短花針茅草原主要植物種群的繁殖特性.pdf

1、內(nèi)蒙古農(nóng)業(yè)大學碩士學位論文不同放牧強度下短花針茅草原主要植物種群的繁殖特性姓名：侯牡丹申請學位級別：碩士專業(yè)：生態(tài)學指導教師：王明玖20080601ReproductiveCharacteristicsofDominatedPopulationinStipabrevifloraDesert—steppeunderDifferentGrazingIntensitiesAbstract111eexperimentwasconductedin

2、SiziwangdesertgrasslandinInnermongoliawhichweredividedinto3differentgrazingintensitiesandachecktreatment，ieHeavyGrazing(HG)，ModerateGrazing(MG)，light—grazing(LG)，andcheck(CK)，withO93、182、271，0sheepunits／hm2／halfyearrespe

3、ctivelymreproductivecharacteristicsofthemainplantsinStipabrevifloradesertsteppefrom3aspectsofvegetativepropagation，soilseedbankandthecorrelationbetweenabovegroundvegetationweresystematicallyinvestigatedinperiodoffromJune

4、toSeptember2007InfluenceofgrazingontheirproductivebehaviorthemainplantswerediscussedfromtheangleofplantadaptationtothelocalenvironmentThemainresearchresultswereasfollows：1LGtreatmentWasmorebenefittovegetativepropagationo

5、fallspecies，andCKtreatmenttookthesecondplace。功eArtemisiafrigidahadastrongvegetativepropagationcapabilityItcouldproduceplentifulbranchesandadventitiousrootsingrazingtreatments眥occupiedlargestcreepingareasinLGRhizomeslengt

6、hofLeymuschinensisdecreasedbyincreasingthegrazingintensityAndthenumberofnodeoftherhizomeWaslargestinHG，leastinlightgrazing，middlepositioninCKandMGThenumberofgerminationbranchesofLeymuschinens括WashighestinLGsecondinCKandl

7、owestinHG；butallwerenotsignificantlydifferenceThetillernumberofStipabrevifloraanditscoverageinLGwerehigherthaninothertreatments111ebigbunchesofStipabreviflorawerebrokenintomanysmallbunchesinHGthatincreasedthedensityofbun

8、ches2hlalltreatmentstheseedpercentageofperennialplantinsoilseedbankWaspredominate，andthepercentageWasupto4348％mpercentageoftheseedofannualandbiannualplantWasquitehigh，upto3971％Semishrubupto1606％neeffectofgrazingonthedens

9、ityofsoilseedbankWassignificantTlledensityofsoilseedbankWashighestincheckplot，8394__21808grairdmzandsignificantlydifferencefromHG，MGandLG(P005)3ThesimilaritybetweenabovegroundvegetationandtheseedcompositioninsoilWaslowes

10、tinHGwith182％similaritycoefficientThedensityofsoilseedbankWashighestinAugust，secondinJulyandlowestinSeptember4Spatialdistributionofthesoilseedbankdifferencedsignificantlyespeciallytheverticaldistributionofthesoilseedbank