学科分类
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32 个结果
  • 简介:Thepatternofprecipitation,includingprecipitationamount,frequencyandintensity,maychangeinthefutureaccordingtothepredictionofclimatechange.Inaridzones,thesoildynamics,plantgrowthandvegetationchange,desertificationandhydrologymightbeaffectedbyprecipitationchange.Ingeneral,theprecipitationinextremearidzoneandaridzoneshowedanincreasetendencywhereastheprecipitationinsomeareainsemi-aridzoneandsub-humidaridzoneshowedadecreasetendency.Theincreaseofprecipitationcouldenhancethegrowthofbiologicalsoilcrust,improvesoilwaterstatus,promoteplantgrowth,increasevegetationcoverage,facilitatethechangefromdesertvegetationtograsslandvegetation,anditisbenefittothereversionoflanddesertification.Inaddition,theincreaseofprecipitationcouldalsoincreasetheriverrunoff,lakestorageandpromotetheoccurrenceofflood,whilethedecreaseofprecipitationhastheadverseeffect.Thesestudieswillbenefitthepredictionofthepossibleresponseofecosystemprocessestothepotentialchangeofprecipitationpatterninaridzonesinthefuture,anditisimportanttotheconservationofnaturalvegetationandthecontrolofdesertification.Morefieldexperimentsandstudiesshouldbeconductedinthefuture,includingtheeffectofincreasedprecipitationortemperature,nitrogendepositionandCO2onsoil,vegetation,desertificationandhydrologyofaridzones,soasthemorepersuasiveresultscouldbeobtainedfromtheseexperimentsandstudies.

  • 标签: ARID zone PRECIPITATION CHANGE soil CHANGE
  • 简介:Background:WithfarmlandafforestationbecomingcommonpolicyinmanyEuropeanUnioncountries,westudiedhowearlyforestsuccession(frommeadowtoyoungstand)influencessmallmammalspeciescomposition,diversity,abundanceandbiomass.Despitenumerousinvestigationsintoforestsuccession,almostnoattentionhasbeengiventothesmallmammalcommunitychangeintheearly-successionalforestecosystems,startingwiththepre-foresthabitatandendingwithstandformationandtheestablishmentoftreedominance.Wecomparedsmallmammalcommunitiesinmeadowsattheinitialstageofregrowth(withsaplingslessthan10cminheight),inyoungforest(5–10yearsold)andmoreadvancedforest(15–20years)inbothcasesofhuman-inducedforestsuccession,wherethetreeshadbeenplanted,andnaturalforestsuccession,wherenaturalregrowthofmeadowshadoccurred.Results:Thegreatestdiversityofsmallmammalspecieswasrecordedinthemeadow(H=2.95),withalowerdiversityfoundintheyoungforest(H=2.61)andevenlowerintheadvancedforest(H=2.04),thelasthabitatbeingthemostmonodominantic.TheorderofspeciesdominancefromMicrotussp.(M.arvalis,M.agrestis),Myodesglareolus,Apodemusflavicollis,Sorexaraneus,A.agrariusinthemeadowchangedtoM.glareolus,S.araneus,M.arvalis,M.agrestisintheyoungforestandtoM.glareolus,A.flavicollis,S.araneusintheadvancedforest.Thelowestrelativeabundanceofsmallmammalswasrecordedinthemeadow(18.19±2.27ind.Per100trap-days),withMicrotusvolesbeingthemostabundant.Relativeabundancewashigherintheyoungforest(22.72±2.25ind.Per100trap-days),withMyodesglareolusbeingthemostabundant(7.59±0.96ind.Per100trap-days)andatitshighestintheadvancedforest(23.91±2.77ind.Per100trap-days),againwithM.glareolusbeingthemostabundant(15.54±2.35ind.Per100trap-days).Conclusions:Thus,ouranalysissuggeststhatthatduringearlymeadow-forestsuccession,thediversityofthe

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  • 简介:氮使用效率(NUE)在中国是很低的,差不多70%应用的氮化肥的损失在high-yielding稻田被报导。以便调查高亲密关系的铵运输或举起的分子的基础进米饭(OryzasativaL.),我们分析了九铵的表示侧面transporters(AMT),OsAMT1的三各个,OsAMT2和OsAMT3,根据外部N地位在象在这些表示模式的变化一样的米饭生长的二个不同N要求阶段(年轻幼苗阶段和tillering阶段)使用即时反向的抄写聚合酶链反应(RT-PCR)。结果建议九OsAMT基因在米饭植物的不同机关被表示,包括成熟的根,新根,茎,旧叶子和新叶子并且表示模式是相应蛋白质的位置在种系发生的树上特定、独立的机关。OsAMT1;1,3;2和3;3在根和射击被表示,首先旧的叶子,OsAMT1;2和1;3主要在根,和OsAMT2;1,2;2,2;3和3;1主要在射击,首先在新叶子,并且相对更在里面茎比另外的基因。在二个不同N要求阶段的表示模式是一样;在有更大的N要求的tillering阶段,然而,OsAMTs抄本层次比在有低N要求的年轻幼苗阶段的那些大。为48h的N饥饿起来调整的OsAMT1;1,1;2,3;1,3;2,3;3并且下面调整的OsAMT1;3mRNA丰富。后面的N饥饿,NH4+和NH4NO3再供给下面调整的OsAMT1;2和3;3并且起来调整的OsAMT1;3,而NO3再供给下面调整的OsAMT1;1和1;2。这些建议OsAMT的器官特定的表示模式能被N要求和外部N地位调整。

  • 标签: 表达模式 水稻植株 氮素营养 硝酸铵 转运体 逆转录聚合酶链反应
  • 简介:Time-temperaturesuperpositionprinciple(TTSP)wasusedtoexaminedynamicviscoelasticpropertiesofChineseFir(Cunninghamialanceolata)woodatanextremelylowmoisturecontent(0.6%).Storagemodulusandlossfactordatawereobtainedatdifferentconstanttemperaturesrangingfrom25℃to150℃infrequencymultiplexingexperiments(0.1-20Hz).Allviscoelasticcurvesatothertemperatureswereshiftedalongthelog-frequencyaxistosuperimposethemonareferencetemperature(i.e.135℃inthisstudy)curve.Theextendedstoragemodulusandlossfactorisothermalmastercurveswereoverawiderangeoffrequency.TheshiftfactorsweredeterminedtobeafunctionoftemperatureandfittedintotheArrheniusequationwiththeleastsquaresmethod.TheresultsshowedthatthestoragemodulusdatawereexcellentlyfittedintotheArrheniusmodel,indicatingthevalidityofthemodeltocharacterizethedynamicstiffnessbehaviorofdrywoodintherangeof25-150℃usingtheTTSP.However,thetime-temperatureequivalencewasnotabletopredictthedampingproperties.

  • 标签: Chinese FIR dynamic VISCOELASTIC property time-temperature
  • 简介:Globalclimatechangehascausedphenologychangeofvegetation.Thisisespeciallyobviousinurbanarea.ThispaperrevealsresponsemechanismofspringphenologyofmaingymnosperminHarbinCitypropertoclimatechangebasedonrelationshipstudybetweentwotypicalphenophases(beginningofbudburstandbeginningofleafexpansion)ofKoreanpine(Pinuskoraiensis),Koyamaspruce(PiceakoraiensisNakai),needlefir(Abiesnephrolepis)andPinussylvestnisvar.mongolicaLitv.andthetemperatureofeveryten...

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  • 简介:Climatechangeisagreatconcernofvariouscountries,thepublicandsciencecommunity,andforestplaysanimportantroleinmitigatingclimatechange.ThepapermadeacomprehensiveanalysisregardingthepolicyselectionsofChinatopromoteforestryresponsetotheglobalclimatechange,andelaboratedtheconcreteactionsandachievementsinthisregard.Policyselectionsinclude:1)Reinforcetreeplantingandafforestation,increasetheforestedareaandenhancethecapacityofcarbonsequestration...

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  • 简介:ThisstudywasconductedintheHuoditangnaturally-regeneratedforest,whichislocatedatthecenterofthenaturalforestregionacrossthesouthern-slopeoftheQinlingMountains.Rainwaterandstreamwatersampleswerecollectedmainlyinrainyseasonsinthearea.ThesamplepHvaluesandchemicalconcentrationsweremeasured.Theresponseofstreamwaterchemistrytorainwateracidificationintheregionwasstudied.TheresultsshowedthatlongtimerainwateracidificationcouldresultinreductionofpHvalue,Ca2+andMg2+concentrationinthestreamwater.ThechangesofK+,Na+concentrationofstreamwaterwerenotcorrelatedwiththerainwateracidification.TherewasnoresponseofZn,PbandCdconcentrationofthestreamwatertorainwateracidification.Theacidifiedrainwaterdidnotresultinthereleaseoftheheavymetalsenrichedintheforestsoil.

  • 标签: QINLING MOUNTAINS FOREST water CHEMISTRY RAINWATER
  • 简介:一个水耕法的文化实验被做在谷胱甘肽内容(GSH)和谷胱甘肽S-transferase上调查Cd应力的效果(GST,EC2.5.1.18)在稻秧的活动。当在答案的Cd水平比10mg/L高时,米饭生长严重地被禁止。在米饭射击,,GSH内容和GST活动在根与增加的Cd水平增加了,GST被Cd处理显然禁止。与射击相比,米饭根有更高的GSH内容和GST活动,显示Cd解毒的能力在比在射击的根是高得多的。在Cd水平和GSH内容或GST活动之间有重要关联,建议两个参数可以被用作在米饭的Cd应力的简历标记。

  • 标签: 谷胱甘肽 稻子 S-转移酶 幼苗
  • 简介:Amultipurposecloneplantspecies,Hippophaerhamniodeshasthecapacityforindefinitelongevity,althoughundersuccessivedroughtstressitmayoftendeclineordieacrosslargeareas.Fieldtrialswereconductedover2yearstoexaminetheeffectsofvariedirrigationintensitiesonmodulargrowthandclonalpropagationinasemi-aridarea.Irrigationlevelsincludedacontrol,aswellastwo,fourandsixtimesthevolumeofwaterthatwastypicallyreceivedvialocalannualaverageprecipitation.Irrigationintensitysignificantlyinfluencedclonalpropagationcapacity(numberofdaughterramets),abovegroundmodulargrowth(height,basediameter,andcrownwidth),belowgroundmodulargrowthincludedrootnoduledryweight,stretchingcapacityoflateralroots(lengthofthelongestlateralroots,anddiameteroffirstgradelateralroots),andbranchingintensityoflateralroots(numberoflateralrootsbifurcationgrade,numberoffirstgradelateralroots).Themodulargrowthandthedensityofdaughterrametsweresmallundernon-irrigationorlowirrigation,andbecamelargerwithincreasedirrigationintensity.Beyondacertainthreshold,however,furtherincreasesinirrigationintensityresultedinareversiontothedevelopment.Theoptimalirrigationintensitiesforgrowthandpropagationwere3.48–5.29timesthevolumeofnominallocalannualaverageprecipitation.Therewereeffectsofirrigationintensitiesonthepositivesignificantcorrelationsbetweenabovegroundandbelowgroundmodulargrowths,andonclonalpropagationcapacities.Undervariouswatertreatments,H.rhamnoidesmayadapttotheenvironmentthroughtheregulationofgrowthandpropagation.WeconcludedthatwatershortagesacttoweakenthegrowthandpropagationofH.rhamniodesplantations.

  • 标签: 灌溉水平 构件生长 繁殖能力 反应强度 模块化 沙棘
  • 简介:火的相互作用骑车,植物硬币的繁殖特征能决定一处风景的植被分发模式。在加拿大的北方的区域,火在小冰川期前骑车(c。1850年代)以后从30-130年和25-234年直到解决时期(c。1930年代)什么时候更长发射周期,响应气候变迁和人的干扰发生了。分析显示火周期与生长期(4月10月)被相关从1961-1990正常的温度和降水离开,由区域变化。假设野火将在过去的世纪,用气候变迁情形CGCM1的一个评价,CGCM2和HadCM2期间对类似于方式的温暖的未来作出回应显示周期将在西方泰加森林盾转移到80-140年的一个范围的火,为北方的盾和东方泰加森林防护的东方的超过700年,和为在2050的北方的平原的300-400年。

  • 标签: 加拿大 北部地区 北方针叶林 森林 火灾周期 全球气候变化
  • 简介:Exogenousapplicationofspermidine(Spd)hasbeenreportedtomodulatephysiologicalprocessesandalleviatesalt-induceddamagetogrowthandproductivityofseveralplantsincludingrice.Employingaproteomicapproach,weaimedatidentifyingriceleafandgrainproteinsdifferentiallyexpressingundersaltstress,andinresponsetoSpdpriortoNaCltreatment.Atotalof9and20differentiallyexpressedproteinspotswereidentifiedintheleavesofsalt-tolerant(Pokkali)andsaltsensitive(KDML105)ricecultivars,respectively.Differentialproteinscommontobothcultivarsincludedaphotosyntheticlightreactionprotein(oxygen-evolvingcomplexprotein1),enzymesofCalvincycleandglycolysis(fructose-bisphosphatealdolaseandtriose-phosphateisomerase),malatedehydrogenase,superoxidedismutaseandahypotheticalprotein(OsI18213).MostproteinswerepresentathigherintensitiesinPokkalileaves.Thephotosyntheticoxygen-evolvingenhancerprotein2wasdetectedonlyinPokkaliandwasup-regulatedbysalt-stressandfurtherenhancedbySpdtreatment.AllthreespotsidentifiedassuperoxidedismutaseinKDML105wereup-regulatedbyNaClbutdown-regulatedwhentreatedwithSpdpriortoNaCl,indicatingthatSpdacteddirectlyasantioxidants.Importantdifferentialstressproteinsdetectedinmaturegrainsofbothricecultivarswerelateembryogenesisabundantproteinswithprotectiverolesandanantioxidantprotein,1-Cys-peroxiredoxin.HighersalttoleranceofPokkalipartlyresultedfromhigherintensitiesandmoreresponsivenessoftheproteinsrelatingtophotosynthesislightreactions,energymetabolism,antioxidantenzymesintheleaves,andstressproteinswithprotectiverolesinthegrains.

  • 标签: 蛋白质组学 籽粒蛋白质 水稻叶片 盐诱导 亚精胺 超氧化物歧化酶
  • 简介:Membersoftheactivityofbc1complex(ABC1)familyareproteinkinasesthatarewidelyfoundinprokaryotesandeukaryotes.PreviousstudiesshowedthatseveralplantABC1genesparticipatedintheabioticstressresponse.Here,wepresentthesystematicidentificationofriceandArabidopsisABC1genesandtheexpressionanalysisofriceABC1genes.Atotalof15and17ABC1genesfromthericeandArabidopsisgenomes,respectively,wereidentifiedusingabioinformaticsapproach.Phylogeneticanalyseso...

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  • 简介:Nitrogenousfertilisersareunderconsiderationforpromotingthegrowthofnursery-rearedhooppine(AraucariacunninghamiiAitonexA.Cunn)seedlingsintheestablishmentphaseofsecondrotation(2R)plantations.Using15N-labelledfertilisers,weinvestigatedtheeffectofdifferentforms(ammoniumsulphate,ammoniumnitrate,potassiumnitrateandurea)andratesofapplication(0,150and300mgNkg-1driedsoil)offertilisersonthegrowth,15Nrecoveryandcarbonisotopecomposition(δ13C)ofhooppineseedlingsina12-monthglasshousetrialinsoutheastQueensland,Australia.The15N-labelledfertiliserswereappliedtonursery-rearedhooppineseedlings,whichwerethengrowninpots,containingca.1.2kgdriedsoil,underwellwateredconditionsfor12months.Fourseedlingsfromeachtreatmentwereharvestedat4-monthintervals,dividedintoroots,stemandfoliage,withafurthersubdivisionfornewandoldfoliage,andthenanalysedfor15N,totalN,δ13CandtotalC.Therewasnosignificantresponseintheseedlinggrowthtotheformorrateofapplicationofnitrogen(N)fertiliserwithinthe12-monthperiod,indicatingthattheseedlingsdidnotexperienceNdeficiencywhengrownonsecondrotationhooppinesoils.Whilethecombined15Nrecoveryfromsoilandplantremainedataround70%throughouttheexperiment,theproportionof15Nrecoveredfromtheplantsincreasingsteadilyovertime.Nitratecontainingfertilisersat150mgNkg-1soilgraduallyincreasedseedlingfoliageδ13Coverthe12-monthperiod,indicatinganincreaseinseedlingwateruseefficiency.

  • 标签: 肯宁南洋杉 水利用效率 森林土壤
  • 简介:三个米饭变化,Zhonghan3,Shanyou63和Aizizhan,当在检测微分活跃甲基的材料骑车并且响应干旱应力转移相关基因表示,被使用。实验被在干旱的条件下面的微分显示器技术与10%PEG6000答案模仿了的基因薄片和mRNA执行。结果显示甲基周期能在Zhonghan3和Shanyou63的叶子被激活,但是在干旱应力下面在Aizizhan的叶子禁止了。而且,干旱应力能导致很多methyltransferase基因的表示,特别Rubisco蛋白质methylation的抄写联系了基因,它是有益的因为Rubisco蛋白质氧化和降级的预防,和干旱应力能禁止DNAmethyltransferase基因和histonemethyltransferase基因的抄写。这结果证实活跃甲基骑车并且转移相关基因涉及米饭干旱抵抗。

  • 标签: 干旱胁迫 水稻叶片 基因表达 活性 移相 MRNA差异显示技术
  • 简介:一个实验被进行用荧光灯的微分显示器(软式磁碟机)方法在干旱应激和正常条件下面在米饭叶子和根比较信使rna表达式差别。一积极碎片被H.A的联合孤立黄页(contained0.1%H.A。黄)分离和宏数组屏蔽方法。比作ArabidopsisthalianaNADPH氧化还原酶基因,它有96%身份。cDNA是1423bp,并且包含了与345氨基酸残余编码蛋白质的1048bp的一个完全的开的读物框架。而且,基因表示水平在正常条件下面比那在干旱应激下面是更高的。在干旱反应下面的NADPH氧化还原酶基因的可能的角色也被讨论。

  • 标签: 水稻 干旱压力 还原型辅酶II类氧化还原酶基因 克隆化 基因表达
  • 简介:WecollectedacornsfromselectedQuercusroburandQuercuspetraeamothertreesgrowingatstationswithdifferentdepthstothewatertable.Weproducedpairsofmicro-cuttingsfromthesesingleacorns.Theobtainedpairsofcuttingsrepresentedphenotypesofhighsimilarityaccordingtophotosyntheticparameters.Thesepairsofcuttingswereusedtotesttheplasticityofresponsetocontrastingwaterregimes.Foreachpair,onecuttingwassubmittedtodroughtandtheotherwassubmittedtowaterlogging.Droughtresponsewasrecordedaccordingtogasexchangetraits(stomatalclosureandwateruseefficiency).TheresponsetowaterloggingwasrecordedaccordingtothecapacitytoformhypertrophiedlenticelsandtomaintaintheCO2assimilationrate.Intermediaryphenotypespresentingbothhighwateruseefficiencyandthecapacitytodevelophypertrophiedlenticelswereexpected.

  • 标签: 土壤水分 微扦插 可塑性 橡子 测试 水分利用效率
  • 简介:FieldexperimentswereconductedintheEbroDeltaarea(Spain),from2007to2009withtworicevarieties:GlevaandTebre.Theexperimentaltreatmentsincludedaseriesofseedrates,twodifferentwatermanagementsystemsandtwodifferentnitrogenfertilizationtimes.Thenumberofleavesonthemainstemsandtheiremergencetimewereperiodicallytagged.Theresultsindicatedthatthefinalleafnumberonthemainstemsinthetworicevarietieswasquitestableoverathree-yearperioddespiteofthedifferencesintheirrespectivegrowthcycles.Interactionbetweennitrogenfertilizationandwatermanagementinfluencedthefinalleafnumberonthemainstems.Plantdensityalsohadasignificantinfluenceontherateofleafappearancebyextendingthephyllochronandpostponingtheonsetofintraspecificcompetitionaftertheemergenceofthe7thleafonthemainstems.Finalleafnumberonthemainstemswasnegativelyrelatedtoplantdensity.Arelationshipbetweenleafappearanceandthermaltimewasestablishedwithastrongnonlinearfunction.Indirect-seededrice,thelengthofthephyllochronincreasesexponentiallyinlinewiththeadvanceofplantdevelopment.Ageneralmodel,derivedfrom2-yearexperimentaldata,wasdevelopedandsatisfactorilyvalidated;ithadarootmeansquareerrorof0.3leaf.Anexponentialmodelcanbeusedtopredictleafemergenceindirect-seededrice.

  • 标签: 施肥时间 水稻品种 种植密度 直播稻田 外观 主茎叶片数
  • 简介:Plantationsofeucalyptsasshort-rotationtreecropsarerapidlyexpandingintropicalandsub-tropicalregions,includingsouthernChina,wherethesoilsareacidicandavailablephosphorus(P)islimited.Weinvestigatedseedlinggrowth,drymatteraccumulation,andthedynamicsofphotosyntheticrateandchlorophyllcontentofsevenEucalyptusspecies/hybrids(E.dunnii,E.grandis,E.grandis×E.camaldulensis,E.urophylla×E.camaldulensis,E.urophylla×E.tereticornis,E.grandis×E.tereticornis,E.urophylla×E.grandis)inresponsetodifferentlevelsofPsupply(0,6,12and18mg?kg-1KH2PO4).ThephotosyntheticrateandthechlorophyllcontentsignificantlydeclinedasthePsupplydeclinedinalmostalinearfashionforallspeciesasthePstressperiodextended.IntheabsenceofPsupply,heightgrowthofseedlingsofallspecieswassignificantlyimpaired,whilerootcollardiametergrowthandwholeplantdrymatteraccumulationwasnotaffectedbythelevelofPsupplyinmostofthespecies.Significantinter-speciesvariationsingrowth,drymatteraccumulationandphotosyntheticrateinresponsetoPsupplyweredetected.EucalyptusdunniihadthelowestgrowthperformanceacrossalllevelsofPsupplywhileE.urophylla×E.tereticornisshowedsuperiorgrowthperformance.Fromapracticalpointofview,E.urophylla×E.tereticornisissuggestedasacandidatehybridforplantingonslightlyP-deficientsitesinsouthernChinawhileE.dunnii,beingaslow-growingspecies,isnotsuitableforshort-rotationplantation.OnplantationsiteswhereseverePdeficiencyexists,Pfertilizationneedstobeconsideredtoboostrapidgrowthofseedlingssoastomeetthemanagementobjectivesofshort-rotationplantation.

  • 标签: 干物质积累 光合速率 供磷水平 桉树 亚热带地区 叶绿素含量
  • 简介:Effectsofshadingatthefloweringandgrainfillingstagesonosmoticregulationsubstancecontentandprotectiveenzymeactivitiesintheleavesofdifferentricegenotypes(e.g.,IIyou498,Gangyou188,Dexiang4103,Gangyou527andChuanxiang9838)wereinvestigated.TheresultsshowedthatthemalondialdehydecontentofGangyou188significantlyincreasedundershading,whereasthoseofIIyou498,Dexiang4103,Gangyou527andChuanxiang9838showednosignificantdifferencescomparedtothecontrol.ThesolublesugarcontentsignificantlydecreasedinIIyou498,Gangyou188,Dexiang4103andChuanxiang9838,whereasitdidnotsignificantlyincreaseinGangyou527undertheweaklightconditions(shading).Moreover,thesolubleproteincontentintheleavesofdifferentgenotypestendedtodecreaseundershading.Further,theprotectiveenzymeactivitiesintheleavesvariedindifferentricegenotypesundertheshadingtreatment.Basedontheosmoticregulationsubstancecontentandtheprotectiveenzymeactivitiesintheleavesofdifferentricegenotypes,itwasconcludedthatGangyou188andGangyou527hadstrongabilitiestoadapttothelowlightconditions.Inaddition,themechanismofdamagetoriceleavesindifferentgenotypesundershadingwasdiscussed.

  • 标签: 水稻基因型 保护酶活性 物质含量 渗透调节 叶片损坏 着色