neaspectofforestsustainabilityisregen-eratingthestandtodesiredspeciesoncethestandisharvested.Usuallythespecies

presentintheoverstoryaremoredesirablethanthoseintheunderstoryandmidstory.Ifmanagementisnotperformedtoadjusttheregeneratingspeciescom-positionpriortotheharvest,theseunderstoryandmidstoryspecieslikelywillbethecompositionofthefuturestand.Managementactionsshouldbetakentoencouragereproductionoffavoredspeciesanddiscouragetheundesirabletreesandothervegetation. Sitepreparationisasilviculturaltreatmentspe-cificallydesignedtoencouragetheregenerationandgrowthofdesiredspecies.Normally,sitepreparationtreatmentsareadministereddirectlybefore,duringorafteraharvest.Thispublicationprovidesspecificinformationonhowandwhysitepreparationtreat-mentsareoftenneededinnaturallyregeneratedhardwoodstandstodevelopfuturestandsoffavoredspecies. Inclosed-canopyforeststhathavenotbeendisturbedformanyyears,mostofthesunlightisinterceptedbytheuppercanopy,limitingthelightthatfiltersthroughtotheground.Thespeciesthatcangrowandsurviveinthoselimitedlightcondi-tionsaretheshade-tolerantspeciesofmaple,beech,dogwood,sourwood,blackgumandothers;theseare

someoftheleastvaluabletimberspecies.Thissitu-ationisacuteintheregenerationofundisturbedoakforestswheretheshade-tolerantspeciesareprevalentintheunderstory.Oakseedlingsgrowslowlyintheunderstory,iftheyareevenpresent.Mostoaksareintermediateorintolerantofshade.Ifacompletehar-vestisconducted,faster-growing,intolerantspeciesoftenoutgrowtheoaksaswellasestablishedseed-lingsofshade-tolerantspecies.Sitepreparationcanbeusedtocontroltheserapidlygrowingintolerantspeciesaswellassproutsofestablishedshade-tolerantspecies.Becauseofthesenumeroussourcesofcom-petition,sitepreparationisoftenrequiredtopromotethedesiredspeciesandcontrolthemoreundesirablespeciestoobtainafavoredspeciescompositioninthenewlyregeneratingstand. Severaltreatmentsormethodscanbeusedwithsitepreparationtoimprovethenumberofdesirablestemsandspecieswhentheoverstoryisharvested.Oneexampleistheoakshelterwoodtreatment(Stringer2006)pioneeredbyLoftis(1990;2004)foruseinuplandhardwoodstofavortheregenerationandperpetuationofoaks.Themidstoryisremovedseveralyearspriortoharvestingtheoverstorysomoresunlightfilterstotheground.Careshouldbetakentoavoidcanopygapsintheoverstoryallowingdirectsunlighttoreachtheground,supportingthegrowth

O

Site Preparation for Natural Regeneration of Hardwoods

PB1799

Wayne K. Clatterbuck, Professor, Department of Forestry, Wildlife & Fisheries, University of Tennessee

Greg R. Armel, Assistant Professor, Department of Plant Sciences, University of Tennessee

ofshade-intolerantspeciesratherthantheslower-growingoaks.Theshade-tolerantunderstoryisalsocontrolledtoprovidemoreresources,particularlysunlight,andlesscompetitionfortheoakseedlings.Bothofthesemanagementactionsincreasetheprobabilityofoaksbecomingacomponentofthefutureoverstorybydevelopinggreateroaksizeandnumbersbeforetheoverstoryorshelterisremoved.Therefore,oakhasaheadstartingrowthoveritscompetitorsthatislackingifsitepreparationisnotconducted.

Reproductive mechanisms Mosthardwoodsreproducefromseed;fromroot,seedlingorstumpsprouts;orfromadvancereproduction,i.e.,seedlingsorsaplingsalreadypres-entbeforetheharvest.Eachreproductivesource(seeds,sprouts,advancereproduction)mayfavoronespeciesoverotherspecies(Table1). Almostallhardwoodspeciesreproducefromsprouting.Theintactrootsystemgivesstemspro-ducedfromsproutingagrowthadvantageoverthosethatoriginatefromseed.Theresidualtreesshouldbecutclosetothegroundtoinducesproutingfromthegroundlevel.Sproutsoriginatingabovegroundonthestumparestructurallyweakandwillusuallybreakwithageorbedeformed.

Althoughstumpsproutingwilloccuronlargerstems,theprobabilityofsproutingdiminisheswithincreasingstemsizeabove8to10inches(Johnson1977;McGee1978).Afewspeciesthatprolificallyrootsproutareblacklocust,sassafrasandsweetgum.Ifthesespeciesarenotdesiredinthefuturestands,residualstemsshouldbetreatedwithherbicidetoensuretherootsystemiskilledandrootswillnotsprout. Poorlyformedtreesofpreferredspeciesthatarelessthan2or3inchesindiameterarefrequentlycuttoencouragesprouting.Thesproutsoftenprovideacentralizedstemthathasbetterqualitypotential(stemform)thantheinitialstemandwillgrowfasterthantheoriginalstem.Theexistingstemwasprobablybarelysurvivingandmaintainingitselfundergrowingconditionsthatwerelessadvanta-geousandmaynotbeabletorespondtoreleaseoncefavorableconditionsforgrowthareprovided. Manystumpsinitiallyhavemultiplesprouts.Withtime,thenumberofsproutsperstumpdimin-ishesastheycompetewitheachotherforresources.Oneormoreofthemostdominantsproutseventu-allywillremain.Growthispartitionedamongthemultiplesprouts.Ifsproutclumpsarethinnedtofewer(oneortwo)sprouts,thensproutgrowthincreases,becausemoreenergy/resourcesareallo-catedtofewerstems.Thinnedsproutsgrowfasterwithgreatergrowthratesthanunthinnedsproutclumps(RogersandJohnson1989). Treeswillalsoreproducefromseed.Themostcriticaltimeduringatree’slifetimeiswhentheseedisgerminating.Moisture,sunlight,temperatureandsoilconditionmustbeadvantageousforagerminat-ingseedtosurvive.Tocontinuegrowing,seedsmustestablisharootsystemaswellasashoottocreateenergyfromphotosynthesis.Thus,initialgrowthformanyspeciesisslow.Shootgrowthfromgerminat-ingseedismuchslowerthansproutsfromintactrootsystems.Theexceptionsareyellow-poplarandblackcherry,whichhavetheinherentabilitytogrowfastfromseed.Thesetwospeciesalsoincreasetheirreproductivenumbersafteraharvestbecausetheirseedremainsviableintheforestduffforfourtosevenyears,whiletheseedofmostotherspeciesremainviableforashortperiodoftime,usuallyoverwinter.Thesoilsurfaceservesasaseedbankforthesespecies.Whentheoverstoryandmidstoryareremoved,thelargenumberofaccumulatedseedsgerminates,growsfastandoverwhelmsotherspe-cies.

Sprouts originating high on the stump are structurally weak. Trees should be cut as close to the ground as pos-sible to induce sprouting near the ground level.

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Relative importance of reproduction source in relation to species regeneration potentiala

Species

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cut trees

Shadetolerance

American basswood 1 1 2 tolerant

American beech 1 3 2 very tolerant

American elm 1 3 2 intermediate

American holly 1 2 2 very tolerant

American hornbeam 1 2 very tolerant

Ash, green & white 1 1 2 intermediate

Bigtooth aspen 2 3 3 1 very intolerant

Black cherry 1 2 2 intolerant

Blackgum 1 2 tolerant

Black locust 2 1 very intolerant

Black walnut 1 1 2 intolerant

Black willow 1 2 2 very intolerant

Boxelder 2 1 1 tolerant

Buckeye 1 1 2 2 tolerant

Butternut 1 2 intolerant

Cucumbertree 1 2 2 intermediate

Eastern cottonwood 1 1 3 very intolerant

Eastern hophornbeam 1 2 very tolerant

Eastern redbud 2 1 1 tolerant

Flowering dogwood 1 2 very tolerant

Hackberry & sugarberry 1 3 intermediate

Hickoriesd 1 3 intermediate

Oakse 1 2 intermediate

Persimmon 2 1 1 2 very tolerant

Red maple 1 2 tolerant

River birch 1 2 2 intolerant

Sassafras 1 2 1 intolerant

Silver maple 1 2 tolerant

Slippery elm 1 3 2 tolerant

Sourwood 2 1 1 tolerant

Sugar maple 1 2 very tolerant

Sweetgum 1 1 1 intolerant

Sycamore 1 2 2 intolerant

Yellow birch 1 2 intermediate

Yellow-poplar 1 2 2 intolerant

Table 1. Sources of reproduction and shade tolerance of some species in hardwood forests.

a 1 = primary source; 2 = potentially significant, but not a primary source; 3 = minor source. Relative importance of reproduction source is for sawtimber-size standsb Includes seedlings, seedling-sprouts and root sprouts in a few species (i.e., species in root sprouts column)c Sprouts originating from stumps of trees ≥ 2 inches dbh d Hickories as a genus are mostly intermediate in shade tolerance. Mockernut and bitternut range toward the intolerant scale.e Oaks as a genus are mostly intermediate in shade tolerance. The red oak family ranges toward the intolerant scale. Sources: Burns, R.M.; Honkala, B.H. 1990. Silvics of North America. Agric. Handb. 654 (2 volumes). Washington, DC: USDA Forest Service Johnson, P.S. 1989. Central hardwood notes. St. Paul, MN: USDA Forest Service, North Central Forest Experiment Station Putnam, J.L.; Furnival, G.M.; McKnight, J.S. 1960. Management and inventory of southern hardwoods. Agric. Handb. 181. Washington, DC: USDA Forest Service

Someseedsgerminateandgrowbeforetheover-storytreesareharvested.This“advancereproduc-tion”ofseedlings5feettallorgreaterhasabetterchanceofbecominglargerwiththeirheadstartingrowthoverthosethatbeginfromseedorfromsproutsaftertheharvest.Slow-growingseedlings,suchasoaksandhickories,relyonadvancereproduc-tiontoassertthemselvesintheregeneratingstand.

Control of Undesirable Vegetation Severaltechniquesareavailabletodeadenstemsofundesirablespecies.Cutting,physicallygirdlingorfrillingwillkilltheabovegroundportionofthetree,butwillnotcontrolstumporrootsprouting.Useofherbicidesisthemostdependablemethodtokillstumpsandrootsandpreventsprouting.Themosteffectiveherbicidesforcontrollingperennialplantsarethosewhicharetranslocatedtotheroots.Iftherootsoftheplantarekilledbytheherbicide,thensproutingdoesnotoccur. Prescribedburninghasoftenbeenproposedasatooltocontrolundesirablevegetation.Burningisnon-selectiveandkillstheabovegroundportionofplants.However,burninghaslittleimpactontheundergroundrootsystem.Mosthardwoodshavethecapabilitytoresproutprolificallyafterburning,asindicatedinTable1.Repeatedburningona1-to3-yearintervalmayinfluencethedeclineofsomespeciesfortimeperiodsof10ormoreyears,deplet-ingthestoredenergyinrootsystems.However,thestandalsohaslost10ormoreyearsofpotentialgrowthwhilethecompositionisbeingadjustedtodesiredspecies.ResearchineasternKentuckysug-geststhatsingleandrepeatedprescribedfirehadlittleeffectinpromotingoakcomparedtootherspe-cies(Alexanderetal.2008;BlankenshipandArthur2006).Burningwillaidinbringingallvegetationbacktothesamestageofdevelopment(bareground)andcreatingseedbedconditionsthatmayenhancegerminationofseed.Thenseedsandsproutshaveanequalopportunitytocompeteforresources.

Researchonprescribedburningtodatehasnotindicatedthatburningcarriesanypreferentialspe-ciesadvantageandcouldevensupportsproutingandgrowthofundesirablesattheexpenseofmoredesir-ablespecies.

Herbicide Application Methods Mostherbicidesforsitepreparationofhard-woodsareappliedonastem-by-stembasisbyhandequipmentsuchasbackpacksprayersandsqueezebottlesprays.Themostcommontreatmentsaredirectedfoliarsprays,basalbarkapplications,treeinjectionandcut-stumpsprays.Thesizeofthetargetstemtobecontrolledwillinfluencetheapplicationmethodused(Table2).

Directed Foliar Sprays Foliarsprayingisoneoftheeasiestherbicideapplicationtechniques.Theherbicideissprayedonthefoliage,absorbedandtransportedwithintheplanttodisruptphysiologicalprocessesthateventu-allykilltheplant.Sometimesasurfactantneedstobemixedwiththeherbicidetopromoteadherenceandspreadoftheherbicidesprayonthefoliage.Oftenwithfoliarsprays,thefoliageiskilledbeforetheherbicidehasachancetobetransportedtootherplaceswithintheplant.Thus,caremustbetakentoapplytheherbicideduringthecorrecttimeandplantstagetoaffecttheentireplant.Otherwise,treatedtreesorplantswillre-sproutandtheherbicidetreat-mentsuspendsplantgrowth,butdoesnotkillit. Propercalibrationofsprayingequipmentanduseofappropriatespraytips(fullcone,adjustableconeorflatfan)onbackpacksprayersareneces-saryforeffectivespraying.Inaccuratecalibrationoftenleadstoeitherunder-orover-applicationoftheherbicide,eachhavingconsequencesindesiredplantcontrolandcost.Directfoliarsprayingisalsothetechniquewiththegreatestchanceofdamagetonon-targetplants.Mostherbicidesforhardwoodcontrolarenon-specificandaffectmostbroadleaf

Table 2. Method of herbicide application that is appropriate for the size of target stem to be controlled.

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Application Method Effective Size of Target Stems

Directed foliar spray Less than 6 feet tall

Basal bark applications Less than 3 inches in diameter

Tree injection All sizes greater than 1 inch in diameter

Cut stump spray All sizes

foliage.Directspraycanharmadjacentdesirablespe-ciesthroughpoordirectionalspraying,volatilization,driftfromwind,dripfromoversprayingtargetplantsandpoortiming.Timingofapplicationisatfullleafemergenceinthesummerthroughthegrowingseasonwhenleavesbegintosenesceneartheendofthegrowingseason(earlySeptember),reducingtheeffectivenessofthefoliarspray.Thegeneralrecom-mendationisnottousedirectfoliarsprayingbecauseofthechanceofaffectingdesirableplants. Directedsprayscaninfluencenon-targetbroad-leafplantsevenwiththebestapplicationprocedures.Thechoiceofherbicidewilldependonthetargetspeciesorthespectrumoftargetspecies,becausemanyoftheherbicideshavedifferentimpactsonvariousspecies.Thistechniquehasmoreapplica-tioninthereleaseofconiferswhenthehardwoodcompetitionislessthan6feettall,notinthesitepreparationforhardwoodregenerationunlessthespeciescontrolledaresmall(lessthan3feettall)andaccessiblewithabackpacksprayer.

Basal Bark Applications Oncetheplantstobecontrolledarelargerthan6feettall,wherefoliarspraysareimpracticalorunsafe,basalbarktreatmentsareoftenused.Astreamlinebasalsprayismostoftenappliedonstemslessthan3inchesindiameteratbreastheight(DBH).Thestreamlineorthinlineherbicideissprayedinaband1to2incheswideonthelower12inchesofthestem.Althoughthespraydoesnotnecessarilyencircletheentirestemduringapplica-tion,theherbicidemixtureshouldpenetrateand

spreadtoencirclesmallstems.Controloflargertreesgreaterthan3inchesDBHandhavingthickerbarkismoredifficultforherbicidespreadandpenetration.Thus,afullbasaltreatmentwheretheentiretreecircumferenceissprayedwithabroaderband(moreherbicide)isrequired.Todeterminetheefficiencyandeffectivenessoftheherbicideapplication,theprescribedbasalbarktreatmentshouldbetested,andtherangeofspeciesandstemsizesthatmightbeencounteredshouldbeconsidered. Theadvantageofthesetreatmentsisthattheydeliverherbicidedirectlytothetargettreewithlittlechanceofthenon-targettreesbeingaffected.Applicationsareusuallymadeduringthelaterpartofthewinter,FebruaryandMarch,whenleavesdo

When using a backpack sprayer, Personal Protective Equipment (PPE) is necessary for safely applying herbicide.

A thin stream of herbicide is applied to a red maple stem as a basal bark treatment.

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A broader band of herbicide is applied to a large red maple sprout clump.

nothinderspraying.Theherbicideismixedwithanoilcarrierthatallowsthemixturetospreadandpen-etratethebark.Onceinsidethebark,theherbicideistranslocatedthroughouttheplant.

Cut-stump Sprays Cut-stumptreatmentsareparticularlyeffectiveonlargerstems/stumpsthatmighthavethepropen-sitytosprout.Herbicidesareappliedtothefreshlycutsurfaceofthestump.Applicationshouldoccurwithinanhourofthecutsothetreecanabsorbtheherbicidebeforeittriestosealthecuttinginjury.Herbicideisappliedfromabackpacksprayerorhandheldspraybottle.Onlytheouter1or2inchesofthecircumferenceofthestumpsurfaceshouldbesprayed.Mostoftheconductingtissueofthestump/treeisinthisarea.Theherbicideisabsorbedandtranslocatedtotheroots. Ifherbicideisnotappliedtothestumpformorethananhourafterthecut,spraythebarkontheouteredgeofthestumpsurfacefortheentirecircumference.Thisapplicationwouldthenneedtopenetratethebarkfortheherbicidetogetinsidethetreeandbetranslocated,similartothebasalbarktreatmentsdiscussedearlier.

Tree Injection Treeinjectors,“hypo-hatchets”(Hypo-Hatchet®treeinjector)andhack-and-squirtarealltoolsforapplicationofherbicideintothetreethroughacutsurface.Treeinjectorsandhypo-hatchetshavefallenintodisfavorbecausetheyaredifficulttouseandmaintain.Hack-and-squirtissimpleandeasybecauseitonlyusesahatchetandasquirtbottle(orbackpacksprayer)thatareeasilycarriedinthe

woods.Theaxisusedtocutthroughthebarkofthetree(usuallywaist-high)intothesapwoodcreatingadownwardnotch,andthentheherbicideisappliedviathesquirtbottleintothenotch.Thespray/squirtshouldbecalibratedtoensurethecorrectamountofherbicideisdelivered.Severalnotchesshouldbeequallyspacedaroundthestemofthetree,dependingonthesizeandspeciesofthetreeandtheherbicideused.Onsomehard-to-killspecies,acon-tinuousfrillorgirdlewithherbicideappliedwithinmayberequired. Treeinjectionhastheadvantagethatalmostanysizetreecanbekilledandthattheherbicideisdeliv-eredtotheinsideofthetargettree.Theherbicideiscontained,transportedandbrokendowninthetreewithlittlechanceofmovementtonon-targetplants.Herbicidesfortreeinjectioncanbeappliedatmosttimesoftheyearexceptduringtimesofheavysapflowinlatewinterandearlyspringbeforeleafemer-genceandduringdroughtsinlatesummer.Water-solubleformsofherbicidesaremostcommonlyusedtoobtainthegreatestmovementoftheherbicidewithinthetree. RecentinformationfromLondoetal.(2008)suggeststhatonlyoneortwofrillswithinjectionsofimazapyrsolutionarerequiredtokillmanyhardwoodspeciesfrom4to6inchesDBH.Themethodgreatlyreducesthetimeandeffortrequiredforinjectionifthetreespeciesissusceptibletoima-zapyr.A6-inchtree(18-inchcircumference)wouldrequiresixormorefrillsspaced2inchesapartforeffectiveness.Readtheherbicidelabeltoascertainmethodologyandspecieseffectiveness.However,auniquecharacteristicwithimazapyristherelativelylongtimeittakestokillthetreeafterapplication.Afterimazapyrisapplied,treeswilllosesomefoli-age,remainingleavesaresmallandtreesgenerallyhaveanabnormalorsicklyappearanceduringthefirstgrowingseason.Completeeffectivenessoftheherbicidedoesnotappearuntilthesecondgrowingseasonaftertreatment. Continuousfrillsthatgirdleatreeordoublegirdlingwithachainsawcanbeaccomplishedtotop-killtreeswithoutherbicides.However,theeffec-tivenesscanbeincreasedbyusingherbicides.Withherbicides,thechemicalistranslocatedtotheroots,killingtherootsandpreventingsprouting.Girdlingtreeswithoutherbicidesisgenerallylessdependable(particularlywithhard-to-killspecies,suchasdog-wood,redmaple,hickoriesandbeech),andrequiresmoretimeandlabortocompletelygirdlethetree.Additionally,safetyisaconsiderationwhenwalk-

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Hack-and-squirt is a method that places a measured amount of herbicide into trees through frills or small incisions in the bark.

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Herbicides Used as Site Preparation for Natural Hardwood Regeneration Herbicideslistedarethosethatarecommonlyusedtocontrolcompetingorundesirabletreeswhenconductingsitepreparationfornaturalhardwoodregeneration,guidingtheexistingregenerationpooltowardmoredesirablespecies.Theherbicideslistedhaveforestrylabels.Theinformationgivenisaguidethatwassynthesizedfromseveralsources(Moorhead2010;Stringer1999;EverestandPatterson1997)andshouldassistinselectingthebestherbicidetoaccomplishtheobjectiveortask. Thispublicationgivesinformationonherbicidesthatwouldcontrolundesirablewoodyvegetationinforestedareasandthathaveforest-useherbicidelabels.Grasses,vinesandmanyherbaceousplantscouldimpairtheestablishmentandgrowthofregen-eratingtreespeciesandrequirecontrol.Ifherbicidesareusedtocontroltheseannualsandperennialsinforestedsituations,becarefulthattheherbicideislabeledforuseinforests.Severalherbicidescom-monlyareusedinnon-cropornon-timbersituationsforsitepreparationpriortoreforestation.These

herbicidesshouldnotbeusedwhentreesarepresentonthesiteunlesstheyarelabeledforforestryuse. Theherbicideinformationgivenshouldnotsupplanttheherbicidelabel.Read the entire label before using any herbicide.Thelabelcontainsinformationforuseoftheherbicide,proceduresforapplication,andpersonalandenvironmentalsafetyconsiderations.Theeffectivenessoftheherbicideincontrollingdifferentspeciesandspeciestolerancetotheherbicideisdescribedonthelabel.Whentoapplytheherbicideforbesteffectivenessisalsolisted.Duetothehighpotentialforherbicidesplashassociatedwithtreeinjectionoperations,particularlyhack-and-squirt,eyeprotectionandprotectivecloth-ing(personalprotectiveequipment–PPE)shouldbewornduringapplication,regardlessoftheherbi-cideused.DangerandWarningarespecificwordsusedinpesticidelicensingtoalertusersofpotentialeffects.Thefollowingsignalwordsareinorderofdecreasingseverity:Danger,WarningandCaution.Formostherbicidesusedinforestryoperations,dangerandwarningsignalwordsrelatetopotentialforeyeinjury.WearPPEandapprovedeyeprotec-tionduringmixing,fillingandapplicationofherbi-cides.Formoreinformationontheenvironmentalsafetyofherbicides,refertoMcNab(1997).

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1. Common Name (Trade Name):Imazapyr(Arsenal/Chopper) Recommended Time of Application:August–March Primary Application:CutStump,TreeInjection Mode of Action:BranchedChainAminoAcidInhibitor Method and Mixture: CutStump:Usedilutedsolutionof6oz.ArsenalAC+1gal.ofwater.Brushorsprayontocambiumarea insidethebarkoffreshlycutstump.Reviewspecificherbicidelabelsforrecommendedrates. TreeInjection:Apply1mlofdilutedArsenalACsolutionintofrillsplacedat2-inchintervalsaroundthe tree.IfconcentratedsolutionofArsenalAC(25%),makeonefrillforevery3inchesintreediameterand apply1mlofsolutioninfrill. Species Tolerant:Hollies,wingedelm,hawthornandlegumessuchasblacklocust Application Exposure:Caution Comments: (a)Costpergallonisrelativelyhigh,butreducedapplicationrequirementsmakeapplicationcosts lowerandcost-effective. (b)Effectivenessoccursinthesecondgrowingseasonaftertreatment.Duringthefirstgrowing season,treeswilllosesomefoliageandappearsickly;leaveswillbesmallandmayexhibit abnormalleafshapesandcolor. (c)Leakagefromrootscandamagenon-targetplants.Herbicideispersistentinsoilsandwillkill seedlings.Careshouldbetakennottospillherbicideduringapplication. (d)Especiallyeffectiveonsassafras,sweetgum,redmaple,sumacandoaks.

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2. Common Name (Trade Name):Glyphosate(Accord) Recommended Application Time:Latesummertoearlyfall Primary Application:CutStump,TreeInjection,Foliar Mode of Action:AromaticAminoacidInhibitor Method and Mixture: CutStump:Useundilutedor1:1withwater.Sprayorbrushoncambialareaof freshlycutstump. TreeInjection:Useundilutedor1:1withwater.Makeonefrillper2inchesofDBH;applyherbicideat rateof1mlperfrill. Foliar:Usea5to10percentsolutionfordirectedsprayofwoodybrushandtrees.Refertolabelforrates andsurfactantrecommendations.Herbicideisnon-selectiveanddriftiscommon,whichcandamage desirableplants. Species Tolerant:Hollies,hickories,redmaple,blackgum,dogwood Application Exposure:Warning:Eyeirritant Comments:(a)Non-selectiveandcankillnon-targetspecies. (b)Manytradenamesandformulations.Readtheherbicidelabel.Useforestrylabelforforestry operations. (c)Effectivecontrolofdogwood,sweetgumandblackgum.

3. Common Name (Trade Name):Hexazinone(Velpar) Recommended Application Time:Summer Primary Application:TreeInjection Mode of Action:PhotosynthesisInhibitor Method and Mixture: TreeInjection:Apply1mlofundilutedVelparLinfrillsspaced2inchesapart. Species Tolerant:Yellow-poplar,hornbeam,sassafras,sumac Application Exposure:Danger:Weareyeandprotectiveclothing Comments:(a)Controlshard-to-killspeciesincludingsweetgum,redmaple,redoaks,hickories,honeylocust andblackcherry. (b)Dangerratingforapplication. (c)Willmoveinthesoil.

4. Common Name (Trade Name): Picloram+2,4-D(TordonRTU,Pathway) Recommended Application Time:Anytimeexceptearlyspringduringsapflow Primary Application: CutStump,TreeInjection Mode of Action: AuxinGrowthRegulator Method and Mixture: CutStump: Treatcambiumlayerinsidebarkonfreshlycutstumpsurfacewithundilutedproduct. TreeInjection:Apply1mlofundilutedPathwayorTordonRTUinfrillscompletelyaroundthestemat 2-3inchintervals. Species Tolerant: Beech,redoak,maple,dogwood Application Exposure: Warning:Eyeirritant Comment: Caninjureorkillnon-targetplants,particularlyyellow-poplar

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5. Common Name (Trade Name): Triclopyr(Garlon3AandGarlon4) Recommended Application Time: Anytimeexceptearlyspring Primary Application: Garlon3A---CutStump,TreeInjection,Foliar Garlon4---CutStump,BasalBark,Foliar Mode of Action: AuxinGrowthRegulator Method and Mixture: CutStump: TreatcambiumlayerinsidebarkonfreshlycutstumpsurfacewithundilutedGarlon3Aor treatstumpsidesandcambiallayeroncutstumpsurfacewithGarlon4(25%indieselfuel). TreeInjection: Garlon3Aonly.Spray1mlundilutedor½mlinadiluted,1:1ratioinwaterinfrills spacedat3-to4-inchintervalsaroundthestem. BasalSpray: Garlon4only.Mix20-30%Garlon4with70-80%oil.Applyasstreamline(atleasttwo streaks)acrosslowerstemofhardwoodssmallerthan3inchesDBH.Applicationcanbeatanytimeof year,butmosteffectivesixweeksbeforeleafexpansionthroughJune.

Foliar:Useasdirectedspray.Actionsshouldbetakentominimizedrift.Theesterformulation(Garlon4)providesbetterpenetrationandcontrolofspecieswithwaxyleavesthantheGarlon3Aamineformula-tion.Applyduringgrowingseasonbeforeleafsenescenceandafterleafemergence(April–mid-Sept.).Use2-4%ofGarlon4withanoil-wateremulsifieror2-5%ofGarlon3awithsurfactantaccordingtolabelinstructions.

Species Tolerant:Dependsonformulationandapplication.RedmapleisfairlyresistanttoinjectionsofGarlon 3A,butsusceptibletobasalsprayofGarlon4.LegumeslesssusceptibletoGarlon4. Application Exposure:Garlon3A---Danger:Eyeirritant Garlon4---Caution Comments: (a)TheesterformulationofGarlon4providesbetterpenetrationofwaxyleafsurfacesthanthe amineformulationofGarlon3A. (b)Garlon4isthesuggestedproducttouseonstreamlinebasalsprayoperations. (c)Aswithalldirectedfoliarsprays,careshouldbetakentominimizedrifttonon-targetspecies.

6. Common Name (Trade Name): Triclopyr(PathfinderII) Recommended Application Time:Anytimeofyear Primary Application:CutStump,BasalBark Mode of Action: AuxinGrowthRegulator Method and Mixture: CutStump: Applyundilutedproducttostumpsidesandcambiallayeronfreshlycutstumpsurface,but nottopointofrunoff. BasalSpray: Applyundilutedproductinspraytostemslessthan6inchesinbasaldiameterbywetting lower12to15inchesofstem.Donotapplytopointofrunoff. Species Resistance: Legumes,sourwood Application Exposure: Caution Comments: (a)Ready-to-useproduct,nomixingrequiredaswithGarlon4.Containsapetroleum-based penetrant. (b)Canbeappliedanytimeofyear. (c)Basalsprayapplicationsforstemsfrom3to6inches.

Herbicide Statements Personal and environmental safety --- To protect people and the environment, herbicides should be used safely. This is everyone’s responsibility, especially the user. Read and follow label directions carefully before you mix, apply, store or dispose of an herbicide. According to laws regulating herbicides, they must be used only as directed by the label. Herbicides in this publication --- Herbicides discussed in this publication were registered for the prescribed uses when printed and their use in this publication was provided as an example of herbicides that could potentially be used in site preparation of natural hardwood regeneration. Specific prescriptions must be determined by the user with a full knowledge of the application site, species involved and label information Herbicide registrations are continuously being reviewed. Should registration of a recommended herbicide be cancelled, it would no longer be discussed, used as an example or recommended by the University of Tennessee or the University of Kentucky. Use of trade names in this publication is for clarity and information; it does not imply approval of the product to the exclusion of others, which may be of similar, suitable composition, nor does it guarantee or warrant the standard of the product.

Summary Sitepreparationiscommonlyconsideredwhenplantingtreestogivethemthebestchanceforsurvivalandgrowth.Thesameshouldapplywhennaturalregenerationwillberelieduponafteraforestharvest.Unfortunately,manytimberharvestsareconductedforshort-termgainwithoutmuchthoughttowardregenerationandfuturestandcompositionandgrowth.Reproductionshouldbesurveyedandinventoriedseveralyearsbeforetheharvesttodeterminewhatispresent.Ifdesirablereproductionispresentinsufficientsizeandnumbertopopulatethenextstand,thentheharvestcanbeconducted.Ifnot,thensitepreparationshouldbeconductedtocontrolundesirablevegetationandtodevelopsuf-ficientnumbersandsizesofdesirablespeciesbefore

theharvest.Consideringthedifferentgrowthratesandreproductivemechanismsofthemanyhardwoodspecies,thepromotionoffavoredspeciesusuallyentailscontrolofundesirableorcompetingspecies. Herbicidesareprimarilyusedtocontrolundesir-ablespeciesduringsitepreparationfornaturalregen-eration.Variousherbicidesandapplicationmethodsareavailable.Forestmanagersshoulddeveloppre-scriptionsthatbestsatisfytheirmanagementobjec-tivesduringsitepreparationtopromotethegrowthanddevelopmentofdesirablespeciesanddiscourageundesirablespeciesthroughtheuseofherbicidesandvariousapplicationmethods.Withadequatesitepreparation,standsshouldbeinaconditiontoaddvaluewithoutadditionalmanagementcosts.Sitepreparationcostsfornaturalregenerationmayalsoqualifyforreforestationtaxincentives.

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7. Common Name (Trade Name):2,4-D(varioustradenames) Recommended Application Time:FullleafemergencethroughJune Primary Application:CutStump,BasalSpray,Foliar Mode of Action:AuxinGrowthRegulator Method and Mixture: CutStump: Spraythebarkandbaseofstumpthoroughly,butnottopointofrunoff,withundiluted product.Esterformulation. BasalSpray:Sprayandencirclethelower18-24inchesofplantstemwithundilutedproduct.Ester formulation. Foliar: Useasadirectedspray.Non-selective.Canapplyeitheramineoresterformulations,usuallyasa4 percentspray. Species Resistance: Usuallyfoliarapplicationsweakeronblackgum,redmaple,ash,dogwoodandwaxyleaf species. Application Exposure: Caution:moderateeyeirritation Comments: (1)2,4-DusuallymixedwithotherproductsforbroaderspectrumspeciesControl;rarelyused alone. (2)Readlabelinstructionscarefully.Canbesoldasanesteroramineformulation.Soldunder varioustradenames.Forforestryoperations,makesureofforestrylabel.

Literature Cited

Alexander,H.D.;Arthur,M.A.;Loftis,D.L.;Green,S.R.2008.Survivalandgrowthofuplandoakandco-occurringcompetitorseedlingsfollowingsingleandrepeatedprescribedfires.ForestEcologyandManagement256:1021-1030.

Blankenship,B.A.;Arthur,M.A.2006.Standstructureovernineyearsinburnandfire-excludedoakstandsontheCumberlandPlateau,Kentucky.ForestEcologyandManagement225:134-145.

Everett,J.W.;Patterson,M.1997.Brushcontrol.PublicationANR-1058.Auburn,AL:AuburnUniversity,AuburnCooperativeExtensionSystem.12p.

Johnson,P.S.1977.PredictingoakstumpsproutingandsproutdevelopmentintheMissouriOzarks.ResearchPaperNC-149.St.Paul,MN:USDAForestService,NorthCentralForestExperimentStation.11p.

Loftis,D.L.2004.Uplandoakregenerationandmanagement.P.163-167inProceedings,uplandoakecologysymposium:history,currentconditions,andsustainability.Spetich,M.A.(ed.).GeneralTechnicalReportSRS-73.Asheville,NC:U.S.DepartmentofAgriculture,ForestService,SouthernResearchStation.311p.

Loftis,D.L.1990.TheshelterwoodmethodforregeneratingoakintheSouthernAppalachians.ForestScience36:917-929.

Londo,A.J.,;Ezell,A.W.;Nelson,L.A.2008.Treeinjectionwithreducedlaborrequirements.InformationSheet1573.MississippiState,MS:MississippiStateUniversity,ExtensionService2p.

McGee,C.E.1978.Sizeandageoftreeaffectwhiteoaksprouting.ResearchNoteSO-239.NewOrleans,LA:USDAForestService,SouthernForestExperimentStation.2p.

McNab,K.1997.Environmentalsafetyofforestryherbicides.PublicationANR-846.Auburn,AL:AuburnUniversity,AuburnCooperativeExtensionSystem.4p.

Moorhead,D.J.2010.Forestherbicides.2010GeorgiaPestManagementHandbook.Athens,GA:UniversityofGeorgiaCollegeofAgriculturalandEnvironmentalSciences.

Rogers,R.;Johnson,P.S.1989.Thinningsproutclumps.CentralHardwoodNotes6.12.St.Paul,MN:USDAForestService,NorthCentralForestExperimentStation.3p.

Stringer,J.2006.Oakshelterwood:Atechniquetoimproveoakregeneration.ProfessionalHardwoodNotes.PublicationSP676.Knoxville,TN:UniversityofTennesseeExtension.8p.

Stringer,J.W.1999.Herbicidesforsmallscaleforestryoperations.ForestryFactSheetFORFS99-9.Lexington,KY:UniversityofKentuckyCooperativeExtensionService,CollegeofAgriculture.4p.

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Citation:Clatterbuck,W.K.;Armel,G.R.2010.Sitepreparationfornaturalregenerationofhardwoods.ProfessionalHardwoodNotes.PublicationPB1799.Knoxville,TN:

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