学科分类
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6 个结果
  • 简介:Background:Oneofthemostimportantdriversofforestbiodiversityisconspecificnegativedensitydependence(CNDD),areductioninperformancewhenconspecificdensitiesarehigh.WhilethemajorityofCNDDresearchhasfocusedontropicalforests,evidenceismountingthatCNDDmayalsoplayanimportantroleintemperateforests.Tofurtherexplorethepotentialreachofthisphenomenon,weinvestigatedCNDDinAmericanbeech(Fagusgrandifolia)inamaturemid-Atlanticforest.Methods:Weusedbivariatepointpatternanalysestoexaminespatialrelationshipsbetweenlargebeechtreesandconspecificsaplings,andwealsocontrastedthesepatternswithcomparablepatternsforheterospecifics.Inaddition,toaddressthepossibilityofdispersallimitationandtheassociatedeffectsonspatialpatterns,weanalyzedseedlingdensityasafunctionofadultconspecificabundance.Results:Wefoundthatbeechsaplingsweremorerepeledfromlargeconspecificsthanlargeheterospecifics,despitethefactthatbeechseedlingdensitywaspositivelycorrelatedwithbeechbasalarea.However,saplingsofothercanopytreespecieswerealsorepeledfromadultbeechtrees,suggestingageneralsuppressiveeffect.Nonetheless,thediscrepancybetweenbeechseedlingandsaplingdensitiesbeneathadultconspecificssuggeststhatbeechseedlingsurvivalrateswerereducedinvicinityofconspecificadults.Conclusions:Regardlessoftheextenttowhichbeechinhibitsheterospecifictrees,anegativeeffectonconspecificrecruitsmaybecriticalforbiodiversitymaintenance.Withoutthisconspecificsuppression,adenselayerofshade-tolerantbeechsaplingscouldformbeneathadultbeechtrees.Ifthisweretooccur,beechwouldhaveasubstantialhead-startfolowingcanopydisturbance,andthislate-successionalspeciescouldpotentialydominateastandinperpetuity,throughrepeateddisturbancecycles.

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  • 简介:适当地在米饭(OryzasativaL.)为否定向光性探索光敏电阻器根,有不同波长的灯被使用在phototropic弯曲上调查轻质量的效果。弯曲的phototropic能被蓝/紫外的光显著地导致,而不由红或far-red光。分别地,从米饭根帽子的提取答案的吸收光谱在350nm和450nm有二座山峰,在在单方的光下面的根帽子的120kD蛋白质的分子的重量在黑暗下面比那大。它建议蓝轻受体可能是为在米饭根的否定向光性的光敏电阻器。

  • 标签: 稻子 植物根部 光感受器 向光性
  • 简介:ThecompleteopenreadingframeofOsPIN1awasamplifiedthroughreversetranscriptase-polymerasechainreaction(RT-PCR)basedonthesequencedepositedinGenBanktoexploretherelationshipbetweentheauxineffluxproteinOsPIN1aandthenegativephototropismofriceroots.SequencingresultsshowedthattheGCcontentofOsPIN1awas65.49%.ThefusionexpressionvectorpCAMBIA-1301-OsPIN1a::GFPcontainingtheOsPIN1ageneandacodinggreenfluorescentprotein(gfp)genewasconstructed.ThefusionvectorwastransferredintoonionepidermalcellsbyAgrobacteriumtumefacienstransformation.ThetransientexpressionofOsPIN1a-GFPwasmainlylocatedinthenucleusandcellmembrane.Moreover,thetransgenicplantswereobtainedbyAgrobacterium-mediatedgenetictransformation.MoleculardetectionperformedbyusingPCRandβ-glucuronidasestainingshowedthatthetargetconstructwasintegratedintothegenomeofrice.Thenegativephototropiccurvaturesofthetransgenicricerootswerehigherthanthoseofthewildtype.Similarly,theexpressionlevelsofOsPIN1ainthetransgenicplantswereconsiderablyhigherthanthoseinthewild-typeplants.TheseresultssuggestthatOsPIN1aiscrucialinthenegativephototropiccurvatureofriceroots.

  • 标签: RICE OsPIN1a green FLUORESCENT protein TRANSIENT
  • 简介:Thisstudywasonsuperiorityofthenon-negativematrixfactorization(NMF)algorithmforapplicationofinformationextractedwithaerialimages.First,NMFwasusedforaerialimageinformationextraction,andthenthisdatawascomparedwithaprincipalcomponentanalysis(PCA)inwhichr(thenumberofrowsorcolumnsofbasicmatrix)andEignum(thenumberofeigenvalues)weregivendifferentvalues.ExperimentalresultsshowedthattheruntimeofNMFwithr=20or50waslessthanthatofPCAwithanEignum=20or50.Also,therecognitionrateofNMFwithr=50washigherthanthatofanEignum=50.Theexperimentshowedthatnonnegativematrixfactorizationhadadvantagesofashorttimeperiodwithahighrecognitionrate.

  • 标签: FOREST management non-negative matrix factorization(NMF) AERIAL
  • 简介:APoissonregressionmodelandanegativebinomialregressionmodel(NBmodel)areoftenusedinareassuchasmedicineandeconomy,butrarelyinthedomesticforestrysector,especiallyintheforestfireforecasting.BasedonthedataofforestfireoccurrencesinDaxing’anlingregionin1980-2005,thispaperprofoundlyanalyzestheapplicationconditionsandtestmethodsofthetwomodels.TheAICmethodwasusedtocheckthefittinglevelofthemodelsandthecapabilityofthemodelsforforecastingforestfireswasdiscussed.ThisstudyprovidednecessarytheoreticalbasisanddatasupportfortheapplicationofthetwomodelsinthefieldofforestryinChina.

  • 标签: FOREST fire POISSON MODEL NEGATIVE BINOMIAL