opularsentimentisthatthesmalltreesin thelowercanopywhenreleasedwillbecome thelargetreesoftomorrow.Thisassump-tionhasbeenperpetuatedinthediameter-limitharveststhathaveledtowhatwecallhigh-gradingtoday.Thelargestandbesttreesarerepeatedlyharvestedleavingthesmaller,inferiortreestoper-petuatethenextstand.Inreality,thetreesbeingreleasedareprobablyofsimilarageasthosebeingcut.Thesmaller,releasedtreesdidnothaveachancetoprosperincompetitionwiththefaster-growing,overstorytrees.Thesereleasedtreesareincapableofcontinuedgrowthwiththeirsmall,spindlycrowns.Theconsequenceofremovingonlyhighlyvaluedtreeswitheachharvestisahardwoodresourcewitheverlowerlevelsofeconomicallyvaluabletrees.

Degraded,lowqualityorproblemhardwoodstandsgenerallyresultfromthehistoricabsenceofmarketsforlow-valuetrees.Aftermanyyearsofonlyharvestingthemostvaluabletrees,millionsofacresofdegradedstandsintheeasternhardwoodregionhavelittlelefttomanage.Thesestandsneedsilvicul-turaltreatmenttoincreasetheirvalueandproductiv-ity.Recentimprovementinthemarketsforpallets,ties,chipsandpulpwoodincreasesthemanagementoptionsavailablefortreatingdegradedstands.

Forestpractitionersandlandownersshouldunderstandwhyandhowtheseproblemstandswerecreatedsothatfewerofthesestandsoccurinthe

Degraded stand with fire-scarred trees and trees with poor form.

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Extension

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Treatments for Improving Degraded Hardwood Stands Wayne K. Clatterbuck, Associate Professor, Forest Management and Silviculture, University of Tennessee, Knoxville

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future.Thegoalofthispublicationistoexplainwhyhardwoodstandsbecomedegradedandtodescribecorrectivemeasuresforimprovingdegradedhard-woodstands.

Degraded Hardwood Stands

DefinitionTheterm“degraded”inthismanuscriptincludes

alllow-qualityandproblemhardwoodstands.Asaresultofpastpractices,degradedhardwoodstandsusuallycontaintreesthatarecrooked,rottenordiseased;areofundesirablespecies;arephysicallydamagedfrompreviousloggingoperationsandarenotgrowingatasatisfactoryrate.Degradedstandsalsocontainpatchesoftoomanyortoofewtreesandregenerationofdesirablespeciesislacking.Mostimportantly,degradedstandsusuallydonotcontainlargevolumesornumbersofdesirablegrowingstocktrees(HaymondandZahner1985).Thesedegradedstandspresentgreatopportunities,buttoughchal-lengesforforestmanagement(McGee1982).Theopportunityforimprovingthesestandsisconsider-able,asmanyacresnowproducejustafractionoftheirpotential.

Itisassumedthatusually,butnotalways,thesestandshavebeencutoverandonlythebesttrees

removed.Butdegradedstandsalsooccuronlow-qualitysitesorasaresultoffire,insectsordisease.Itisalwaysimportanttodetermine“why”astandisdegraded.Ifthedegradedstandoccursonapoorsite,carefulplanningoftreatmentisrecommendedbecausethereislittlethatcanimprovetreegrowthonpoorsites.

How Did These Stands Become Degraded? Acauseofdegradedhardwoodstandsisrepeated

cuttingsthroughpractices(commonlycalledhighgrading,diameter-limitcuttingorselectcutting),wherethebesttreesareharvestedandpreviouslydescribednon-marketableanddefectivetreesareleft.Cuttingonlythelargestandbesttreesremovesthosetreesthatarebestsuitedforthesiteandleavestreesforgrowingstockthatarelessadaptedtothesite.Yet,repeatedhighgradingwithnostandimprovementhasprogressivelyremovedthebesttimberandleftthestandinadegradedcondition.

Mostoftheseharvestsareconductedforshort-termeconomicgain,withoutconsiderationforthegrowthandcompositionofthegrowingstockthatisleftandregenerationofthefutureforest.Histori-cally,theonlymarketsavailablewereforthebesttrees,whichpromoteshigh-grading.Thistypeofcuttingdoesnotmakeprovisionsfortheregenera-tionofmanydesirablespecies,especiallyoaksandhickories.Themostlyundesirable,shade-tolerantspecies(blackgum,redmaple,sugarberry,boxelder,hornbeam,sourwoodandbeech)inthemidstoryandunderstorypriortotheharvestremain,suppressingthegrowthanddevelopmentofdesirable,regenerat-ingspecies.However,withtheexpansionofmarketsforlow-qualityproducts,landownerswillhavemoreoptionsforaddressingdegradedstands.

Manyoftheseharvestsweredoneinthenameofgoodforestmanagement(Ezell1992).Landownersthoughtthatthelargetreesweretheoldertrees,sotheyremovedthemtogiveroomforyoungtreestodevelop.Wenowknowthatsmalltreesthatareleftarenotnecessarilyyoungtrees(Clatterbuck2004)andthatcuttingthebiggestandbesttreesoutofastandusuallyresultsindegradedstands.

Repeatedharvestingentriesintoastandusuallyresultindamagetosomeresidualtreesfromloggingwounds.Inadditiontopoorharvestingpractices,fire,insectsanddisease,wind,ice,grazingandgrapevineshavedegradedmanytreesinhardwoodstands.Whatwefindinmanydegradedstandstodayisamosaicofdegradedremnantsleftoverfrompreviousharvests,someregrowthofdesirablespecies

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Damaged trees usually do not improve with growth as shown by this fire-scarred yellow-poplar on a good site.

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andalargeproportionofshade-tolerantspeciesthatareundesirablefortimberproduction(Ezell1992).Often,standshaveapatchydistributionoftrees,includingcrowdedconditionsinsomeareas(over-stocked)andsizableopeningsorwidelyspacedtrees(understocked)inothers(Nyland2006).

Sitequalityisanothercauseofdegradedstands.Somesitesaresopoor,theyarenotcapableofgrowinggoodhardwoods.Thesesitesmightincludethethinsoilsanddroughtyconditionsfoundonexposedridgesandsteep,southslopes.Typicalspe-ciescompositionisblackjackoak,postoak,chestnutoak,easternredcedar,Virginiapineandvacciniums.However,manydegradedstandsoccuronmedium-tobetter-qualitysites.Better-qualitystandscanberegeneratedonthesesites(McGee1982).Inmostcases,ratherthanrepresentingthetruepotentialofstandsonthesesites,thetreespresentareoftenaresultofacombinationofharvestingpracticesandotherfactorssuchasburningorgrazing,andnotjustbecausethesiteispoor(Smalley1982,McGee1982,HaymondandZahner1985).Becauseofthepresenceofdegradedtreesonthesesites,manyland-

A degraded hardwood stand with oak decline.

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Causes of Stand Degradation

1.HighGradingorDiameterLimitLogging

• Reducesstemquality• Reducesmerchantablevolume• Maychangespeciescomposition• Promotescanopydiscontinuity• Changesdiameterdistribution

2.GrazingorFire---Increasesrotandcanreduceregeneration

3.RepeatedLoggingEntries---Loggingdamagetoresidualtreesand

regeneration

4.Insectsanddisease,wind,icestormsandotherfactors

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ownersandpractitionersinferthatthesesitesarepoor.However,withcarefulplanningandharvestofpoorertrees,thesebettersitescanproducebetterstandsofhardwoods.

Insummary,degradedstandsusuallyhavethefollowingfeatures(Nyland2006):

• fewtreesofdesirablespecies,goodvigororgoodformremainasgrowingstock,limitingthefuturepotentialforvolumeandvaluegrowth

• thestandoftenhasapatchydistributionofresid-ualtrees,resultinginincompletesiteutilizationandlittlecontroloverunderstorydevelopment

• limitedusablevolumeremains,makingfurthercuttingcommerciallymarginalorinfeasible

• fewlargeseedtreesremain,complicatingattemptstoestablishanewcohort

•understoryplantsmaydominatetheunderstory,particularlyinthemoreopenareas,furtherchal-lengingchancestoregeneratenewseedlingsacrossthestand

Why Does the Problem of Degraded Stands Persist?

Whilesomecausesofdegradedtreesarecon-trollable,themajorityofdegradedstandsarenotmanaged.Thesimpleansweristhatthelandownershavelittleeconomicincentivetoimprovethestand(McGee1982).Marketsfordegradedhardwoodsarenotgenerallyavailable,andwheretheydoexist,theincomeismarginalatbest.Moreoptionsareavail-abletorectifyadegradedsituationwhenmarketsexistforsmallandlow-valuematerial.

Improvementofsomeseverelydegradedstandsmayrequireacashoutlayandthecostofremovingpoortreesmayexceedthevalueofthestumpage.Manyownersarereluctantorunwillingtoinvestinthesestands.Oftentheyfeelthatotherinvestmentsmayyieldmorecertainresults.Moreover,timbermaybeviewedasaone-timewindfallratherthanalong-terminvestment.Someowners,awareofthelengthoftimeandassociatedriskofforestinvest-ments,choosenottospendfundsonthesestands.Often,becausetheycannotproperlyevaluatethesitepotentialandlackknowledgeofstandmanagementandmarkets,ownerscannotproperlyevaluatethepossiblereturnontheirinvestment(McGee1982).

Withdegradedstands,threeoptionsformanage-

mentaregenerallyavailable:(1)rehabilitatethestand,(2)regeneratethestand,or(3)postponeactionorleavethestandalone.

Unfortunately,leavingthestandaloneistheoptionusedtoooften,evenonsitescapableofgrow-ingqualitytimber.Rehabilitationofadegradedstandrequiresthemeasureofacceptablegrowingstock.Ifthereisnotenoughgrowingstocktopro-duceanewstand,thenregenerationofthestandisnecessary.Regeneratingthestandoftenhasthepotentialtocreateabetterqualitystandthanwhatiscurrentlyonthesite.

Corrective Measures for Degraded Hardwood Stands

Standdegradationcanoccurquickly,butusuallydevelopsoveralongperiodfollowingsuccessivehar-vestsandwildfire.Acceptablegrowingstock(AGS)referstotreesofcommercialanddesirablespeciesthatarecapableofincreasinginvalueandvolume,andareorcanbecomeviablecroptrees.Standsarenotconsideredseriouslydegradediftheycontainatleast50ft2ofbasalareaofAGSperacre.Degradedstandsusuallylacktreesinthesawtimbersizeclass.Thinningisusuallynoteconomicallyfeasiblein

Assessing Degraded Stands(Adapted from: Ezell 1992)

1.Performaforestinventory

2.Determinesitequality

3.Determinestockinganddistributionofdesirabletrees(AGS)

4.Considerspeciescomposition(desiredvs.unwantedtrees)

5.Estimatetreequalitybyconsideringtreeform,potentialtreegradeandtreecrownsofresiduals

6.Evaluateregenerationpotentialthrougharegenerationsurvey,bothdesirablespeciesandcontrolofinterferingvegetation

7. Estimateageofthestand

8.Determineobjectivesofmanagementandmarkets

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degradedstandsbecauseofthelackofgrowingstock.Thustoaddressdegradation,treatmentsshouldincreasegrowingstockeitherbyrehabilitationoftheexistingdegradedstandorbyregeneration. The major key to deciding to rehabilitate or to regenerate is the measure of adequate growing stock.Therec-ognitionandclassificationofAGSwilloftenrequireprofessionalassistance.

Determining a Course of Action

Degradedstandsmustbeevaluatedtodeter-minethecauseandtheleveloftheproblem,aswellastheirpotentialforvalueincreaseswithtreat-ment.McGee(1982)providesausefulchecklistforevaluatingandprescribingtreatmentsfordegradedandproblemhardwoodstands.Ezell(1992)andMcGee(1982)basestandevaluationonsixcrite-ria:sitequality,manageabilityoftrees,cullingoftrees,desirabilityofthespecies,advanceregenera-tionandstandage.Highlyproductivesitesbringahigherreturnoninvestment,sincethesite qualityisgreater.Themanageability of treesisdeterminedbyspecies,stemformandtheabilitytorespondtosil-viculturaltreatmentbasedoncrownposition(dom-

inant,codominant,intermediate,overtopped)andcondition.Crownconditionisevaluatedonthefull-nessorsizerelativetoexpectedsizeofatreeofthatheightanddiameter.Theestimatedbasalarea(measureofstanddensity)ofdesirabletreesfeasi-bleforfuturemanagementis30to50squarefeetperacreorabout40to50smallsawlog-sizetreesperacre.

Trees to be culledmayormaynotbeanassettothestand.Althoughtheymayhavelittletimbervalue,theymaybedesirabletowildlifeandtopoten-tialregenerationthroughsproutingorseedingiftheyareofapreferredspecies.Undesirable speciessuchasredmaple,beech,hickories,dogwoodandothersareusuallyshade-tolerant,takinggrowingspacefrommorevaluablespecies,orinhibitingregenera-tion,sotheyshouldbecontrolled.Theamountanddistributionofadvanced regenerationandtheseedingandsproutingofdesirablespeciesmustbeassessedtodetermineregenerationpotential.Theabilityofresidualtreestorespondtosilviculturaltreatmentsisrelatedtoage:young,vigoroustreeswithbalancedcrownshaveagreatercapacitytorespondtoreleasethanoldertreesapproachingmaturity.

Degraded stand with a few acceptable growing stock (AGS) trees.

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The Decision to RegenerateIfasufficientnumberofAGStreesarenot

presentinthedegradedstand,thenthestandshouldberegenerated,becauseanewyoungstandgenerallyhasthepotentialtocreateabetter-qualitystand.Methodsofregenerationincludeclearcut-ting,patchclearcut,shelterwoodandgroupselec-tion.Mosthardwoodspeciescanberegeneratedbyone,twoorallthreeofthesemethods.Thespecieslikelytobepresentfollowingtheregenerationhar-vestwillvaryforeachstandandwilldependuponmanyfactorsincludingadvanceregeneration,seedandsproutsources.

Obviously,desirablespeciesshouldbefavoredthroughpre-andpost-harvestsitepreparation.Equallyimportantisthedeterminationoftheunwantedspeciesthatmightneedtobecontrolled;simplyharvestingdegradedstandsandallowingnaturetotakeitscoursemaynotimprovethestandcomposition.Midstoryspeciessuchasmaple,black-

gum,dogwoodandbeechsproutprolifically,canbeaproblemandwillneedtobecontrolled(probablybyherbicides).

Mostspecieshavespecificpathwaysthatpromotesuccessfulregeneration.Yellow-poplar,sweetgum,blackcherryandashreproducefromseed;oaksandwalnutfromadvanceregeneration;andalmostallsmallhardwoodstumpswillsprouttosomedegree.Recognizingtheregenerationsources,regenerationmethods,siteproductivityandthegrowthhabitofeachspeciesandhowtheyallinter-actintheirassociatedcompetitiveenvironmentswillassistinyourassessmentofsitepreparationneedsforsuccessfulregenerationofthefavoredspecies.

Whilemosthardwoodsregeneratequicklyandreadilyfollowingsomeformofclearfelling,oneofourmostfavoredgroups,theoaks,presentsspecialregenerationproblems(LoftisandMcGee1993).Fortheoaks,advanceregeneration(pre-existingseedlingsfrom1to4feettall)mustbepresentor

A diameter-limit harvest leaving white oak trees with little potential to increase in value. The second photo is of the same tree 15 years after the harvest. Note that the tree still retains surface defects (knots and branches) that degrades the stem. The tree grew 1.5 inches in diameter in fifteen years after release.

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developedpriortothefinalharvest.Establishedadvanceregenerationgivesoaksaninitialadvan-tageoverfaster-growingspecies.Withoutadvanceregeneration,oakwillprobablynotbeacomponentofthenewstand.Seriousmistakesareoftenmadeassumingthatsmall(lessthan1foot)oakseedlingswillcompetewithfaster-growingyellow-poplar,birch,ashandlocustwhenreleased.Onhigher-qual-itysites,oakadvanceregenerationofsufficientsize(greaterthan4feet)andnumber(60to80peracre)mustbeculturedatleastthreetofiveyearsormoretoincreasetheprobabilitythatoakswillbecomeanoverstoryspecies(Stringer2005).Onpoorersites,oaksaremuchmorereadilyregenerated,oftenfromsmallstumps.

Regenerationofmostdegradedstandsrequiresremovalofoverstoryandmidstorytrees,usuallythroughclearcutting.Otherwise,thesetreeswillinfluencethegrowthanddevelopmentoftheregeneration.Ideally,theclearcutisachievedbyacommercialharvestandnocashoutlayisrequiredofthelandowner.However,manydegradedstandsmaynotcontainenoughtimbervaluefortheharvesttobeprofitable.Regardless,clearcuttingisanefficientregenerationmethodtoquicklyremedydegradedhardwoodstands.Fortunately,mostdegradedstandsregeneratereadilyfollowingclearcutting.

The Decision to Rehabilitate Standrehabilitationinvolvesimprovingthe

existingdegradedstandby(1)harvestinglessdesir-abletreesandretainingdesirablegrowingstock,and(2)securingandprotectingdesirableregenerationintheopenspaces.Nyland(2006)listsfourstepsthatoccurduringtherecoveryofdegradedstandswhenadequategrowingstockispresent.

•protectdesirableresidualtreesorgroupsoftreesbyremovingthepoorandundesirabletrees

•growthisconcentratedonresidualtreesofAGS

• regenerationfillsthespacesbetweenthewidely-spacedtrees

•enhancedesirableseedlingregenerationanddevel-opmentsuccessbycontrolling,withherbicides,interferingunderstoryandmidstoryvegetation

Theremovaloflessdesirabletreesprovidesmoregrowingspacefortheresidualtrees.McGee(1982)

callsthis“sparsetreeretention”anditleadsbrieflytotwo-agedstandstructure(Stringer2002)withasparse,olderageclassandaregeneratingageclass.Fromastandproductivitypointofview,thegrowthofthesparsetreescanproduceaquickreturnin10to20years(Milleretal.2004).However,whensparsetreesareharvested,damageislikelytooccurtothe10to20yearregenerationhardwoods.

Anadvantageofrehabilitatedstandswithtwo-agestructureisthatregenerationofthestandoccurswithoutclearcutting.Additionally,somefutureshort-termincomeisgeneratedfromreten-tiontreesthatotherwisewouldnotbeavailableifthesetreeswereharvested.Developmentofhigher-gradebuttlogsispossiblethroughadditionalgrowthwhenretentiontreesareselectedwiththepotentialtoincreaseingrade.Also,byleavingsomelargertreesonthesite,sexualreproductioncanstilltakeplace,providingseedforregenerationaswellasmastforwildlife.

Ontheotherhand,rehabilitatingstandsdoeshaveseveralpotentialproblems(McGee1982).Treesselectedforretentionmusthavetheabilitytogrowquicklyintohighersizeandvaluecategories.Epicor-micbranchingmayreducethegradeoftheseretained

Silvicultural Treatments for Rehabilitation of Degraded Stands

1. Two-agemanagementordefermentcuttingorsparsetreeretention

2.Sitepreparationtechniques(eitherpre-orpost-harvest)ofclearcutsanddefermentcutstofavorregenerationofdesiredspecies

3.Enrichmentplantings(ifprescribed)andcontrolofundesirablespeciesinthemidstoryandunderstory

4.Croptreereleaseofacceptablegrowingstock(AGS)

5.Adjustingharvestopeningsizetotargetadvantageousconditionsbasedonregenerationpresent,site-qualityconditionsandAGS

6.Considermixedpine-hardwoodstandsonlower-qualitysites

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trees.Inaddition,treesmustbeloggedandcullscontrolledwithoutphysicallydamagingtheretentiontrees.Manysmallertreesmustbecut,loppedandinjected,whichisusuallydoneasanexpense.Oncethesesmallertreesarecontrolled,thentheregenera-tionwillhaveanopportunitytogrowunhindered.Asretentiontreesreachharvestablesize,theremustbeameanstoharvestthesetreeswithminimaldam-agetothedevelopingregeneration.

Rehabilitatingdegradedstandsisnotapanacea.Itisastop-gaptreatmentthatprovidessomebenefitwhileshapingthestandtobemoreproductiveinthefuture.Manydegradedstandsdonothaveenoughdesirabletreestomaketheeffortworthwhile.Thedecisiontorehabilitateratherthanregenerateshouldbebasedonanobjectiveevaluationofavailablegrow-ingstock.Iftherehabilitatedstandcanprovidesomeincomeandlogsinthefuture,thestandcanbereha-bilitated;otherwise,thestandshouldberegenerated.Regardless,rehabilitatedstandswillprobablyneedtoberegeneratedin10to30years.

Choosing Other OptionsSitesonupperslopes,ridgesanderodedsoils

haveinherentlypoorproductivityandtendtoslowlygrowshort-bodiedhardwoodtrees.Manyofthesetreeshavebeensubjectedtofireandoccasionalcutting,whichhasfurtherdegradedstandquality.Thesesitesmaybebettermanagedforotherusessuchaswildlifehabitat.Anotherpossibilityismixedhardwood-pinestandswherepineisplantedatawidespacing(perhaps100ormorepinesperacre)andnaturalhardwoodsareallowedtogrowbetweenthepines(Mullinsetal.1998).Pinesarewell-adaptedtoandgrowatafasterratethanhardwoodsonthesepooreranddriersites.Theattractivenessofthistwo-stagemethodisthatthepinecanprovideanearlierincome,whilehardwoodsgrowforalon-gertime.

Manydegradedhardwoodstandsonlowproduc-tivitysitescanalsobeconvertedtopine.However,controlofhardwoodcompetitioncanbecostly.Marketsfordegradedhardwoodscansubstantiallyreducesitepreparationneeds.

Forked and poor quality trees remaining after repeated high-grading.

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Actionispostponedormanydegradedhardwoodstandsareleftalonewithsomehopethattheymayimprove.Degradedstandsarenotlikelytoimprovemuchwithouttreatment.Afewtreesperacremayincreaseinvalue,buttheculls,damaged,poorlyformedandundesirabletreeswillalsocontinuetogrow.Adegradedstandtodaywill,withoutsometypeoftreatment,remainadegradedstand.Ownersshouldcarefullyassesstheirpropertyanddeterminethepriorityofdegradedstandswithintheirmanage-mentgoals.

Enrichmentplantingisalow-costcompromisebetweendoingnothingandspendingthetimeandmoneytocompletelyharvestandregeneratethestand(HaymondandZahner1985).Whereacertainspeciesissparseorabsent,enrichmentplant-ingwouldallowtheintroductionofoneormoredesirablespecieswithoutcompletelyregeneratingthestand.Competingvegetationinthevicinityoftheplantedseedlingmustbecontrolledtogivetheplantedseedlingachancetoprosper.Anothermethodistoplantseedlingsaftercompletevegeta-tionremoval(clearcutting)toenhanceaspeciesthatmaynotbepartofthenaturalregenerationpool.Enrichmentplantinghasbeendiscussedbypractitionersandresearchers,butfewtrialshavebeenconducted,especiallyinplantinghardwoodseedlingsinaresidualhardwoodstand.Althoughrecommendationscannotbemadebasedonresearchdata,introducingpinesinhardwoodstandstocreateadiversified,mixedstandhasbeensuccessfulonmedium-tolow-qualitysites(Mullinset.al1998).

Anotheralternativemightbetoadjustmanage-mentsoonlyportionsofthestandaretreatedwithaprescriptionratherthantreatingtheentirestand.Thisalternativeisappropriateintargetedareaswherestocking(AGS)isfavorableoronbetter-qual-itysites.Inthesecircumstances,methodstoenhanceindividualtreedevelopmentmaybemorepositivethanstandleveltreatments.Managingthesizeofopeningsisameansofprovidingregenerationtotar-getedareaswithinstands(LeDoux1999).Crop-treerelease(Mercker2004;Stringeretal.1988)canbeparticularlyusefulwhenfocusingonindividualtrees.

SummaryDegradedhardwoodsilvicultureiscomplex,due

totherangeofspecies,sitesandlevelofdegradation.Degradedstandsoftenresultfrommistreatmentandneglect,butsomepoorstandsresultfromnaturalcauses.Mostanysetoftreatmentsthatcanbeprescribedthatwillimprovethestandwill

Factors That May Affect Degraded Stands

1.Standswithmorethan50squarefeetofbasalareaperacreofacceptablegrowingstock(AGS)aregenerallynotconsidereddegraded.

2.Normalthinningisgenerallynotpracticalindegradedstands,buttimberstandimprove-ment(TSI)toremoveunwantedtreesmaybe.ThereisnotenoughAGStojustifyathinning.Regenerationharvestingandthinningareseparateoperationswithdifferentpurposes.Thinningisanintermediateoperationtopro-moteresidualtrees.Regenerationharvestingistoinitiateanddevelopregeneration.

3.Capitalisusuallylimitedforimprovingdegradedstands.Thecostsandbenefitsofpracticesshouldbecarefullyconsidered.Dividingstandsmaybenecessarybecausedegradedstandsoftenhaveareasthatshouldberegeneratedandareaswhereresidualtreescanbemanaged.Itmightbeacceptabletocultureportionsofthestandratherthanimplementingtreatmentsacrosstheentirestand.

4.Generallytreathigh-qualitysitesfirst.

5.StandregenerationisthebetteralternativethanstandrehabilitationwhenAGSisnotadequate.

6.Two-agemethodsaresuggestedfortreat-mentofdegradedstandsinestablishingviableanddesirableregenerationaswellassomepotentialincreaseinvalueoftrees.Favoredresidualtreesorgroupsoftreesshouldbewidelyspacedwithregenera-tionbeingpromotedintheopenspacesbetweentrees.

7.Treatmentofatolerant,undesirablemidstoryandunderstoryisusuallynecessary.Pre-harvestsitepreparationcostsmaybelowerinhardwoodstandsthanpost-harvestactivities.

8.Onlower-qualitysites,considermixedpine-hardwoodstands.

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resultinbetterconditionsandincreasedproductivity,butcomeatacostthatmaybeaseriousdeterrent.Judgingwhetherenoughacceptablegrowingstockispresentiskeyindeterminingwhethertorehabilitateortoregeneratedegradedstands.Thereisnoperfect,one-size-fits-allmethodforsuccess.Individualstandconditionsmustbeassessedandtechniquesappliedthatwouldbringthestandclosertoconditionsfavor-ableforproducingdesirabletrees,whilekeepingcostsataminimum.Mostlandownersareinterestedandprefertodosomethingenvironmentallypositivetoreturndegradedstandstomoredesirableconditions.Standrehabilitation,whereappropriate,andregenera-tion,wherenecessary,willsetthestageforagradualstandrecovery.

ReferencesClatterbuck,W.K.2004.Bigtrees,littletrees

–Istherealwaysacorrelationwithage?ForestLandowner63(1):26-27.

Ezell,A.W.1992.Evaluatinghigh-gradedhardwoodstands.Publication1834.MississippiState,MS:MississippiStateUniversity,CooperativeExtensionService.6p.

Haymond,J.L.,R.Zahner.1985.Forestryacrebyacre:Improvinglow-qualityoak-pinewoodlands.Bulletin131,Clemson,SC:CooperativeExtensionService,ClemsonUniversity.37p.

LeDoux,C.B.1999.Anintegratedapproachfordeterminingsizeofhardwoodgroup-selectionopenings.ForestProductsJournal49(3):34-37.

Loftis,D.L.,C.E.McGee,eds.1993.Oakregeneration:Seriousproblems,practicalrecommendations.GeneralTechnicalReportSE-84.Asheville,NC:U.S.DepartmentofAgriculture,ForestService,SoutheasternForestExperimentStation.319p.

McGee,C.E,1982.Low-qualityhardwoodstands.OpportunitiesformanagementintheInteriorUplands.GeneralTechnicalReportSO-40.NewOrleans,LA:U.S.Dept.ofAgriculture,ForestService,SouthernForestExperimentStation.22p.

Mercker,D.C.2004.Croptreereleaseinprecommercialhardwoodstands.PublicationSP559.Knoxville,TN:UniversityofTennessee,Extension.8p.

Miller,G.W.,J.N.Kochenderfer,D.Fekedulegn.2004.Compositionanddevelopmentofreproductionintwo-ageAppalachianhardwoodstands:20-yearresults.In:Silvicultureinspecialplaces:ProceedingsoftheNationalSilvicultureWorkshop.RMRS-P-34.FortCollins,CO:U.S.DepartmentofAgriculture,ForestService,RockyMountainResearchStation.p.171-181.

Mullins,J.A.,E.R.Buckner.T.A.Waldrop,R.M.Evans.1998.Sitepreparationtechniquesforestablishingmixedpine-hardwoodstandsinthesouthernAppalachians.GeneralTechnicalReportSRS-20.Proc.,9thBiennialSouthernSilviculturalResearchConference(T.A.Waldrop,ed.).Asheville,NC:U.S.DepartmentofAgriculture,ForestService,SouthernResearchStation.p,22-25.

Nyland,R.D.2006.Rehabilitatingcutoverstands:Someideastoponder.GeneralTechnicalReportNE-342.Proc.,ConferenceonDiameter-LimitCuttinginNortheasternForests(L.S.KeneficandR.D.Nyland,eds.).NewtownSquare,PA:U.S.DepartmentofAgriculture,ForestService,NortheasternResearchStation.p.47-51.

Smalley,G.L.1982.ClassificationandevaluationofforestsitesontheMid-CumberlandPlateau.GeneralTechnicalReportSO-38.NewOrleans,LA:U.S.Dept.ofAgriculture,ForestService,SouthernForestExperimentStation.58p.

Stringer,J.2005.Oakshelterwood:Howtoapplythesystemtostimulateoakregeneration.ForestLandowner64(3):27-29.

Stringer,J.W.2002.Oakregenerationusingthetwo-agedsystem.GeneralTechnicalReportSRS-48.Proc.,11thBiennialSouthernSilviculturalResearchConference(K.W.Outcalt,ed.).Asheville,NC:U.S.DepartmentofAgriculture,ForestService,SouthernResearchStation.p.379-382.

Stringer,J.W.,G.W.Miller,R.F.Wittwer.1988. Applyingacrop-treereleaseinsmall-sawtimber

whiteoakstandsResearchPaperNE-620.Broomall,PA:U.S.DepartmentofAgriculture,ForestService,NortheasternForestExperimentStation.5p..

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Regeneration Potential Recommendations for Degraded Stands

Species Acceptable Unacceptable

Stem Quality Good Poor Good/Poor

Vigor/Age Vigorous/Young Poor/Old Vigorous/Young Poor/Old Vigorous/Young Poor/Old

RegenerationPotential

AdequatePresent

CompleteregenerationpossibleConcentratesitepreparationforregenerationonunwantedoverstoryandmidstorytreesOR

Culturesparseoverstorytrees

Completeregenerationrequiredinnearfuture

Concentratesitepreparationonoverstoryandmidstorytrees

Completeregenerationrequired

Concentratesitepreparationforregenerationonunwantedoverstoryandmidstorytrees

Completeregenerationrequired

Concentratesitepreparationforregenerationonunwantedoverstoryandmidstorytrees

RegenerationPotentialCurrently

InadequatePresent,butinneedofculturing

tobecomeadequate

Postponeharvest

Usemidstoryremoval.

Ifharvestisrequired,leavegroupsofoverstorytreesConcentratesitepreparationforregenerationoncompetingunderstoryvegetation

Postponeharvest

Usemidstoryremoval

Ifharvestisrequired,leavegroupsofoverstorytrees

Concentratesitepreparationoncompetingoverstoryandmidstorytrees

Postponeharvest

Usemidstoryremoval

Ifharvestisrequired,concentratesitepreparationonoverstoryandmidstorytrees

Postponeharvest.Usemidstoryremovaltocultureregeneration

Ifharvestisrequired,concentratesitepreparationforregenerationonoverstoryandmidstory

RegenerationPotential

InadequateNotpresent

Postponeharvest

Culturespareoverstoryuntiladequateregenerationisestablished

Ifharvestisrequired,considerleavinggroupsofoverstorytrees

Completeregenerationrequired

Considercompleteorpartialartificialregeneration(speciesenrichment,mixedpine/hardwood,orcompletepineconversion)

Postponeharvest

Retainpoor-formedoverstoryasaseedsourceforregeneration

Ifharvestisrequired,considerleavinggroupsofoverstorytrees

Completeregenerationrequired

Considercompleteorpartialartificialregeneration(speciesenrichment,mixedpine/hardwood,orcompletepineconversion)

Completeregenerationrequired

Considercompleteorpartialartificialregeneration(speciesenrichment,mixedpine/hardwood,orcompletepineconversion)

Source: Adapted from Dr. Jeff Stringer, Dept. of Forestry, University of Kentucky

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R12-4910-026-002-06SP680-1.5M-6/0606-0335

A Regional Peer-Reviewed Technology Extension Publication

ProfessionalHardwoodNote#6forTennesseeandKentucky

PublishedasUniversityofKentucky’sCooperativeExtensionpublicationFOR-104

PublishedasSouthernRegionalExtensionForestrypublicationSREF-FM-009

PartialfundingofthispublicationprovidedbyTennesseeDepartmentofAgriculture,DivisionofForestry

Programs in agriculture and natural resources, 4-H youth development, family and consumer sciences, and resource development.University of Tennessee Institute of Agriculture, U.S. Department of Agriculture and county governments cooperating.

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