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LoblollyPineHealthintheSoutheasternU.S.KamalJ.K.Gandhi,DavidR.Coyle,BrittanyF.Barnes,KierD.Klepzig,LawrenceMorris,andJohnT.Nowak

ImportanceofSouthernPinesSouthernpinespeciessuchasloblolly,longleaf,shortleaf,andslashcovermuchofthesoutheasternU.S.,andareacriticalcomponentoftheregion’seconomy1.Loblollypineisthemostwidelyplantedspeciesinthesoutheasternregion,iscommerciallymanagedinplantationsandnaturalstands,andaccountsfornearlyhalfofthepinegrowingstock2.Thesepinestandsareecologicallyandeconomicallycriticaltotheregionastheyimprovesoilandwaterquality,createhabitatforvariouswildlifespecies,andprovidetimberandpulpwoodproductsworthtensofbillionsofdollarseachyearwithmanybenefitstolocalcommunities3,4.Asdemandsonourpineresourcesincrease,forestthreatssuchasurbanization,climatechange,andinvasionbynon-nativespeciesarealsoexpectedtoincrease1.Implementingspecificmanagementpracticescanminimizethesethreatsandassistmanagersandlandownerswithmaintainingthesustainabilityofpineforests.AbioticFactorsAffectingLoblollyPinesSoutheasternforestsarehistoricallymaintainedanddisturbedbyabioticandbioticfactors.Amongstabioticfactors,frequentunderstoryfiresareimportantinmaintainingandregeneratingpineforests,howeverfiresareusedlessfrequentlyinloblollypineplantations5.Inthelate19thandearly20thcenturies,manysoutheasternforestswereclearcutandharvested,thenconvertedintofarms,whichresultedinmajorsoilerosionissues(especiallyinthePiedmontregion)5(Fig.1A).Whenthesefarmlandswereabandonedinthe1930sand1940s,theynaturallyregeneratedtoforests,howevertheoriginalcover-typeandmanyassociatednativespecieswerelargelylostfromthesesystems1,5.Adverseweatherconditionssuchasdroughtandwind/ice-stormscanincreasepinesusceptibilitytoinsectsanddiseases6(Fig.1B).Thefrequency,duration,andunpredictabilityofdroughtandstormsareexpectedtoincreaseunderclimaticchangeswithensuingimpactstopinesustainability7.Forexample,catastrophicandseverefiresduetodroughtin2016-2017heavilyimpactedforestsespeciallyinGeorgia,NorthCarolina,andTennessee(Fig.1C).

Fig.1.Examplesofabioticfactorssuchas(A)soil-erosionafterfarming;(B)drought;and(C)severewildfiresthathavehistoricallyandarecurrentlynegativelyimpactingpineproductivity.

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BioticFactorsAffectingLoblollyPinesInsectPestsBioticagentssuchasbarkandwoodboringbeetlesaremajorfactorsaffectingpineplantationsandnaturalforests8,9.Thesebeetlescreatetunnelsunderthebarkandinwoodofthetree,thusgirdlingandkillingit.Anumberofbarkbeetlesarealsoassociatedwithpathogenicfungalspeciesthatfurthercontributetotreemortality.Southernpinebeetle(Dendroctonusfrontalis)isconsideredthemostdamaginginsectaffectingloblollypines10(Fig.2A).Southernpinebeetleoutbreakscankillhundredsofthousandsofpinetreeswithinaregioninagivenyear.Treestressanddamagethatresultfromdrought,poorsoilconditions,lightningstrikes,fungalinfectionsormechanicaldamageincreaseactivitiesofotherdamagingspeciesincludingpineengraverbeetles(Ips),blackturpentinebeetle(Dendroctonusterebrans),anddeodarweevil(Pissodesnemorensis)11(Fig.2B-C).Manywoodboringinsectssuchaspinesawyer(Monochamus),andotherlonghornandjewelbeetlesalsoshowincreasedactivityonstressed

trees,furthercontributingtodamageanddeath9(Fig.2D).Generalsignsandsymptomsofbarkandwoodboringbeetlesareroundorovalexit/entranceholes(<0.5inch)onthebark,sawdust(finetocoarse),pitchtubes,beetlegalleriesunderbark,branchdieback("flagging"),andgrowthreduction(Fig.3,Table1)11.

B

Fig.2.Examplesofeconomicallyimportantadultbarkandwoodboringbeetlespeciesinloblollypineplantations:(A)Dendroctonusfrontalis;(B)Ipsavulsus;(C)Pissodesnemorensis;and(D)Monochamusspecies(nottoscale).

A

C D

BFig.3.Examplesofsignsofbarkandwoodboringbeetleactivityonloblollypinetrees:(A)pitchtubesandboringdust;(B)Ipsbeetlegalleriesunderbark;(C)Dendroctonusfrontalisgalleriesunderbark;and(D)chipcocoonsofPissodesnemorensis.

A C D

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Species CommonSigns(Fig.3)BlackTurpentineBeetle

Large(quarter-sized)pitchtubesalongrootflareuptoabout5feet,reddishbrownboringdust,largerentrance/exitholes,J-shapedfeedinggalleriesunderthebark

DeodarWeevil ChipcocoonsunderthebarkIpsBeetles Smaller(dime-sized)pitchtubesthroughoutthebole,reddishbrownboringdust,

smallentrance/exitholes,H,YorX-shapedgalleriesunderthebarkSouthernPineBeetle Smaller(dime-sized)pitchtubesthroughoutthebole,reddishbrownboringdust,

smallentrance/exitholes,S-shapedgalleriesunderthebarkWoodborers Coarseorfinewhiteboringdustorchips,roundorD-shapedexitholesFungalPestsFungalpathogensarecommoninloblollypinestands,andtheiractivityvarieswithsoiltypesandland-usehistory.Inmoststands,activityoftheseorganismshasminimalimpactontreehealth;howeverundersomeconditionstheycanhavemajorimpacts.Heterobasidion(i.e.,Fomes/Annosus/Annosum)rootdisease(causedbyHeterobasidionirregulare)ismostactiveinstandswithwell-drained,coarse-texturedsurfacesoils(sandandsandyloamAhorizons)afterthinninginwintertimewhensporeproductionisthehighest12.Fungalsporesinfectstumpsandmoveintotreerootsandsurroundingtreesgenerallythroughrootcontactcausingtreedeath(Fig.4).Infectioncentersofdeadanddyingtreesoccuraroundinfectedstumpsthatcontinuetoexpandforupto10years.Stumptreatmentsorsummerthinning(below34°latitudeonly)cansignificantlyreduceinfection.

Littleleafdiseaseisamajorproblemonoldertrees(>40yearsold)growingonsoilsthathavehighsubsoilclaycontent,poorinternalsoildrainage(eithernaturallyorduetosoilcompaction),andlownutrientavailability,especiallyphosphoruslevels13.Phytophthoracinnamomiisthepathogenthatismostcommonlyassociatedwithlittleleafdisease14.Symptomsoflittleleafdiseaseincludeshorteningofneedles,abundantsterileconeproduction,androotdeath.Sincethisdiseaseaffectsoldertreesthatarenotveryresponsivetofertilizerorothertreatments,harvestingfollowedbysitepreparationthatincludessoiltillage(suchasa

Table1.Commonsignsofinsectsonstressed,dying,anddeadloblollypinetrees.

A B Fig.4.Heterobasidionrootdiseasewith(A)stringyrootsshowingsapstain;and(B)fruitingbodiesatthebaseofthetree.

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combinationplow),fertilization,andreplantingmaybetheonlyoptionavailabletothelandowner.LoblollyPineDiebackandMortalityDuringthelastseveraldecades,therehavebeenreportsofdiebackandmortalityofloblollypinesinthePiedmont,Sandhills,andUpperCoastalPlainphysiographicregions.Countiesinwest-centralGeorgiaandeast-centralAlabamaarereportedtohavethehighestlevelsoftreediebackanddeath.Thisphenomenonhasbeenreferredtoas"loblollypinedecline"or"southernpinedecline"(SPD)bysomeresearchersandforestmanagers,andsymptomsincludecrownthinning,yellowingofneedles,reductionsingrowth,androotandbranchdeath15.AnalysisofFIAdataandfieldvisitstositespreviouslycharacterizedashavingSPDhadavarietyofabiotic(e.g.,soiltypesandclimate)andbiotic(e.g.,insects,pathogens,andgenetics)factorsthatwerecausingindividualstandstoshowsymptomsofdecline16.FromthisresearchitappearsthatanumberofunrelatedproblemsarebeinglumpedunderthenameSPD,whichleadstomisdiagnosisofcausalfactorsofdamagedstands.Furthercontroversyhasalsoarisenduetothefocusofresearchoncommoncontributingfungiandinsects.SouthernLeptographiumfungiandtheirvectors(Hylastes,Hylurgops,andPachylobiusspecies)areubiquitousindamagedpinestands15,17.Therearemanyunknownsabouttheecologicalandeconomicimpactsofthesesouthernroot-feedingweevilsandLeptographiumspeciesinhealthyandstressedloblollypinestands.However,nonehaveproventobeprimarypathogens16,18.Recentstudiesshowroot-feedingweevilsmainlyattackstumpsandstressed/dyingtreesinsteadofhealthyones,whichsuggeststhatsilviculturalactivitiesthatoptimizetreehealthwillminimizetheiractivities18.MaintainingLoblollyPineHealthLoblollypinetreehealthcanbemaintainedbycorrectivetreatmentsatstandestablishmentcombinedwithappropriateintermediatestandtreatments.Sitepreparationtillagethatbreaksuprestrictivesubsoillayerscanimprovegrowthandtreevigorinmostsitesandmaybeparticularlyvaluableonsiteswherelittleleafdiseaseisexpectedtooccur19.Atestablishment,fertilizationwithphosphorusorphosphorusplusnitrogenshouldalsobeconsideredforthesesitesaswellasothersiteswheresoilstestsindicatelowphosphorusavailability20.Herbaceousweedcontrolduringthefirstgrowingseasonisgenerallyrecommendedandisalwaysrecommendedwhenfertilizationatestablishmentincludesnitrogen.Hardwoodcontrolmayormaynotbeneeded.Onsiteswithlowhardwoodcompetition(<1,800hardwoodrootstock/acre),herbaceousweedcontrolissufficient20.Post-planting,regularlow-intensityprescribeburningorherbicidetreatmentswillalsoreducehardwoodplantcompetition(Fig.5A).Iftreeswereplantedathighdensity,thenthinningisrecommendedto80-100ft2/ac(oftenthiswillbetimedtocoincidewithnitrogenandphosphorusfertilization)21(Fig.5B).Duringthinning,damagetotreeboleandrootsshouldbeavoidedotherwisepestproblemscanbeexacerbated.Selectionofqualitycontractorscoupledwithon-siteinspectionduringtheoperationandcontractualprovisionstoceaseoperationsduringwetweatherwillhelpminimizedamage.Healthyloblollystandsmayhaveafewdeadtrees,butwidespreaddiebackshouldnotbepresent.

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Contactanextensionagent,stateforestryagent,oraconsultingforesterforfurtherassistancewithpinetreehealthissuesandmanagementoptions.Alwaysusealicensedpesticideapplicatoranduselabeldirectionswhenapplyingpesticides.MoreinformationonpesticideapplicationisavailablefromtheUSDAForestService(http://www.fs.fed.us/foresthealth/pesticide/),orfromyourstate’scooperativeextensionservice.AcknowledgementsWearegratefulforthefundingprovidedbyD.B.WarnellSchoolofForestryandNaturalResources,UniversityofGeorgia;USDAForestService,ForestHealthProtection;andUSDAForestService,SouthernResearchStation.ValuablecommentswereprovidedbyChrisAsaroandMichelleCram(USDAForestService,ForestHealthProtection),andElizabethBentonandJayShelton(D.B.WarnellSchoolofForestryandNaturalResources,UniversityofGeorgia).Photocredits-AuburnUniversity;J.R.Baker&S.B.Bambara,NorthCarolinaStateUniversity;ChuckBargeron,UniversityofGeorgia;ChrisEvans,UniversityofIllinois;GeorgiaForestryCommission;LacyL.Hyche,AuburnUniversity;GeraldJ.Lenhard,LouisianaStateUniversity;PaulA.Mistretta,USDAForestService;MinnesotaDepartmentofNaturalResources;andErichG.Vallery,USDAForestService-SRS-4552,allatBugwood.org,andKamalJ.K.Gandhi,UniversityofGeorgia.

References1. Wear,D.N.,andGries,J.G.2012.Thesouthernforest

futuresproject:summaryreport.GeneralTechnicalReportSRS-GTR-168.USDAForestService,Asheville,NorthCarolina.

2. Wear,D.N.,andGries,J.G.2002.Southernforestresourceassessment–summaryreport.GeneralTechnicalReportSRS-54.USDAForestService,SouthernResearchStation,Asheville,NorthCarolina.

3. Moore,R.,Williams,T.,Rodriguez,E.,andHepinstall-Cymmerman,J.2013.Usingnon-marketvaluationtotargetconservationpayments:AnexampleinvolvingGeorgia'sprivateforests.JournalofForestry111:261-270.

4. GeorgiaInstituteofTechnologyandGeorgiaForestry

Commission.2016.2015EconomicbenefitsoftheforestryindustryinGeorgia.URL:http://forestryimpacts.net/reports/georgia/2015%20Economic%20Benefits%20Report%20FINAL.pdf.

5. Marshall,D.J.,Wimberly,M.,Bettinger,P.,andStanturf,J.2008.Synthesisofknowledgeofhazardousfuelsmanagementinloblollypineforests.GeneralTechnicalReportSRS-110.USDAForestService,SouthernResearchStation,Asheville,NorthCarolina.

6. Negrón,J.F.,McMillin,J.D.,Anhold,J.A.,andCoulson,D.2009.Barkbeetle-causedmortalityinadrought-affectedponderosapinelandscapeinArizona,USA.ForestEcologyandManagement257:1353-1362.

7. Dale,V.H.,Joyce,L.A.,McNulty,S.,Neilson,R.P.,Ayres,M.P.,Flannigan,M.D.,Hanson,P.J.,Irland,L.C.,Lugo,A.E.,Peterson,C.,Simberloff,D.,Swanson,F.J.,

A B

Fig.5.Standsundergoing(A)prescribedburningand(B)thinningactivitiesthatassistwithforesthealth.

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Stocks,B.J.,andWotton,B.M.2001.Climatechangeandforestdisturbances:climatechangecanaffectforestsbyalteringthefrequency,intensity,duration,andtimingoffire,drought,introducedspecies,insectandpathogenoutbreaks,hurricanes,windstorms,icestorms,orlandslides.BioScience51:723-734.

8. Wood,S.L.1982.ThebarkandambrosiabeetlesofNorthandCentralAmerica(Coleoptera:Scolytidae):ataxonomicmonograph.GreatBasinNaturalistMemoirs:Number6,BrighamYoungUniversity.

9. Lingafelter,S.W.2007.Illustratedkeytothelonghornedwoodboringbeetlesofthe easternUnitedStates.TheColeopteristsBulletin,SpecialPublicationNumber3.

10. Coulson,R.N.,andK.D.Klepzig.2011.SouthernpinebeetleII.GeneralTechnicalReportSRS-140.USDA-ForestService,Southern ResearchStation,Asheville,NorthCarolina.

11. GeorgiaForestryCommission.2008.ForesthealthguideforGeorgia.GeorgiaForestryCommission.

12. Stambaugh,W.J.1989.AnnosusrootdiseaseinEuropeandthesoutheasternUnitedStates:occurrence,research,andhistoricalperspective.In:ProceedingsoftheSymposiumonResearchandManagementofAnnosusRootDisease(Heterobasidionannosum),Eds.W.J.OtrosinaandR.F.Scharpf,USDAForestService,Monterey,California.Pp.3-9.

13. Roth,E.R.1954.Spreadandintensificationofthelittleleafdiseaseofpine.JournalofForestry52:592-596.

14. Mistretta,P.A.1998.Littleleafdisease.ForestInsectandDiseaseLeaflet,Number20.USDAForestService.

15. Eckhardt,L.G.,SwordSayer,M.A.,andImm,D.W.

2010.StateofpinedeclineinthesoutheasternUnitedStates.SouthernJournalofAppliedForestry34:138-141.

16. Coyle,D.R.,Klepzig,K.D.,Koch,F.H.,Morris,L.A.,Nowak,J.T.,Oak,S.W.,Otrosina,W.J.,Smith,W.D.,andGandhi,K.J.K.2015.AreviewofsouthernpinedeclineinNorthAmerica.ForestEcologyandManagement349:134-148.

17. Matusick,G.,Menard,R.D.,Zeng,Y.,andEckhardt,L.G.2013.Root-inhabitingbarkbeetles(Coleoptera:Curculionidae)andtheirfungalassociatesbreedingindyingloblollypineinAlabama.FloridaEntomologist96:238-241.

18. Helbig,C.E.,Coyle,D.R.,Klepzig,K.D.,Nowak,J.T.,andGandhi,K.J.K.2016.Colonizationdynamicsofsubcorticalinsectsonstressedandunstressedloblollypinetrees.JournalofEconomicEntomology109:1729-1740.

19. Fox,T.R.,Allen,H.L.,Albaugh,T.J.,Rubila,R.A.,andCarlson,C.A.2007.TreenutritionandforestfertilizationofpineplantationsintheSouthernUnitedStates.SouthernJournalofAppliedForestry31:5-11.

20. Miller,J.H.,Zutter,B.R.,Zedaker,S.M.,Edwards,M.B.,andNewbold,R.A.2003.Growthandyieldrelativetocompetitionforloblollypineplantationstomidrotation-asoutheasternUnitedStatesregionalstudy.SouthernJournalofAppliedForestry27:1-16.

21. Sayer,M.A.S.,Goelz,J.C.G.,Chambers,J.L.,Tang,Z.,Dean,T.J.,Haywood,J.S.,andLeduc,D.J.2004.Long-termtrendsinloblollypineproductivityandstandcharacteristicsinresponsetothinningandfertilizationintheWestGulfregion.ForestEcologyandManagement192:71-96.

Authors:KamalJ.K.GandhiisanAssociateProfessorattheD.B.WarnellSchoolofForestryandNaturalResources,UniversityofGeorgia,Athens,Georgia.DavidR.CoyleisanExtensionSpecialistattheSouthernExtensionRegionalForestry,Athens,Georgia.BrittanyF.BarnesisaResearchProfessionalattheD.B.WarnellSchoolofForestryandNaturalResources,UniversityofGeorgia,Athens,Georgia.KierD.KlepzigisDirectoroftheJosephW.JonesEcologicalResearchCenter,Newton,Georgia.LawrenceMorrisisaProfessorattheD.B.WarnellSchoolofForestryandNaturalResources,UniversityofGeorgia,Athens,Georgia.JohnT.NowakisaForestEntomologistwiththeUSDAForestService,ForestHealthProtection,Asheville,NorthCarolina.

PublicationWSFNR-17-39 August2017

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