简介：Background:Attentionhasrecentlybeendrawntotheissueoftransboundaryinvasions,wherespeciesintroducedandnaturalizedinonecountrycrossinternationalbordersandbecomeproblematicinneighbouringcountries.Robustmodellingframeworks,abletoidentifytheenvironmentaldriversofinvasionandforecastthecurrentandfuturepotentialdistributionofinvasivespecies,areneededtostudyandmanageinvasions.Limitationsduetothelackofspeciesdistributionandenvironmentaldata,orassumptionsofmodellingtools,oftenconstrainthereliabilityofmodelpredictions.Methods:Wepresentamultiscalespatialmodellingframeworkfortransboundaryinvasions,incorporatingrobustmodellingframeworks(MultimodelInferenceandEnsembleModelling)toovercomesomeofthelimitations.TheframeworkisillustratedusingHakeasericeaSchrad.(Proteaceae),ashruborsmalltreenativetoAustraliaandinvasiveinseveralregionsoftheworld,includingtheIberianPeninsula.Twostudyscaleswereconsidered:regionalscale(westernIberia,includingmainlandPortugalandGalicia)andlocalscale(northwestPortugal).Attheregionalscale,therelativeimportanceofenvironmentalpredictorssetswasevaluatedandrankedtodeterminethemaingeneraldriversforthespeciesdistribution,whiletheimportanceofeachenvironmentalpredictorwasassessedatthelocalscale.ThepotentialdistributionofH.sericeawasspatiallyprojectedforbothscaleareas.Results:ModelprojectionsforwesternIberiasuggestthatalargeareaisenvironmentallysuitableinbothPortugalandSpain.Climateandlandscapecompositionsetswerethemostimportantdeterminantsofthisregionaldistributionofthespecies.Conversely,ageologicalpredictor(schistlithology)wasmoreimportantinexplainingitslocal-scaledistribution.Conclusions:AfterbeingintroducedtoPortugal,H.sericeahasbecomeatransboundaryinvaderbyexpandinginpartsofGalicia(Spain).ThefactthatalargerareaispredictedasenvironmentallysuitableinSpainraisesconcern

简介：Multi-functionaldendrometerisakindofforestrytoolthatcanmeasuremultiplefactorsofforest.Bycombiningsensortechnologyandcomputertechnology,adigitalmulti-functiondendrometerhasbeendeveloped,whichintegratedthefunctionsofmeasuringheight,distance,azimuth,slope,elevation,formquotientofanypartsofthestemintoonebodyatthesametest.Thedendrometercanfitthecomplexforestenvironment,solvethedifficultproblemsinaspectsofplantheight,measuredistance,centraldiameterandformquotientofbreastheight.Theaccuracycanmeettherequirementsofgeneralforestsurvey.

简介：Thispaperproposesanautomaticmethodofporecombinationrecognition,whichisanimportantfeaturetohardwoodrecognition.Afterextractingedgefromwoodmicroscopiccross-section,basedonareahistogramofthesimilarcircleregions,themethodclassifiesallregionsintotwoclasseswithmaximumbetween-classvariance,soastodistinguishtheporefromothertextures,whicharesimilarinshapesbutdifferentinsizes.Meanwhile,secondobjectivefunctionaboutaverageareaofclosedregionsisusedtoimprovetheporesegmentationperformance.Atlast,themethodusesadjacencydegreeofporesettojudgeporecombination.Theexperimentsdemonstratethatthetaskofporesegmentationcanbecompletedsuccessfullyforallkindsofporedistributionandcombination,andalsothecorrectcombinationsofporesaregiven.

简介：目前，关于防风林的保护的效果的大多数研究根据森林带和网络的二规模。与关于全球环境变化的进一步的研究，然而，更多的注意对防风林的地区性的气候效果被给予。在现在的学习，我们由使用陆地表面温度(LST)在地区性的规模分析了防风林的温度效果从在在到在2008的10月的从三月的中国的吉林省的Yushu，Nongan，Dehui，和Fuyu的中等决定成像分光辐射函数(MODIS)的数据。结果证明防风林能作为与没有防风林地区相比增加保护的农田的土壤温度，与0.57的增长吗？

简介：Thechangeofpinescale(HemiberlesiapitysophilaTakagi)populationdensityonpineforestinurbanparkbetweentreatment(tendingoperations)andCK(notendingoperations)wasresearchedinthispaper.Theresultswereshownasfollows:populationdensitydeclinedto0.63headperbundlefrom2.61headsperbundlewhencrowndensityofpineinurbanparkhadbecome0.5orsobymeansofcultivationactivitiessuchasfelling,pruningandthinningandsoon,anddropgotto75.86percent.Thepinewoodswouldsoongetrevivedonceusingthesecultivationactivities,sotendingoperationswasmainmeasurescontrollingoverharmofpinescaleinurbanpark;Atthesametime,populationdensityofpinescaleonpinewoodsinthesunnyslopewasmorethanthatinthesomberslopeandithadbecomelessandlessfromsunnyslopetosomberslope.Therefore,treespeciesmustbechosenintheplanninganddesignofurbanparkforpreventingharmandhappeningofpinescale.

简介：MetropolitanManila,thecapitalregionofthePhilippines,initiatedurbanforestryprojectstoshowcaseitsenvironmentalbenefits.MetroManilawasonceapartofatropicalmangroveforestdominatedbysmalltreeslocallycallednilad(Scyphiphorahydrophyllaceae).Thefast-pacedurbanizationtransformedtheoriginalecosystemintoabustlingmetropolissubjectedtoenvironmentaldecay.Theestablishmentofurbanforestryisoneoftheinterventionssoughtbythegovernmenttomitigatetheenvironmentalconditions.Thus,theconceptofparticipatoryurbanforestrywasformalizedin1988bythenationalgovernment.However,itwasduringtheearlyyearsofthe1970sthattheideaofexertingcollectiveeffortingreeningMetroManilastartedthroughtheGreenRevolution,withtheprimarymotiveofupliftingtheeconomicconditionofthepeopleratherthanonecologicalenhancement.Theprojectwasforcedonthepeopletoplantvegetablesandfruittreeswithlessemphasisonforesttreesspecies.Althoughtheprojectwasnotsuccessful,thegovernmentrealizedthatthecitizenrycouldbeagreatpartnerforacollectiveworthwhileundertaking.

简介：BasedonthepreviousstudyoncultivationnutritionofCunninghamialanceolataplantationsoffirstgeneration,thecultivationnutritionofC.lanceolataplantationswithmulti-generationwasstudied.Theresultsshowthattherearesignificantdifferencesinthegrowth,developmentandnutrientassimilationamongC.lanceolataplantationswithdifferentgenerationsandnutritionconditions.ThesedifferencesarecloselyrelatedtothelandfertilitydeclineofC.lanceolataplantations.Thispaperde...

简介：Background:Withthelossofspeciesworldwideduetoanthropogenicfactors,especiallyinforestedecosystems,ithasbecomemoreurgentthanevertounderstandthebiodiversity-ecosystemfunctioningrelationship(BEFR).BEFRresearchinforestedecosystemsisverylimitedandthusstudiesthatincorporategreatergeographiccoverageandstructuralcomplexityareneeded.Methods:Wecompiledground-measureddatafromapprox.onehalfmilionforestinventorysampleplotsacrossthecontiguousUnitedStates,Alaska,andnortheasternChinatomaptreespeciesrichness,foreststocking,andproductivityatacontinentalscale.Basedonthesedata,weinvestigatedtherelationshipbetweenforestproductivityandtreespeciesdiversity,usingamultipleregressionanalysisandanon-parametricapproachtoaccountforspatialautocorrelation.Results:Ingeneral,forestsintheeasternUnitedStatesconsistedofmoretreespeciesthananyotherregionsinthecountry.ThehighestforeststockingvaluesovertheentirestudyareawereconcentratedinthewesternUnitedStatesandCentralAppalachia.Overall,96.4%ofsampleplots(477,281)showedasignificantpositiveeffectofspeciesrichnessonsiteproductivity,andonly3.6%(17,349)hadaninsignificantornegativeeffect.Conclusions:Thelargenumberofground-measuredplots,aswellasthemagnitudeofgeographicscale,renderedoverwhelmingevidenceinsupportofapositiveBEFR.Thisempiricalevidenceprovidesinsightstoforestmanagementandbiologicalconservationacrossdifferenttypesofforestedecosystems.Foresttimberproductivitymaybeimpairedbythelossofspeciesinforests,andbiologicalconservation,duetoitspotentialbenefitsonmaintainingspeciesrichnessandproductivity,canhaveprofoundimpactsonthefunctioningandservicesofforestedecosystems.

简介：密云水库集水区水源保护林在北京地区饮用水源保护中起着非常重要的作用．本文给出了该区小流域对比实验的初步研究结果，有林小流域和无林小流域对１９９６年７月３０日降雨过程较为一致的径流响应表明，土壤前期含水量对流域产流有较大的影响，在降雨较多土壤含水量较大的情况下该区产流方式可以表现为饱和地表径流．尽管该区以霍顿超渗产流为主，但对于１９９７年７月３１日至８月１日降雨过程，森林流域产流总量为１３９３．８０ｍ３，无林流域为２２０２．４３ｍ３，森林流域减少洪水总量３６．７％，消减洪峰流量达３７３％．然而，１９９７年７月１９日降雨过程森林流域径流洪峰量与洪水泥沙含量均较无林流域高，这表明预处理措施对径流泥沙过程有极为显著的影响

简介：在考虑地表流边界条件情况下，森林对降雨径流和泥沙的影响是一个非常复杂的过程．本文给出了水源保护林在自然坡面尺度上对径流泥沙影响的初步试验研究结果，森林在自然坡面尺度上对１９９７年７月３１日至８月１日降雨过程的洪峰流量消减率达４５５９％，洪水总量的消减率为６．８％，森林坡面径流总量为９８０．７８ｍ３，荒草坡为１０５２２３ｍ３．森林对１９９６年７月３０日降雨过程的洪峰流量消减率为１７．９５％，森林坡面的径流总量为１５．０８ｍ３，荒草坡为１８．３８ｍ３．从１９９６年森林对降雨径流较低的消减率看，降雨量与降雨强度对径流泥沙有很大的影响．

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简介：TwoclonaltrialstandsofChineseFir（Cunninghamialanceolata）wereusedinthisstudy,onewas19-year-oldstandwhichincluded38clones,andtheotherwas17-year-oldstandincluding102clones.Thestatisticalanalysesshowedthattherewereverysignificantgeneticvariationsinheight,DBH,volumeandratioofheartwood(Rhw),woodbasicdensity（ρb）oftheclonesinthetwostands.Therepeatabilityofcloneswasinmediantohighlevel,andthegeneticCVwasdifferentovertheallfivetraits.Therewereverysignificantphenotypicandgeneticcorrelationsamongheight,DBHandvolume,andnegativecorrelationsamonggrowth,Rhwandρb.Theselectionmethodexperimentindicatedthatindexselectioncouldimprovevolume,Rhwandρb,showingsyntheticallysuperiorselectioneffectscomparedtoanyindividualtraitselectionmethods.

简介：Background:Theimportanceofstructurallydiverseforestsfortheconservationofbiodiversityandprovisionofawiderangeofecosystemserviceshasbeenwidelyrecognised.However,toolstoquantifystructuraldiversityofforestsinanobjectiveandquantitativewayacrossmanyforesttypesandsitesarestillneeded,forexampletosupportbiodiversitymonitoring.Theexistingapproachestoquantifyforeststructuraldiversityarebasedonsmallgeographicalregionsorsingleforesttypes,typicallyusingonlysmalldatasets.Results:HerewedevelopedanindexofstructuraldiversitybasedonNationalForestInventory(NFI)dataofBadenWurttemberg,Germany,astatewith1.3millionhaofdiverseforesttypesindifferentownerships.Basedonaliteraturereview,11aspectsofstructuraldiversitywereidentifiedaprioriascruciallyimportanttodescribestructuraldiversity.Aninitialcomprehensivelistof52variablesderivedfromNationalForestInventory(NFI)datarelatedtostructuraldiversitywasreducedbyapplyingfiveselectioncriteriatoarriveatonevariableforeachaspectofstructuraldiversity.Thesevariablescomprise1)quadraticmeandiameteratbreastheight(DBH),2)standarddeviationofDBH,3)standarddeviationofstandheight,4)numberofdecayclasses,5)bark-diversityindex,6)treeswithDBH>40cm,7)diversityoffloweringandfructification,8)averagemeandiameterofdowneddeadwood,9)meanDBHofstandingdeadwood,10)treespeciesrichnessand11)treespeciesrichnessintheregenerationlayer.Thesevariableswerecombinedintoasimple,additiveindextoquantifythelevelofstructuraldiversity,whichassumesvaluesbetween0and1.Weappliedthisindexinanexemplarywaytobroadforestcategoriesandownershipstoassessitsfeasibilitytoanalysestructuraldiversityinlarge-scaleforestinventories.Conclusions:Theforeststructureindexpresentedherecanbederivedinasimilarwayfromstandardinventoryvariablesformostotherlarge-scaleforestin

简介：Blacklocust(RobiniapseudoacaciaL.)wasthefirstNorth-AmericantreespeciesimportedtoEuropeatthebeginningoftheseventeenthcentury.Itiscommonlyplantedworldwidebecauseofitsadaptabilitytoenvironmentalstresses,itsvaluablewood,easypropagation,frequentandabundantseedproduction,excellentcoppicing,highseedlingsurvival,andrelativelyhighwoodyield.InEurope,RomaniaandHungaryhavethemosthighly-developedblacklocustgrowingtechniquesandexperiences.Asaresultofincreasinginterestinblacklocustinmanycountries,thisreviewaimstoprovideacomprehensiveoverviewofstate-of-the-artsiterequirements,propagation,improvementandmanagement(includinggrowthandyieldaswellasuseinenergyplantations).

简介：Globalclimatechangeposesnewopportunitiesandchallengesforforestrydevelopment,andthereforedevelopingmultiple-purposeforestryisanimportantmeasuretostrengthenforestryresponsetoclimatechange.Atpresent,plantationinChinarankstheworldfirstinarea,butwithrelativelylowproductivity.Constantlyexpandingforestareaandimprovingforestmanagementforenhancingmultiplefunctionsandpurposesofplantationsarethekeymeasurestoupgradeplantationcapacitytomitigateandadap...