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1.
落叶松树皮厚度变化规律的研究   总被引:2,自引:0,他引:2  
以黑龙江省带岭林业局大青川林场84株人工落叶松解析木数据为例,研究胸径处树皮厚度(BT)与胸径(D)、树高(H)、树冠宽度(CD)、冠长率(CR)、冠长(CL)和相对高度(RH)的关系。用多元逐步回归的方法建立落叶松人工林树皮厚度模型。结果表明,人工落叶松树皮厚度最优模型为BT=0.4221+0.0583D-0.046H。模型检验(F=32.46,P〈0.0001)及拟合统计量(R2=0.5155,RMSE=0.1507)都表明该模型较好的描述落叶松树皮厚度的变化。这对于合理的经营和管理落叶松人工林具有重要的理论和实际指导意义。  相似文献   

2.
TllcbiologicalcycIingofnutricntclc-lllcntslntl1cccosystclnisthecyclingbctweentllcplantconununityandsoilwitl1intheccosys-tclll(Ot/ington,l986).ltformsol1ebranchofbiogQochcn1icalcyclesandislnarkedwitl1higl1spccdal1dil1tcl1sit}'.Biologicalcyclcofnutri-cntclenlcntsiscorrelatedwithforestproduc-tit'it3'closcly-tbeabsorptionandutilizatio11ofthe11utricntelemcntsoftheplantareillflu-cnccddircctl3'orindirectlybykindsofenvi-ronn1cntallbctorsandsomephysiologicalandlllatcrialproducingprocessareattectcd.Sot…  相似文献   

3.
袁金兰 《林业研究》1999,10(4):233-235
IntroductionDahurianlarch(L8risgmeliniiRupr.)isoneofthemostimportanttimberspeciesinChina.AsaresuItofovercuttingforseveraIdecades,thenaturaIDahurianIarchforestresourcesaredecliningrapidly.PIantationsofdahurianIarchhavebecomeanimportantpartofforestpreserveresourcesinDaxing'anMountains.ConsequentIystudyingthegroWthofDahurianlarchandformingtheforesttabfesareofsignrficancetofor-estproduction.ThispaperpresentsinformationongroWthandyieIdmodeIsofDahurianlarchpIantations.MethodsDataof4O5stema…  相似文献   

4.
周文起 《林业研究》1996,7(1):77-80
DahurianlarchandMongolianscotchpinearetwomajorconunerciaIconilbroustTeesinDaxing'anlingForesnyArea.Itisob-viousthattbcwoodproPertiesandworkability'ofthetWoplantsarecompletelydifferent.Butlnrecert'years,ltlsfoundthattherearetwodiffer':nttypesinparameterofwood'scolour.phy'sicalandmechanicalproPertiesandwork-ability'inDahurianlarch,namelyredwoodandx"hite..od.l']Andthepropertiesofwhite`voodaresligl1tlyyellow-white,medianweightandhardness,goodinworkability'andLard-ness,goodinwodability'anduneas…  相似文献   

5.
Now,thereisagreatlargeareaoflarchplantationinNortheastofChina.Withtheincreasingofthestandage,competitionsamongtreeindividualschangefromexploitationcompetitiontointerferencecompetitions-Inordertofullyutilizetheresourceofsoilandclimate,effectivetechniquesshou1dbetakentoregulatetherelationshipoftreeindividuals,So,thestabilityandbioproductivityaswellaseconomicbenefitcanbeincaersed.CHARACTERSOFSTANDThestandisdahurianlarchplantati-onthatwasplantedinthespringofl958.Thesiteisabandonedfarmlandw…  相似文献   

6.
王凤霞 《林业研究》1996,7(2):20-24
STUDYAREAANDareTH0DThestUdyareawasatthecompatheentllofXinkenIllWorkingUnitinchoershanExPenmentalForestFann,NortheastF0restryUniversity.Dunngthespnngofl967,Dahu-nanlarchwasplantedintheleftlandofsecon-daryf0rest.Beforeorafterplanhng,mal1yMancl1tlrial1ash,e1l11withwhitebarkandsolneotherbroad-leavedtLreesinvadedandgrewwell.NowManchunanashandDahu-nanlarchn1ixedforestshavebeenf0n11ed,inwhichManchurianashisdolninant.lnl984,2Pen1lanentplotsweresetupwiththeslzeof0.O6hnl',facil1gsoutheast,…  相似文献   

7.
王录  陈祥伟  刘强 《林业研究》1994,5(2):22-28
NaturalregenerationofmanchurianashusuallytakesplacewheretherearesuitablesoilmoistureandseedbankofsecondarymanchurianashforestintheEasternMountainousAreaofNortheastChina.Sometimes,naturalregenerationofmanchurianashcanbefoundinpureconiferousplantation.Inordertofindoutthepossibilityofintroducingnaturalregenerationofmanchurianashinpureconiferousplantation,trialsandresear-cheshavebeencarriedoutindahurianlarchp1antationbyopeningupeffectbeltinthestands.lntheend,charactersofcommunitystructureandmicr…  相似文献   

8.
The larch (Larix) genus is the most important species group in the forest ecosystems in Northeastern China, occupying about 25% of the forest areas. The high tolerance to coldness and relatively fast growth rate make this genus the main species group for forestation. According to the predictions of the global circulation model CGCM3, temperature could rise by 2–4 °C over the next 100 years. Few studies have been conducted on the response of larch species to climate warming in Northeastern China. Such studies are becoming increasingly needed due to the economic and ecological significance of this genus. This paper studies the potential distribution ranges of three larch species under the current and the warming climate conditions. A new classification and regression tree technique, Random Forest, was used to investigate the potential distributions of three larch species, based on 18 environmental variables which reflect the climate, topography and soil conditions of Northeastern China. The results showed that the biological coldness index (BCI) is the most important factor for Dahurian larch, annual precipitation (AP) is the most important factor for Korean larch and elevation (DEM) is the most important factor for Prince Rupprecht larch.  相似文献   

9.
Dahurianlarch(LarixgmeliniRupr.)isoneofthemostimportanttimberspeciesinthenortheastofChina.Becauseofovercuttingforseveraldecades-naturalfOrestresourceshavebeendeclinedrapidly.Plantationsofdahurianlarchhavebecomeanimportantpartofforestreserveresourcesinthisarea.Butthereisalackofsystematicstudiesonthebiomassandthenetproductivityfordahurianlarchplanta-tions.Inthispaper,wepresentsomeusefuldataofthebiomassandtheproductivityoflburstructuretypes'fordahurianlarchplantations.Itwillprovidesomeinformati…  相似文献   

10.
李茹秀 《林业研究》1995,6(3):71-73
Lastvears.manvrescarchaboutintcr-sPecificrclationshipofmixcdstandsforIarchandasht`crcrePeatcd,mostof\`tich,hot`cvcr,isfortheplantingtypeoflinc-bclt.Thispaperanalysisash-larchrclationshipfor26agcdartificialIarchstandmixedwithcvenagcdashinnaturalreqencration.SlTEANDMEASUREMENTMETHOl)ArtincialIarchstandmcasuredlocatcdatecologicaIcxPCrimcntstationinMaocrshanMountainForcstryFarmofNortbcastForcstryUnivcrsity'(El27'34',N45"24').LarchttasplantcdonagrcatPCaccofdescrtcdfieIdinl967t"itha…  相似文献   

11.
国庆喜 《林业研究》1995,6(3):105-108
StUdiesontheundeopundsboctUfCofmanchurianash-dahurianlarchmixedstandrevealedthatseveralrowsofmanchurianashtreesnearestdahurianlarchbelthaveobviouschangesofrootSindistribution,densityandgrowthtCndenCy.Numerousrootsofmanchu-rianashgrowtowardthelarchbelt,indicatingthattherewerefavorableconditionsfOrtherootstogrowinthelarchbelt.ThedahurianlarchtrCesmusthaveimprovedtheenviron-mentinsomeaspect.STUDYSlTESStUdysitessitUatedinHeilonaiiangProv-ince,mainlyinDongxingForestFarmofKe-dongcounty,wes…  相似文献   

12.
Growth and yield models were developed for individual tress and stands based on336 temporary plots with 405 stem analysis trees of dahurian larch(Larix gmelinii(Rupr.)Rupr.)plantations throughout Daxing’anling mountains.Several equations were selected using nonlinearregression analysis.Results showed that the Richards equation was the best model for estimatingtree height,stand mean helght and stand dominant height from age; The Power equation was thebest model for prediction tree volume from DBH and tree height; The logarithmic stand volumeequation was good for predicting stand volume from age,mean height,basal area and other standvariables.These models can be used to construct the volume table, the site index table and other for-estry tables for dahurian larch plantations.  相似文献   

13.
The Dahurian larch forest in northeast China is important due to its vastness and location within a transitional zone from boreal to temperate and at the southern distribution edge of the vast Siberian larch forest. The continuous carbon fluxes were measured from May 2004 to April 2005 in the Dahurian larch forest in Northeast China using an eddy covariance method. The results showed that the ecosystem released carbon in the dormant season from mid-October 2004 to April 2005, while it assimilated CO2 from the atmosphere in the growing season from May to September 2004. The net carbon sequestration reached its peak of 112 g.m^-2.month ^-1 in June 2004 (simplified expression of g (carbon).m^-2.month^-1) and then gradually decreased. Annually, the larch forest was a carbon sink that sequestered carbon of 146 g-m^-2.a^-1 (simplified expression of g (carbon).m^-2.a^-1) during the measurements. The photosynthetic process of the larch forest ecosystem was largely affected by the vapor pressure deficit (VPD) and temperature. Under humid conditions (VPD 〈 1.0 kPa), the gross ecosystem production (GEP) increased with increasing temperature. But the net ecosystem production (NEP) showed almost no change with increasing temperature because the increment of GEP was counterbalanced by that of the ecosystem respiration. Under a dry environment (VPD 〉 1.0 kPa), the GEP decreased with the increasing VPD at a rate of 3.0 μmol.m^-2.s^-1kPa -1 and the ecosystem respiration was also enhanced simultaneously due to the increase of air temperature, which was linearly correlated with the VPD. As a result, the net ecosystem carbon sequestration rapidly decreased with the increasing VPD at a rate of 5.2 μmol.m^-2.s-1.kPa^-1. Under humid conditions (VPD 〈 1.0 kPa), both the GEP and NEP were obviously restricted by the low air temperature but were insensitive to the high temperature because the observed high temperature value comes within the category of the optimum range.  相似文献   

14.
基于线性混合模型的落叶松枝条基径模型   总被引:4,自引:0,他引:4       下载免费PDF全文
以黑龙江省五营林业局丽林林场30株人工落叶松2 190个枝条基径数据为例,利用逐步回归技术建立了落叶松枝条基径模型:BD=b1+b2DINC+b3DINC2+b4DBH.DINC2。然后,利用S-PLUS软件中的LME过程,拟合线性枝基径模型。采用AIC、BIC、对数似然值和似然比检验等模型评价统计指标对不同模型的拟合效果进行比较分析。结果表明:当拟合枝条基径模型时,b1、b2、b3同时作为混合参数时模型拟合最好。为了矫正混合模型构建过程中产生的异方差现象,把幂函数和指数函数加入到枝条基径混合模型中。指数函数显著提高了枝条基径混合模型的拟合效果,并且消除了异方差现象。模型模拟表明:对于大小相同树木,枝条基径随着着枝深度(DINC)的增加而增大,对于大小不同的树木,枝条基径随着胸径(DBH)的增加而增大。林木的胸径变量很好地反映了不同大小树木的枝条基径的变化。在不知道详细林分信息的前提下,可以利用树木变量合理地预测兴安落叶松人工林的枝条基径的变化规律。  相似文献   

15.
基于近红外光谱与BP神经网络预测落叶松木屑的含水率   总被引:2,自引:0,他引:2  
利用近红外光谱(NIR)技术结合BP神经网络定量预测了落叶松木屑的含水率。首先对采集的落叶松木屑原始近红外光谱进行9点平滑及多元散射校正预处理,然后利用主成分分析法提取光谱数据主成分作为BP神经网络的输入,最后建立BP神经网络预测模型并采用交叉验证法对模型进行验证。所建模型校正集的相关系数R为0.98,校正集的均方根误差RMSEC为0.001 7;预测集的相关系数R为0.99,预测集的均方根误差RMSEP为0.001 5。研究表明,此方法可以实现对落叶松木屑含水率的快速预测。  相似文献   

16.
INTRODUCTIONSitequalityisoneofthemostimpor-tantfactorsinfluencingtheproductivityofforeststands.Eva1uatingsitequalityisba-sictostudystandgrowthanddeviseman-agementtreatments.Basisofsitequalityissoil,whichhasacontrollinginfluenceontheforestproductivity-Soilpropertieschangeslowlyovertime,andsoilindexcanbeappliedincutover,deforested,andnonforestedareasinadditiontoareaswheretimberstandsarepresent.Underundisturbed,naturalconditions,somein-dicatorplantscomprisingthelesservegeta-tionmaybeassociat…  相似文献   

17.
Daxing'a11lingforcstregionislocatedintllcllorthcrnpart0fcoldten1peratczoncinChinacharctcri/cdbyl1arsl1climate,shortagcofacculnulatcdtcn1pcraturc,shortgrowingscas0n.Io\`s0iltel1lpcraturclncarly'sprlng'ctcThcmodclsforcultl\'atingsccdlingsarediffcrcntfrol11tI1oscinotherrcgions.lnordcrtoflndouttI1coptll11ul11l11odclsforcultl1atingsccdllngsofDahurlnlarcI1'oncof111alntimbcrtrccspcclcsinthlsrcglon.\"chadcarriedoutcxpcrilllcntlYo111l()89toI9()3andobtaincdtllcsllllplcbutpracticallncthodlbrdctcnnining…  相似文献   

18.
Variations in carbon content in wood among 102 clones, selected from almost the entire natural distribution area, were investigated in Larix kaempferi. The average carbon content was 50.50%, 50.94%, and 50.80% in sapwood, heartwood, and whole wood, respectively. The difference in carbon content between clones was significant. The clonal repeatabilities were 0.46, 0.38, and 0.44 in heartwood, sapwood and whole wood, respectively. The coefficients of variation in the clonal mean carbon content were only 0.43%, 0.42%, and 0.41% in heartwood, sapwood, and whole wood, respectively. This small genetic variation and resulting small relative genetic gain of carbon content indicate that the genetic improvement of carbon content by selection has a small effect on the genetic improvement of carbon sequestration capacity by selection in L. kaempferi.  相似文献   

19.
Wang Ke  Zhang Yu 《林业研究》1995,6(1):12-17
Comparative analyses were conducted on the nutrient element content and returning amount of main fractional compositions of litter in Korean pine (KP), Mongolian Scots pine (MSP) and Dahurian larch (DL) plantations in Laoshan Plantation Experiment Station of Maoershan Experiment Forest Farm of Northeast Forestry University. The results are as follows: (1) The nutrient element content and returning amount in litter varies among different fractional compositions and tree species, the total returning amount of all nutrient elements and the returning amount of K, Ca, Mg, N and P are DL > MSP > KP, the returning amount of Cu is DL > KP > MSP, the returning amount of Fe and Mn are MSP > DL > KP; (2) To KP and DL plantations, the main nutrient element returned is dead needles; dead branches, bark scales and dead cones account for a little proportion; whereas to MSP plantation, besides dead needles, dead branches and bark scales also play an important role in the return of nutrient elements; (3) A little deal of dead leaves can provided a great deal of returning amount of nutrient elements.  相似文献   

20.
落叶松着火性的研究   总被引:1,自引:0,他引:1  
通过对1969-1995年间全省和地区的落叶松林火个例的统计与分析,获得了该林分着火性的特点,即落叶松在幼龄阶段,疏密度在0.7以下时易发生火灾,在气温6-20℃的季节以及在5级以下风力时火灾次数发生最多,在一年中春季两季为火灾频繁季节,特别是春季;在落叶松林火中人为火源占98.3%。  相似文献   

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