What are invasive species?
An invasive species is defined as an organism (plant, animal, fungus, or bacterium) that is introduced and has negative effects on our economy, our environment, or our health. Not all introduced species are invasive. The term “invasive” is reserved for the most aggressive species that reproduce rapidly and cause major changes to the areas where they become established.
An invasive species is defined as an organism (plant, animal, fungus, or bacterium) that is introduced and has negative effects on our economy, our environment, or our health. Not all introduced species are invasive. The term “invasive” is reserved for the most aggressive species that reproduce rapidly and cause major changes to the areas where they become established.
Brochures:
Yukon Invaders: Mini-pamphlet, edition 2007. A pocket identification guide to help reduce the spread of invasive plants in the Yukon. PLAN OF ATTACK Three broad categories cover most invasive plant control :mechanical, chemical, and biological. Mechanical control means physically removing plants from the environment through cutting or pulling. Chemical control uses herbicides to kill plants and inhibit growth. Techniques and chemicals used will vary depending on the species. Biological controls use plant diseases or insect predators, typically from the targeted species ’home range. Several techniques may be effective in controlling a single species,but there is usually one preferred method—the one that is most resource efficient with minimal impact on non-target species and the environment .MECHANICAL CONTROL METHODS Mechanical treatments are usually the first ones to look at when evaluating an invasive plant removal project. These procedures do not require special licensing or introduce chemicals into the environment. They do require permits in some situations, such as wetland zones. Mechanical removal is highly labor intensive and creates a significant amount of site disturbance, which can lead to rapid reinvasion if not handled properly. Pulling and digging Many herbaceous plants and some woody species,if present in limited quantities, can be pulled out or dug up. It’s important to remove as much of the root system as possible; even a small portion can restart the infestation. Pull plants by hand or use a digging fork, as shovels can shear off portions of the root system, allowing for regrowth. To remove larger woody stems (up to about three inches in diameter), use a Weed Wrench™, Root Jack, or Root Talon. These tools, available from several manufacturers, are designed to remove the above ground portion of the plant as well as the entire root system. Spraying chemicals to control invasive plants. Using tools tore move woody stems. Managing Invasive Plants Methods of Control by ChristopherMattrickConservationNotesoftheNewEnglandWildFlowerSociety– 21Suffocation Try suffocating smal lseedlings and herbaceous plants. PlacedoubleortriplelayersofthickUV-stabilizedplasticsheeting,eitherclearorblack(personallyIlikeclear),overtheinfestationandsecuretheplasticwithstakesorweights.Makesuretheplasticextendsatleastfivefeetpasttheedgeofinfestationonallsides.Leavetheplasticinplaceforatleasttwoyears.Thistechniquewillkillevery-thingbeneaththeplastic—invasiveandnon-invasiveplantsalike.Oncetheplasticisremoved,sowacovercropsuchasannualryetopreventnewinvasions.CuttingormowingThistechniqueisbestsuitedforlocationsyoucanvisitandtreatoften.Tobeeffective,youwillneedtomoworcutinfestedareasthreeorfourtimesayearforuptofiveyears.Thegoalistointerrupttheplant’sabilitytophotosynthe-sizebyremovingasmuchleafymaterialaspossible.Cuttheplantsatgroundlevelandremoveallresultingdebrisfromthesite.Withthistreatment,theinfestationmayactuallyappeartogetworseatfirst,soyouwillneedtobeaspersistentastheinvasiveplantsthemselves.Eachtimeyoucuttheplantsback,therootsystemgetsslightlylarger,butmustalsorelyonitsenergyreservestopushupnewgrowth.Eventually,youwillexhaustthesereservesandtheplantswilldie.Thismaytakemanyyears,soyouhavetoremaincommittedtothisprocessonceyoustart;otherwisethetreatmentcanbackfire,makingtheproblemworse.CHEMICALCONTROLMETHODSHerbicidesareamongthemosteffectiveandresource-effi-cienttoolstotreatinvasivespecies.Mostofthecommonlyknowninvasiveplantscanbetreatedusingonlytwoherbi-cides—glyphosate(theactiveingredientinRoundup™andRodeo™)andtriclopyr(theactiveingredientinBrush-B-Gone™andGarlon™).Glyphosateisnon-selective,mean-ingitkillseverythingitcontacts.Triclopyrisselectiveanddoesnotinjuremonocots(grasses,orchids,lilies,etc.).Pleasereadlabelsandfollowdirectionspreciselyforbothenvironmentalandpersonalsafety.Thesearerelativelybenignherbicides,butimproperlyusedtheycanstillcausebothshort-andlong-termhealthandenvironmentalprob-lems.Specialaquaticformulationsarerequiredwhenwork-inginwetlandzones.Youarerequiredtohaveastate-issuedpesticideapplicatorlicensewhenapplyingthesechemicalsonlandyoudonotown.Tolearnmoreaboutthepesticideregulationsinyourstate,visitorcallyourstate’spesticidecontroldivision,usuallypartofthestate’sDepartmentofAgriculture.Inwetlandareas,additionalpermitsareusuallyrequiredbytheWetlandsProtectionAct.[Seesidebaronpage23.]FoliarapplicationsWhenproblemsareonasmallscale,thistypeoftreatmentisusuallyappliedwithabackpacksprayerorevenasmallhandheldspraybottle.Itisanexcellentwaytotreatlargemonoculturesofherbaceousplants,ortospot-treatindivid-ualplantsthataredifficulttoremovemechanically,suchasgoutweed,swallowwort,orpurpleloosestrife.Itisalsoaneffectivetreatmentforsomewoodyspecies,suchasJapanesebarberry,multiflorarose,Japanesehoneysuckle,andOrientalbittersweetthatgrowindensemassesorlargenumbersovermanyacres.Theherbicidemixtureshouldcontainnomorethanfivepercentoftheactiveingredient,butitisimportanttofollowtheinstructionsontheproductlabel.Thistreatmentismosteffectivewhentheplantsareactivelygrowing,ideallywhentheyarefloweringorbegin-ningtoformfruit.Ithasbeenshownthatplantsareoftenmoresusceptibletothistypeoftreatmentiftheexistingstemsarecutoffandtheregrowthistreated.Thisisespe-ciallytrueforJapaneseknotweed.Thetargetplantsshouldbethoroughlywettedwiththeherbicideonadaywhenthereisnorainintheforecastforthenext24to48hours.Volunteershandpullinginvasiveplants.22–NewEnglandWildFlowerCutstemtreatmentsThereareseveraldifferenttypesofcutstemtreatments,butherewewillreviewonlytheonemostcommonlyused.Alltreatmentsofthistyperequireahigherconcentrationoftheactiveingredientthanisusedinfoliarapplications.A25to35percentsolutionoftheactiveingredientshouldbeusedforcutstemtreatments,butreadandfollowalllabelinstructions.Inmostcases,theappropriateherbicideisglyphosate,exceptforOrientalbittersweet,onwhichtri-clopyrshouldbeused.Thistreatmentcanbeusedonallwoodystems,aswellasphragmitesandJapaneseknotweed.Forwoodystems,treatmentsaremosteffectivewhenappliedinthelatesummerandautumn—betweenlateAugustandNovember.Stemsshouldbecutclosetotheground,butnotsoclosethatyouwilllosetrackofthem.Applyherbicidedirectlytothecutsurfaceassoonaspossi-bleaftercutting.Delayingtheapplicationwillreducetheeffectivenessofthetreatment.Theherbicidecanbeappliedwithasponge,paintbrush,orspraybottle.ForphragmitesandJapaneseknotweed,treatmentisthesame,butthetim-ingandequipmentaredifferent.Plantsshouldbetreatedanytimefrommid-JulythroughSeptember,butthehottest,mosthumiddaysofthesummerarebestforthismethod.Cutthestemshalfwaybetweentwoleafnodesatacomfortableheight.Inject(orsquirt)herbicideintotheexposedhollowstem.Allstemsinaninfestationshouldbetreated.Awashbottleisthemosteffectiveappli-cationtool,butyoucanalsouseaneyedropper,spraybottle,oroneoftherecentlydevelopedhigh-techinjectionsystems.Itishelpfultomixadyeinwiththeherbicidesolution.Thedyewillstainthetreatedsurfaceandmarktheareasthathavebeentreated,preventingunnecessaryreapplica-tion.Youcanbuyaspeciallyformulatedherbicidedye,orusefoodcoloringorlaundrydye.Thereisnotenoughspaceinthisarticletodescribeallthepossiblewaystocontrolinvasiveplants.Youcanfindothertreatments,alongwithmoredetailsontheabove-describedmethods,andspecies-specificrecommendationsonTheNatureConservancyWebsite(tncweeds.ucdavis.edu).AnupcomingpostingontheInvasivePlantAtlasofNewEngland(www.ipane.org)andtheNewEnglandWildFlowerSociety(www.newfs.org)Websiteswillalsoprovidefurtherdetails.Biologicalcontrols—stillonthehorizonBiologicalcontrolsaremovingintotheforefrontofcon-trolmethodology,butcurrentlytheonlywidelyavailableandappliedbiocontrolrelatestopurpleloosestrife.Moreinformationonpurpleloosestrifeandotherbiologicalcon-trolprojectscanbefoundatwww.invasiveplants.net.DISPOSALOFINVASIVEPLANTSProperdisposalofremovedinvasiveplantmaterialiscriti-caltothecontrolprocess.Leftoverplantmaterialcancausenewinfestationsorreinfesttheexistingprojectarea.Therearemanyappropriatewaystodisposeofinvasiveplantdebris.I’velistedthemhereinorderofpreference.1.Burnit—Makeabrushpileandburnthematerialfol-lowinglocalsafetyregulationsandrestrictions,orhaulittoyourtown’slandfillandplaceitintheirburnpile.2.Pileit—Makeapileofthewoodydebris.Thistechniquewillprovideshelterforwildlifeaswell.3.Compostit—Placeallyourherbaceousinvasiveplantdebrisinapileandprocessascompost.Watchthepilecloselyforresproutsandremoveasnecessary.Donotusetheresultingcompostinyourgarden.Thepileisforinvasiveplantsonly.Hollowsteminjectiontools.Cutstemtreatmenttools.Injectingherbicideintothehollowstemofphragmites. 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