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简介：中国园林一贯强调'因地制宜',不论是在造景设计还是材料使用上都遵循这一原则.大多情况下,人们一说到假山,首先想到的是苏州园林的太湖石假山,许多教科书里面所列出的假山石材也只有有限的几种,其实自然界的石头基本上都可以作为假山用材,只是设计、堆砌的方式有区别而已.采用产于当地的石材不但可以降低成本,而且可以体现地方特色,可谓一举两得.

简介：<正>本文按草坪植物,景观野花和灌木三大类专用于边坡绿化和岩面修复工程用植物材料给大家作一介绍。介绍的种子均适宜直接喷播施工和植生带方式施工两种方式。一、草坪植物草坪植物是最为主要的水土保持植物,草种一般都发芽容易,见绿快,成坪快,使施工地段在最短的时间内达到100％的地面覆盖,防止水土流失。评价草种水土保持的性能好坏,主要从以下8个方面进行:

简介：Background:Theglobalsearchfornewwaystosequestercarbonhasalreadyreachedagriculturallands.Suchlandconstitutesamajorpotentialcarbonsink.Theproductionofhighvaluetimberwithinagroforestrysystemscanfacilitateanin-situcarbonstoragefunction.Thisisfollowedbyapotentiallongtermex-situcarbonsinkwithinlonglastingproductssuchasveneerandfurniture.Forthispurposewildcherry(PrunusaviumL.)isaninterestingoptionformiddleEurope,yieldinghighpricesonthetimbermarket.Methods:Atotalnumberof39wildcherryweresampledin2012and2013toassesstheleaflessabovegroundbiomass.Thecompletetreesincludingstemandbrancheswereseparatedinto1cmdiameterclasses.Woodandbarkfromsub-sampleswereanalysedseparatelyandnutrientcontentwasderived.Modelsforbiomassestimationwereconstructedforalltreecompartments.Results:Thesmallestdiameterclassespossessthehighestproportionofbarkduetosmallercrosssectionalarea.Treeboleswithagreateramountofstemwoodabove10cmindiameterwillhaveamoreconstantbarkproportion.Totalbranchbarkproportionalsoremainsrelativelyconstantaboved_(1.3m)measurementsof8cm.Abalanceisevidentbetweentheproductionofnewbrancheswithalowdiameterandhighbarkproportionoffsetbythethickeningandarelativereductioninbarkproportioninlargerbranches.Theresultsshowthatasingletreewithanageof17and18yearscanstoreupto85kgofcarbonwithintheabovegroundbiomassportion,anamountthatwillincreaseasthetreematures.Branchesdisplaygreaternutrientcontentthanstemsectionspervolumeunitwhichcanbeattributedtoagreaterbarkproportion.Conclusions:Usingthederivedmodelsthecarbonandthenutrientcontentofabove-groundwoodybiomassofwholetreescanbecalculated.Suggestedvaluesforcarbonwithothermajorandminornutrientsheldwithinrelativelyimmaturetreesstronglysupportstheideaoftheinclusionofwildcherrywithinagroforestrysystemsasan

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

简介：Apotexperimentwasconductedtoinvestigatetheeffectsofnitrogencontent[N1(nofertilizer),N2(0.15g?kg–1),andN3(0.3g?kg–1)]onthegrowthandthehydrauliccharacteristicsofpeachseedlingsunderdifferentsoilmoistureconditions(W1,W2andW3,inwhichthesoilwatercontentwas45%to55%,60%to70%,and75%to80%ofthefieldwatercapacity,respectively)byusingaspecializedhighpressureflowmeterwitharootchamberandacoupling,whichwasconnectedtoplantorgans.Leafareaandleafhydraulicconductivity(KL)increasedsignificantlyintheseedlingsbecauseofincreasedsoilmoistureandNcontent.KLincreasedwithleafarea.AlinearcorrelationwasdocumentedbetweenKLandleafarea.KLwashigherinthemorningandbegantodeclinesharplyafter16:00,atwhichKLdeclinedafteraninitialincrease.SoilmoistureandNcontentenhancedshoot(Ks)androot(Kr)hydraulicconductivities,therebyimprovingthelowsoilmoistureconditiontoalargeextent.KsandKroftheseedlingswerereducedby32%and27%respectivelyinN1,andby14.7%and9.4%,respectivelyinN2,andbothinW1,comparedwiththecontroltreatment.N3hadnosignificanteffectonKsandKrundersimilarconditions.LinearnegativecorrelationswereobservedbetweenKrandtheexcisedrootdiameteraswellasbetweenKsandtheshootstemdiameter.Theshoot-to-rootratioincreasedwithincreaseinNcontent.Theshoot-to-rootratioinN3wasincreasedby14.37%,comparedwithN1inW1aswellasby12%and4.39%inW2andW3,respectively.KnowledgeoftheeffectsofsoilmoistureandNfertilizeronhydrauliccharacteristicsandgrowthisimportant.Ourresultsprovidebasicguidelinesfortheimplementationofwater-savingirrigationandfertilizationmanagementofnurserystock.

简介：我们使用了联合代理人改进在小麦稻草粒子和UF树脂之间的结合的能力的silane，并且调查了表面性质(wettability和表面粗糙)和用与由联合代理人内容和稻草/白杨木头粒子比率的silane影响了的白杨木头相结合的结合UF的小麦稻草(TriticumaestivumL.)做的particleboard的坚硬。我们在0，5%和10%的三个层次在稻草的四不同比率生产了一个分层的particleboard面板到白杨木头粒子(0%，15%，30%和45%小麦稻草)和silane联合代理人内容。粗糙大小，平均粗糙(R),平均数peak-to-valley高度(Rz),和根平均数平方粗糙(Rq)被使用跟踪技术的一支好尖笔在unsanded样品上测量。我们由使用连接到一个数字照相机和计算机系统的角度计获得了接触角度大小。包含白杨粒子的更大的数量的板与控制样品相比有优异坚硬并且有更低的wettability。与有的silane的更高的数量做的面板降低R<潜水艇class=“a-plus-plus”>q值。

简介：风景视觉吸收力是景观综合视觉质量的重要组成部分,是进行风景资源评估和景区区划的依据。文章以天宝岩自然保护区为例,在制定该保护区的生态旅游规划时,探讨了对全区森林景观视觉吸收力进行评价的具体方法,从而为景区的建设和生态旅游路线的规划提供科学依据。

简介：在以前的研究中我们报道了经质壁分离预处理刺五加合子胚下胚轴,促进了体细胞胚形成。在本研究中,我们利用RT-PCR方法分析了刺五加合子胚经2,4-D,蔗糖,甘露醇处理后胼胝质合成酶基因的表达水平。结果显示：蔗糖和甘露醇处理明显促进了胼胝质合成酶基因的表达水平。而且我们观察到,体细胞胚发生过程中,外植体经质壁分离处理后细胞壁明显加厚。因此我们推测：胼胝质可能使表皮层细胞相互之间产生分离从而使其转变为具有胚性潜能的细胞。

简介：采用盆栽法对4种重金属（Cd2＋、Pb2＋、Cu2＋、Zn2＋）胁迫下的菲黄竹与菲白竹叶片中的超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）活性及脂质过氧化产物（MDA）进行了研究。结果表明，菲黄竹的SOD、POD、及CAT活性随着重金属浓度的增加总体趋势是先增大，之后降低，最后又增大；而菲白竹则是先升高，后降低；过氧化产物（MDA）则于酶活性的变化趋势相反。表明重金属胁迫下，2种地被竹体内的抗氧化酶活性被诱导，且菲白竹比菲黄竹有更强的耐重金属胁迫性。

简介：天宝岩国家级自然保护区管理局,通过对实验区林下药用植物栽培试验,在郁闭度0.7阔叶林下,草珊瑚种植株三年平均分孽24.9杆,第三年生长高度达到52.6cm,已可进行地面杆径采收;在郁闭度0.8毛竹林下,多花黄精三年平均亩产约251.5kg;在郁闭度0.4-0.5的阔叶林下,种植玉竹,亩产量2335kg。药用植物试验栽培的生长及产量表现较好,以目前市场药材收购价计算,多花黄精亩产值在1300元以上,玉竹亩产值1万元以上,经济效益明显,可以考虑在相同类型生态公益林中扩大试种,以期为林下药用植物栽培提供理论基础。