简介:理解在地志的索引和庄稼收益可变性之间的关系在卷风景为土壤管理和庄稼生产是重要的。在Alvena和赫本,的二块农业地萨克其万,加拿大被选择检验索引怎么地志与小麦产量在下面有关二地志并且在加拿大人的天气条件大草原。二个地点的风景作为圆丘般被分类,主导的土壤类型是AridicUstoll。在产量,地形学,土壤,和天气之中的关系用小麦(TriticumaestivumL.)被分析从在2001的Alvena(干燥的年)的谷物产量并且2004(湿年)并且从在1998的赫本(干燥的年)。Topographic/soil索引包括了相对举起,湿索引在斜坡长度上面,弯曲,土壤有机物,和在播种前的土壤潮湿存储。结果显示了那,在干燥的年里,关联系数在之间在斜坡上面,长度和谷物产量在1998为浅轻轻的滚动风景(赫本)在2001和0.73为典型滚动风景(Alvena)是0.79。在湿年(2004)里,在产量和topographic/soil属性之间的关系不象在干燥的年里一样强壮。因此,在斜坡上面,长度是为干燥的年里的二处风景的最好的收益指示物,而没有地志的索引高度被相关在湿年里收割产量。那些地志的索引在识别收益可变性并且描出似乎有用合适的管理地区。
简介:ThepaperanalyzesthesedimentsourceofwatershedbymeansofstudyingwatershedinwestemShanxioftheLossesPlateau.Onthebasisofwatershedsclassification,7typicalwatershedswerechosenandobservedfor11years.Theresultshowsthatthesedimentatthesmallwatershedmainlycomesfromgullies,whichis60%ofthetotalsediment.Erosionmodulusofvalley(includinggullyhead,gullybed,valleyside)is1.28-2.48timesasthatoftheareabetweenchannels(includinghillslopeandmoundoftheLoessPlateau).Themainsedimentsourceofslopeerosioniscultivatedlandonslopewithoutwaterandsoilconservationmeasures.
简介:Background:ThefragilelandscapesoftheHimalayanregionarehighlysusceptibletonaturalhazards,andthereisongoingconcernaboutcurrentandpotentialclimatechangeimpacts.ThisstudyprovidesbackgroundinformationonIndia'sWesternHimalayasandreviewsevidenceofwarmingaswellasvariabilityinprecipitationandextremeevents.Methods:UnderstandingandanticipatingtheimpactsofclimatechangeonHimalayanforestecosystemsandtheservicestheyprovidetopeoplearecritical.Effortstodevelopandimplementeffectivepoliciesandmanagementstrategiesforclimatechangemitigationandadaptationrequiresparticularnewresearchinitiatives.Thevariousstudiesinitiatedandconductedintheregionarecompiledhere.Results:SeveralnewinitiativestakenbytheHimalayanForestResearchInstituteinShimlaaredescribed.Thisincludesnewpermanentobservationalfieldstudies,somewithmappedtrees,inhighaltitudetransitionalzonesforcontinuousmonitoringofvegetationresponse.WehavealsopresentednewstrategiesformitigatingpotentialclimatechangeeffectsinHimalayanforestecosystems.Conclusions:AssessmentoftheecologicalandgeneticdiversityoftheHimalayanconifersisrequiredtoevaluatepotentialresponsestochangingclimaticconditions.Conservationstrategiesfortheimportanttemperatemedicinalplantsneedtobedeveloped.TheimpactofclimatechangeoninsectsandpathogensintheHimalayasalsoneedtobeassessed.Coordinatedeffortsarenecessarytodevelopeffectivestrategiesforadaptationandmitigation.
简介:Macronutrients(N,P,K,Ca,Mg,andS)inlitterofthreeprimarilyspruce(PiceapurpureaMasters)(SF),fir(AbiesfaxonianaRehder&E.H.Wilson)(FF),andbirch(BetulaplatyphyllaSukaczev)(BF)subalpineforestsinwesternChinaweremeasuredtounderstandthemonthlyvariationsinlitternutrientconcentrationsandannualandmonthlynutrientreturnsvialitterfall.NutrientconcentrationinlittershowedtherankorderofCa>N>Mg>K>S>P.Monthlyvariationsinnutrientconcentrationsweregreaterinleaflitter(LL)thanotherlittercomponents.ThehighestandlowestconcentrationsofN,P,K,andSinLLwerefoundinthegrowingseasonandthenongrowingseason,respectively,butCaandMgweretheopposite.NutrientreturnsvialitterfallshowedamarkedmonthlypatternwithamajorpeakinOctoberandoneortwosmallpeaksinFebruaryand/orMay,varyingwiththeelementandstandtype,butnomarkedmonthlyvariationsinnutrientreturnsviawoodylitter,reproductivelitter,exceptinMayfortheBF,andmosslitter.Notonlylitterproductionbutalsonutrientconcentrationcontrolledtheannualnutrientreturnandthemonthlynutrientreturnpattern.Themonthlypatternsofthenutrientconcentrationandreturnwereofecologicalimportancefornutrientcyclingandplantgrowthinthesubalpineforestecosystems.
简介:Investigationswereconductedtoquantifylitterfall,andlitterandnutrientaccumulationinforestfloor,andtoacquireinformationonlitterdecompositionandnitrogenandphosphorusreleasepatternsinthreedifferentsubalpineconiferousforests,aplantation(Pl),asecondaryforest(SF),andaprimitiveforest(PF),inwesternSichuan,China.Thelittertrapmethodwasusedtoevaluatelitterfallwiththelitterbagmethodbeingutilizedforlitterdecomposition.Seasonalpatternsoflitterfallweresimilarinthethreeforests,withtwopeaksoccurringinSeptember-NovemberandMarch-May.Theplantationrevealedanannuallitterfallof4.38×103kgha-1,whichwassimilartothoseofSFandPF,butPlhadalowermasslossrateandahigherC/Nratio.TheC/Nratiomaybeasoundpredictorforthedecompositiondifferences.Nconcentrationsofleaflitterinboththesecondaryforestandprimitiveforestincreasedfirstandthendecreased,andthepercentagesoftheirfinal/initialvalueswere108.9%and99.9%,respectively.Pconcentrationinthethreeforestsincreasedbytheendofthestudy.TheresultsoflitterfallanddecompositionindicatedthatintheplantationthepotentialtoprovidenutrientsforsoilorganicmatterwassimilartothoseofSFandPF;however,itsslowerdecompositionratecouldresultinasomewhattransientaccumulationoflitterintheforestfloor.
简介:AimingatnaturalenvironmentconditionsinChina’swesternregions,theStateCouncilhasdecidedtoimplementnaturalenvironmentprotectionanddevelopmentwithmaincomponentsofnaturalforestprotection,afforestationandgrassgrowingonsuitablewastelandandsystematicallyreturningcultivatedlandtoforest(grass),thisisanimporta
简介:Exclosureisamethodofrehabilitatingdegradedlandsbyprotectingthemfromtheinterferenceofanimalsandfromhumanencroachment,andisusedtoregeneratenativevegetationasawaytoreducesoilerosion,increaserainwaterinfiltrationandprovidefodderandwoodybiomassindegradedgrazinglands.Therefore,westudiedwoodyplantstructure,diversityandregenerationpotentialsin5-and10-yeargrazingexclosuresincomparisonwithopengrazedsitesinasemi-aridenvironment.Dataonspeciesdiversity,abundance,structure,basalarea,frequency,density,andregenerationstatuswerecollectedfrom270sampleplots.Forty-onewoodyspeciesrepresenting20familieswereidentified,with18,28and38speciesfoundinopengrazedareas,andin5-and10-yeargrazingexclosures,respectively.The10-yeargrazingexclosureshadahigher(P<0.05)speciesrichnessandplantdensitiescomparedtothe5-yeargrazingexclosuresandtheopengrazedareas.ThepopulationstructureandregenerationstatusofwoodyspeciesinbothgrazingexclosuresshowedaninvertedJ-shape,indicatingahealthyregenerationstatus,whereashamperedregenerationwasobservedinopengrazedareas.Theestablishmentofgrazingexclosureshadpositiveeffectsinrestoringwoodyplantdiversityandimprovingvegetationstructureandregenerationpotentialsofdegradedgrazinglands.
简介:Background:Volumeandtaperequationsareessentialforobtainingestimatesoftotalandmerchantablestemvolume.Taperfunctionsprovideadvantagestomerchantablevolumeequationsbecausetheyestimatediameterinsideoroutsidebarkatspecificheightsonthestem,enablingtheestimationoftotalandmerchantablestemvolume,volumeofindividuallogs,andaheightatagivendiameter.Methods:Usingdatacollectedfrom1218trees(1093Douglas-fir(Pseudotsugamenziesii(Mirbel)Franco)and125westernhemlock(Tsugaheterophylla)),weevaluatedtheperformanceofonesimplepolynomialfunctionandfourvariable-exponenttaperfunctionsinpredictingupperstemdiameter.SampletreeswerecollectedfromdifferentpartsofthestatesofOregon,Washington,andCalifornia.Wecomparedinside-barkvolumeestimatesobtainedfromtheselectedtaperequationwithestimatesobtainedfromasimplelogarithmicvolumeequationforthedataobtainedinthisstudyandtheequationsusedbytheForestInventoryandAnalysisprograminthePacificNorthwest(FIA-PNW)inthestateofCaliforniaandwesternhalfofthestatesofOregonandWashington.Results:Variableexponenttaperequationsweregenerallybetterthanthesimplepolynomialtaperequations.TheFIA-PNWvolumeequationsperformedfairlywellbutvolumeequationswithfewerparametersfittedinthisstudyprovidedcomparableresults.TheRMSEobtainedfromtaper-basedvolumeestimateswerealsocomparablewiththeRMSEoftheFIA-PNWvolumeequationsforDouglas-firandwesternhemlocktreesrespectively.Conclusions:ThetaperequationsfittedinthisstudyprovideaddedbenefittotheusersovertheFIA-PNWvolumeequationsbyenablingtheuserstopredictdiameteratanyheight,heighttoagivendiameter,andmerchantablevolumeinadditiontocubicvolumeincludingtopandstump(CVTS)ofDouglas-firandwesternhemlocktreesinthePacificNorthwest.ThefindingsofthisstudyalsogivemoreconfidencetotheusersofFIA-PNWvolumeequations.
简介:Astudyonbalancedfertilizationwasconductedbymeansoflong-termfieldexperiments,andaconve-nienttableforbalancedfertilizationwascompiled.Theexperimentalresultsabouttheeffectoffertilizationonwateruseefficiencyofuplandwheatshowedthattheinputofinorganicfertilizershouldbereducedindryyears.
简介:Background:Theeffectofforestfireonsoiliscomplexandrelativelylessunderstoodthanitsabovegroundeffect.Understandingtheeffectoffireonforestsoilscanallowimprovingmanagementofvaluableforestecosystemsasadequateandproperinformationisveryimportantforefficientmanagement.Wehavestudiedtherecoveryofsoilpropertiesafterfire,usingachronosequenceapproach(two,fiveandfifteenyearsafterfireandcontrol).Soilsampleswerecollectedfromeachplotoffourfirepatches(B0,B2,B5&B15)fromthreedifferentdepthsviz.0–10(Top),10–20(Middle),and20–30cm(Bottom).Results:Soilorganiccarbonwaslowerthanunburnedplotsafterthefireandcouldnotrecovertothelevelofunburnedplot(B0)evenin15years.TotalN,availableP,andextractableKwerelower2-yearsand5-yearsafterthefirebutarehigherthanunburnedplotafter15-years.Availablenitrogen(NO3^-andNH4^+)remainunchangedorhigherthanB0inburnedpatches.SoilpH,BulkDensity,WaterHoldingCapacity,andElectricalConductivitywaslowerinitiallyafterthefire.Forestfireshaveaffectedsoilpropertiesconsiderably.Theresponseofsoilpropertiesvariedwithyearsafterfireandsoildepth.Conclusion:Forestfiresoccurveryfrequentlyinthestudyarea.Significantquantitiesofcarbonandtotalnitrogenarelosttotheatmospherebyburningoflitter,duff,andsoilOM.Becausenitrogenisoneofthemostimportantsoilnutrients,therecaptureofNlostbyvolatilizationduringafiremustreceivespecialattention.Long-termstudiesarerequiredtobetterunderstandtherecoveryofsoilnitrogen.
简介:一个总数3611真菌孤立从在季风,冬季和夏天期间从7药用的植物孵化的4200个叶片断被恢复季节。这些真菌孤立属于teleomorphicAscomycota(23.5%),生产conidiomata(17.4%)的歪像的Ascomycota,没有conidiomata(46.9%)的歪像的Ascomycota,Zygomycota(1.42%)和无菌的形式(10.6%)。Chaetomiumglobosum,曲霉属菌尼日尔,Aureobasidiumpullulans,Curvularialunata,镰刀霉spp,毛丛spp,Pestalotiopsisspp,Trichodermaviridae,Cladosporiumcladosporioides,经常从超过一主人植物被孤立。endophytic的数字孤立比在季风和夏天季节在冬季是更高的。
简介:Soilmacroinvertebratesarehighlydiverseandtheirmajorecologicalserviceincludebreakdownoforganicmatterandinturnimprovesoilfertilityandpill-millipedesarewell-knownfortheirsigni?cantroleiningestion,disintegrationanddecompositionoforganicmatterinsoil.Thisstudycharacterizedthefeed,thedecomposingleaflitterofcoconut(Cocosnucifera),andfaecesoftwoendemicgiantpill-millipedesArthrosphaeradistictaandA.fumosacollectedfromforestsoftheWesternGhatsofIndiabasedonchemicalfeaturesandmicrobialpro?le.Inbothmillipedes,electricconductivityandtotalphosphorusweresigni?cantlyincreasedinfaeces,whilethecrudeprotein,organiccarbon,totalnitrogenandtotalphenolicsweresigni?cantlydecreased,ascomparedtothoseinfeed.Heterotrophicbacteria,actinomycetes,rhizobiaandphosphate-solubilizingbacteriaweresigni?cantlyhigherinfaecesthaninfeed,while?lamentousfungiandyeastsubstantiallydecreasedinfacescomparedtofeedinboththemillipedes.Spectrumoffattyacidmethylesterswasconsiderablydifferentbetweenfeedandfaecesofboththemillipedes.Thetotalsaturatedfattyacidswerehigherthanthetotalunsaturatedfattyacidsinfeedaswellasfaeces,whiletheratioofunsaturated/saturatedfattyacidsdecreasedfromfeedtofaeces.DodecanoicandtetradecanoicacidsinA.distictaandoctadecanoicacidinA.fumosasigni?cantlyincreased,while(9Z)-octadec-9-enoicand(9E,12E)-octadeca-9,12-dienoicacidsinA.distictaandhexadecanoic,tetracosanoicand(9E,12E)-octadeca-9,12-dienoicacidsinA.fumosasigni?cantlydecreasedinfaecescomparedtofeed,indicatingmillipede-dependentchangesinfattyacids.Icosanoicacidwaspresentinfaecesofboththemillipedes,andhexadec-9-enoicacidwascon?nedtofaecesofA.disticta,whilepentadecanoic,heneicosanoic,(9Z,12Z,15Z)-9,12,15-octadecatrienoicandeicosenoicacidswerecon?nedtofaecesofA.fumosa.Pill-millipedesenrichthesoilqualitybyleaflitterconditioningintheirgutthroughspeci?cmi
简介:在干燥陆地的系统的木质的植物的地位是关键生态系统进程的一个基本决定因素。这地位监视在在干旱、半干旱的生态系统理解木质的植物的动力学起一个重要作用。现在的学习用遥感和地理信息系统技术和统计科学在伊朗决定了Zagros森林的精力。结果证明树的密度从10~53变化了?%根据半干旱的区域的地文学、气候的条件。在植被索引和森林密度之间的最好、最低的关联为全球环境监视索引被获得(GEMI;R2?=?0.94)和土壤调整植被索引(R2?=?0.81),分别地。GEMI被用来监视使用在一个10年的时期上改变的土地。结果显示出那2720?哈森林的2被人的干扰和耕种在也导致了肥沃的土壤层的损失的这个时期期间在陡峭的斜坡上破坏了。GEMI决定了区域与一树的生物资源并且有从没有华盖的区域的树的低生物资源密度的通常分开的边阶区域能盖住。结果用卫星在干旱、半干旱的艰巨森林区域揭示了对森林和植被盖子的那个评价数字数字和平常的采样服从于无常。一个成层的组织过程应该被建立增加评价的精确性。
简介:Background:Improvedunderstandingoftheprocessesshapingtheassemblyoftropicaltreecommunitiesiscrucialforgaininginsightsintotheevolutionofforestcommunitiesandbiologicaldiversity.Theclimateisthoughttobethefirstorderdeterminantofabundanceanddistributionpatternsoftreespecieswithcontrastingtraitssuchasevergreenanddeciduousleafphenology.However,therelativeroleofneutral,andniche-basedprocessesintheevolutionofthesepatternsremainpoorlyunderstood.Methods:Here,weperformanintegratedanalysisofthedataontreespeciesabundance,functionaltraitsandcommunityphylogenyfromanetworkof96forestplots,each1hainsize,distributedalongabroadenvironmentalgradientinthecentralWesternGhats,India.Then,wedeterminetherelativeimportanceofvariousprocessinassemblyandstructuringoftropicalforestcommunitieswithevergreenanddeciduousleafphenology.Results:Thedeciduousleafphenologicaltraithasrepeatedlyevolvedamongmultipledistantlyrelatedlineages.Treecommunitiesindrydeciduousforestswerephylogeneticallyclusteredandshowedalowrangeandvarianceof.functionaltraitsrelatedtolightharvesting,reproduction,andgrowthsuggestingniche-basedprocessessuchasenvironmentalfilteringplayavitalroleintheassemblyoftreecommunitiesintheseforests.Theexternalfactorssuchashuman-mediateddisturbancealsosignificantly,buttoalesserextent,influencesthespeciesandphylogeneticturnover.Conclusions:ThesefindingsrevealedthattheenvironmentalfilteringplaysasignificantroleinassemblyoftreecommunitiesinthebiologicallydiversetropicalforestsintheWesternGhatsbiodiversityhotspot.