简介：研究被进行在C在碱新陈代谢的变化上调查高温的效果。升起我们在福雷斯特植物生态学的关键实验室的幼苗，东北林地大学，Heilongiang，中国。60-day-oldC。玫瑰我们有34片叶子的幼苗与30°C的温度在房间被孵化；为短期的热的40°C震惊实验；20°C，25°C；为长期的实验的35°C。vindoline的内容，catharanthine，vinblastine；在C的长春新碱。玫瑰我们离开；根在短术语(16h)在不同温度被检查；长期(116d)。结果在短期的热吃惊下面显示出那，vindoline的内容，catharanthine；在幼苗的叶子的vinblastine在40°C是更高的与比在30°C，但是在6h处理以后，vindoline的内容；在二温度下面的catharanthine来到了一样的水平。Catharanthine只在C被散布。升起我们根；它的内容被40%在40°C在二小时孵化以后增加，当在30°C孵化慢慢地增加了时；在6h到达了最高的价值。在长期的实验，monomeric碱catharanthine的集中；vindoline比在25°C在20°C是更高的；在35°C的条件下面有锋利的增加。当时为二聚的碱，越高，看了那温度，vinblastine内容的山峰价值越earlier出现。长春新碱有连续改进；达到了0.027mg·g[1]在在比处于另外的条件的那些高的35°C状况下面的第16白天。高温能在C支持不同的碱的累积，这被结束。升起我们；累积特征是高度与处理时间有关。

简介：Plantationresourceisanimportantcomponentofforestresources.OverallplantationqualityisnothighinChina,andtheproblemslikelowgrowth,lowpreservingrateandlowproductivityarecommonlyobserved.Thispaperreviewedthehistoricalbackgroundoftheresearchonplantationproductivity,describedfactorsaffectingplantationproductivityincludingsiteconditions,initialplantingdensity,thinningmeasures,groundclearance,andcontinuousplantedalgebraandfertilization.Finally,itwasproposedtocarryoutkeytechnologysystemresearchonplantationproductivitymaintenanceandstrengthentheresearchonthelong-termness,systematicdevelopmentandmulti-purposeofplantationproductivity.

简介：ThenitrogendepositionexperimentsonCinnamomumcamphoraplantationofHunanprovincialbotanicalgardenweresimulatedfromJunethe7thtoOctoberthe7th,2010,thenitrogendepositionlevelswasrespectivelyascontrol(CK,0g·m-2a-1),lownitrogen(LN,5g·m-2a-1),mediumnitrogen(MN,15g·m-2a-1)andhighnitrogen(HN,30g·m-2a-1).ThesoilrespirationspeedandsoilsurfacetemperatureandthesurfacewatercontentofthesoilweredeterminedbyLI-8100measuringinstrument.TheresultsshowthattheaveragevaluesofsoilrespirationspeedwereCK(4.09±0.66μmol·m-2s-1),LN(2.39±029μmol·m-2s-1),MN(2.18±0.19μmol·m-2s-1),HN(2.28±0.25μmol·m-2s-1),andthetreatmentoftheCKwasobviouslyhigherthantheotherthreetreatments（P<0.01）.Withdifferentnitrogenconcentrationsdepositiontreatments,theQ10（temperaturesensitivitycoefficients）forsoilrespirationofCK,LN,MNandHNtreatmentswere1.84,1.71,1.83and1.56.Itwaspositivecorrelationbetweentherespirationspeedandthesurface（≤10cm）temperatureoftestedsoil.Itwasnegativecorrelationbetweentherespirationspeedandthesurface（≤5cm）watercontentoftestedsoil（P>0.05）.Volumetricwatercontentof5-cmsoilwasbetween0.2666-0.2944(m3·m-3),andthemonthlycontentdidnotvarytoomuchduringtheresearchperiod（1.8%-9.4%）.ThefindingssuggestthattheinitialstageofnitrogendepositionobviouslyinfluencedthesoilrespirationofC.camphoraplantation.

简介：Along-termexperimentbeginningin1981inJinxianCountyofJiangxiProvince,subtropicalChina,wasconductedinapaddyfieldunderadoublericecroppingsystemwithfourdifferentfertilizationregimes,including1)nofertilizerascontrol(CK),2)balancedchemicalN,P,andKfertilizers(NPK),3)organicmanureusingmilkvetchandpigmanureintheearlyandlatericegrowingseason,respectively(OM),and4)balancedchemicalfertilizerscombinedwithorganicmanure(NPKM).Samples(0-17cm)ofthepaddyfieldsoil,whichwasderivedfromQuaternaryredclay,werecollectedafterthelatericeharvestinNovember2003fordeterminationoftotalorganiccarbon(TOC)andtotalnitrogen(TN)andfractionsoforganicCandN.ResultsshowedthatTOCandTNintheNPKMandOMtreatmentsweresignificantlyhigherthanthoseinothertwotreatments(CKandNPK).ApplicationoforganicmanurewithorwithoutchemicalfertilizerssignificantlyincreasedthecontentsofallfractionsoforganicCandN,whereaschemicalfertilizerapplicationonlyincreasedthecontentsofoccludedparticulateorganicC(oPOC)andaminoacidN.Inaddition,applicationoforganicmanuresignificantlyenhancedtheproportionsoffreeparticulateorganiccarbon(fPOC)andoPOCintotalC,andthoseofaminosugarNandaminoacidN(P<0.01)intotalN.Incontrast,chemicalfertilizerapplicationonlyincreasedtheproportionsofoPOCandaminoacidN(P<0.05).TherewerenosignificantdifferencesineithercontentsorproportionsofsoilorganicCandorganicNfractionsbetweentheNPKMandOMtreatments.TheseindicatedthatorganicmanureapplicationwithorwithoutchemicalfertilizersplayedthemostsignificantroleinenhancingsoilorganicCandNquantityandqualityinthepaddyfieldstudied.

简介：A15-yearfertilizationexperimentwithdifferentapplicationsofinorganicN,PandKfertilizersandfarmyardmanure(M)wasconductedtostudytheyieldandsoilresponsestolong-termfertilizationatQiyang,HunanProvince,China.Averagegrainyieldsofwheatandcorn(1672and5111kgha-1,respectively)forthetreatmentNPKMweresignificantlyhigherthanthose(405and310kgha-1)oftheunfertilizedcontrolandsingleinorganicfertilizertreatments.Comparedwiththecorrespondinginitialvaluesoftheexperiment,alltreatmentsshowedayielddeclineof9to111kgha-1year-1inwheatand35to260kgha-1year-1incorn,respectively,andasignificantpHdeclineof0.07to0.12pHyear?1,exceptforthetreatmentsPKandNPKM.Afterlong-termfertilization,thesoilorganicC,soilavailableP,exchangeableCa2+andMg2+andavailableCu2+andZn2+contentswerehigherinthetreatmentNPKMthaninthetreatmentsappliedwithinorganicfertilizeronly.ComparedtothetreatmentNPK,thetreatmentNPKM,wheremanurepartiallyreplacedinorganicN,hadapositiveimpactonarrestingthedeclineofsoilpH.Thisimprovedgrainyieldsofwheatandcorn,suggestingthatapplicationofNPKfertilizerincombinationwithfarmyardmanureisimportanttomaintainsoilfertilityandbufferingcapacityinredsoil.

简介：Background:InWesternNorthAmerica,increasingwildfireandoutbreaksofnativebarkbeetleshavebeenmediatedbywarmingclimateconditions.Bioclimaticmodelsforecastthelossofkeyhighelevationspeciesthroughouttheregion.Thisstudyusesretrospectivevegetationandfirehistorydatatoreconstructthedriversofpastdisturbanceandenvironmentalchange.Understandingtherelationshipamongclimate,antecedentdisturbances,andthelegacyeffectsofsettlement-eraloggingcanhelpidentifythepatternsandprocessesthatcreatelandscapessusceptibletobarkbeetleepidemics.Methods:Ouranalysisusesdatafromlakesedimentcores,standinventories,andhistoricalrecords.Sedimentcoresweredatedwithradiometrictechniques(~(14)Cand~(210)Pb/~(137)Cs)andsubsampledforpollenandcharcoaltomaximizethetemporalresolutionduringthehistoricalperiod(1800CEtopresent)andtoprovideenvironmentalbaselinedata(last10,500years).Pollendataforsprucewerecalibratedtocarbonbiomass(Ct/ha)usingstandardallometricequationsandatransferfunction.Charcoalsampleswereanalyzedwithstatisticalmodelstofacilitatepeakdetectionanddeterminefirerecurrenceintervals.Results:TheWasatchPlateauhasbeendominatedbyEngelmannspruceforestsforthelast~10,500years,withsubalpinefirbecomingmoreprominentsince6000yearsago.Thislandscapehasexperiencedadynamicfireregime,whereburningeventsaremorefrequentandofhighermagnitudeduringthelast3000years.TwoimportantdisturbanceshaveimpactedEngelmannspruceinthehistoricalperiod:1)high-gradeloggingduringthelate19~(th)century;and(2)ahighseveritysprucebeetleoutbreakinthelate20~(th)centurythatkilled>90%ofmaturespruce(>10cmdbh).Conclusions:Ourstudyshowsthatspruce-dominatedforestsinthisregionareresilienttoarangeofclimateanddisturbanceregimes.Severallinesofevidencesuggestthat19~(th)centuryloggingpromotedalegacyofsimplifiedstandstructureandcompositionsuchthat,whencli

简介：Background:Tropicaldryforestscoverlessthan13%oftheworld'stropicalforestsandtheirareaandbiodiversityaredeclining.InsouthernAfrica,themajorthreatisincreasingpopulationpressure,whiledroughtcausedbyclimatechangeisapotentialthreatinthedriertransitionzonestoshrubland.Monitoringclimatechangeimpactsinthesetransitionzonesisdifficultasthereisinadequateinformationonforestcompositiontoallowdisentanglementfromotherenvironmentaldrivers.Methods:Thisstudycombinedhistoricalandmodernforestinventoriescoveringanareaof21,000km~2inatransitionzoneinNamibiaandAngolatodistinguishlatesuccessiontreecommunities,tounderstandtheirdependenceonsitefactors,andtodetecttrendsintheforestcompositionoverthelast40years.Results:Thewoodlandsweredominatedbysixtreespeciesthatrepresented84%ofthetotalbasalareaandcanbereferredtoasBaikiaea-Pterocarpuswoodlands.Aboostedregressiontreeanalysisrevealedthatlatesuccessiontreecommunitiesareprimarilydeterminedbyclimateandtopography.TheSchinziophytonrautaneniiandBaikiaeaplurijugacommunitiesarecommononslightlyinclinedduneorvalleyslopesandhadthehighestbasalarea(5.5-6.2m~2ha~(-1)).TheBurkeaafricana-GuibourtiacoleospermaandPterocarpusangolensis-Dialiumenglerianumcommunitiesaretypicalforthesandyplateauxandhaveahigherproportionofsmallerstemscausedbyahigherfirefrequency.AdecreaseinoverallbasalareaoratrendofincreasingdominationbythemoredroughtandcoldresilientB.africanacommunitywasnotconfirmedbythehistoricaldata,butthereweresignificantdecreasesinbasalareaforOchnapulchraandthevaluablefruittreeD.englerianum.Conclusions:Theslopecommunitiesaremoreshelteredfromfire,frostanddroughtbutaremoresusceptibletohumanexpansion.ThecommunitywiththeimportanttimbertreeP.angolensiscanbestwithstandhighfirefrequencybutshowssignsofahighervulnerabilitytoclimatechange.Conse

简介：Background:Thispaperexploredthelong-term,ceteris-paribuseffectsofpotentialCO,fertilizationontheglobalforestsector.BasedonthefindingsofNorbyetal.(PNAS2005,102(50))aboutforestresponsetoelevated[CO_2].Methods:ForestproductivitywasincreasedintheGlobalForestProductsModel(GFPM)inproportiontotherising[CO.,]projectedintheIPCCscenarioA1B,A2,andB2.Projectionsoftheforestareaandforeststockandoftheproduction,consumption,prices,andtradeofproductsrangingfromfuelwoodtopaperandpaperboardwereobtainedwiththeGFPMforeachscenario,withandwithoutCO_2fertilizationbeginningin2011andupto2065.Results:C02fertilizationincreasedwoodsupply,leadingtolowerwoodpriceswhichinturninducedmodestlowerpricesofendproductsandhigherglobalconsumption.However,productionandvalueaddedinindustriesdecreasedinsomeregionsduetotherelativecompetitiveadvantagesandtothevaryingregionaleffectsofCO_2fertilization.Conclusion:ThemaineffectofCO,fertilizationwastoraisetheleveloftheworldforeststockin2065by9to10%forscenariosA2andB2andby20%forscenarioA1B.Theriseinforeststockinducedbyfertilizationwasinpartcounteractedbyitsstimulationofthewoodsupplywhichresultedinlowerwoodpricesandincreasedharvests.

简介：Background:Stemradialgrowthinforestsisnotuniform.Rather,itischaracterizedbyperiodsofrelativelyfastorslowgrowth,orsometimesnogrowthatall.Thesefluctuationsaregenerallyafunctionofvaryingenvironmentalconditions(e.g.wateravailability)and,importantly,willalsobeassociatedwithadjustmentsinpropertiesinthewoodformed.Standlevelconditionsandforestmanagement,particularlythinningandstanddensitywill,however,alsohaveamajorinfluenceonpatternsofgrowthvariation.Weexplorehowdifferentthinninghistoriesand/orstanddensitiesinfluencethesedynamicsoftreegrowthintheimportantcommercialplantationspeciesPinusradiotaD.Don.Methods:DailystemsizechangewasmeasuredusingelectronicpointdendrometersovertwogrowingseasonsonP.rodiatatreesattwosites,subjectedtodifferentthinningregimes.Timing,ratesandperiodicityofannualgrowthwerecalculatedfromthesedata.Results:Greateroverallcross-seaionalgrowthinthinnedplotswasdrivenmainlybytwodynamics.First,thecessationofseasonalgrowthoccurredatleast3weekslaterinthestandsinwhichthinninghadtakenplace.Therewasnodifferencebetweenthinned/unthinnedstands,however,inthetimingofgrowthonset.Second,withinthelongerseason,treesinthinnedplotshadmoregrowthdays(asmuchas20%more)thanunthinnedplots.Theratesofgrowthondayswhengrowthoccurredwerenotdifferent,however.Inthiscontext,itisnotablethatintreesintheunthinnedplotsexperiencingthemostseverecompetitiontherewerestrongMpulsesMofgrowthfollowingdrought-breakingrainfallevents.Unthinnedplotsathighstanddensitiesalsomaintainedasmaller(butconsistent)zoneofdividingcellsthroughouttheseasonthanthinnedplots.Conclusions:InPinusradiatogrowingunderconditionsasinourstudy,conditionslateinsummer,particularlydrought,haveanimportanteffectonthetimingofcessationofgrowth.Earlyseasontemperatureappearstohavenoeffectin

简介：作为常规授精的一种选择评估器官的修正案的使用，沃土土壤的一个10年的实验在在Guadalquivir河山谷与化肥(NPK)和植物的堆肥(器官的化肥)使用的温室和室外的阴谋在一个庄稼旋转系统下面被进行，西班牙。土壤上的这二不同授精政体的效果物理性质被评估。玷污器官的碳(OC)，土壤体积密度(BD)，土壤水保留(WR)，可得到的水内容(AWC)，总数稳定性(作为)，并且玷污物理质量(德克斯特的索引，S)被决定。器官的化肥的使用增加了OC并且导致了的重要增加作为并且在与在温室和室外的阴谋的矿物质化肥申请相比的BD的减少。而温室阴谋出现了，室外的阴谋显示出最低BD价值象价值最高。在10年的实验的最后年里，S参数在器官的化肥阴谋是显著地更高的，特别为温室阴谋。在学习经期的结束，在在在在两个系统的治疗之间的领域能力(FC)的WR没有重要差别；AWC在矿物质在温室阴谋，但是更高也是类似的室外的阴谋。在矿物质化肥处理，在物理性质的小改进也与以前的集中的收割系统相比由于不太好攻击的耕种的利用被观察。物理土壤性质与土壤OC被相关。持续管理技术象器官的修正案的使用那样并且低或没有耕种改进了土壤物理性质，尽管有在管理的差别，那显著地逻辑地影响了结果。

简介：Soilmicrobialbiomassandcommunitystructuresarecommonlyusedasindicatorsforsoilqualityandfertility.Ainvestigationwasperformedtostudytheeffectsoflong-termnaturalrestoration,cropping,andbarefallowmanagementsonthesoilmicrobialbiomassandbacterialcommunitystructuresindepthsof0–10,20–30,and40–50cminablacksoil(Mollisol).Microbialbiomasswasestimatedfromchloroformfumigation-extraction,andbacterialcommunitystructuresweredeterminedbyanalysisof16SrDNAusingpolymerasechainreaction-denaturinggradientgelelectrophoresis(PCR-DGGE).Experimentalresultsshowedthatmicrobialbiomasssignificantlydeclinedwithsoildepthinthemanagementsofrestorationandcropping,butnotinthebarefallow.DGGEprofilesindicatedthatthebandnumberintop0–10cmsoilswaslessthanthatindepthof20–30or40–50cm.Thesesuggestedthatthemicrobialpopulationwashighbutthebacterialcommunitystructurewassimpleinthetopsoil.ClusterandprinciplecomponentanalysisbasedonDGGEbandingpatternsshowedthatthebacterialcommunitystructurewasa?ectedbysoildepthmoreprimarilythanbymanagements,andthesuccessionofbacterialcommunityasincreaseofsoildepthhasasimilartendencyinthethreemanagements.FourteenpredominatingDGGEbandswereexcisedandsequenced,inwhich6bandswereidentifiedasthetaxaofVerrucomicrobia,2bandsasActinobacteria,2bandsasα-Proteobacteria,andtheother4bandsasδ-Proteobacteria,Acidobacteria,Nitrospira,andunclassifiedbacteria.Inaddition,thesequencesof11DGGEbandswerecloselyrelatedtounculturedbacteria.Thus,thebacterialcommunitystructureinblacksoilwasstable,andthepredominatingbacterialgroupswereuncultured.

简介：Background:Themainobjectiveofthisstudywastoexaminetheclimaticsensitivityoftheradialgrowthresponseof13easternwhitepine(PinusstrobusL.)provenancesplantedatseventestsitesthroughoutthenorthernpartofthespecies’nativedistributionineasternNorthAmerica.Methods:Thetestsites(i.e.,Wabeno,Wisconsin,USA;Manistique,Michigan,USA;PineRiver,Michigan,USA;Newaygo,Michigan,USA;TurkeyPoint,Ontario,Canada;Ganaraska,Ontario,Canada;andOrono,Maine,USA)examinedinthisstudywerepartofarange-widewhitepineprovenancetrialestablishedintheearly1960sintheeasternUnitedStatesandCanada.Principalcomponentsanalysis(PCA)wasusedtoexaminethemainmodesofvariation[first(PC1)andsecond(PC2)principalcomponentaxes]inthestandardizedradialgrowthindicesoftheprovenancesateachtestsite.TheyearscoresforPC1andPC2wereexaminedinrelationtoanarrayoftestsiteclimatevariablesusingmultipleregressionanalysistoexaminethecommonalityofgrowthresponseacrossallprovenancestotheclimateofeachtestsite.ProvenanceloadingsonPC1andPC2werecorrelatedwithgeographicparameters(i.e.,latitude,longitude,elevation)andasuiteofbiophysicalparametersassociatedwithprovenanceoriginlocation.Results:TheamountofvariationinradialgrowthexplainedbyPC1andPC2rangedfrom43.4%to89.6%.Dendroclimaticmodelsrevealedthatwhitepineradialgrowthresponsestoclimatewerecomplexanddifferedamongsites.Thekeydendroclimaticrelationshipsobservedincludedsensitivitytohightemperatureinwinterandsummer,coldtemperatureinthespringandfal(i.e.,beginningandendofthegrowingseason),summermoisturestress,potentialsensitivitytostorminduceddamageinspringandfal,andbothpositiveandnegativeeffectsofhigherwintersnowfal.Separationoftheloadingsofprovenancesonprincipalcomponentaxeswasmainlyassociatedwithtemperature-relatedbioclimaticparametersofprovenanceoriginat5ofth