Wisconsin’s Forests 2009

Resource Bulletin

NRS-67

United States Department of Agriculture

Forest Service

Northern Research Station

Abstract

The second full annual inventory of Wisconsin’s forests reports more than 16.7 million acres of forest land with an average volume of more than 1,400 cubic feet per acre. Forest land is dominated by the oak/hickory forest-type group, which occupies slightly more than one quarter of the total forest land area; the maple/beech/birch forest-type group occupies an additional 23 percent. Forty-two percent of forest land consists of large diameter stands, 23 percent contains medium diameter stands, and 8 percent contains small diameter stands. The volume of growing stock on timberland has been rising since the 1980s and currently totals more than 21.1 billion cubic feet. The average annual net growth of growing stock on forest land from 2005 to 2009 is approximately 572 million cubic feet per year. This report includes additional information on forest attributes, land use change, carbon, timber products, forest health, and statistics and quality assurance of data collection.

Acknowledgments

Field crew and QA staff over the 2005-2009 field inventory cycle included John Benaszeski, Andrew Bird, Dana Carothers, Tom Castonguay, Nathan Cochran, Ron Colatskie, Alison Dibble, Ian Diffenderfer, Michael Downs, Michael Hough, Gary Inhelder, Daniel Johnson, Michael Johnson, Mike Kangas, Paul Kodanko, Peter Koehler, Cassandra Kurtz, Chris La Cosse, Rebecca Langenecker, Dominic Lewer, Mike Long, Steve Lorenz, Mark Majewsky, Paul Mueller, Pat Nelson, Benjamin Nurre, Jeff Nyquist, Charles Paulson, Emil Peter, Nick Reynolds, Matthew Riederer, Bob Rother, Sjana Schanning, Terry Schreiber, Thomas Seablom, Jennifer Smith, Willard Smith, Aimee Stephens, Brad Totten, and Brian Wall.

Published by: For additional copies:U.S. FOREST SERVICE U.S. Forest Service11 CAMPUS BLVD SUITE 200 Publications DistributionNEWTOWN SQUARE PA 19073-3294 359 Main Road Delaware, OH 43015-8640

August 2012

Visit our homepage at: http://www.nrs.fs.fed.us

Cover: Paper birch. Photo by David Lee, Bugwood.org.

Manuscript received for publication January 2012

Printed on recycled paper

Charles H. Perry, Vern A. Everson, Brett J. Butler, Susan J. Crocker, Sally E. Dahir, Andrea L. Diss-Torrance, Grant M. Domke, Dale D. Gormanson, Mark A. Hatfield, Sarah K. Herrick, Steven S. Hubbard, Terry R. Mace, Patrick D. Miles, Mark D. Nelson, Richard B. Rideout, Luke T. Saunders, Kirk M. Stueve, Barry T. Wilson, Christopher W. Woodall

Contact Author:

Charles H. Perry

651-649-5191

charleshperry@fs.fed.us

Charles H. Perry is a research soil scientist with the Forest Inventory and Analysis (FIA) program, Northern Research Station, St. Paul, MN.

Vern A. Everson is a forest resource analyst with the Wisconsin Department of Natural Resources (WNDR), Madison, WI.

Brett J. Butler is a research forester with FIA, Northern Research Station, Amherst, MA.

Susan J. Crocker is a research forester with FIA, Northern Research Station, St. Paul, MN.

Sally E. Dahir is a plant pest and disease specialist with WDNR, Dodgeville, WI.

Andrea L. Diss-Torrance is the Invasive Forest Insect Program Coordinator with WDNR, Madison, WI.

Grant M. Domke is a research forester with FIA, Northern Research Station, St. Paul, MN.

Dale D. Gormanson and Mark A. Hatfield are foresters with FIA, Northern Research Station, St. Paul, MN.

Sarah K. Herrick is a research scientist with WDNR, Madison, WI.

Steven S. Hubbard and Terry R. Mace are forest products utilization and marketing specialists with WDNR, Madison, WI.

Patrick D. Miles and Mark D. Nelson are research foresters with FIA, St. Paul, MN.

Richard B. Rideout is the urban forestry coordinator with WDNR, Madison, WI.

Luke T. Saunders is a forest products utilization and marketing specialist with WDNR, Madison, WI.

Kirk M. Stueve was a research ecologist with FIA, Northern Research Station, St. Paul, MN. He currently is a visiting assistant professor of geography at North Dakota State University, Fargo, ND.

Barry T. Wilson and Christopher W. Woodall are research foresters with FIA, St. Paul, MN.

Wisconsin’s Forests 2009

About the Authors

Foreword

Our forests are one of our most precious assets. Today, Wisconsin’s forests cover 46 percent of our State, totaling more than 16.7 million acres. Since the mid-1960s the extent of forest land in Wisconsin has been expanding, while both the average age and volume of trees has been increasing.

We know our forests are expanding and diversifying because of the information collected by the Forest Inventory and Analysis (FIA) Program of the U.S. Forest Service. The annual inventory of Wisconsin’s forests is administered through the FIA Program in partnership with the Wisconsin Department of Natural Resources, Division of Forestry. The latest 5-year inventory of Wisconsin covers the period 2005-2009, with analysis having been completed in 2011 by the U.S. Forest Service.

FIA collects, analyzes, and reports information on the status and trends of America’s forests: how much forest exists, where it exists, who owns it, and how it is changing, as well as how the trees and other forest vegetation are growing and how much has died or has been removed in recent years. Since 1968, Wisconsin has provided funding to intensify the inventory by doubling the number of permanent plots from which data are collected. The reason for intensifying the inventory is to provide more reliable data on areas smaller than on a statewide basis and stratified components of the data such as forest type, condition class, species volume, etc.

The information provided by FIA can be used in many ways, such as in evaluating wildlife habitat conditions, assessing the sustainability of forest management practices, and supporting planning and decisionmaking activities undertaken by public and private enterprises. FIA combines its information with related data on insects, diseases, and other types of forest damages and stressors to assess the health condition and potential future risks to forests. FIA also projects what the forests are likely to be in 10 to 50 years under various scenarios. This information is essential for evaluating whether current forest management practices are sustainable and will allow future generations to enjoy America’s forests.

Wisconsin proudly supports the nation’s largest forest products industry. We employ more people and produce more value from forest products than any other state. The forest industry often uses FIA information in making business decisions regarding the timber resource quantity, quality, and availability in their area. Information can be provided to industry on a county level basis or radius from a mill location. This information, whether for a traditional wood processing plant or a biomass facility, is invaluable in determining whether there will be an adequate supply of the desired species and size in the area to sustain both the current or proposed operation, and the forest itself.

In this report, we briefly describe and highlight the current status and trends observed within Wisconsin’s forests. We hope this information will stimulate discussion about the State’s forest resources and motivate additional research and analysis, as well as increase our shared commitment to protect and sustainably manage one of Wisconsin’s most precious assets.

Paul DeLongChief State Forester

Contents

Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Forest Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Forest Health Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Forest Economics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Data Sources and Techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Literature Cited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Statistics, Methods, and Quality Assurance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DVD

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On the Plus Side

• Wisconsin’sforestlandareahasbeensteadilyincreasingsince1968withsignificantgainsincentralandsouthwesternWisconsin.CountiesinnorthernWisconsincontinuetohavethehighestproportionofforestcover.Seventy-sixpercentofWisconsincountiesgainedforestlandareaoverthelast5years.

• Ninety-eightpercentoftheareathatwasforestlandin2004remainedforestlandin2009.Only1.5percentoftheareathatwasforestedin2004divertedtononforestlanduses,butreversionstoforestlandthatwereequivalenttoapproximately5percentofthe2004forestlandarea.

• CarbonstocksinWisconsin’sforestshaveincreasedsubstantiallyoverthelastseveraldecades.ThemajorityofforestcarbonintheStateisfoundinrelativelyyoungstandsdominatedbyrelativelylong-livedspecies.

• Speciesthataremoreshadetolerantareincreasinginnumberandvolume.Theseincludehardandsoftmaples,bothredandwhiteoaks,balsamfir,easternwhitepine,andAmericanbasswood.

• LevelsoftreemortalityacrossWisconsincontinuetoincrease,butthisincreasemaybeslowing.

• Whenannualgrowthisviewedrelativetothetotalgrowing-stockvolumeontimberland,all10majorspeciesbyvolumeareaddingpositivegrowthinexcessof2percenteachyear.Thesecommerciallyimportantspecies(withthepossibleexceptionofaspen)shouldcontinuetoprovidewoodproductsandotherenvironmentalservicesforsocietywellintothefuture.

• In2009,thereweremorethan260millionstandingdeadtreespresentonWisconsinforestlandwithsimilardensitiesonpublicandprivateland.

• CrownindicatorsshowtherearenomajorhealthproblemsrelatedtocrownconditionsinWisconsin.

• CoarsewoodydebrisconstitutesasmallbutimportantcarbonstockacrossWisconsin’sforests.ThequantityofdownwoodymaterialsinWisconsin’sforestsisconsistentwithnearbystates.

• ThelevelofsoilacidificationinWisconsinislow,particularlycomparedtomanyeasternstates.

• Growing-stockvolumeonWisconsin’stimberlandhasbeenincreasingsteadilyoverthepast50yearsandthenumberandvolumeofseveralvaluablecommercialspeciessuchasaspen,hardmaple,northernredoak,redpine,andeasternwhitepine,hasincreasedsubstantiallysince1983.

• ThesupplyofsawtimberonWisconsintimberlandhasincreasedsteadilysincethe1980s.Thepercentageofhighqualitysawtimberhasalsoincreased.

• Individualtreevolume,whichaddstoitseconomicvalue,hasbeenincreasinginthelast5years.

• Wisconsinisrankedasthenumberonepaper-makingstateinthenation.

• Despiterecentdeclinesintheforestproductsindustry,attributesthatattractedforestindustrysectorstotheStateacenturyagostillexistrepresentingsignificantopportunitiestoregainandexpandtheforestindustry.

• Ratherthanbeingshippedbackaftermanufacturing,anincreasingamountofourdomesticwoodisstayinginChinaforthegrowingmiddleclasspopulationthereandisincreasingsomeofWisconsin’smarketshareandexportopportunitiesabroad.

• Innovativetechnologyandnovelresearchintheforestproductsindustryisexpandingopportunitiestooffsetfossilfuelsusethroughincreasedbiomassutilization.

Highlights

Yellow birch. Photo by Steven Katovich, U.S. Forest Service.

2

• Wisconsin’swoodresourceiswellpositionedtomeetgrowingdemandfor“green”projectsthatfavortheuseofindependentlyverifiedenvironmentalcertificationsystems.

• Thisisastablemillcountof280activeprimarywoodprocessingmillssincethelastinventory.

Areas of Concern

• WhiletheextentofoakforestsinWisconsinappearstobeslowlyincreasing,ageclassdisparitiescontinue,especiallyonmediumtohighqualitysites.Olderoakforestsonsitesofmedium-to-highproductivityarebeinglostandyoungoakforestsareregeneratingpoorly.

• Treespeciesthatdependondisturbancetoregeneratearedecreasinginnumberand/orvolume.Theseincludequakingaspen,bigtoothaspen,jackpine,andpaperbirch.

• Removalsdeclinedbetween2004and2009,verylikelytheresultoftwoprimaryfactors:1)thedeclineinthenumberofhousingstarts,whichaffectslumberdemand,and2)theaccompanyingeconomicdownturn,whichhasnegativelyimpactedallsectorsoftheeconomy,includingtheforestproductsindustry—especiallypaper.

• Theabundanceofsmalldiameterstand-sizeclasscontinuestodecline.Concurrently,thedistributionoflarge-diameterstand-sizeclasshasincreaseddramatically.

• Emeraldashborer(EAB)andbeechbarkdiseasehavebecomeestablishedinWisconsin.EABhasthepotentialtokillmillionsofblack,whiteandgreenashtreesthroughoutWisconsin.TheimpactofEABisexpectedtorivalthatofchestnutblightandDutchelmdisease.

• Thefrequencyoftwoormoreinvasivespeciesperplotisgreaterinthe2009inventorythanthe2004inventory(21and13percent,respectively).Reedcanarygrasswasoneof15specieswhichincreasedinoccurrencebetween2004and2009.Onlytwospecies(multifloraroseandblacklocust)declinedinoccurrencebetween2004and2009.Thesamplingofinvasivespeciesisstillrelativelynew,sothisdatadoesnotdefineasolidtrend.

• Jackpineshowedsignificantdeclinesinsawtimbervolume.

• AspenisamajorspeciesgroupusedbytheeconomicallyimportantpaperindustryinWisconsin.Theannualgrowthtoremovalratiosforquakingaspen(0.9)andbigtoothaspen(0.9)werelessthan1.0,whichisnotsustainableinthelongrun.However,aspenisapioneer,short-livedspeciesthatisexpectedtodeclineinvolumeovertimeduetonaturalsuccession.

• Downturnsinourdomesticeconomyhaveresultedinasignificantlossofforestproductscompaniesandthejobstheysupported;sixofWisconsin’spulpandcompositepanelmillsclosedsince2000.

Issues to Watch

• Growing-stockvolumeofeconomicallyimportantredandwhiteoakspeciesonmedium-to-highqualitysitesremainedthesameorincreasedslightlyinthelast5yearspossiblyasaresultofincreasedknowledgeaboutproblemswithoakforestsinWisconsinandbettermanagementtechniques.

• Itisimportanttorememberthatland-usechangeresultsinthisreportareaggregatedattheStatescale;therewillbelocalvariationwheremoreforestlandisbeinglostthangained.

3

• Familyforestownersarediverseandtimberproductionisnottheprimaryownershipobjectiveformostofthem.Policiesandprogramsshouldbedesignedtomeettheowners’diversesituationsandneeds.

• Comparingthefieldandsatelliteurbanforestinventorymethodsrevealsthatbothareneededtoprovidecommunityleaderstheurbanforestinformationtomakemanagementdecisions.

• Maturingforestsarereflectedindecreasingforestdensityandincreasingtreevolume.Ifspeciesthatdependondisturbancetoregeneratearetoremaineconomicallyimportant,measuresshouldbeundertakentoencourageregenerationandpreventconversiontootherforesttypes.

• Seedlingregenerationmaybecompromisedinclosedcanopy,late-successionalforests.Managersneedtoensurethatregenerationoflight-demandingspecies,suchasquakingaspen,paperbirch,andjackpine,ismaintained.

• Aspenharvestlevelsareonlymarginallysustainableoverthelongterm.Aspenharvestlevelshavebeendeclining,however,andwillprobablycontinuetodeclineasaresultofglobalcompetitioninthepaperandpulpindustriesandtheeconomicdownturn.

• Thougheconomicallyimportantspeciesgroupshaveshowngrowthintotalvolumeandaveragevolumeperacre,therateofincreasehasnotbeenequallyapportionedacrossallspeciesgroups.

• Averageannualremovalsofgrowing-stockvolumeonWisconsin’stimberlandincreasedsteadilyfrom1956to2004.Since2004removalshavedecreased.Thedeclineinremovalsbetweenthelasttwoinventorieswasdueprimarilytotheeconomicdownturnandglobalcompetition.

• Averageannualmortalityofgrowing-stockvolumeonWisconsin’stimberlandhasbeenincreasingsincethemid-1960s.However,therateofincreasehasdiminishedsince1996indicatingadecadeofmorestableforestmortality.

• Sawtimbervolumesinsomeeconomicallyimportantspeciesgroups,suchasselectredoakandhardmaple,haveremainedaboutthesamesince1996whilemostothershaveincreased.

• Ourforestsareagingandspeciesthatarelatesuccessional,suchasthemaples,arereplacingearlysuccessionalspecies,suchasquakingaspenandpaperbirch.

• Changingclimatewillcausestresstotrees,makingthemmoresusceptibletoopportunisticpestsanddiseasesthatmaynothavebeenasignificantthreatinthepast.

• Asweseekwaystoreduceourdependenceontraditionalfossilfuels,woodybiomassislikelytoplayanincreasinglyimportantroleinthisarea.

• Toremaincompetitive,theforestproductsindustryinWisconsinwillneedtocontinueexploringinnovativewaysoffindingnewopportunitiesforgrowthinnicheandglobalwoodproductsmarkets.

• Woodproductsmanufacturersareheavilydependentonthehealthofhousingmarketsandotherconstructionindustriesthatutilizestheirproducts.

• Morethan60percentofthelandareaintheState’surbanforestsisavailablefortreeplanting.Exploitingthisopportunity,aswellasmaintainingexistinglarge-canopytrees,wouldsignificantlyincreasetheenvironmental,social,andeconomicservicestheseforestsprovidetotheStateandatthesametimereducetheimpendingimpactofemeraldashborerontheurbanforestcanopy.

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55

Background

Yellow lady’s slipper. Photo by Linda Haugen, U.S. Forest Service.

6

BACKGROUND

A Beginner’s Guide to Forest Inventory

What is a tree?

Weknowatreewhenweseeoneandwecanagreeonsomecommontreeattributes.Atreeisaperennialwoodyplantwithacentralstemanddistinctcrown.TheForestInventoryandAnalysis(FIA)programoftheU.S.DepartmentofAgriculture,ForestServicedefinesatreeasanyperennialwoodyplantspeciesthatcanattainaheightof15feetatmaturity.InWisconsin,theproblemisindecidingwhichspeciesshouldbeclassifiedasshrubsandwhichshouldbeclassifiedastrees.AcompletelistofthetreespeciesmeasuredinthisinventorycanbefoundinAppendixAof“Wisconsin’sForests2009:Statistics,Methods,andQualityAssurance,”ontheDVDintheinsidebackcoverpocketofthisbulletin.

What is a forest?

Weallknowwhataforestis,butwheredoestheforeststopandtheprairiebegin?It’sanimportantquestion.ThegrossareaofforestlandorrangelandoftendeterminestheallocationoffundingforcertainStateandFederalprograms.Forestmanagerswantmorelandclassifiedasforestland,andrangemanagerswantmorelandclassifiedasprairie.Somewhereyouhavetodrawtheline.

FIAdefinesforestlandaslandthatisatleast10percentstockedbytreesofanysizeorformerlyhavinghadsuchtreecoverandnotcurrentlydevelopedfornonforestuse.Theareawithtreesmustbeatleast1acreinsize,androadside,streamside,andshelterbeltstripsmustbeatleast120feetwidetoqualifyasforestland.

TheurbanforestisanothertypeofforestthatFIAistryingtoquantify.Theurbanforestmeetsthedefinitionofforestlandabovebutisfoundwithintheboundariesofcities,villages,andotherdensedevelopments.

What is the difference between timberland, reserved forest land, and other forest land?

FromanFIAperspective,therearethreetypesofforestland:timberland,reservedforestland,andotherforestland.InWisconsin,98.4percentoftheforestlandistimberland,0.6percentisreservedforestland,and1.0percentisotherforestland.

• Timberlandisunreservedforestlandthatmeetstheminimumproductivityrequirementof20cubicfeetperacreperyearatitspeak.

• Reservedforestlandislandwithdrawnfromtimberutilizationthroughlegislationoradministrativeregulation.InWisconsin,theNationalParkServiceowns40percentofthereservedland;theStateofWisconsinandNationalForestsown30and27percent,respectively.

• Otherforestlandiscommonlyfoundonlow-lyingsiteswithpoorsoilswheretheforestisincapableofproducing20cubicfeetperacreperyearatitspeak.

Before2000onlytreesontimberlandplotsweremeasuredinWisconsin.Therefore,whilewecanreportvolumeontimberlandforthoseinventories,wecan’treportvolumeonforestland.Underthenewannualinventorysystem,treesweremeasuredonallforestlandsoforestvolumeestimatescanbeproduced.Becausetheseannualplotshavebeenremeasureduponcompletionofthesecondannualinventoryin2009,wearenowabletoreportgrowth,removals,andmortalityonallforestland,notjustontimberland.

Where are Wisconsin’s forests, and how many trees are in Wisconsin?

Wisconsin’sforestsaregenerallylocatedinthenorthernandwesternpartsoftheState(Fig.1).Thereareapproximately2.5billiontreesonWisconsin’sforestland(giveortakeafewmillion)thatareatleast5inchesindiameterasmeasuredat4.5feetabovetheground.Wedon’tknowtheexactnumberbecausewe

7

BACKGROUND

Figure 1.—FIA Survey Units and distribution of forest land by forest-type group, Wisconsin, 2009.

Forest-type Groups White/red/jack pine Spruce/fir Oak/pine Oak/hickory Elm/ash/cottonwood Maple/beech/birch Aspen/birch Nonstocked

Survey Units

Counties

Plot locations

50 Miles0

Plot locations are approximate

Northwest

Northeast

Southeast

Central

Southwest

8

BACKGROUND

measuredonlyabout1outofevery16,600trees.Inall,133,449trees5inchesandlargerweresampledon6,189forestedplots.1

How do we estimate a tree’s volume?

FIAhastypicallyexpressedvolumesincubicfeet.But,inWisconsin,woodismorecommonlymeasuredincords(astackoflogs8feetlong4feetwideand4feethigh).Acordhasapproximately79cubicfeetofsolidwoodand49cubicfeetofbarkandair.

Volumecanbepreciselydeterminedbyimmersingatreeinapoolofwaterandmeasuringtheamountofwaterdisplaced.Lessprecise,butmuchcheaper,wasthemethodusedbytheNorthCentralResearchStation(whichlatermergedwiththeNortheasternResearchStationtobecometheNorthernResearchStation).Severalhundredcuttreesweremeasuredbytakingdetaileddiametermeasurementsalongtheirlengthstoaccuratelydeterminetheirvolumes(Hahn1984).Regressionlineswerethenfittothesedatabyspeciesgroup.Usingtheseregressionequations,wecanproduceindividualtree-volumeestimatesbasedonspecies,diameter,andtreesiteindex.

Thesamemethodwasusedtodeterminesawtimbervolumes.FIAreportssawtimbervolumesin¼-inchInternationalboardfootscale.ConversionfactorsforconvertingtoScribnerboardfootscalearealsoavailable(Smith1991).

How much does a tree weigh?

TheU.S.ForestService’sForestProductsLaboratoryandothersdevelopedspecificgravityestimatesforanumberoftreespecies(MilesandSmith2009).Thesespecificgravitieswerethenappliedtotreevolumeestimatestoderiveestimatesofmerchantabletreebiomass(theweightofthebole).Toestimatelivebiomass,wehave

1During the 2009 inventory of Wisconsin (from 2005 to 2009), we measured

one 1/6-acre plot for approximately every 3,084 acres of forest land. See

“Wisconsin’s Forests 2009: Statistics, Methods, and Quality Assurance” on the

DVD in the back of this book.

toaddinthestump(Raile1982)andlimbsandbark(Heathetal.2009).Wedonotcurrentlyreportthelivebiomassestimatesofrootsorfoliage.

Forestinventoriesreportbiomassasgreenoroven-dryweight.Greenweightistheweightofafreshlycuttree;oven-dryweightistheweightofatreewithzeropercentmoisturecontent.Onaverage,1tonofoven-drybiomassisroughlyequalto2tonsofgreenbiomass.

How do we estimate all the forest carbon pools?

FIAdoesnotmeasurethecarboninstandingtreesorcarboninbelowgroundpools.FIAassumesthathalfthebiomassinstandinglive/deadtreesconsistsofcarbon.Theremainingcarbonpools(e.g.,soil,understoryvegetation,belowgroundbiomass)aremodeledbasedonstand/sitecharacteristics(e.g.,standageandforesttype).

How do we compare data from different inventories?

Datafromnewinventoriesareoftencomparedwithdatafromearlierinventoriestodeterminetrendsinforestresources.Thisiscertainlyvalidwhencomparingthe2004inventorytothe2009inventory.Butcomparisonswithinventoriesconductedbefore2000areproblematicbecauseproceduresforassigningstandcharacteristics,suchasforesttypeandstandsize,havechangedasaresultofFIA’songoingeffortstoimprovetheefficiencyandreliabilityoftheinventory.Severalchangesinproceduresanddefinitionshaveoccurredsincethe1996Wisconsininventory.Althoughthesechangeswillhavelittleimpactonstatewideestimatesofforestarea,timbervolume,andtreebiomass,theymayhavesignificantimpactsonplotclassificationvariablessuchasforesttypeandstand-sizeclass.Someofthesechangesmakeitinappropriatetodirectlycomparethe2009and2004annualinventorytableswithperiodicinventoriespublishedfor1936,1956,1968,1983,and1996.

The1996inventoryalsousedmodeledplots,i.e.,plotsmeasuredin1983andprojectedforwardusing

9

BACKGROUND

theSTEMS(Belcheretal.1982)growthmodel.Thiswasdonetosavemoneybyreducingthenumberofundisturbedplotsthatweresenttothefieldforremeasurement.Disturbancewasdeterminedbycomparingaerialphotographsoftheplotsandlookingforreductionsincanopycover.TheideawasthatparametersfortheSTEMSgrowthmodelcouldbefinetunedusingthemeasured,undisturbedplotsandthenappliedtotheremainingunmeasured,undisturbedplots.Unfortunately,theuseofmodeledplotsintroducederrors,sothecurrentinventoryincludesfullremeasurements.Thus,onlyfieldmeasuredplotsareusedforcomparisonswiththe1996inventoryinthispublication.

A word of caution on suitability and availability…

FIAdoesnotattempttoidentifywhichlandsaresuitableoravailablefortimberharvesting,particularlybecausesuchsuitabilityandavailabilityaresubjecttochanginglaws,economic/marketconstraints,physicalconditions,adjacencytohumanpopulations,andownershipobjectives.Theclassificationoflandastimberlanddoesnotnecessarilymeanitissuitableoravailablefortimberproduction.

Thus,forestinventorydataaloneareinadequatefordeterminingtheareaofforestlandavailablefortimberproduction.Additionalfactors,suchassocialtrends,needtobeconsideredwhenestimatingthetimberbase.

FIAendeavorstobepreciseindefinitionsandimplementation.Theprogramtriestominimizechangestothesedefinitionsandtocollectionprocedures,butthatisnotalwayspossibleordesirableinaworldofchangingvaluesandobjectives.Whilechangeisinevitable,wehopethatthroughclarityandtransparencyforestinventorydatawillbeofusetoanalystsfordecadestocome.

10

1111

Forest Features

Black spruce. Photo by Steven Katovich, U.S. Forest Service.

12

FOREST FEATURES

Forest Area

Background

Formanydecades,Wisconsinhashadamixofagriculturalandforestlanduses.Trendsinforestareaareoftenapredictoroffutureforestresourcetrends.Fluctuationsinforestareamayindicatechanginglanduseorforesthealthconditions.Monitoringthesechangesprovidesessentialinformationformanagementanddecisionmaking.

What We Found

ForestlandareainWisconsinhasincreasedto16.7millionacresin2009(Fig.2)upfrom16.0millionacresin2004.Thiscontinuesanupwardtrendthatbeganinthe1960s.Approximately16.5millionacres(98.5percent)areclassifiedastimberland.NorthernWisconsincountiescontinuetohavethehighestproportionofforestcover(Fig.3).Florence,Iron,Menominee,andVilasCountieshavethegreatestforestcover,eachexceeding90percentforestland.CountiesincentralandsouthwesternWisconsinhavegenerallyexperiencedlargerincreasesinpercentageofforestlandsincethe1960s.However,inthelast5yearsthelargestgainsandlossesinforestcoverhavebeenprimarilyinsoutheasternWisconsin(Figs.3and4).Ofthe39countieswheregainsinforestcoverexceeded5percentsince2004,DodgeandMilwaukeeCountieshadthegreatestgainswith66and56percent,respectively;onlythreecountieslostmorethan5percentforestland:Ozaukee(26percent),Racine(13percent),andAshland(13percent)(Fig.4).

What this means

Statewide,Wisconsin’sforestlandareahasbeensteadilyincreasingsincethe1960swithsignificantgainsincentralandsouthwesternWisconsin(Figs.2and3).Statewidegainsweretheresultof39countiesthatgainedforestland(Fig.4).ThelossofforestlandinthelesserpopulatednorthernthirdofWisconsinespeciallythesignificantlossinAshlandCountywarrantcloserstudy.

Forest land

Timberland

0

2

4

6

8

10

12

14

16

18

1920 1940 1960 1980 2000 2020

Are

a (m

illio

ns o

f acr

es)

Year of Inventory

Figure 2.—Area of forest land and timberland, Wisconsin, 1936-2009.

Error bars (too small to be seen in this figure) show the 68 percent

confidence interval.

Figure 4.—Change in forest land area as a percentage of total land area by

county, Wisconsin, 2004-2009.

Change in Forest Land as Percent of Total Land Area 2004-2009 > 5.0 2.6 to 5.0 -2.4 to 2.5 -5.0 to -2.5 < -5.0

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FOREST FEATURES

Forest Land as Percent of County Land Area 81-97 61-80 41-60 21-40 3-20

Figure 3.—County forest land area as a percentage of total land area, Wisconsin, 1956-2009.

1956 1968

1983 1996

2004 2009

14

FOREST FEATURES

Changes to Oak Forests

Background

Oakforestsareimportantfortheirecologicalandeconomicvalues.Manywildlifespeciesdependonoaksforfoodandforagingopportunities.Inaddition,oaksareveryimportanttoWisconsin’seconomybecauseoftheirhighvaluelumber.ThroughouttheMidwest,oakforestshavebeendecreasinginextentforseveraldecadesespeciallyonmediumandhigh-productivitysites(siteindex>60).Historically,regenerationintheseforestswasfacilitatedbyaperiodicfireregimewhichreducedcompetitionfromnativeandnon-nativeplants.Theabsenceofperiodicfirealongwithbrowsingbywhite-taileddeer(Odocoileus virginianus)hasmadeoakregenerationdifficultonnutrient-richsites.Poorregenerationandselectiveharvestinghaveleadtothegradualsuccessionofoakforeststoonesdominatedbyredandsugarmaple,basswood,elms,greenandwhiteash,andironwood.

What We Found

Theoak/hickoryforest-typegroupoccupiedabout3.9millionacresofWisconsinin2004andincreasedtoabout4.1millionacresby2009.Whiletheextentofthisgroupexpandedby5percent,acloserlookatthedatarevealstroublingtrends.Therewasanonlyslightincreaseintheoldestandyoungestageclassesofoakbetween2004and2009.Unevenage-classdistributionindicatesacontinuedscarcityofolderandyoungeroakforests,especiallyonmediumandhighproductivitysites(Figs.5and6).Growing-stockvolumeonmediumtohighqualitysitesincreasedorremainedthesameforcommerciallyimportantselectredandwhiteoakspecies—thosethatareinmostdemandforlumberproductsincludingnorthernred,white,swampwhite,andburoaks(Fig.7).

0

100

200

300

400

500

600

700

800

900

1,000

0-20 21-40 41-60 61-80 81-100 Greater

than 100

Are

a of

Tim

berla

nd (t

hous

and

acre

s)

Stand-age Class (years)

1983

1996

2004

2009

1983

1996

2004

2009

0

100

200

300

400

500

600

700

800

900

1,000

0-20 21-40 41-60 61-80 81-100 Greater

than 100

Are

a of

Tim

berla

nd (t

hous

and

acre

s)

Stand-age Class (years)

select red oaks

select white oaks

0

200

400

600

800

1,000

1,200

1,400

1,600

1980 1985 1990 1995 2000 2005 2010

Gro

win

g-st

ock

Volu

me

on T

imbe

rland

(mill

ion

cuft)

Inventory Year

Figure 5.— Age-class distribution of the oak/hickory forest-type group on low

quality sites (site index < 60) by inventory year, Wisconsin. Error bars show the

68 percent confidence interval.

Figure 6.— Age-class distribution of the oak/hickory forest-type group on

medium-high quality sites (site index ≥ 60) by inventory year, Wisconsin. Error

bars show the 68 percent confidence interval.

Figure 7.—Growing-stock volume of select red and white oaks on medium-

high productivity sites (site index ≥ 60) by inventory year, Wisconsin. Error bars

show the 68 percent confidence interval.

15

FOREST FEATURES

What This Means

WhiletheextentofoakforestsinWisconsinappearstobeslowlyincreasing,age-classdisparitiescontinue,especiallyonmedium-highqualitysites.Olderoakforestsonsitesofmediumtohighproductivityarebeinglostandoakforestsareregeneratingpoorly.Oakregenerationmaybedeclining,thoughtheratioofseedlingdensitytogrowing-stockvolumeappearssatisfactory.Growing-stockvolumeofeconomicallyimportantredandwhiteoakspeciesonmediumtohighqualitysitesremainedthesameorincreasedslightlyinthelast5yearspossiblyasaresultofincreasedknowledgeaboutproblemswithoakforestsinWisconsinandbettermanagementtechniques.

Land-use Change

Background

Informationonland-usechangeisimportantforunderstandingthefuturedirectionoflanduseinWisconsin.Inpresettlementtimes,therewereapproximately22millionacresofforestlandwithanadditional9.6millionacresofsavanna(Curtis1959).Mostofthechangeinforestlandareaoccurredbeforethefirstforestinventoryinthe1930s.Inthisreport,wefocusonthechangeinforestareabetween2004and2009.

What we found

Approximately46percentofWisconsinwasforestedin2009.Ninety-eightpercentoftheareathatwasforestlandin2004remainedforestlandin2009(Fig.8).TwopercentofWisconsin’sareaconvertedtoforestlandfromnonforestland.Landsthatconverttoforestlandaretypicallyreferredtoasreversionbecauseweassumethatinpresettlementtimesthelandshadbeenforestedandwerenowrevertingbacktotheiroriginallanduse.Fifty-onepercentofWisconsinwasclassifiedasnonforest

Forest in 2004 and 2009

Reversion (nonforest to forest)

Diversion (forest to nonforest)

Nonforest in 2004 and 2009

1%

51% 46%

2%

18%

20% 46%

16%

6%

Agriculture

Pasture

Wetland

Right-of-way

Urban

in2009.OnepercentoftheareaofWisconsinconvertedfromforestlandtononforestland.Landsthatconvertfromforestlandtononforestlandaretypicallyreferredtoasdiversion.

Fifty-sixpercentofreversionscomefromtwosources:agriculture(40percent)andpasture(16percent)(Fig.9).Theremainingreversionscomefromwetlands(18percent),rights-of-way(6percent),andurban(20percent).

Nearlyhalfofthelossesofforestlandwereduetodiversiontoagriculture(Fig.10).Theotherdiversionsweretopasture(8percent),wetlands(20percent),rights-of-way(4percent),urban(20percent),andother(4percent).

Figure 8.—Land-use change, Wisconsin, 2009.

Figure 9.—Forest land reversions by previous land use, Wisconsin, 2009.

16

FOREST FEATURES

What this means

TheforestlandareaofWisconsinis,forthemostpart,fairlystable.Approximately98.5percentofthelandthatwasforestedin2004remainedforestedin2009.Only1.5percentoftheareathatwasforestedin2004divertedtononforestlanduses,butthiswasmorethanoffsetbyreversionstoforestlandthatwereequivalenttoapproximately5percentofthe2004forestlandarea.Theneteffectwasa3.3-percentincreaseintheareaofforestlandbetween2004and2009.

Low-lyingareasappeartomovebetweenforestandnonforestclassificationsduetoweather(drought/flooding)andothernaturalcausessuchasbeaverdams.Theseconditionsareoftennotpermanentandthereforemovementislikelytocontinueinthefuture.

Whose Woods Are These?

Background

Itistheownersoftheforestlandwhoultimatelycontrolitsfateanddecideifandhowitwillbemanaged.Byunderstandingforestowners,theforestconservationcommunitycanbetterhelptheownersmeettheirneeds,andinsodoing,helpprotecttheState’sforestsforfuturegenerations.FIAconductstheNationalWoodland

OwnerSurvey(NWOS)tobetterunderstandwhoownstheforests,whytheyownit,howtheyhaveusedit,andwhattheyplantodowithit(Butler2008).

What we found

Two-thirdsoftheforestsofWisconsinareprivatelyownedandoftheseprivateacres,82percentareownedbyfamilies,individuals,andotherunincorporatedgroups,collectivelyreferredtoasfamilyforestowners(Fig.11).Otherprivateownersincludeforestindustryandothercompanies,NativeAmericantribes,nongovernmentalorganizations,andclubsandpartnerships.ThepubliclyownedforestlandsarecontrolledbyFederal,State,county,andmunicipalagenciesthatmanagethelandsformultiplereasons,includingwaterprotection,timberproduction,andrecreation.

10%

15% 56%

12%

7%

Family

Other private

Federal

State

Local

20%

20%

4%

44%

8%

6%

Agriculture

Pasture

Wetland

Right-of-way

Urban

Other

Figure 10.—Forest land use diversions by current land use,

Wisconsin, 2009.

Approximately352,000familyforestownerscontrol9.1millionforestedacresacrossWisconsin.Halfofthesefamilyforestownershavebetween1and9acresofforestland,buttwo-thirdsofthefamilyforestlandisinholdingsof50acresormore(Fig.12).Theaverageholdingsizeis26acres.Theprimaryreasonsforfamilyforestownerstohavelandarerelatedtoaestheticsandforhuntingand/orfishing(Fig.13).

Althoughtimberproductionisnotaprimaryownershipobjectiveofmostfamilyforestowners,62percentofthefamilyforestlandisownedbypeoplewhohavecommerciallyharvestedtrees.Twenty-ninepercentofthefamilyforestlandisownedbypeoplewhohave

Figure 11.—Forest ownership, Wisconsin, 2006.

17

FOREST FEATURES

awrittenmanagementplan,and44percentofthefamilyforestlandisownedbypeoplewhohavereceivedmanagementadvice.

What this means

Privateforestowners,andinparticularfamilyforestowners,arethedominanttypeofownershipinWisconsin,astheyareinmuchoftheeasternUnitedStates.AlthoughtheindividualdecisionsofthethousandsofWisconsinfamilyforestownerswillhaveonlyamarginalimpactontheforestresources,theircollectivedecisionswilldetermineboththecurrentandfuturestateofWisconsin’sforests.Familyforestownersarediverseandtimberproductionisnottheprimaryownershipobjectiveformostofthem.Policiesandprogramsshouldbedesignedtomeettheowners’diversesituationsandneeds.

Forest Biomass

Background

JustasmeasuresofWisconsin’sforestacreagehelpusunderstandourresourcesmoreclearly,measuresoftotalbiomassanditsallocationamongstandcomponents,suchassmalldiametertrees,downwoodydebris,andlivecanopycrowns,helpsusrefineourunderstandingofthecomponentsinaforeststandandwhatisavailablefordifferentuses.Forestbiomassbeyondatree’smerchantabletrunkisplayinganincreasinglysignificantroleasabiofuelcomponentineffortstogainU.S.energyindependence.

What we found

Itisestimatedthattotallive-treebiomassfortheforestsofWisconsinexceeds609milliondrytons.Seventy-onepercentofthismaterialisonprivateproperty(Fig.14).Thedistributionoflive-treebiomass(drytons)amongcountiesissimilartothatofforestland(Figs.3and15).Thenorthern22countiesinWisconsincontain58percentofthebiomasswhilethemorepopulatedcountiesinsoutheastWisconsincontain8percent.

Area

Owners

0

5

10

15

20

25

30

35

40

45

50

1-9

10

-19

20

-49

50

-99

10

0-1

99

20

0-4

99

50

0-9

99

1,0

00

+

Are

a or

Ow

ners

(%)

Size of Family Forest Holdings (acres)

0 10 20 30 40 50 60 70 80 90

Family legacy

Part of home or cabin

Nature protection

Privacy

Hunting or fishing

Aesthetics

Area or Owners (%)

Owners Area

Figure 12.—Size of family forest holdings, Wisconsin, 2006.

Figure 13.—Primary ownership objectives of family forest owners,

Wisconsin, 2006.

0 100 200 300 400 500

Public

Private

Live-tree Biomass (million tons)

Onw

ersh

ip G

roup

Figure 14.—Distribution of live-tree biomass on forest land by ownership,

Wisconsin, 2009. Error bars show the 68 percent confidence interval.

18

FOREST FEATURES

What this means

TotalforestbiomassinWisconsinisincreasing.Overthelast45years,themanagementofforestareasacrossmostofWisconsinhassupportedthesizablegrowthofforestbiomass.

Asnewtechnologiesandinnovativeapproachestoutilizingwoodresiduesemerge,theuseofwoodybiomassasanalternativetotraditionalenergysourcesisgainingmomentum.Mostforestbiomassresidesinthetrunksofgrowing-stocktreesonprivateland.Managementoftheseforestsisimportantbecauseitstronglyaffectsthedynamicsofcarbonstorageandemission.Whentreesarecut,decomposingslashandexposedsoilcanemitcarbon(asource).Asnewtreesregenerateandgrowafteracut,theforesttransitionsfromasourceofcarbontoaplacethatstoresit(asink).Inadditiontothecarbonfoundingrowing-stocktreesandforestsoils,carbonalsoresidesinstandinganddowndeadtrees,roots,andnon-treevegetation(liveanddead).

Carbon Stocks

Background

Collectively,forestecosystemsrepresentthelargestterrestrialcarbonsinkonearth.Theaccumulationofcarboninforeststhroughsequestrationhelpstooffsetemissionsofcarbondioxidetotheatmospherefromsourcessuchasforestfiresandburningoffossilfuels.TheFIAprogramdoesnotdirectlymeasureforestcarbonstocksinWisconsin.Instead,acombinationofempiricallyderivedcarbonestimates(e.g.,standinglivetrees)andmodels(e.g.,carboninsoilorganicmatterarebasedonstandageandforesttype)areusedtoestimateWisconsin’sforestcarbon.EstimationproceduresaredetailedbySmithetal.(2006).

What we found

Wisconsinforestcurrentlycontainsmorethan1.6billiontonsofcarbon.Soilorganicmatter(SOM)representsthelargestforestecosystemcarbonstockintheStateatmorethan1.04billiontons,followedbylivetreesatmorethan304milliontons(Fig.16).Withinthelive-treepool,merchantablebolescontainthebulkofthecarbon(~207milliontons)followedbyroots(~62milliontons)andtopsandlimbs(~53milliontons).MostofWisconsin’sforestcarbonstocksarefoundinrelativelyyoungstands,41to80yearsold(Fig.17).EarlyinstanddevelopmentmostoftheforestecosystemcarbonisintheSOMandbelowgroundtreecomponents.Asforeststandsmature,theratioofabove-tobelowgroundcarbonslowlyshiftsascarbonaccumulatesinliveanddeadabovegroundcomponents.Alookatcarbonbyforest-typegrouponaper-unit-areabasisfoundthatfiveoftheeighttypeshavebetween78and98tonsofcarbonperacre(Fig.18).Despitethesimilarityinper-acreestimates,thedistributionofforestcarbonstocksbyforesttypeisquitevariable.Intheoak/hickorygroup,forexample,35percent(~27tonsperacre)oftheforestcarbonisinlivebiomass,whereasinthespruce/firgrouponly10percentisinlivebiomass.

Figure 15.—Spatial distribution of live-tree biomass on forest land,

Wisconsin, 2009.

Live-tree Biomass(tons/acre) > 50 25-50 10-25 5-10 < 5

19

FOREST FEATURES

What this means

ThemajorityofforestcarbonintheStateisfoundinrelativelyyoungstandsdominatedbyrelativelylong-livedspecies.ThissuggeststhatWisconsin’sforestcarbonwillcontinuetoincreaseasstandsmatureandaccumulatecarboninabove-andbelowgroundcomponents.Giventheage-classstructureandspeciescompositionofforestsinWisconsintherearemanyopportunitiestoincreaseforestcarbonstocks.Thatsaid,managingforcarbonincombinationwithotherlandmanagementobjectiveswillrequirecarefulplanningandcreativesilviculturebeyondsimplymanagingtomaximizegrowthandyield.

Tree Species Composition

Background

Forestcompositionisdynamic,changingovertimebothwithinstandsoftreesandacrossforestedlandscapes.Forestchangeoftenisslowbutsometimesitcanbeabruptanddrastic.Importantfactorsthatinfluenceforestcompositionincludeclimateandsoil;forestdisturbancessuchasfires,storms,insectsanddiseases,andtreecutting;regenerativeabilityofnearbytreespecies;andforest-managementdecisions.Thecompositionoftreeswithinaforestcaninfluencethecompositionofotherplantsandanimalsorbeinfluencedbythem.

What we found

Number of trees:Theestimatednumberofgrowing-stocktreesmorethan5inchesd.b.h.hasincreasedby3percentoverthelast26years.In2009,redmaplewasthemostabundanttreespeciesinWisconsin’sforestswith12percentofallstems(Fig.19).Redmaplegrowing-stocktreesincreasedinnumberby42percentsince1983.Otherabundantspeciesthathaveincreasedsignificantlyinnumbersince1983includeeasternwhitepine,redpine,andblackash(82,33,and31percent,respectively).

65%

1%

3%

7%

1%

Soil organic matter

Total understory

Standing dead

Down dead

Litter

Saplings

Tops/limbs

Merchantable boles

Stumps

Roots

1%

4%

13%

3%

2%

Aboveground

Belowground

Acres

85%

77%

70% 65%

63%

62%

15% 23%

30% 35%

37%

38%

0

1

2

3

4

5

6

0

100

200

300

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500

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0-20 21-40 41-60 61-80 81-100 100+

Acr

es (m

illio

ns)

Fore

st C

Sto

cks

(mill

ion

shor

t ton

s)

Age Class (years)

C in live biomass C in dead wood C in litter C in soil

0 20 40 60 80 100 120 140 160

Spruce/fir

Elm/ash/cottonwood

Maple/beech/birch

Nonstock

Aspen/birch

White/red/jack pine

Oak/pine

Oak/hickory

Other softwoods

Other hardwoods

Forest C Stocks per Acre (short tons)

Fore

st-ty

pe G

roup

Figure 16.—Estimated total carbon stocks on forest land by forest

ecosystem component, Wisconsin, 2009.

Figure 17.—Estimated above and belowground carbon stocks on forest land

by stand-age class, Wisconsin, 2009.

Figure 18.—Estimated carbon stocks on forest land by forest-type group and

carbon pool per acre, Wisconsin, 2009. Note that the other softwoods group

includes other exotic softwoods the other hardwoods group includes exotic

hardwoods.

20

FOREST FEATURES

Species

0 500 1,000 1,500 2,000 2,500

White oak

Sugar maple

Red pine

Red maple

Quaking aspen

Northern white-cedar

Northern red oak

Eastern white pine

Bigtooth aspen

American basswood

Growing-stock Volume on Timberland (million ft3)

1983

1996

2004

2009

Severalcommontreespecieshavedeclinedinthenumberofgrowing-stocktreessince1983.Theseinclude:paperbirch,northernredoak,balsamfir,andquakingaspen(-52,-25,-21,and-18percent,respectively).

Volume of trees:Between1983and2009,thevolumeofgrowing-stocktreesontimberlandincreasedby36percent(Fig.20).Ofthemorecommonspecies,severalincreasedinvolumebymorethan10percentoverthelast5years.Theseinclude:northernpinoak(30percent),greenash(23percent),easternwhitepine(18percent),tamarack(14percent),andburoak(13percent).Commontreespeciesshowingdeclinesinvolumeoverthelast5yearsincludejackpine(-12percent)andpaperbirch(-9percent).

0 100 200 300

Sugar maple

Red pine

Red maple

Quaking aspen

Paper birch

Northern white-cedar

Northern red oak

Eastern white pine

Black ash

Balsam fir

American basswood

Number of Growing-stock Trees on Timberland (million trees)

Species 1983

1996

2004

2009

Figure 19.—Number of growing-stock trees on timberland for select species

by inventory year, Wisconsin. Error bars show the 68 percent confidence

interval.

Figure 20.—Volume of growing-stock trees on timberland by inventory

year, Wisconsin. Error bars show the 68 percent confidence interval.

What this means

Thedominanceofcertaintreespeciesisconstantlyevolvingbutcertaintrendsstandoutfromthedata.Forinstance,successiontoshadetolerantandlongerlivedspecieswilltakeplaceintheabsenceofmajordisturbancesuchasfire,storms,orlarge-scalelogging.InWisconsin’sforests,treespeciesthatdependondisturbancetoregeneratearedecreasinginnumberand/orvolume.Theseincludequakingaspen,bigtoothaspen,jackpineandpaperbirch.

Speciesthataremoreshadetolerant—andtypicallyfollowtheearlysuccessionalspecies—areincreasinginnumberandvolume.Theseincludehardandsoftmaples,redandwhiteoaks,balsamfir,easternwhitepine,andAmericanbasswood.

21

FOREST FEATURES

How Thick Are the Woods?

Background

Thedensityofaforestindicatesthecurrentphaseofstanddevelopmentandhasimplicationsfordiametergrowth,treemortality,andyield.Densityistypicallymeasuredintermsofnumberoftreesorbasalareaperunitarea.

What we found

ThedensityofWisconsin’sforestsincreaseddramaticallybetween1983and2004astreenumbersincreasedmorequicklythanacreageinforests(Fig.21).Morerecently,forestdensityhasstabilizedasforestsage,addingvolumepertreeinsteadofnewtrees.Averageannualnetgrowthofgrowing-stocktreesontimberlandwashigherin2004and2009whencomparedwith1983,32and16percentrespectively(Fig.22).Asforestsmature,treesbecomelargerandlessnumerous.Individualtreevolumeincreasedby6percentonaveragebetween2004and2009(Fig.23).Thenumberoflargetrees(over23inchesd.b.h.)hasincreasedby115percentsince1983whilethenumberofsmallergrowing-stocktrees(5to9inches)hasdecreasedby9percent(Fig.24).

ForestdensityishighestinthenortheastandnorthwestpartsoftheState;itincreasedsignificantlybetween1983and2004andhasleveledoffsince(Fig.25).Incontrast,thedensityofforestsinthesoutheastern,mosturbanized,regionoftheStatehasdeclinedsince1996.Atthesametime,thevolumepergrowing-stocktreeisgreaterinthesouthernpartoftheStatethaninthenorth(Fig.26).

Trees per acre

Area of timberland

12

13

14

15

16

17

18

400

420

440

460

480

500

520

540

560

580

600

1980 1985 1990 1995 2000 2005 2010 2015

Are

a of

Tim

berla

nd (m

illio

n ac

res)

Num

ber o

f Gro

win

g-st

ock

Tree

s pe

r Acr

e of

Tim

berla

nd

Inventory Year

0

100

200

300

400

500

600

700

800

1980 1985 1990 1995 2000 2005 20152010

Net

Gro

wth

of G

row

ing-

stoc

k Tr

ees

on T

imbe

rland

(mill

ion

ft3 /yea

r)

Inventory Year

Figure 21.—Number of growing-stock trees on timberland and timberland

area by inventory year, Wisconsin. Error bars show the 68 percent confidence

interval.

Figure 22.—Average annual net growth of growing-stock trees on timberland

by inventory year, Wisconsin. Error bars show the 68 percent confidence

interval.

0.0

2.0

4.0

6.0

8.0

10.0

12.0

1980 1985 1990 1995 2000 2005 2010 2015

Volu

me

of G

row

ing-

stoc

k Tr

ees

on T

imbe

rland

(ft3 /t

ree)

Inventory Year

Figure 23.—Estimated mean per-tree volume of growing-stock trees on

timberland by inventory year, Wisconsin.

22

FOREST FEATURES

What this means

Thematuringofourforestsisreflectedindecreasingforestdensityandincreasingtreevolume.Thisisanaturalprocessofsuccessionwheremanysmallimmaturetreesarereplacedbyfewerandlargermaturetrees.Asmaturetreesdominate,however,lesslightreachestheforestfloortopromotethesurvivalofseedlingsandlessshadetoleranttrees.Thefuturediversityofourforestswilldependonmaintainingadequateregenerationevenastheyage.

InthenorthernregionoftheState,thestabilizationofforestdensityandtheslightincreaseinindividualtreevolumeinthelast5yearssuggeststhatforestsarematuring,addingfewertreeswhileincreasinginvolumeonestablishedtrees.Themorepronounceddecreaseintreedensityandincreaseinindividualtreevolumeinthesouthmayreflecttheincreasedconversionofagriculturallandtoforest.Thesemarginallands,whichhavefewertreesperacre,mayeventuallyqualifyasforest,resultinginadecreaseintheaveragedensityofforestlandinthesouthernpartoftheState.

1983

1996

2004

2009

0

100

200

300

400

500

600

700

800

Northeast Northwest Central Southeast Southwest

Gro

win

g-st

ock

Tree

s on

Tim

berla

nd

(tree

s pe

r acr

e)

Survey Unit

1983

1996

2004

2009

Northeast Northwest Central Southeast Southwest

Survey Unit

0

2

4

6

8

10

12

14

Aver

age

Volu

me

of G

row

ing-

stoc

k Tr

ees

on T

imbe

rland

(cu

ft/tr

ee)

Figure 25.—Number of growing-stock trees on timberland by survey unit and

inventory year, Wisconsin. Error bars show the 68 percent confidence interval.

Figure 26.—Average per-tree volume of growing-stock trees on timberland by

inventory year and survey unit, Wisconsin.0 200 400 600 800 1,000

5.0-6.9

7.0-8.9

9.0-10.9

11.0-12.9

13.0-14.9

15.0-16.9

17.0-18.9

19.0-20.9

21.0-22.9

23.0+

Growing-stock Trees on Timberland (million trees)

Dia

met

er C

lass

(inc

hes)

1983

1996

2004

2009

Figure 24.—Number of growing-stock trees on timberland by diameter class

and inventory year, Wisconsin. Error bars show the 68 percent confidence

interval.

23

FOREST FEATURES

Forest Growth

Background

Forestgrowthismeasuredasaverageannualnetgrowth,or,theannualchangeinvolumeofsoundwoodinlivetreesequaltoorgreaterthan5-inchdiameter,plusthetotalvolumeoftreesenteringthisclassthroughin-growth,minusthevolumelossesfromnaturalcauses(mortality).Averageannualnetgrowthistheaveragefortheyearsbetweeninventories,mostrecentlybetween2000-2004and2005-2009.

What we found

Theaverageannualnetgrowthofgrowing-stocktreesonWisconsin’stimberlandalmostdoubledbetween1956and2009(Fig.27);thegrowthin2009wasapproximately593millioncubicfeet.Amongthetop10speciesbyvolumeredmaple,redpine,sugarmaple,andeasternwhitepinewerethetopfourspeciesintermsofaverageannualnetvolumegrowth;redmaplegrewalmost70millioncubicfeetperyearstatewide(Fig.28).Theaverageannualnetgrowthasapercentoftotalgrowing-stockvolumeaveraged2.7percentforallspecies(Fig.29).Redpine,easternwhitepine,redmaple,andquakingaspenhadthehighestgrowth-to-volumeratiosamongthetop10species.Eachofthesespeciesaveragedover3percentgrowthinvolumein2009(Fig.29).

0

100

200

300

400

500

600

700

800

1950 1960 1970 1980 1990 2000 2010

Gro

wth

of G

row

ing-

stoc

k Tr

ees

on T

imbe

rland

(mill

ion

ft3 )

Inventory Year

Species 2009

2004

1996

1983

1968

0 20 40 60 80 100 120

White oak

Sugar maple

Red pine

Red maple

Quaking aspen

Northern white-cedar

Northern red oak

Eastern white pine

Bigtooth aspen

American basswood

Growth of Growing-stock Trees on Timberland (million ft3/yr)

Species

0 1 2 3 4

White oak

Sugar maple

Red pine

Red maple

Quaking aspen

Northern white-cedar

Northern red oak

Eastern white pine

Bigtooth aspen

American basswood

All

Growth as a Proportion of Total Growing-stock Volume (%)

Figure 27.—Average annual growth of growing-stock trees on timberland by

inventory year, Wisconsin. Error bars show the 68 percent confidence interval.

Figure 28.—Average annual growth of the 10 most voluminous growing-stock

trees on timberland by inventory year, Wisconsin. Error bars show the 68

percent confidence interval.

Figure 29.—Average annual growth as a function of total growing-stock

volume, Wisconsin, 2009.

Theaverageannualnetgrowthrateofgrowing-stocktreesontimberlandasapercentofstandingvolumevariesbylandownerclass.TherateishighestforFederallandsotherthanNationalForest(3.9percent),followedbyState(3.6percent),countyandotherlocalgovernments(2.9percent),privatelandowners(2.8percent)andfinallyNationalForests(2.2percent).

24

FOREST FEATURES

What this means

TheaverageannualnetgrowthofWisconsin’sforestshasanincreasingtrendfrom1956to2009indicatinganoverallsustainableresource.Whenannualgrowthisviewedrelativetothetotalgrowing-stockvolumeontimberland,allofthe10majorspeciesbyvolumeareaddingpositivegrowthinexcessof2percenteachyear.Asaresult,thesecommerciallyimportantspecies(withthepossibleexceptionoftheaspenspeciesforreasonsdiscussedbelow)shouldcontinuetoprovidewoodproductsandotherenvironmentalservicesforsocietywellintothefuture.

Growthprovidesonlyonepieceofthesustainabilityquestion,however.Informationonmortalityandremovalsisalsoneededtomonitorthechangingcompositionoftheforest.

Tree Removals

Background

Treesareremovedfromtimberlandtomeetavarietyofmanagementobjectivesorland-usechanges.Changesinthequantityofgrowingstockremovedhelptoidentifytrendsinland-usechangeandforestmanagement.Becauseremovalsaregenerallyobservedonalimitednumberofplots,theestimatesforremovalsshowgreatervariancethanthoseforgrowth,mortality,orarea.Likeforestgrowth,therateatwhichtreeswereremovedrepresentstheaverageannualgrowing-stockremovalsthatoccurredbetweeninventories,mostrecentlybetween2000-2004and2005-2009.

What we found

Averageannualremovalsofgrowing-stocktreesonWisconsin’stimberlandincreasedfrom1956to1996;however,since1996removalshaveleveledoff(Fig.30).Averageannualremovalsforallspeciesin2009were

approximately322millioncubicfeet.Amongthetop10speciesbygrowing-stockvolume,quakingaspen,northernredoak,sugarmaple,andredpinehadthegreatestremovals(byvolume)in2009.Quakingaspenremovalswerealmost54millioncubicfeetperyearstatewide(Fig.31).Averageannualremovalsasapercentoftotalgrowing-stockvolumewas1.5percentforallspeciesin2009(Fig.32).Bigtoothaspen(3.2percent),quakingaspen(3.2percent),andredpine(1.9percent)hadthehighestremovals-to-volumeratiosamongthetop10species,whilenorthern-whitecedar(0.3percent),easternwhitepine(1.0percent),andAmericanbasswood(1.0percent)hadthelowestremovals-to-volumeratios(Fig.32).

Theaverageannualremovalsrateofgrowing-stocktreesontimberlandasapercentofstandingvolumevariesbylandownerclass.TherateishighestforFederalotherthanNationalForest(2.8percent),followedbycountyandotherlocalgovernments(1.9percent),privatelandowners(1.6percent),State(1.3percent),andNationalForestswiththelowestremovalsrate(0.5percent).

0

50

100

150

200

250

300

350

400

1950 1960 1970 1980 1990 2000 2010

Rem

oval

s of

Gro

win

g-st

ock

Tree

s on

Tim

berla

nd (m

illio

n ft3 )

Inventory Year

Figure 30.—Average annual growing-stock removals on timberland by

inventory year, Wisconsin. Error bars show the 68 percent confidence interval.

25

FOREST FEATURES

What this means

Growing-stocktreeremovalsacrossWisconsinhavestabilized,toalargeextent,overthelastdecade.Themostrecentdeclineinremovalsbetween2004and2009isverylikelytheresultoftwofactors:1)thedeclineinthenumberofhousingstarts(whichaffectslumberdemand);and2)theaccompanyingeconomicdownturnwhichhasnegativelyimpactedallsectorsoftheeconomy,includingtheforestproductsindustry—especiallypaper.Treeremovalsthroughharvestingforproductsorland-usechangeareimportantcomponentsofoverallforestsustainabilityandshouldbemonitoredintothefuture.

Tree Mortality

Background

Mortalitycanbecausedbyinsects,disease,adverseweather,succession,competition,fire,oldage,orhumanoranimalactivity;mortalityisoftentheresultofacombinationofthesefactors.Treevolumelostasaresultoflandclearingorharvestingisnotincludedinmortalityestimates.Growing-stocktreemortalityestimatesrepresenttheaveragevolumeofsoundwoodingrowing-stocktreesthatdiedeachyearasanaveragefortheyearsbetweeninventories,mostrecentlybetween2000-2004and2005-2009.

What we found

Theaverageannualmortalityofgrowing-stocktreesonWisconsin’stimberlandhasgenerallybeenincreasingalongwithtotalgrowing-stockvolumesincethemid-1960s.However,therateofincreasehasdiminishedslightlysince1996(Fig.33).Theannualmortalityforallspeciesin2009wasapproximately211millioncubicfeet.Amongthetop10speciesbyvolume,quakingaspen,bigtoothaspen,northernredoak,and

Species

2009

2004

1996

1983

0 20 40 60 80

White oak

Sugar maple

Red pine

Red maple

Quaking aspen

Northern white-cedar

Northern red oak

Eastern white pine

Bigtooth aspen

American basswood

Removals of Growing-stock Trees on Timberland (million ft3)

Species

2009

2004

1996

1983

0 1 2 3 4

All species

White oak

Sugar maple

Red pine

Red maple

Quaking aspen

Northern white-cedar

Northern red oak

Eastern white pine

Bigtooth aspen

American basswood

Removals as a Percentage of Growing-stock Volume (%)

Figure 31.—Average annual removals of the top 10 most voluminous

growing-stock trees by inventory year, Wisconsin. Error bars show the 68

percent confidence interval.

Figure 32.—Growing-stock tree removals as a percentage of growing-stock

volume by inventory year, Wisconsin.

26

FOREST FEATURES

whiteoakhadthehighestannualmortalityvolumein2009.Quakingaspenmortalitywasover44millioncubicfeetperyearstatewide(Fig.34).Theaverageannualmortalityasapercentoftotalvolumeaveraged1.0percentforallspecies(Fig.35).Quakingaspen(2.6percent)andbigtoothaspen(1.7percent)hadthehighestmortality-to-volumeratiosamongthetop10species,whileredpine,sugarmaple,andnorthern-whitecedarhadthelowestmortalitytovolumeratios,about0.2percenteach(Fig.35).

Theaverageannualmortalityrateofgrowing-stocktreesontimberlandasapercentofstandingvolumevariesbylandownerclass.TherateishighestforFederallandotherthanNationalForest(1.2percent),followedbyState(1.0percent),privatelandowners(1.0percent),countyandotherlocalgovernments(0.9percent)andNationalForests(0.9percent).

0

50

100

150

200

250

1950 1960 1970 1980 1990 2000 2010 2020

Mor

talit

y of

Gro

win

g-st

ock

Tree

s on

Tim

berla

nd (m

illio

n ft3 )

Inventory Year

Species

2009

2004

1996

1983

0 10 20 30 40 50

White oak

Sugar maple

Red pine

Red maple

Quaking aspen

Northern white-cedar

Northern red oak

Eastern white pine

Bigtooth aspen

American basswood

Mortality of Growing-stock Trees on Timberland (million ft3)

Species

2009

2004

1996

1983

0.0 0.5 1.0 1.5 2.0 2.5 3.0

All species

White oak

Sugar maple

Red pine

Red maple

Quaking aspen

Northern white-cedar

Northern red oak

Eastern white pine

Bigtooth aspen

American basswood

Mortality as a Percentage of Growing-stock Volume (%)

Figure 33.—Average annual morality of growing-stock trees on timberland by

inventory year, Wisconsin. Error bars show the 68 percent confidence interval.

Figure 34.—Average annual mortality of the top 10 most voluminous growing-

stock trees by inventory year, Wisconsin. Error bars show the 68 percent

confidence interval.

Figure 35.—Average annual mortality as a function of total growing-stock

tree volume by inventory year, Wisconsin.

27

FOREST FEATURES

What this means

TreemortalityacrossWisconsincontinuestoincrease,butmaybeslowingoverthelastdecade.Mortalityisanaturalprocessinforeststandsastheydevelopandchangeovertime.Quakingaspenandbigtoothaspenareshort-lived,pioneerspeciessoitcomesasnosurprisethattheyhavethehighestmortalityratesamongthetop10commercialspeciesinWisconsin.Treemortalityisacrucialcomponentofoverallforesthealthandshouldcontinuetobemonitored.

Growth-to-Removals Ratio

Background

Aprimarymeasureofsustainabilityisthenetannualgrowth-to-removals(G/R)ratio.TheG/Rratioisannualnetgrowthdividedbyremovalswherenetgrowthisequaltogrossgrowthminusmortality.Anumbergreaterthan1.0indicatesthatnetannualgrowthofthespeciesexceedsannualremovalsandthisremovalrateissustainable.Anumberlessthan1.0indicatesthatgrowthislessthanremovalsandthisspecieswillnotbesustainedifremovalscontinueatthislevelovertime.

What we found

TheannualG/Rratioofgrowing-stocktreesonWisconsin’stimberlandremainedrelativelystablefrom1956to2009,varyingbetween1.5and2.0(Fig.36).TheannualG/Rratioforallspeciesin2009was1.84(Fig.37).Amongthetop10speciesbyvolume,quakingaspen(0.95)andbigtoothaspen(0.88)weretheonlyspeciestohaveG/Rratioslessthan1.0.Northernwhite-cedar(7.52)andeasternwhitepine(3.73)hadthetwohighestG/Rratiosin2009(Fig.37).

TheannualG/Rratioofgrowing-stocktreesontimberlandvariesbylandownerclass.TherateishighestforNationalForests(4.7),followedbyState(2.8),

privatelandowners(1.9),andcountyandotherlocalgovernments(1.5).FederalotherthanNationalForestshadthelowestG/Rratio(1.4).

0.0

0.5

1.0

1.5

2.0

2.5

1950 1960 1970 1980 1990 2000 2010

Gro

win

g-st

ock

Gro

wth

to R

emov

als

Rat

io

Inventory Year

Species

1.84

1.47

1.96

2.23

2.49

0.95

7.52

1.58

3.73

0.88

2.32

0 1 2 3 4 5 6 7 8

All species

White oak

Sugar maple

Red pine

Red maple

Quaking aspen

Northern white-cedar

Northern red oak

Eastern white pine

Bigtooth aspen

American basswood

Growing-stock Growth to Removals Ratio

What this means

ThestatewideG/Rratioof1.84in2009confirmsthatnetannualgrowthexceededremovalsandisanindicatorthatharvestandland-coverchangeremovalsaregenerallysustainableifcontinuedatthisrate.Bothquakingaspenandbigtoothaspenhadhighremovals-to-volumeratios.Quakingaspenalsohadaverysmall(lessthan1)G/Rratiobecauseitsannualmortalitynearlymatchednetgrowth.Asaresult,currentaspenharvestlevelsareonlymarginallysustainableoverthelongterm.However,aspenharvestlevelshavebeendecliningandwillprobablycontinuetodeclineasaresultofglobalcompetition

Figure 36.—G/R ratios by inventory year, Wisconsin.

Figure 37.—G/R ratios for top 10 most voluminous species, Wisconsin, 2009.

28

FOREST FEATURES

inthepaperandpulpindustriesandthedownturnintheeconomy.Asnotedpreviously,aspenareshort-lived,earlysuccessionalspeciesthatwillbereplacedbylatersuccessionalforesttypesovertimeregardlessofharvestintensity.Ofthethreecomponentsofchange(growth,removals,andmortality),removalsarethemostdirectlytiedtohumanactivityandasaresultarethemostresponsivetochangingeconomicconditions.

Patterns of Forest Canopy Disturbance

Background

TemporarydisturbancestotheforestcanopyarecommoninWisconsin.Thislossofexistingtreesandsubsequentregenerationisknownassecondarysuccession.Permanentforestland-usechanges,suchasreversionofabandonedpastureoragriculturallandstoforestordiversionofforestintononforestuses,arefarlesscommonoccurrencesinWisconsininrecentyearsandarediscussedelsewhereinthisreport.Forestcanopydisturbancesresultfromavarietyofcauses,includingharvest,wind,ice,fire,insectsanddisease,etc.,allofwhichimpactforestecosystemcomposition,structure,andfunction.Severityofdisturbanceisaffectedbythesusceptibilityoftrees(e.g.,rootingdepth)andtheintensityofthedisturbanceagent(e.g.,windspeed).Scalesofdisturbancealsovarywidely,affectingthetotalareaandvolumeimpacted,andalsothenumberandsizeofresultingpatches.Abundanceofyoungforesthabitat,forexample,isdirectlydependentonthefrequency,severity,andscaleofcanopydisturbances.

Weproducedsatelliteimage-basedmapsandstatisticstobetterunderstandforestcanopydisturbances.Using13LandsatTimeSeriesStacks(LTSS)spanningmorethan25yearsanda‘vegetationchangetracker’algorithm(VCTw)(Huangetal.2010,Stueveetal.2011a),wemappedtheyearofthemostrecentforestcanopydisturbancesacrosstheentirestateofWisconsin.Fromthesemapswedeterminedtheageoftheresultingforestpatches,theirnumber,andtheirsize.

What we found

Canopydisturbancesoccurringduringthepastfewdecadesarereflectedbytheageofsubsequentregeneration(Fig.38).Olderforest,water,andnonforestlandalsoareshownforcontext.PatternsofyoungforestvarygeographicallyacrosstheStateasdoestherelativeabundanceofdisturbance(Fig.39).Forexample,thepredominatelyforestedmatrixinnorthwestWisconsincontainsnumerouslargepatches,whilefewerandsmallerpatchesarenotedwithinthepredominatelyforestedmatrixinthenortheast.Smallpatchesareseenwithinasparselyforestedmatrixinthesouth.Specificdisturbanceeventsareclearlyevident,likethecatastrophictornadoof2007,resultinginalong,narrowswathofdamageinnortheasternWisconsin(Fig.38,rightinset).Figure40portraysthespatialdistributionofdisturbancesbythesize(area)ofregeneratingpatches.Althoughverylargepatchesaremorenoticeable,thevastmajorityofforestdisturbancesaresmall,manyunder10acres.BasedonFIAestimates,thepredominantsourceofcanopydisturbanceiscutting,withweatheranddiseasedisturbancescomprisingthelargestcomponentofnon-human-causeddisturbancesinWisconsin(Fig.41).

Figure 39.—Relative abundance of disturbed and persistent forest land by

county, Wisconsin.

Relative Abundance of Disturbed and Persistent Forest Land Persistent forest land Disturbed forest land (1984-2009)

Source: Data derived from LTSS using the VCTw algorithm (Huang et al. 2010, Stueve et al. 2011a). Note: Pies are sized by the total amount of forest land area in each county.

29

FOREST FEATURES

Figure 38.—Forest stand age derived from LTSS and VCTw, Wisconsin, 2009.

Sources: This map was produced by processing Landsat time-series stacks with the VCTw algorithm (Huang et al. 2010, Stueve et al. 2011a).

5 miles5 miles5 miles

Age of Disturbance(years)

0-5 6-10 11-15 15-20 > 20

Persistent nonforest Persistent forest Water Counties

30

FOREST FEATURES

Figure 40.—Size of young forest patches (0-20 years) derived from LTSS and VCTw, Wisconsin, 2009.

Patch Size of Disturbed Forest Land (acres) > 1,000 101-1,000 11-100 0-10

Persistent nonforest Persistent forest Water

Counties

Sources: This map was produced by processing Landsat time-series stacks with the VCTw algorithm (Huang et al. 2010, Stueve et al. 2011a).

5 miles 5 miles 5 miles

31

FOREST FEATURES

Insect

Disease

Fire

Animal

Weather

Other/unknown

Other human

Cutting

Area Disturbed (million acres)

2.01.81.61.41.21.00.80.60.40.20.0

Disturbance Agent 2004

2009

What this means

ForestcanopydisturbancesareprevalentacrossWisconsin,buttheirnumberandsizevarygeographically.Themostprevalentnaturaldisturbancesarethosecausedbywinddamage.SupportingworkbyStueveetal.(2011b)determinedthatwind-causeddisturbancesofintermediatemagnituderesultinsimilarextentofdamageasfromcatastrophicbutrarewindevents.Informationabouttheageofforestfollowingdisturbance,andthelandscapecharacteristicsofthoseearlysuccessionalforestpatchesisbeingsharedwithwildlifemanagerstosupporthabitatworkforAmericanwoodcock(Scolopax minor),golden-wingedwarbler(Vermivora chrysoptera),andotherspecies,asisdiscussedelsewhereinthisreport.

Forest Age/Size (Wildlife)

Background

Wisconsin’sWildlifeActionPlan(WDNR2005)identifieswildlifespeciesofgreatestconservationneed(SGCN)andthreatstotheirhabitats.SeveraloftheState’sSGCNareassociatedwithforesthabitats.Wisconsinforestsprovidehabitatfornumerousspeciesofmammals,birds,reptiles,andamphibians,aswellasforfish,invertebratesandplants.Forestcompositionandstructureaffectthesuitabilityofhabitatforeachspecies.Somespecies,suchasAmericanwoodcockandgolden-

wingedwarbler,dependuponearlysuccessionalforestscomprisedofsmaller,youngertrees,especiallyaspen,adeciduousspecies.BothoftheseSGCNhaveshowndeclinesinpopulationduringthepastseveraldecades,believedtobeassociatedwithdecliningabundanceofyoungforest.Anotherearlysuccessionalspecies,Kirtland’swarbler(Setophaga kirtlandii),isarecentarrivaltotheState,inhabitingonlyyoungjackpineforest.AnotherSGCN,ceruleanwarbler(Setophaga cerulean),requiresolder,interiorforestscontaininglargetreeswithcomplexcanopystructure.Otherspeciesinhabittheecotone(edge)betweendifferentforeststages,andmanyrequiremultiplestructuralstagesofforeststomeetdifferentphasesoftheirlifehistoryneeds.Abundanceandtrendsinthesestructuralandsuccessionalstagesserveasindicatorsofpopulationcarryingcapacityforwildlifespecies(Hunteretal.2001).SeveralindicatorsofwildlifehabitatabundancecanbederivedfromFIAdata.HistoricaltrendsinWisconsin’sforesthabitatsarereportedfortimberland,whichcomprisesmorethan98percentofallforestlandintheState.Forthecurrenthabitatconditions,estimatesarereportedforallforestland.Habitatcharacteristicsrelatedtopatchsizearediscussedelsewhereinthisreport.

What we found

Treesinthesmalldiameterstand-sizeclass,whichisanindicatorofearlysuccessionalstages,hasdeclinedfrom1956and1968(38and31percent,respectively)tothemostrecentdecade(21percent)(Fig.42).Concurrently,thedistributionoftreesinthelarge-diameterstand-sizeclasshasincreaseddramaticallyfrom14percentin1956to42percentduringthecurrentinventory.Forestwithmediumdiametertreesshowamoreconsistentpatternofabundanceduringthepastsixdecades(Fig.42).MostofWisconsinforestlandisinstand-ageclassesover40years,onlyatinyfractionofwhichisover150yearsofage.Smalldiameterstand-sizeclasspredominatesyoungforests(0-20years),decreasinginrelativeabundancewithincreasingstandage(Fig.43).Theoppositetrendisseenforlargediameterstand-sizeclass,whichincreasesinrelativeabundancewithincreasingstandage,becomingpredominantat61-80years(Fig.43).

Figure 41.—Forest land area disturbed by agent and inventory year, Wisconsin.

32

FOREST FEATURES

What this means

Decreasingabundanceoftreesinthesmall-diameterstand-sizeclassisoffsetbyincreasingabundanceinthelarge-diameterclass.However,almostthree-fourthsoflarge-diameterclassislessthan80yearsofage,withonly7percentolderthan100years.Whilebothstand-sizeclassandstand-ageclassprovideindicatorsofforestsuccessionalstage,itisinterestingtoseethepersistenceofsomesmall-diameterforestinolderstandagesandsomelarge-diameterforestinyoungerstandages.Thus,thesetwoattributesarenotdirectlyinterchangeablebutarebestusedincombination.Thoughseeminglycontradictory,thereisaneedtomaintainforestconditionsinbothsmallerandlargerstructuralstagestomaintainearlierandlatersuccessionalhabitatsforallforest-associatedspecies.

Standing Dead Trees

Background

Specifichabitatfeaturessuchasnestingcavitiesandstandingdeadtrees(atleast5inchesd.b.h.)providecriticalhabitatcomponentsformanyforest-associatedwildlifespecies,includingred-headedwoodpecker(Melanerpes erythrocephalus),aWisconsinspeciesofgreatestconservationneed(SGCN)thathasdeclinedbymorethan50percent.Standingdeadtreesthatarelargeenoughtomeethabitatrequirementsforwildlifearereferredtoas‘snags’.Standingdeadtreesserveasimportantindicatorsnotonlyofwildlifehabitat,butalsoforpastmortalityeventsandcarbonstorage.Theyalsoserveassourcesofdownwoodymaterial(discussedelsewhereinthisreport),whichalsoprovideshabitatfeaturesforwildlife.Thenumberanddensityofstandingdeadtrees,togetherwithdecayclasses,species,andsizes,defineanimportantwildlifehabitatfeatureacrossWisconsinforests.

What we found

FIAcollectsdataonstandingdeadtreesofnumerousspeciesandsizesinvaryingstagesofdecay.Morethan260millionstandingdeadtreesarepresentonWisconsinforestland.Thisequatestoanoveralldensityof15.6standingdeadtreesperacreofforestland,withsimilardensitiesonpublic(16.4)andprivate(15.2)forestland.Sevenspeciesgroupseachcontributedmorethan10millionstandingdeadtrees,withthetopgroup,‘othereasternhardhardwoods’exceeding56million(Fig.44).Relativetothetotalnumberoflivetreesineachspeciesgroup,eighteenspeciesgroupsexceededonestandingdeadtreeper100livetrees,withjackpinespeciesgroup(comprisedentirelybyjackpine,Pinus banksiana)toppingthelistat7.7standingdeadtreesper100livetrees(Fig.45).Eighty-fourpercentofstandingdeadtreesweresmallerthan11inchesd.b.h.,withalmost45percentbetween5and6.9inchesd.b.h.(Fig.46).Theclassofmostdecay(‘noevidenceofbranchesremain’)containedthefeweststandingdeadtrees(10percent).

Large diameter

Medium diameter

Small diameter

Nonstocked

0

10

20

30

40

50

60

70

80

90

100

1956 1968 1983 1996 2004 2009

Rel

ativ

e Fr

eque

ncy

of S

tand

-siz

e C

lass

on

Tim

berla

nd (%

)

Inventory Year

Small diameter

Medium diameter

Large diameter

0

500

1,000

1,500

2,000

2,500

3,000

3,500

0-20 21-40 41-60 61-80 81-100 101-150 151-200+

Are

a of

For

est L

and

(thou

sand

acr

es)

Stand Age (years)

Figure 42.—Relative frequency of stand size-class on timberland by inventory

year, Wisconsin.

Figure 43.—Area of forest land by stand age and stand-size class, Wisconsin,

2009. Error bars show the 68 percent confidence interval.

33

FOREST FEATURES

Theotherfourdecayclasseseachcontainedbetween20and24percentofstandingdeadtrees(Fig.46).

What this means

Snagsresultfromavarietyofpotentialcauses,includingdiseasesandinsects,weatherdamage,fire,flooding,drought,competition,andotherfactors.Comparedtolivetrees,thenumberofstandingdeadtreesissmall,buttheycontainsignificantlymorecavitiesthanoccurinlivetrees(Fanetal.2003).Standingdeadtreesprovideareasforforaging,nesting,roosting,huntingperches,andcavityexcavationforwildlife,fromprimarycolonizerssuchasinsects,bacteria,andfungitobirds,mammals,andreptiles.Mostcavitynestingbirdsareinsectivoreswhichhelptocontrolinsectpopulations.Providingavarietyofforeststructuralstagesandretainingspecificfeatureslikesnagsonbothprivateandpubliclandsarewaysthatforestmanagersmaintaintheabundanceandqualityofhabitatforforest-associatedwildlifespeciesinWisconsin.

Urban Forests

Background

Large-scaleinventoryandassessmentoftheurbanforestisarelativelynewandrapidlyevolvingfield.Currentlythereisnonationalstandardorprotocolforcontinuousurbanforestinventoryandassessment,butthereareseveralmethodsandtechnologiesbeingusedandevaluated.The2004inventoryofWisconsin(Perryetal.2007)reportedresultsofa2002ForestServicestatewidepiloturbanforesthealthmonitoringstudythatusedfieldplotdatagatheredusingtraditionalFIAprotocolsmodifiedforurbanforestattributes.Thisstudywillberepeatedin2012tocollecttrenddataandassess

Species Group

0 10 20 30 40 50 60

Other eastern soft hardwoods

Cottonwood and aspen

Spruce and balsam fir

Other red oaks

Soft maple

Jack pine

Other eastern softwoods

Eastern white and red pine

Hard maple

Ash

Select red oaks

Select white oaks

Yellow birch

Basswood

Eastern hemlock

Standing Dead Trees (millions)

Species Group

0 1 2 3 4 5 6 7 8 9

Jack pine

Other red oaks

Other eastern soft hardwoods

Yellow birch

Select white oaks

Select red oaks

Eastern hemlock

Cottonwood and aspen

Other eastern softwoods

Spruce and balsam fir

Standing Dead Trees per 100 Live Trees

All limbs and branches present

Few limbs and no fine branches

Only limb stubs present

Few or no limb stubs remain

No evidence of branches remain

0

5

10

15

20

25

30

35

5.0-6.9 7.0-8.9 9.0-10.9 11.0-12.9 13.0-14.9 15.0-16.9 17.0+

Stan

ding

Dea

d Tr

ees

(mill

ions

)

Diameter Class (inches)

Figure 44.—Number of standing dead trees by species group, Wisconsin,

2009.

Figure 45.—Number of standing dead trees per 100 live trees by species

group, Wisconsin, 2009.

Figure 46.—Distribution of standing dead trees by decay and diameter

classes for all dead trees, Wisconsin, 2009.

34

FOREST FEATURES

theabilityofthistooltoprovideurbanforestinventory,value,andmanagementinformation.

Intheinterim,weused2001landcoversatelliteimagerycombinedwith1990and2000U.S.censusdatatocompleteanurbanforestassessment.ThisstudylookedattheState’sentireurbanforestcanopyusing30-meterpixels(NowakandGreenfield2010).Thenumberoftreesandthepercentageoftreecanopy,greenspace,andimpervioussurfacecoverwereestimatedusingautomatedclassification.Thisinformationwasoverlaidontocommunitygeographicboundariesandcensusblockdatatoprovideadditionalcanopycoverattributes:

• Treecanopypercapita—treecanopycoverdividedbynumberofpeople

• Totalgreenspace—totalcommunityareaminusimpervioussurfaceandwaterwhichestimatespervioussurface

• Availablegreenspace—totalgreenspaceminustreecanopy,whichestimatesgreenspacepotentiallyavailablefortreeplanting

Thisstudyalsocomparedtwodifferentboundariesofurbanandcommunityforestwhichoverlap.The“urban”classificationusedpopulationdensitytodelineatetheboundary.“Urban”areacrossespoliticalboundariesandexcludesundevelopedareasoutsidethepopulationdensitythreshold.The“community”classificationusedthelegalbordersofcommunities,the“citylimits”ifyouwill,whichincludesallarea,developedorundevelopedwithinapoliticalboundary.The“urban”areaallowsmanagerstofocusontheattributesofdevelopedareaswhichrequiremoreintensemanagement,whereasthe“community”areagivesamanagerthefullviewofthelandcoverintheircommunity,bothwhatiscurrentlydevelopedandwhatcouldbedevelopedinthefuture.

What we found

Duringthe1990s,Wisconsin’spopulationincreasedby14.1percentinurbanareasandby9.3percentincommunities.Thelandareaconsideredurban

increasedby17.7percentandthelandencompassedbycommunitiesincreasedby13.4percentoverthesametimeperiod(Fig.47).Asaresult,thepopulationdensity(peoplepersquaremile)actuallydecreasedby3.1and3.6percentrespectively.

State land area Area change from 1990

0 5 10 15 20

Urban

Community

Urban or

Community

Percent

Urb

an C

lass

ifica

tion

Thereareanestimated26.2milliontreesinurbanareasand66.1milliontreesincommunities.Becausetheseareasoverlap,thereareanestimated74milliontreesinurbanorcommunityareascombined.Urbanareashaveanaveragetreecanopycoverof13.1percentandcommunitieshave20.2percent.Treecanopycoverpercapita(squarefeetperperson)is1,615inurbanareasand3,934incommunities.Inurbanareas,75.7percentofthelandisgreenspaceand24.3percentisimpervious,whileincommunities,82.8percentisgreenspaceand17.2percentisimpervious(Fig.48).Inbothurbanandcommunityareas,62.6percentoftheexistinggreenspaceispotentiallyavailablefortreeplanting.

0 25 50 75 100

Percent

Urb

an C

lass

ifica

tion

Impervious surface

Green space available for tree planting

Land area that is green space

Urban

Community

Urban or

Community

Figure 47.—Area of land by urban classification, Wisconsin, 2000.

Figure 48.—Urban land cover by use, Wisconsin, 2000.

35

FOREST FEATURES

Thetreesinthecombinedareasstore14.1millionmetrictonsofcarbonvaluedat$321.5million.Theysequesteranadditional466,000metrictonsofcarbonannuallyvaluedat$10.6millionandtheyremove9,610metrictonsofairpollutants(ozone,particulatematter,nitrogenoxides,sulfuroxides,andcarbonmonoxide)annuallyvaluedat$82million(Fig.49).

aremoretreesandundevelopedland,concentratingonpreservingexistinglargecanopytreesandconservingexistingforestedarea,ratherthanclearingandplantingnewtrees,willbethechallengetominimizelostcanopyservicesduringnewdevelopment.

Similartotheplot-basedassessment,thesatelliteimageryassessmentprovidesasnapshotofcurrentconditionsandabaselineforfuturetrendanalysis.Comparingthetwomethodsrevealsthatbothareneededtoprovidecommunityleaderstheurbanforestinformationtomakemanagementdecisions.Samplefieldplotsprovidedetailsaboutthespecies,structure,andhealthoftheurbanforestonabroadscale,whilethesatellite/censusanalysisprovidesmoredetailonlandcoverandprioritizationofcanopypreservationandplanting.Satellite/censusanalysiscanalsoprovideresolutiondowntoasmallerscalesinceallurbanandcommunitylandareaisanalyzed.

What this means

Wisconsin’spopulationisincreasingandbecomingmoreurban.Inaddition,thelandareathatcomprisestheurbanforestisincreasingfasterthanthepopulation.Ifthesetrendscontinue,urbanforestsandurbanforestrywillhaveanevergreaterimpactonboththelandandthepeopleoftheState.

Thevalueoftheeconomic,social,andenvironmentalservicestheState’surbanforestsprovidestoitsresidentsissignificant.Thisvalueisbasedontheextentandvitalityoftheforestaswellastheproximityoftreecanopytobuildingsandinfrastructure.ThetreecanopycoverinthedenselypopulatedareasandtheoverallcommunityareasarebothwellbelowtheAmericanForests’recommendedgoalof40percentsothereissignificantroomforimprovement.Notonlyisthereplentyofspacetoplanttrees,butbecauseittakestreessolongtoreachasizethatwillprovidemaximumbenefits,preservationofexistingcanopywillbeessentialtomaintainandincreaseservicesovertime.Inurbanareas,thechallengewillbepreservationoflargecanopytreesduringreconstructionandredevelopmenttoreachcanopygoals.Intheoverallcommunitywherethere

Pollution removal value

Carbon sequestration value

Urban

Community

Urban or

Community

Urb

an C

lass

ifica

tion

0 25 50 75 100

Dollars per Year (millions)

Figure 49.—Selected economic impacts of urban forests, Wisconsin, 2000.

Note: pollutants removed by the urban forest include: ozone, particulate

matter, nitrogen oxides, sulfur oxides, and carbon monoxide.

36

3737

Forest Health Indicators

American hornbeam. Photo by David Lee, Bugwood.org.

38

FOREST HEALTH INDICATORS

Crown conditions

Background

Theconditionoftreecrownswithinastandreflectstheoverallhealthofaforest.Diebackisthepercentageofdeadbranchtipsinthecrown.Thecategoriesforthediebackindicatorarenone(0to5percent),light(6to20),moderate(21to50),andsevere(51to100).Crowntransparencyisameasureoftheproportionofthecrownthroughwhichtheskyisvisible.Aforestsufferingfromadiseaseepidemicwillhaveobviousdiebackandhightransparency.

What we found

TreecrownsgenerallyarehealthyacrossWisconsinformostspecies;theoverwhelmingmajorityoftreesobservedhadnoorlightdamage(Fig.50).Theash,cottonwoodandaspen,otherredoaks(includingnorthernpinoak),andyellowbirchhadthebiggestchangessince2004(Fig.51);however,theseamountsofcrowndiebackstillfallwithinthe“light”category.

What this means

ThesemeasurementsofcrownindicatorsappeartoindicatetherearenomajorhealthproblemsrelatedtocrownconditionsinWisconsin.However,thesemeasurementshaveonlybeencollectedtwiceduringtheperiodofrecord.Additionalmeasurementswillprovidevaluablecontextformanagersinthefuture.Particularattentionshouldbegiventotheashandotherredoakspeciesgroups.

None

Light

Moderate

Severe

2% 3%

68%

27%

Dieback

2004

2009

Species Group

0 5 10 15

Yellow birch

Spruce and balsam fir

Soft maple

Select white oaks

Select red oaks

Other red oaks

Jack pine

Hickory

Hard maple

Eastern white and red pines

Eastern hemlock

Cottonwood and aspen

Basswood

Ash

Mean Crown Dieback (%)

Thecrowntransparencyofthehickoryspeciesgroupincreasedby53percentbetween2004and2009,thelargestincreaseofallspeciesgroups(Fig.52).Thecrowntransparencyofselectredoaksdecreasedby19percent.

2004

2009

Species Group

0 5 10 15 20 25 30

Yellow birch

Spruce and balsam fir

Soft maple

Select white oaks

Select red oaks

Other red oaks

Jack pine

Hickory

Hard maple

Eastern white and red pines

Eastern hemlock

Cottonwood and aspen

Basswood

Ash

Mean Crown Transparency (%)

Figure 50.—Dieback classes of all species, Wisconsin, 2009.

Figure 51.—Mean crown dieback by species group and inventory year,

Wisconsin. Error bars show the 68 percent confidence interval.

Figure 52.—Mean crown transparency by species group and inventory year,

Wisconsin. Error bars show the 68 percent confidence interval.

39

FOREST HEALTH INDICATORS

Down Woody Material

Background

Downwoodymaterial,includingfallentreesandbranches,fillsacriticalecologicalnicheinWisconsin’sforests(TyrrellandCrow1994).Itprovidesvaluablewildlifehabitatintheformofcoarsewoodydebris,contributestoforestfirehazardsviasurfacewoodyfuels,andstorescarbonintheformofslowlydecayinglargelogs.

What we found

ThefuelloadingsandsubsequentfirehazardsofdeadanddownwoodymaterialinWisconsin’sforestsarerelativelylow,especiallywhencomparedwiththenearbystatesofMichiganandMinnesota(Fig.53).Thesizedistributionofcoarsewoodydebris(diameterlargerthan3inches)isoverwhelminglydominated(83percent)bypieceslessthan8inchesindiameter(Fig.54).Moderatelydecayedcoarsewoodypieces(decayclasses2,3,and4)constituted91percentofthedecayclassdistribution(Fig.55).Thecarbonstocksofcoarsewoodydebrisappeartobestable(around1ton/acre)acrossclassesofstandinglive-treebasalareaonWisconsin’sforestland(Fig.56).

What this means

Thefuelloadingsofdownedwoodymaterialcanbeconsideredaforesthealthhazardonlyintimesofdroughtorinisolatedstandswithexcessivetreemortality.Theecosystemservices(e.g.,habitatforfaunaorshadefortreeregeneration)providedbydownwoody

Michigan

Wisconsin

Minnesota

0

1

2

3

4

5

1-hr 10-hr 100-hr 1,000+hr

Mea

n Fu

el L

oadi

ngs

(tons

/acr

e)

Fuel-hour Classes

0.2% 15.2% 82.9%

1.7%

3.0-7.9

8.0-12.9

13.0-17.9

18.0+

41%

2% 7%

26%

24%

1

2

3

4

5

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0.0-30.0 30.1-60.0 60.1-90.0 90.1-120.0 120.1+

Coa

rse

Woo

dy D

ebris

Car

bon

(tons

/acr

e)

Basal Area (ft2/acre)

Figure 53.—Down wood fuel loadings in the Lake States, 2009. Error bars

show the 68 percent confidence interval.

Figure 54.—Diameter distribution of down wood pieces, Wisconsin, 2009.

Figure 55.—Distribution of down wood pieces by decay class, Wisconsin,

2009.

Figure 56.—Distribution of coarse woody debris carbon by forest land basal

area, Wisconsin, 2009. Error bars show the 68 percent confidence interval.

40

FOREST HEALTH INDICATORS

materialexceedsanynegativeforesthealthaspects.ThepopulationofcoarsewoodydebrisacrossWisconsinconsistsmostlyofsmallpiecesthataremoderatelydecayed.Duetothis,coarsewoodydebrisconstitutesasmall,albeitimportantcarbonstockacrossWisconsin’sforests.ThepopulationofdownwoodymaterialinWisconsin’sforestsappearsconsistentwithnearbystates.

Ozone

Background

Ozoneisanaturalconstituentofboththelower(groundlevel)andupperatmosphere.Elevatedozoneconcentrationsintheloweratmospherearecommonlyfoundwithinanddownwindofmajorurbanandindustrialareas.Hotsummersoftenproducesignificantexposureswhilecoolwetsummersresultinlowexposures.

Ozoneisanairpollutantthatdamagestrees,reducestheirgrowth,andthusmakesthemvulnerabletoinsectsanddiseases.ThegrowthratesandbiomassofbioindicatorspecieshavebeenreducedincontrolledexposurestudiesaroundsouthernLakeMichigan(Bennettetal.2006).Individualspeciesandsensitivepopulationswithinspeciesmayhavelowerproductivity,thusinfluencingoverallcompetitivenessandforestcomposition.

What we found

Biositeindexvaluescanvarywidelyoverindividualyearsduetovaryingozoneconcentrationsanddistributionacrossforestlandscapes.Thetrendinbiositeindexvaluesisbestcalculatedasarolling5-yearaverage.ThemeanbiositeindexvaluehasdecreasedinWisconsin’sforestssincethelate1990s(Fig.57).Whencomparingtheseverityofdamageobservedin2004and2009forindividualbioindicatorplants,thesametrendemerges:decreasingozonedamageseverity(Fig.58).Most

bioindicatorplantshaddamagehalfassevereorlessin2009thanin2004.Commonandtallmilkweed(Asclepias syriaca)wasthemostseverelydamagedplantinbothinventories.Meanplantinjury,agaugeoftherelativenumberofplantsthatshowedanylevelofozonedamage,decreasedsubstantiallyfrom2004to2009(Fig.59).

0.0000

0.0002

0.0004

0.0006

0.0008

0.0010

0.0012

0.0014

0.0016

0.0018

0.0020

1996 1998 2000 2002 2004 2006 2008 2010

Mea

n B

iosi

te In

dex

(5-y

ear r

unni

ng a

vera

ge)

Inventory Year

0 0.01 0.02 0.03 0.04

White ash

Spreading dogbane

Common and tall milkweed

Blackberry

Black cherry

Big leaf aster

Mean Plant Damage Severity

Bioindicator Species 2004

2009

Bioindicator Species

0 0.05 0.1 0.15

White ash

Spreading dogbane

Common and tall milkweed

Blackberry

Black cherry

Big leaf aster

Mean Plant Damage Amount

2004

2009

Figure 57.—Five-year moving average of biosite index by inventory year,

Wisconsin.

Figure 58.—Mean plant damage severity (unitless ratio of ozone damage, 1

indicates complete damage) by inventory year, Wisconsin.

Figure 59.—Mean plant damage amount (unitless ratio of number of plants

damaged by total number of plants samples) by inventory year, Wisconsin.

41

FOREST HEALTH INDICATORS

What this means

TheexposureofWisconsin’sforestlandtoozonecontinuestodecline.Theforestsareatlowriskoffoliarinjuryandgrowthandproductivitylosses.Thepotentialeffectsofozonestressshouldbeevenlesssevereonthemostcommontreespecies(e.g.,maplesandoaks)asthesearerelativelytolerantofozone.However,themonitoredozoneexposures,theconfirmingevidenceoffoliarinjury,andtheoverallinjuryscoresindicatethepotentialforreducedgrowthandnegativeimpactonthehealthofWisconsin’sforests.Ofparticularconcernwillbeozone-sensitivetreespecies,suchasquakingaspen,blackcherry,chokecherry,whiteash,andgreenash,thatoccuralongLakeMichigan.

Forest Insects and Diseases

Background

InsectsanddiseaseshavealwaysbeenapartofWisconsin’sforestecosystemandhavebeenmonitoredsincethemid-1950s.Inthepastdecade,thethreatandimpactfromexoticinsectsanddiseaseshasincreasedasthenumberofthemestablishedinWisconsinandtheUnitedStatesincreases.Combinedimpactsfrommultiplestressors,bothlivingandnonliving,alsoappeartobeanincreasingproblem.

What We Found

WeatherandavarietyofinsectsanddiseasesimpactedWisconsin’sforestsduring2005-2009.Thisperiodwascharacterizedbydiebacksanddeclinesinseveraltreespeciesduetomultiplefactors.NorthernWisconsincountiesexperienceddroughtduringthe2005-2007growingseasonsandin2009(Fig.60).Droughtwasparticularlysevereinnorthwesterncounties.

InvasivepestsanddiseasesareanissueofincreasingconcerninWisconsin.Emeraldashborer(Agrilus

planipennis-—seetheEABsection)andbeechbarkdisease(Cryptococcus fagisuga and Nectria coccinea var.faginata)(Fig.61)werefirstfoundintheStateduringthis5-yearperiod.Ashyellows(Fig.62),Annosumrootrotofpine(Heterobasidion irregulare)(Fig.63)andoakwilt(Ceratocystis fagacearum)(Fig.64)continuetospreadacrossthestate.Gypsymoth,(Lymantria dispar)whichwasalreadyestablishedintheeasternhalfofthestate,increasedtooutbreaklevelsforthesecondtimeinStevensonTownshipinnortheasternWisconsinandinthecentralcountiesofAdamsandJuneau,causing23,000acresofdefoliationin2007(Fig.65).

Jackpinebudworm(Choristoneura pinus)atitspeakin2005caused222,500acresofdefoliationofjackpine,mostlyinnorthwesterncountiesandextendingsouthtothewest-centralcountiesofEauClaire,Jackson,Monroe,Juneau,andAdams.Theoutbreakcollapsedoverthefollowing2yearsascommonlyoccurswiththecyclicaloutbreaksthatcharacterizethisnativepest.Whatwasnottypicalofthisinsectwasitsshifttofeedingonredpinein2005-2008.Feedingdamage,whichcharacteristicallyoccursonolderjackpine,wasnowoccurringonyoungerredpine(20to30yearsold)oronindividualoldertrees.

What this means

Decline,dieback,andmortalityoftreesduetothecombinedstressofmultiplefactors,bothlivingandnonliving,isnotnewtoWisconsin.Ithasbeendocumentedasoccurringinpreviousdecadesandcanbeexpectedinthefuture.Itshouldberecognized,however,thattheinitialsourceofstressthatopenstreestoattackbyopportunisticorweakpestsanddiseasesisoftenweathereventssuchasdrought,stormdamage,frost,orflooding.Wisconsinhasexperiencedwarmingweatherinthelasttwodecadesandachangingclimatewillcauseanincreaseinthebackgroundlevelofstressexperiencedbytreesleavingthemincreasinglysusceptibletotheaccumulationofstressfromminororsecondarypestsanddiseases.

42

FOREST HEALTH INDICATORS

Figure 60.— Drought conditions, Wisconsin, 2005-2009.

2005

2007

2006

2008

2009

Sources: National Drought Mitigation Center (NDMC), the U.S. Department of Agriculture (USDA) and the National Oceanic and Atmospheric Association (NOAA).

Drought Monitor Class(Conditions in August of Each Year) Exceptional drought Extreme drought Severe drought Moderate drought Abnormally dry

43

FOREST HEALTH INDICATORS

Figure 61.— Beech bark disease distribution in Wisconsin, 2009. Beech

bark disease progresses from high populations of scale through white fuzz to

identification of beech scale and beech bark disease.

Figure 62.—Wisconsin counties where ash yellows has been confirmed as of

2009.

Figure 63.—Wisconsin counties where Annosum root rot of pine has been

confirmed as of 2009.

Figure 64.—Wisconsin counties where oak wilt has been confirmed as of

2009.

Sources: Wisconsin Department of Natural Resources

Sources: Wisconsin Department of Natural Resources.

50 Miles0

Ash YellowsYear of First Confirmation 2009 2008 2007 2006 2005 2004

Annosum Root Rot Detections

Northern Red OakBasal Area (ft2/acre) > 20 11-20 5-10 < 5 Oak wilt detections

Sources: Wisconsin Department of Natural Resources.

Results of Beech Bark Disease Survey Beech bark disease (1st find) Beech scale (lab confirmed) Beech scale (not lab confirmed) White fuzz present High population of scale No scale

Basal Area of American Beech(ft2/acre) > 20 11-20 5-10 < 5

Sources: Wisconsin Department of Natural Resources. Survey records accurate as of 1 December 2009.

Area of Interest

44

FOREST HEALTH INDICATORS

Invasivepestsanddiseasehavethepotentialtochangeforestcomposition,someindramaticwaysandothersmoresubtlety.Forpestswherethehosthaslittleresistance,suchasemeraldashborerandbeechbarkdisease,thehostspeciesarelikelytobeeventuallyremovedfromtheforestcommunity,ashasbeenthecasewithAmericanelm(Ulmus americana)andAmericanchestnut(Castanea dentata).Collectionandpropagationofresistantstrainsofashandbeechmayalloweventualreintroductionofthesespeciesintotheforestincombinationwithestablishmentofnaturalcontrolsofthepestsandotheraspectsofanintegratedpestmanagementapproach.Otherinvasivepests,suchasgypsymoth,stressbutdonoteliminatetheirhosts.AshasbeenobservedelsewhereinNorthAmerica,wecanexpectoutbreaksaboutevery5yearsinareaswithdry,sandysoil,andcontiguousoakoraspensimilartotheStevensonTownshipareaorpartsofcentralWisconsin.Inmixedforestsonmoistersoils,outbreaksareexpectedfrequentlywith10ormoreyearsbetweendefoliationbyhighnumbersofgypsymoth.InPennsylvania,periodicdefoliationbygypsymothsincethemid-20thcenturyisconsideredtohaveledtoa3percentreductionintheoakcomponentofthatState’sforestsandwemay

eventuallyseeasimilarsmallchange.Thelong-termeffectofsomeinvasivespecies,suchasashyellows,Annosumrootrot,andoakwilt,isnotclearatthistime.

Inadditiontonewinvasivepests,ournativepestspecieshavethepotentialtochangebehaviorandimpact.Itisnotcleariffeedingbyjackpinebudwormonredpinealongthesouthernedgeofthepest’srangerepresentsaresponsetoashort-termincreaseinthepalatabilityofredpineinthatareaoralongertermhostshiftbythelocalpopulation.Furtherobservationmayclarifythesituation.

Emerald Ash Borer

Background

Theemeraldashborer(EAB;Agrilus planipennis)isnativetoAsiaandisthoughttohavebeenintroducedaccidentallytotheDetroitareainthemid-1990sbeforebeingfirstdetectedtherein2002.InNorthAmerica,EABhasonlybeenidentifiedasapestofashandallnativespeciesofashappeartobesusceptible,evenwhenhealthy(Cappaertetal.2005,PolandandMcCullough2006).Thisinsectcausesashtreedeathwhenlarvaefeedunderthebark,cuttingofftheflowofwaterandnutrients.SpreadofEABhasbeenfacilitatedbyhumantransportationofinfestedmaterial,typicallyfirewood.Systemicinsecticidesinjectedintotreescanprovide1to3yearsofprotection,andthreespeciesofparasitoidshavebeenclearedforintroductionintotheUnitedStates.

What We Found

InAugust2008,EABwasobservedforthefirsttimeinWisconsin;awellestablishedpopulationofEABwasfoundinNewburg,OzaukeeCounty(Fig.66).TheareaisruralresidentialwithashdominatedwoodlandalongtheupperreachesoftheMilwaukeeRiver.Dendrochronology,ortreeringdating,indicatesthe

Figure 65.—Distribution of defoliation in Wisconsin by gypsy moth between

2004 and 2009.

Gypsy MothYear of Defoliations 2009 2008 2007Sources: Wisconsin Department of Natural Resources.

Area of Interest

45

FOREST HEALTH INDICATORS

onbottomlandsites.Whiteashmaybeacomponentofseveralforesttypesandismorecommononuplandsites.AshisfoundthroughoutWisconsinbutismostcommoninthenorthernhalfoftheState(Fig.67).Ashispresenton5.8millionacres,or35percentofforestland,butisrarelythemostabundantspeciesinastand(Fig.68).Instead,ashgenerallymakesuplessthan25percentoftotallive-treebasalarea.GreenandwhiteashtogetherarethesecondmostcommontreeinWisconsincommunities,makingupanaverageof20percentofurbantreesandpotentiallyservingasaconduitforestablishmentofEABintoWisconsinforests.

insecthadbeenthereatleastsince2004.InApril2009,apopulationthatcoveredalargerareawasfoundontheoppositesideofthestatealongtheMississippiRiverinVictory,VernonCounty,anddatedbackto2006.

Astheyearprogressed,manyinfestedtreeswerefoundintheMilwaukee-areacommunitiesofOakCreek,Franklin,andKenoshaandanadultEABwastrappedinGreenBay.

TheriskofspreadofEABthroughouttherestofWisconsinisthoughttobehighlydependentontheamountofash,onhumanpopulationdensity,andtoalesserextentonthenumberofcampsitesandseasonalhomes(Fig.66).TheriskmodeldevelopedbytheWisconsinDNRhashelpedguideStateandFederalofficialsonwheretoconductdetectionsurveys.

Agreatdealoftheforestresourceisthreatened.Wisconsin’sforestlandcontainsanestimated807.5millionashtrees(greaterthan1-inchdiameter)and1.4billioncubicfeetofliveashvolume(greaterthan5-inchdiameter).Blackash,whichgrowsonmesicandwetsites,isthemostcommonspeciesofash.Greenashisfoundgrowingmostcommonlywithotherhardwoods

0

2

4

6

8

10

12

No ash 0.1-25.0 25.1-50.0 50.1-75.0 75.1-100.0

Tota

l For

est L

and

(mill

ion

acre

s)

Ash BA per Acre/Total Live BA per Acre (%)

Figure 66.—Risk model of emerald ash borer introduction into Wisconsin’s

forests with counties under quarantine as of August, 2011.

Figure 67.— Ash density on forest land, Wisconsin, 2009.

Figure 68.—Presence of ash on forest land, as a percentage of live-tree basal

area (BA), Wisconsin, 2009.

Risk of Emerald Ash Borer Introduction into Wisconsin’s Forests High Medium Low Quarantined counties

Live Ash Volume on Forest Land(ft2/acre) > 10.0 5.1-10.0 2.6-5.0 1.0-2.5

Sources: Wisconsin Department of Natural Resources and Department of Agriculture, Trade, and Consumer Protection. List of quarantine counties updated August, 2011.

46

FOREST HEALTH INDICATORS

What This Means

TheemeraldashborerhasthepotentialtokillmillionsofashtreesonseveralforesttypesthroughoutWisconsin.TheimpactofEABisexpectedtorivalthatofchestnutblightandDutchelmdisease.Inadditiontoeconomiclosses,ashmortalityinforestedecosystemswillaffectspeciescompositionandaltercommunitydynamics.Ofparticularconcernisthelossofblackandgreenashonmesictowetsites.Thesewetsitesmayhavefewtonootherspeciesoftreespresent.Growingotherspeciestoreplacelostashonthesewetsitesislimitedbyourknowledgeofregenerationpracticesandchallengedbyinvasionofexoticplantssuchasreedcanarygrass(Phalaris arundinacea).NaturalspreadalongrivercorridorsappearstobealreadyhappeningparticularlyalongtheMississippiRiverwhereEABhassincebeenfoundonthewesternshoreinMinnesotaandIowaandnorthandsouthfromtheoriginalVictoryfind.Widespreadmortalityofashalongtheriverhasnotyetoccurredbutisexpectedinthenextfewyearsaspopulationsofthepestbuildinalreadyinfestedtrees.

QuarantineshavebeenplacedoncountieswhereEABhasbeenfoundinornear.ThesequarantineslimitmovementanddestinationofashfromquarantinedareastopreventspreadofEAB.Millsoutsidethequarantinedareamayonlyreceiveashlogsfromquarantinedareasiftheyagreetocomplywithshippingandprocessingrequirements.LogsmaybemovedfromquarantinedareastomillsoutsideofthequarantinefromOctobertotheendofMarchwhenEABareinthepre-pupalstagewithinlogs.ThereceivingmillsmustprocessthelogsandanywastebytheendofApriltopreventemergenceofadultEAB.AllhardwoodfirewoodisprohibitedfromleavingthequarantinedareaunlesstreatedtokillinfestingEAB.NoashnurserystockisallowedtoleavethequarantinedareaasthereisnotreatmenttoensureitisfreeofEAB.

Nonnative and Invasive Plants Species

Background

Nonnativeplantscanbedetrimentaltonativeforestecosystems,threateningecologicaldiversity,increasingforestmanagementcoststhroughtheirimpactonforesttreeregenerationandgrowth,andlimitingmanagementoptions.

What we found

Forestinventorydatawascollectedon96vegetationdiversityplotsfrom2007to2009.Aregionalguidetononnativeinvasiveplantswasusedtoidentifyspeciesofinterest(OlsonandCholewa2009).SeventeendifferentspecieswereidentifiedinWisconsin’sforestsin2009(Fig.69;Table1);thisisanincreasefromninespeciesin2004.Thetwomostcommonnonnativeinvasivespecieswerereedcanarygrass(Phalaris arundinacea)andcommonbuckthorn(Rhamnus cathartica).Oneormorespecieswerefoundon50plots(Fig.70),butitwasrelativelyuncommontofindtwoormorespeciesoccurringonthesameplot(21percent).Particularconcernsareraisedwhencomparingthe2009inventorywiththe2004inventory.Thefrequencyoftwoormoreinvasivespeciesperplotisgreaterinthe2009inventorythanthe2004inventory(21and13percent,respectively).Reedcanarygrasswasoneof15specieswhichincreasedinoccurrencebetween2004and2009;onlytwospecies(multiflorarose(Rosa multiflora)andblacklocust(Robinia pseudoacacia))declinedinoccurrencebetween2004and2009.Thesamplingofinvasivespeciesisstillrelativelynew,sothisdatadoesnotdefineasolidtrend.

47

FOREST HEALTH INDICATORS

What this means

AlthoughnonnativeplantspeciesrepresentaminorityofspeciesinWisconsin’sforests,theyareaforesthealthconcernbecausetheycanout-competenativeplantspecies,includingtrees,andthreatenecologicaldiversitybyalteringnaturalplantcommunities.SomespeciesalreadyaredistributedacrosstheStatebutseveralarenot,andthismaypresentmanagerswithopportunitiesforlimitingrangeexpansion.Thevegetationdiversitysampleisrelativelysmall(96plotsover3years);theincreasingnumbersofseveralinvasivespeciesrequirescontinuedattentiontodetermineifthisisalong-termtrend.

0 5 10 15 20

Tatarian honeysuckle

Spotted knapweed

Russian olive

Reed canarygrass

Multiflora rose

Morrow's honeysuckle

Japanese barberry

Glossy buckthorn

Garlic mustard

European cranberrybush

Creeping jenny

Common buckthorn

Canada thistle

Bull thistle

Black locust

Autumn olive

Amur honeysuckle

Frequency of Occurrence on Plots (%)

Species 2004

2009

2004

2009

0

10

20

30

40

50

60

0 1 2 3 4 5 6

Plot

s (n

umbe

r)

Number of Species Per Plot

Figure 69.—Frequency of occurrence of nonnative invasive understory plants,

Wisconsin, 2004 and 2009.

Figure 70.—Distribution of nonnative invasive species observed on vegetation

diversity plots, Wisconsin, 2004 and 2009.

Table 1. List of nonnative invasive species observed in Wisconsin, 2007-

2009. Additional information is available in the USDA Plants Database (USDA

NRCS 2012).

Amur honeysuckle Lonicera maackiiAutumn olive Elaeagnus umbellataBlack locust Robinia pseudoacaciaBull thistle Cirsium vulgareCanada thistle Cirsium arvenseCommon buckthorn Rhamnus catharticaCreeping jenny Lysimachia nummulariaEuropean cranberrybush Viburnum opulusGarlic mustard Alliaria petiolataGlossy buckthorn Frangula alnusJapanese barberry Berberis thunbergiiMorrow’s honeysuckle Lonicera morrowiiMultiflora rose Rosa multifloraReed canarygrass Phalaris arundinaceaRussian olive Elaeagnus angustifoliaSpotted knapweed Centaurea biebersteiniiTatarian honeysuckle Lonicera tatarica

Common name Scientific name

48

4949

Forest Economics

Red pine stand. Photo by Steven Katovich, U.S. Forest Service, bugwood.org.

50

FOREST ECONOMICS

Growing-stock Volume

Background

Thegrowing-stockvolumedistributedacrossWisconsin’stimberlandconstitutesanimportantresourceintheState’seconomy.Wisconsinleadsthenationinpaperproduction,asithasformanyyears.Toevaluatetheeffectsofpastpaperandlumberproductionaswellasestimatefutureresourceproduction,itishelpfultoknowthegrowing-stockvolumeofcertaintreespeciesandhowthisischanging.

What we found

ThetotalvolumeofgrowingstockonWisconsintimberlandhasincreasedsince1956;thecurrentestimateis21.1billioncubicfeet(Fig.71).Thevolumesofseveralspeciesgroupshaveincreasedwhileseveralothershavedecreasedoverthepastthreeinventories(Figs.72and73).Theeasternwhiteandredpinesgrouphasthelargestsoftwoodgrowing-stockvolumeacrossWisconsin.Inthehardwoodspeciesgroups,cottonwoodandaspen,followedbysoftmaple,hardmaple,andselectredoakshavethelargestgrowing-stockvolumesintheState.Theeasternwhiteandredpines(softwoods)andsoftmaple(hardwoods)groupshavehadthegreatestgainsingrowing-stockvolumesince1983.Thetotalvolumesinlargerdiameterclasseshaveincreasedsince1983inbothsoftwoods(Fig.74)andhardwoods(FigureFig.75).Growing-stockvolumeinmostWisconsincountiesincreasedbetween1983and2009,withthelargestgainsintheheavilyforestednortherncounties(Fig.76).

Softwoods

Hardwoods

0

2

4

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8

10

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14

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18

1950 1960 1970 1980 1990 2000 2010

Gro

win

g-st

ock

Volu

me

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ion

ft3)

Inventory Year

2009

2004

1996

1983

0 1,000 2,000 3,000 4,000

Spruce and balsam fir

Other eastern softwoods

Jack pine

Eastern white and red pine

Eastern hemlock

Volume of Growing-stock Trees on Timberland (million ft3)

Species Group

2009

2004

1996

1983

Species Group

0 500 1,000 1,500 2,000 2,500 3,000

Yellow birch

Soft maple

Select white oaks

Select red oaks

Other red oaks

Other eastern soft hardwoods

Hickory

Hard maple

Cottonwood and aspen

Basswood

Ash

Volume of Growing-stock Trees on Timberland (million ft3)

Figure 71.—Growing-stock volume on timberland by major species group and

inventory year, Wisconsin. Error bars show the 68 percent confidence interval.

Figure 72.—Volume of softwood growing-stock trees on timberland by

inventory year, Wisconsin. Error bars show the 68 percent confidence interval.

Figure 73.—Volume of hardwood growing-stock trees on timberland by

inventory year, Wisconsin. Error bars show the 68 percent confidence interval.

51

FOREST ECONOMICS

What this means

ThevolumeofgrowingstockonWisconsin’stimberlandhasbeenincreasingsteadilyoverthepast50years.Althougheconomicallyimportantspeciesgroupshaveshowngrowthintotalvolumeandaveragevolumeperacre,therateofincreasehasnotbeenequallyapportionedacrossallspeciesgroups.Speciesgroupssuchaseasternwhiteandredpinesandsoftmaplehaveexperiencedlargeincreasesingrowing-stockvolumes,butjackpine,aspen,andtheoakshaveshownsmallerincreasesordecreases.Theincreaseingrowing-stockvolumecanbeattributedtotheagingoftheforest,limitedmortality,netgrowthexceedingremovals,andincreasingtimberlandareaoverthelast50years.Wisconsin’sgrowing-stockinventoryappearsstableandgrowing,butitcouldbecompromisedbyinvasiveplantspecies,insectsanddiseases,andlossoftimberlandtodevelopment.

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1996

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2009

0

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Figure 74.—Volume of softwood growing-stock trees on timberland by

diameter class and inventory year, Wisconsin. Error bars show the 68 percent

confidence interval.

Figure 75.—Volume of hardwood growing-stock trees on timberland by

diameter class and inventory year, Wisconsin. Error bars show the 68 percent

confidence interval.

52

FOREST ECONOMICS

Figure 76.—Distribution of change in growing-stock volume in Wisconsin. Observations of change are significant at the 68 percent confidence interval

(1 standard error).

Change in Growing-stock Volume Over Time Gain No Change Loss

1993 1996

2004 2009

1983-2009 2004-2009

Growing-stock Volume on Timberland (million ft3) > 800 600-800 400-600 200-400 < 200

53

FOREST ECONOMICS

Sawtimber Volume

Background

SawtimbervolumeisanimportantindicatoroftheeconomicvalueofWisconsin’sforests.Thisresourcenotonlyprovidesdirecteconomicbenefitthroughsawtimberandveneersalesbutalsosupportswood-usingsecondaryindustriessuchasfurnitureandmillworkmanufacturing.Thequantityofsawtimberneedstobemeasuredtoaccuratelygaugeitseconomicvalue.

What we found

SawtimbervolumehasincreasedsteadilyacrossWisconsinsince1956anditiscurrentlyestimatedtobe62.1billionboardfeet(Fig.77).Thisincreasehasnotbeenuniformacrossallspeciesgroups.Thesawtimbervolumeofmosteconomicallyvaluablespeciesgroupsincreasedbetween1996and2009.Theeasternwhiteandredpines,softmaple,andotherredoaksgroupshaveincreasedinsawtimbervolumebymorethan30percentsince1996(Fig.78).Therewasamajordeclineinjackpinesawtimbervolume(27percent).Thenetgrowth,removals,andmortalityofsawtimberhaveremainedrelativelyconstantsince1983(Fig.79).

What this means

Sawtimbergrowth,removals,andmortalityhavestabilizedsincethe1980s,andthishasresultedinasteadyincreaseinthesupplyofsawtimberonWisconsintimberland.

Hardwoods

Softwoods

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Eastern white and red pine

Soft maple

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Select white oaks

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Eastern hemlock

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Jack pine

Change in Sawtimber Volume, 1996-2009 (%)

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Figure 77.—Volume of sawtimber on timberland by major species group and

inventory year, Wisconsin. Error bars show the 68 percent confidence interval.

Figure 78.—Change in sawtimber volume on timberland by species group and

inventory year, Wisconsin.

Figure 79.—Components of change for sawtimber on timberland by inventory

year, Wisconsin.

54

FOREST ECONOMICS

Sawtimber Quality

Background

JustasthesawtimbervolumeisanimportantindicatoroftheeconomicvalueofWisconsin’sforests,itisalsoimportanttounderstandthequalityofthatsawtimber.Thequalityofsawtimberdirectlyimpactstheeconomicbenefitsofsawtimberandveneersalesandalsosupportswood-usingsecondaryindustriessuchasfurnitureandmillworkmanufacturing.Boththequalityandquantityofsawtimberneedstobemeasuredtoaccuratelygaugeitseconomicvalue.

What we found

Sawtimberqualityisclassifiedbygrades1to3;1representsthehighestqualityand3thelowest.Overall,allgradesofsawtimberincreasedinvolumebetween1983and1996.Grade1increasedby7percentbetween2004and2009andgrade2hasremainedfairlyconstantasapercentageoftotalsawtimbersince1996(Fig.80).

What this means

Thereareever-increasingglobaldemandsforwoodproducts,continueddevelopmentpressures,andthreatsfrominvasivepests.DevelopingwellinformedpolicyandmanagementdecisionsthatsustainhighqualityforestresourcesinWisconsinrequirecontinuedmonitoringofsawtimberquantityandquality.

Timber Products

Background

Wisconsin’swoodproductsandprocessingindustryissignificanttotheState’seconomyandisakeycomponentofsustainableforestmanagement.Theharvestingandprocessingoftimberproductsproducesastreamofincomesharedbytimberowner,managers,marketers,loggers,truckers,andprocessors.Theprimaryandsecondarywood-usingindustriesencompasssectorsincluding,butnotlimitedto,sawmills,pulpmills,veneerandplywoodmanufacturers,andflooring,millwork,andfurnitureproducers.Theindustryprovidesemploymentfornearly61,000workersintheStateandgeneratesavalueofshipmentsworth$17.9billion(WDNR2010).TobettermanagetheState’sforests,itisimportanttoknowthespecies,amounts,andlocationsoftimberbeingharvested.

Below grade Grade 3 Grade 2 Grade 1

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1983 1996 2004 2009

Saw

timbe

r Vol

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by G

rade

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berla

nd (%

)

Inventory Year

Figure 80.—Distribution of sawtimber volume on timberland by grade and

inventory year, Wisconsin.

55

FOREST ECONOMICS

What We Found

SurveysofWisconsin’swood-processingmillsareconductedperiodicallytoestimatetheamountofwoodvolumethatisprocessedintoproducts(HaugenandEversoninpreparation2).ThisissupplementedwiththemostrecentsurveysconductedinsurroundingstatesthatprocessedwoodharvestedfromWisconsin.In2008,therewere226activeprimarywoodprocessingmillssurveyedtodeterminethespeciesthatwereprocessedandthesourceofwoodmaterial;thisrepresentsastablemillcountsincethelastinventory(Fig.81).Thesemillsprocessed230.9millionboardfeetofsawlogs,veneerlogs,pulpwood,andotherwoodproducts.

Intheprocessofharvestingindustrialroundwood,106.3millioncubicfeetofharvestresidueswereleftontheground(Fig.84).Eight-fivepercentoftheharvestresiduescamefromnongrowing-stocksourcessuchascrookedorrottentrees,topsandlimbs,anddeadtrees.TheprocessingofindustrialroundwoodintheState’sprimarywood-usingmillsgenerated1.9milliongreentonsofwoodandbarkresidues.Justoverhalfofthemillresiduesgeneratedwereusedforindustrialfuelwoodandaquarterwasusedforfiberforthepulpandparticleboardindustry.OthersecondaryproductsfromWisconsin’sprimarymillresiduesincluderesidentialfuelwood,woodpellets,mulch,andanimalbedding.Only3percentofthemillresidueswereunused(Fig.85).

0

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Pine

Spruce

Fir

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Aspen

Maple

Oak

Basswood

Birch

Ash

Other hardwoods

Industrial Roundwood Harvest (million ft3)

Species Group

706050403020100

Figure 81.—Number of active primary wood-using mills by inventory year,

Wisconsin.

Figure 82.—Allocation of industrial roundwood harvest by product type,

Wisconsin, 2008.

Figure 83.—Allocation of industrial roundwood harvest by species group,

Wisconsin, 2008.

2Manuscript in preparation, Daugen, D.E.; Everson V.A. Wisconsin timber

industry—an assessment of timber product output and use, 2008. To be

published by the Northern Research Station, U.S. Forest Service.

In2008,261.3millioncubicfeetofindustrialroundwoodwasharvestedfromWisconsin’sforestland.Pulpwoodaccountedfor65percentofthetotalindustrialroundwoodharvested,andsawlogsaccountedfor30percent(Fig.82).Otherproductsharvestedwereveneerlogs,excelsior/shavings,post,poles,cooperage,cabinlogs,andindustrialfuelwood.Maple,aspen,andpineaccountedforalmost70percentofthetotalindustrialroundwoodharvestin2008(Fig.83).Otherimportantspeciesgroupsharvestedweretheoak,basswood,birch,andspruce.

56

FOREST ECONOMICS

What This Means

Welldesignedforestharvestsareanessentialpartofmaintainingforesthealth,ecologicalservices,andourState’seconomy.Thepooreconomyhasledtotheidlingandclosureofanincreasednumberofprimarywood-processingfacilities.Animportantconsiderationforthefutureoftheprimarywood-productsindustryisitsabilitytoretainindustrialroundwoodprocessingfacilities.Thelossofprocessingfacilitiesisnotonlyimportantforthenumberofjobsthatarelost,butitmakesitharderforlandownerstofindmarketsforthetimberharvestedfrommanagementactivitiesontheirforestland.

TheclosureofsixofWisconsin’spulpandcompositepanelmillssince2000meansthattherearefeweroptionsforutilizationofthesmaller-diametersectionsoftheharvestedtrees.Nearly15percentoftheharvestresiduegeneratedduringtheharvestisfromgrowingstocksources(woodmaterialthatcouldbeusedtoproduceproducts).Industrialfuelwoodorwoodpelletscouldbepossiblemarketsforthesmallerdiametermaterial,andthus,couldleadtobetterutilizationoftheforestresource.

Fiber products

Industrial fuel

Residential fuelwood

and pellets

Mulch

Other uses

Not used

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100

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Bark Coarse Fine

Mill

Res

idue

s (1

,000

gre

en to

ns)

Type of Residue

Figure 85.—Disposition of mill residue generated by primary wood-using

mills, Wisconsin, 2008.

Softwood used for product

Hardwood used for product

Softwood harvest residue

Hardwood harvest residue

0

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Growing stock Nongrowing stock

Har

vest

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s (m

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Figure 84.—Allocation of industrial harvest removals by tree class and use,

Wisconsin, 2008.

5757

Data Sources and Techniques

Eastern white pine. Photo by Linda Haugen, U.S. Forest Service.

58

DATA SOURCES AND TECHNIQUES

Forest InventoryInformationontheconditionandstatusofforestsinWisconsinwasobtainedfromtheNorthernResearchStation’sForestInventoryandAnalysis(NRS-FIA)program.PreviousinventoriesoftheState’sforestresourceswerecompletedin1936,1956,1968,1983,1996,and2004(CunninghamandMoser1938;Cunninghametal.1939;Kotaretal.1999;Perryetal.2007;Schmidt1998;SpencerandThorne1972;Spenceretal.1988;StoneandThorne1961).

TabulardatacanbegeneratedattheForestInventoryandAnalysisDataCenterWebpageathttp://www.fiatools.fs.fed.us/.Additionaldetailscanbefoundin“Wisconsin’sForests2009:Statistics,Methods,andQualityAssurance,”ontheDVDintheinsidebackcoverpocketofthisbulletin.

ForadditionalinformationaboutFIA,contact:ProgramManager,ForestInventoryandAnalysis,NorthernResearchStation,1992FolwellAvenue,St.Paul,MN55108orStateForester,WisconsinDepartmentofNaturalResources,DivisionofForestry,P.O.Box7921,Madison,WI53707-7921.

National Woodland Owner Survey

InformationaboutfamilyforestownersiscollectedthroughtheU.S.ForestService’sNationalWoodlandOwnerSurvey(NWOS).TheNWOSisdesignedtoincreaseourunderstandingofowners’attitudes,behaviors,andrelatedcharacteristics(Butleretal.2005).IndividualsandprivategroupsidentifiedasforestownersbyFIAareinvitedtoparticipateintheNWOS.Datapresentedherearebasedonsurveyresponsescollectedbetween2002and2006from1,525randomlyselectedfamiliesandindividualswhoownforestlandinWisconsin.ForadditionalinformationabouttheNWOS,visit:http://www.fia.fs.fed.us/nwos.

Timber Products Output Inventory

InformationontheharvestanduseofforestproductsiscollectedunderacooperativeeffortoftheDivisionofForestryoftheWisconsinDepartmentofNaturalResources(WIDNR)andtheNorthernResearchStation(NRS).UsingaquestionnairedesignedtodeterminethesizeandcompositionofWisconsin’sforestproductsindustry,itsuseofroundwood(roundsectionscutfromtrees),anditsgenerationanddispositionofwoodresidues,WisconsinDivisionofForestrypersonnelvisitedall“known”primarywood-usingmillswithintheState.CompletedquestionnairesweresenttoNRSforprocessingandanalysis.Thelastcompletesurveywascollectedin2008(HaugenandEversoninpreparation2).Aspartofthisinventory,allindustrialroundwoodvolumesreportedonthequestionnaireswereconvertedtostandardunitsofmeasureusingregionalconversionfactors.TimberremovalsbysourceofmaterialandharvestresiduesgeneratedduringloggingwereestimatedfromstandardproductvolumesusingfactorsdevelopedfromloggingutilizationstudiespreviouslyconductedbyNRS.

Mapping Procedures

Mapsinthisreportwereconstructedusing(1)categoricalcoloringofWisconsin’scountiesaccordingtoforestattributes(suchasforestlandarea);(2)avariationofthek-nearest-neighbor(kNN)techniquetoapplyinformationfromforestinventoryplotstoremotelysensedMODISimagery(250-mpixelsize)basedonthespectralcharacterizationofpixelsandadditionalgeospatialinformation(Wilsonetal.2012);or(3)coloreddotstorepresentplotattributesatapproximateplotlocations.GeographicbasedatawasprovidedbytheNationalAtlasoftheUnitedStates(U.S.GeologicalSurvey2012).Anyadditionaldatasourcesarereportedwiththerelevantmaps.

59

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Perry, Charles H.; Everson, Vern A.; Butler, Brett J.; Crocker, Susan J.; Dahir, Sally E.;

Diss-Torrance, Andrea L.; Domke, Grant M; Gormanson, Dale D.; Herrick, Sarah K.;

Hubbard, Steven S.; Mace, Terry R.; Miles, Patrick D.; Nelson, Mark D.; Rodeout, Richard B.;

Saunders, Luke T.; Stueve, Kirk M.; Wilson, Barry T.; Woodall, Christopher W. 2012.

Wisconsin’s Forests 2009. Resour. Bull. NRS-67. Newtown Square, PA: U.S. Department

of Agriculture, Forest Service, Northern Research Station. 62 p. [Includes DVD].

The second full annual inventory of Wisconsin’s forests reports more than 16.7 million acres

of forest land with an average volume of more than 1,400 cubic feet per acre. Forest land

is dominated by the oak/hickory forest-type group, which occupies slightly more than one

quarter of the total forest land area; the maple/beech/birch forest-type group occupies an

additional 23 percent. Forty-two percent of forest land consists of large diameter stands,

23 percent contains medium diameter stands, and 8 percent contains small diameter

stands. The volume of growing stock on timberland has been rising since the 1980s and

currently totals more than 21.1 billion cubic feet. The average annual net growth of growing

stock on forest land from 2005 to 2009 is approximately 572 million cubic feet per year. This

report includes additional information on forest attributes, land use change, carbon, timber

products, forest health, and statistics and quality assurance of data collection.

KEY WORDS: inventory, forest statistics, forest land, volume, biomass, carbon, growth,

removals, mortality, and forest health

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital or family status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326-W, Whitten Building, 14th and Independence Avenue, SW, Washington, DC 20250-9410, or call (202) 720-5964 (voice or TDD). USDA is an equal opportunity provider and employer.

DVD Contents

Wisconsin’s Forests 2009 (PDF)

Wisconsin’s Forests: Statistics, Methods, and Quality Assurance (PDF)

Wisconsin Inventory Database (CSV file folder)

Wisconsin Inventory Database (Access file)

Field guides that describe inventory procedures (PDF)

Database User Guides (PDF)

Wisconsin’s Forests 2009Statistics, Methods,

and Quality Assurance

United States Department of Agriculture

Forest Service

Resource Bulletin NRS-67

http://www.nrs.fs.fed.us