Fore

stry & Natural Resources

PURDUE UNIVERSITY

FNR-182

Purdue University Cooperative Extension Service • West Lafayette, Indiana

Purdue University - Forestry and Natural Resources

Part 3. Keeping the Forest Healthy

and Productive Ron Rathfon, Department of Forestry and Natural Resources, Purdue University

Lenny Farlee, Indiana Department of Natural Resources, Division of Forestry

A Landowner’s Guide to

Sustainable Forestryin Indiana

A remarkable variety of forests grow in Indiana. Over100 different native species of trees intermingle invarious combinations. They flourish in swamps, anchorsand dunes, cling precariously to limestone precipices,bind riverbanks against ravaging spring floods, and sinktap roots deep into rich, fertile loam.

Trees, like all other green plants, require sunlight, heat,water, nutrients, and space to thrive. Environmentdetermines the availability of essential requirements.Foresters refer to this availability as site productivity.Heredity determines the individual tree’s ability to use itsenvironment as it competes for survival.

Sustainable forestmanagement requires anunderstanding of siteproductivity and heredi-tary factors that affectforest growth and devel-opment, as well as factorslike climate, soil, topogra-phy or lay of the land, andhow fungi, plants, andanimals interact and helpor harm each other.Sustainable forestmanagement also requiresknowledge of eachspecies’ unique needs andadaptations, how a forestchanges over time, andhow it responds whendisturbed by fire, insect

outbreak, tornado, or timber harvesting.

Basing forest management decisions on this knowledgeand working with nature results in healthy forests,

Environmental Factors Affecting

Forest Growth and Development

• Climate

• Soil

• Topography or lay of the land

• Fungi, plant & animal interactions

• Disturbances

Forests growing on shallow, rocky soils on south-facingslopes, such as this post oak glade in Perry County,indicate a dry site.

Deep soils and ample soilmoisture on this northeast-facing, upland site promotethe growth of a lushunderstory shrub layer andfast-growing, well-formedtrees.

Only uniquely adapted tree species thrive in the frequentlyflooded environment along our large rivers and associatedwetland environments like this oxbow on the Patoka River.

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factors are within partial control of the forest managerand owner, such as protecting and building the soil,favoring selected species of vegetation, and controllinglivestock and deer.

SoilSoil is the product of millennia of soil-building

processes. This life-sustaining substance has beenabused, squandered, degraded, and lost during recenthistory. Though we cannot speed the chemical andphysical weathering of rocks and minerals to build newsoil, sustainable forest management protects that whichwe have. Most importantly, forests build soil.

When forest soils are trafficked with heavy equipmentsuch as tractors or log skidders or by large animals suchas cows or horses, compaction occurs. Regardless of themethods used, the harvest and removal of timber disturbsand compacts soil. Sustainable forestry practices limitsoil erosion and compaction. Part 5 of the Sustainable

Forestry series, entitled Forests and Water (FNR-184),provides more information on preventing erosion.

A well-planned logging job, choice of logging equip-ment, and logger skill and initiative can limit the amountof soil compaction. Your forester, working with thelogger, helps minimize soil damage. Purdue CooperativeExtension Publication FNR-101, Timber Harvesting and

thriving populations of wildlife, a diverse flora, and moreproductive soils. You and your heirs also benefit fromincreased long-term income from timber or other forestproducts and continued personal enjoyment. Decisionsmade in ignorance of natural laws result in diminishedproductivity and profits, at best; or, at worst, ecologicalcatastrophe from which it takes many decades to recover.

Principles of sustainable forest management forkeeping the forest healthy and productive include:

• Maintaining and enhancing site productivity;• Improving tree growth, health and timber quality; and• Appropriately regenerating the forest.

The remainder of this chapter is devoted to explainingthese principles.

Maintaining and Enhancing

Site ProductivitySome environmental factors affecting site productivity

are not easily altered or improved. Climate and topogra-phy are examples. Sustainable forest management isconfined by the limits these factors impose. Other

A mature tree is the product ofits heredity and environment.The embryo curled and foldedinside a tulip poplar seedcontains the potential to grow into a majestic, stately giant,150 feet tall and 5 feet in diameter. This potential can onlybe achieved if the tree’s environment is favorable . . . andwith a little luck.

Tulip tree seed

A well-planned logging joblocates log yarding areasand skid trails prior to thestart of logging to reducedamage to the soil, water,and timber.

Logging Practices for Private Woodlands, provides moreinformation on sustainable logging practices.

There are many reasons for fencing livestock out of theforest. One is to protect the soil from compaction anderosion. Livestock trampling also damages the finefeeder roots of trees that are close to the soil surface.These roots supply the tree with the majority of required

Mature tulip poplar

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Checklist

Maintain & Enhance Site Productivity

✔ Prevent soil erosion

✔ Reduce soil compaction

✔ Fence out livestock

✔ Maintain the leaf layer on forest floor

✔ Allow logging slash and other dead wood to decompose

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No need to fret over an occasionaldead or dieing tree; nature will putit to good use as with this wildlifeapartment house.

nutrients. Damage to roots and bark weakens the tree andleaves it vulnerable to insects, disease, and decay.

Dead WoodDead wood from limb fall, natural death of trees, and

from logging or other forest management activitiescontributes to soil building in the forest. Although not ashigh in plant nutrients as leaf matter, it provides a richsource of carbon for building up soil organic matter.Such organic matter has the ability to absorb and holdlarge quantities of water and nutrients for later uptake bytree roots. It forms miniature dams on the soil surface toslow surface water runoff and trap sediment. Deadwood, in the form of standing dead trees, called snags,and fallen logs, also provide wildlife habitat. See PurdueCooperative Extension Publication FNR-102, Woodland

owners regard this slashas unsightly and want itremoved. Convenientlylocated tops can be cutfor firewood, but theremainder should be leftin place to build soil andprovide wildlife habitat.Part 6 of the Sustainable

Forestry series, entitledMaintaining the Aes-

thetic Beauty and

Enhancing the Recre-

ational and Cultural

Values of Your Forest

(FNR-185), discusseslogging aesthetics.

Between timberharvests, an occasionaltree dies or blows over. If the dead trees are of suchspecies and quality to make them very valuable, it maybe worthwhile to salvage them. Otherwise, you need notfret over an occasional dead tree. Nature does not allowanything to go to waste.

Improving Tree Growth,

Health, and Timber QualityForest researchers and the lumber industry have

documented the decline in timber quality over the lastcentury as the last of the old growth hardwood timber hasbeen cut. Today, nearly 100% of the timber harvested inIndiana is second growth; i.e., timber that grew upfollowing previous logging. This second growth timberis generally of lower wood quality than previous genera-tions of timber, largely because we don’t let it grow 150to 200 years before harvesting it. The average harvestingage in Indiana is closer to 70 to 90 years old. Because

Wildlife Management for more information on how deadwood benefits wildlife.

When timber is logged, the tops of the trees are usuallyleft lying in the forest — they simply are not useable bymost sawmills or veneer mills. Tree tops and otherlogging debris are referred to as slash. Some forest

Most of Indiana’s old growth timber, like this large logbeing brought to a mill in Jasper, has been cut (ca. 1900).Virtually all timber cut today is second growth.

Fencing livestock out of the forest prevents soil erosion andcompaction and damage to tree roots and bark.

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Tree tops left after logging is complete may affront oursensibilities, but they contribute nutrients to the soil andprovide habitat for wildlife.

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trees are harvested at a younger age, they have less clear,knot-free, defect-free wood.

The wood manufacturing industry has adapted to thedecline in timber size and quality. New technologiesenable mills to cut more quality lumber from today’slower grade logs and to utilize low quality lumber in newways. Nonetheless, premiums are still paid for timber ofexceptional quality. Where site quality is high enough(i.e., good soils and adequate moisture), sustainablymanaged forests grow high quality timber. With a littleloving attention, your forest will grow greater quantitiesof valuable, high quality timber.

Improvement HarvestDue to a long history of neglect, mismanagement, and

abuse, many Indiana forests need some rehabilitationwork to bring them into a productive, healthy condition.In forests that contain trees of harvestable size, the firstpractice often applied is a timber harvest called animprovement harvest. Trees that are declining in healthor are damaged, diseased, or of poor quality are harvestedto make room for more vigorous trees of better quality,

species, or value. Theremaining crop trees arethen allowed to grow tomaturity before beingharvested.

Harvesting timber,when done according tosound forest manage-ment principles, canimprove the health andproductivity of theforest. Care must betaken during logging toprotect the remainingtrees from damage caused by falling trees and heavyequipment. Well-trained, conscientious loggers and agood timber sale contract minimize such damage.Employing the services of a professional forester canhelp ensure a good logging job. You may request that

It requires great skill to remove long logs from the forestwith large skidding equipment without doing a lot ofdamage to the remaining trees. Such damage to a tree’sbark allows wood boring insects and decay fungi to attackand destroy the interior wood and weaken the tree.

only loggers who have completed logger training coursesbe permitted to work in your forest.

Timber Stand ImprovementA practice called Timber Stand Improvement (TSI)

may need to be applied in forests not yet ready for aharvest. TSI is a broad term encompassing a variety ofpractices designed to favor the growth of those trees thatwill best meet your management objectives and promotethe long term health and productivity of the forest. Somepractices included under TSI include grape vine control,pruning, thinning, crop tree release, and cull tree killingor removal.

Checklist

Improving Tree Growth, Health, and

Timber Quality At Timber Harvest

(Improvement Harvest):✔ Allow crop trees to grow to maturity.✔ Thin to proper stocking (number of trees

per acre).✔ Remove dying, diseased, decaying, and poor

quality trees.✔ Protect trees from logging damage.✔ Use low-impact logging methods where feasible.

Between Timber Harvests

(Timber Stand Improvement):

✔ Control grape vines.✔ Release crop trees from competition.✔ Thin dense areas.✔ Kill cull trees.✔ Prune selected crop trees to produce more clear

lumber.

Anytime:

✔ Promote tree species diversity.✔ Monitor your forest for insect and disease

outbreaks.✔ Cooperate with government agencies in

controlling forest insect and disease outbreaks.✔ Prevent wild fire.

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Grape vine control is one of the simplest and mostproductive practices to improve growth and quality oftrees. Left uncontrolled, grape vines grow over the topsof trees, shading them out, deforming them and evenbreaking their crowns. Vines should be cut at least twoto three years prior to a timber harvest. This eliminatesthe need to spray herbicide on the vine stumps. If vinesare cut immediately prior to or following the harvest of

trees. Crop trees are those that help you meet yourmanagement objectives. Crop trees are selected basedon desirable traits such as species, trunk straightness, fastgrowth, wildlife food value, or resistance to insects anddisease.

By no means should all defective, undesirable trees beremoved in TSI. Only those whose removal will help usaccomplish our management objectives to improve thehealth and productivity of crop trees and new tree growthshould be killed or cut. A professional forester can helpyou in planning how best to treat your forest to make ithealthy and vigorous.

Pruning may be done to maintain a straight trunk andto remove lower branches. Pruning is as much art asscience, so professional advice is an important part ofmaking decisions on what and how to prune. PurdueCooperative Extension Publication FNR-76, Corrective

Pruning of Black Walnut for Timber Form, providesmore information on pruning.

Species MixIn Indiana, sustainable forest management should

favor managing our forests for a mixture of species,encouraging those best adapted to a given site. This isthe natural pattern. Monocultures, forests composedprimarily of one tree species, are at higher risk forcatastrophic insect and disease outbreaks. They lack thecomplexity and structure needed to achieve a diversehabitat, capable of supporting a large variety of plant andanimal life.

Insects and DiseaseHistorically, major insect and disease outbreaks occur

infrequently in Indiana and rarely cause widespreadforest destruction. Dutch elm disease and chestnut blightare exceptions. These diseases eliminated or reducedAmerican chestnut and American elm in the forestlandscape. An occasional outbreak of defoliating insects,like forest tent caterpillars, or loopers, may causelocalized death, with individual forest landownerssuffering economic loss. This is rare, however. Chronicdiseases, such as ash yellows, and drought contribute tothe gradual decline and death of individual trees andsmall groups of trees.

(Left) Though usually not a threat to people, out-of-controlgrapevines wreak havoc on trees. (Right) Cutting grapevines may be the most beneficial thing you can do topromote the growth of quality timber, and it can be donewithout special training and equipment.

(Left) This woods in northern Indiana was poorly managedin the past. Timber stand improvement will help bring itback into full productivity. (Right) A well-managed forestgrows high-quality timber.

timber, an herbicide should be used. Otherwise, vinestumps and roots resprout vigorously.

Although damaging to trees, grape vines are animportant source of food and cover for birds. It may bedesirable to leave some vines on the edge of the forestand in some low quality trees in order to accommodatewildlife needs.

Thinning dense areas and killing cull trees (trees withno useable wood volume or commercial value) improvesthe health and increases the rate of growth of the crop

TSI $

Timber stand improvement (TSI)

improves timber growth and quality and

provides a favorable return on your

investment.

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Gypsy moth, a native of Europe, was brought toMassachusetts in 1869. It spread westward, defoliatingvast areas of forest throughout the northeast, into theupper southeast and across Ohio and Michigan. It has avaried palate but prefers oak foliage. Gypsy moth hasreduced the predominance of oaks in many northeasternU.S. forests, opening up the forest to other tree species.Red maple has replaced oak as the dominant species insome areas of the northeastern states.

The Indiana Department of Natural Resources,Division of Forestry, and Division of Entomology andPlant Pathology, in cooperation with other state andfederal agencies and Purdue University, aggressivelymonitor and attack gypsy moth introductions to Indiana.In spite of efforts to slow the spread of gypsy moth, most

forestry officials agree that it will spread to all parts ofthe state and become a permanent resident of our forests.

A healthy, vigorous, species-diverse forest is the bestdefense against this destructive invader and most otherinsects and diseases. You can cooperate with gypsymoth control efforts by allowing officials to locatemonitoring traps on your property, learning what gypsymoth caterpillars and other signs and symptoms of themoth look like, and reporting when you observe it. If anoutbreak occurs in your forest, cooperate with officials incombating it.

FireFire can be a friend or foe of Indiana’s forests. Wild

fire damages and kills standing trees. Damaged barkallows insects and decay fungi to enter and destroy atree’s interior wood. Controlled burning, however, is auseful tool in certain circumstances. Part 4 of theSustainable Forestry series, entitled Conserving Nature

(FNR-183), discusses fire as a forest management tool.

You can protect the health and quality of timber bypreventing wild fire, providing fire access trails for firefighters, and observing guidelines issued by publicofficials during periods of high fire danger.

Regenerating the ForestRegenerating a forest refers to its renewal with new,

young trees. Foresters use the term “regeneration”interchangeably to refer to new trees, seedlings, andyoung sprouts, or to the management activity thatpromotes the growth and development of those newtrees. Ironically, the regeneration of a forest necessarilyinvolves the death or cutting of larger, mature trees.

A bacterium called Bt (Bacillus thuringiensis) is

one of the materials available to control gypsy

moths. It targets moth larvae and is considered

environmentally safe. Organic farmers use Bt as

an alternative to chemical pesticides.

Checklist

Regenerate the Forest

✔ Plan timber harvesting with natural regenerationin mind.

✔ Encourage tree species best adapted to the site.

✔ Plant trees in native forest under the guidance of aforester.

✔ Release regeneration from overhead competitionfollowing a timber harvest.

✔ With the help of a forester, choose an appropriatetimber harvesting method to obtain the desiredregeneration and to meet other objectives.

✔ Protect regeneration from deer.

✔ Avoid high grading and diameter-limit cutting.

✔ Consult with a forester before selling timber.

For more information on gypsy moth in Indiana contact:

Indiana Department of Natural Resources,

Division of Entomology & Plant Pathology

402 W. Washington Street, Rm. W-290Indianapolis, IN 46204-2649(317) 232-4120www.state.in.us/dnr/entomolo

Purdue Cooperative Extension Service publishes a seriesof extension publications and maintains a Web site on thegypsy moth. For more information contact:

Purdue University,

Department of Entomology

West Lafayette, IN 47907-11581-888-EXT-INFOwww.entm.purdue.edu/Entomology/ext/Moth

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Nature accomplishes the regeneration of a forestthrough wind, ice, tornado, insect, disease, fire, ornatural death. Sustainable forestry mimics naturaldisturbance, with foresters using professional judgmentand experience based on scientific research rather thannature’s randomness. Foresters carefully plan and selectthe right trees to remove in a timber harvest to stimulatedesirable regeneration, as well as achieve other manage-ment goals.

Encourage Best-Adapted SpeciesEncouraging the species that are best adapted to a site

is the primary consideration when regenerating a forest.Forests should be regenerated to maintain speciesdiversity. Rarely should native forest be converted to amonoculture or a single species forest. Within theseparameters, you can choose species that help you fulfillyour objectives; e.g., valuable timber species, wildlifefood and cover, aesthetic appeal, or enhancing speciesdiversity.

Planting Trees or Natural

Regeneration?Many people think new trees must be planted follow-

ing timber cutting. In fact, the overwhelming majority ofIndiana’s forests regenerate naturally. They grow fromseeds that drop to the ground or are buried by squirrels,that blow on the wind or that float on river currents toeventually land on suitable soil, germinate, and competefor their place in the forest. Some trees originate assprouts growing on the stump of a cut or fire-killed tree.There are no laws in Indiana requiring trees to be plantedin the wake of logging.

Regenerating a forest is its renewal with new, young trees.

“Return of the Native”American Chestnut on the Verge

of a Comeback.

The American chestnutwas at one time one of themost common tree speciesof the Eastern UnitedStates. They were highlyprized for their rot-resistant, attractive, easily-machined lumber and, ofcourse, for their deliciousnuts.

Chestnut blight was firstdiscovered in this country,in New York City, in 1904.The blight, a fungus that isnative to Asia, formscankers on the trunk of the tree, ultimately girdling itand killing its top. Roots of infected trees persist andsend up new shoots. These shoots are also killed backonce they reach between 10 to 30 years of age. Rarelydoes an infected American chestnut attain a seed-bearing age or size.

By 1950, virtually all of this once-numerous andvaluable tree species were reduced to shrubby sproutswith no future but virtual extinction from its nativerange. Plant pathologists and tree breeders spent manyyears trying to develop an American chestnut withblight resistance. Chinese chestnut, which has naturalresistance to the blight, was crossbred with Americanchestnut. The trick was to get a tree that was close to99% American chestnut and 1% Chinese chestnut, the1% being its resistance to the blight.

After many decades of breeding, collecting seed,waiting for promising crosses to grow big enough totest for blight resistance and produce seed, and con-tinuing to breed, researchers are getting closer to ablight-resistant American chestnut. It is now conceiv-able that blight-resistant American chestnut will beplanted in Indiana forests by 2040,thus fulfilling the long awaited“return of the native.”

For more information contact:

The American Chestnut Foundation469 Main Street, P.O. Box 4044Bennington, VT 05201-4044www.chestnut.acf.org

American Chestnut Foundation

There are no laws requiring tree planting

following logging. Indiana’s hardwood

forests regenerate naturally.

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Natural regeneration is almost always preferred overhuman-planted trees in a native forest. Occasionallyyour plans might call for “enrichment plantings” orplanting much-desired species of trees or shrubs toaugment natural regeneration. This can be done toensure that a particular species maintains its representa-tion in the forest. Tree planting in native forests can alsobe done to increase species diversity, so long as thespecies being introduced are adapted to the site and arenative in the area. It can be used to reintroduce a speciesthat once grew in the area, but, through disease or overcutting, has since disappeared. Tree planting can also bea means to improve and diversify the gene pool of theforest. Trees grown from parents possessing desirabletraits, such as faster growth, good form, or diseaseresistance can be introduced into forests that have beendegraded over the years through poor logging practices.

Consult a forester before attempting to plant trees in anative forest. Without proper care, natural vegetationwill quickly out-grow all the planted trees, resulting in atotal loss and a waste of your time, sweat, and money.Although tree planting is not frequently encouraged innative forests, foresters and other conservationistsenthusiastically promote it on cleared land. PurdueCooperative Extension Publication FNR-36, Tree

Planting in Indiana, provides more information.

Release RegenerationTimber stand improvement should be done immedi-

ately following a timber harvest. Undesirable, poorlyformed, low vigor, defective trees that are competingwith crop trees should be cut or killed. Regenerationopenings where groups of trees have been harvestedshould have remaining trees cut or killed to complete theopening and allow full sunlight to reach the regeneration.In these openings, trees of desirable species, but perhapsless desirable form (crooked, twisted, stunted, etc.), canbe cut close to the ground. This usually stimulates

Deer and Trees

Whether planted ornatural, new tree seedlingsmay need protection.Insects, disease, and fireare possible threats.Perhaps the biggest threatto new forests, however, isbrowsing deer. Sincetheir re-introduction toIndiana in 1934, deerpopulations have steadilyincreased to current peaklevels. Excessively large deer herds devastate newtree plantings and recently regenerated forests. Theyalso contribute to declines in other native plantspecies, including shrubs and ground flora. This, inturn, impacts the food, nesting, and cover of manyspecies of wildlife. Imbalances in deer populations

contribute to declines in rare andendangered plants and animals.

Many methods for protectingnewly planted trees from deerdamage have been devised; e.g.,fencing, a wide variety of concoc-tions for making the trees smell ortaste repulsive, metal rods, paperor fabric bud caps, protective

plastic netting, and plastic tree tube shelters. Somemethods have research to support them, while effec-tiveness information for others is anecdotal. The mostcost-effective means of protecting young trees frombrowsing deer is to control the size of the herd throughhunting. Where deer damage may be a problem,encourage deer hunting. Depredation permits may beobtained to shoot additional deer above the legal baglimit. The Indiana Department of Natural Resources,Division of Fish and Wildlife issues depredationpermits. Deer play an important role in the sustainablymanaged forest. Like most things, having “too muchof a good thing” can actually be counterproductive.

sprouting from the cut stump. These sprouts generallymake good regeneration. This is an especially effectiveway to regenerate oak. Grape vines should be controlledtwo to three years prior to the harvest to protect youngregeneration.

Regeneration MethodsRegeneration methods include clearcutting,

shelterwood, and seed tree cuts, which produce a newforest of trees of all the same or nearly the same age.

Stump sprouts are often an important partof forest regeneration.

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Single-tree selection and group selection methodsresult in a forest of many different aged trees.

Clearcutting removes all trees within a given area,usually five acres or more in size. Shelterwood and seedtree cuts prescribe one or two initial cuts to give moregrowing space to desired seed trees to expand theircrowns and increase seed production. When desiredregeneration has established itself, the remaining over-story trees are harvested. Single-tree selection involvesjudiciously selecting individual trees to cut. Groupselection harvests groups of trees to create small open-ings in the forest ranging in size from one-half acre tofive acres.

Foresters in Indiana most frequently use the combina-tion of single-tree selection and group selection whenmarking a timber harvest. There are a variety of reasonsfor this: most Indiana forest landowners own relativelysmall forests (under 100 acres) and don’t want to see theentire forest or large sections of their forest clearcut;foresters want to avoid the negative publicity associatedwith clearcutting; and foresters and landowners prefer

not cutting smaller trees prior to their reaching fullmaturity. Immature trees of desirable species and qualityare “money in the bank,” often accruing value at a veryhandsome rate-of-return (See Purdue CooperativeExtension Publication FNR 138, Tips on How to Get the

Most From Your Timber Harvest.)

Some of these methods, particularly clearcutting,receive harsh criticism for their perceived “destruction”of the forest. When appropriately employed, any ofthese methods are sustainable. It is a matter of choosingthe best method to meet your objectives.

Non-Sustainable Harvesting

Practices to AvoidAll too often, maximizing the immediate financial gain

of the landowner or timber buyer is the sole criterion fordeciding which trees to harvest. This is done at theexpense of long-term productivity and income potential.Many forests in Indiana are degraded through high

grading or diameter-limit cutting. High grading refersto timber harvesting where only high-value trees are cut,

There are five generally recognized methods of regenerating the forest, each with a number of variations. A) Clearcuttingremoves all trees within an area five acres or more in size. B) A seed tree cut removes all but a few scattered trees to providedesired seed for regeneration. C) A shelterwood cut leaves between 50% and 60% of the trees as a source of desirable seed.It also provides partial shade, which favors the establishment of certain species of regeneration, like the oaks. Once desiredregeneration is well established, the shelterwood trees are harvested. D) Single-tree selection harvests carefully selectindividual trees that are widely scattered throughout the forest. E) Group selection removes groups of trees, resulting insmall openings in the forest that range in size from one-half acre to five acres.

Single-tree selection Group selection

Shelterwood cut

Clearcutting Seed tree cut

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leaving poor quality, low vigor or decadent trees of lessdesirable species. All too many Indiana forests have theoak, tulip poplar, walnut, and cherry logged out, leavingslow growing, stunted hickory and maple, hollow beech,and crooked elm. All these species have their rightfulplace in a sustainably managed forest. However, if theyare the only species left, or if most remaining trees are inpoor health or form, the forest has been degraded.

Diameter-limit cutting refers to the practice of cuttingall trees above a certain diameter. This method requireslittle forest management knowledge or skill. Forestersneed the flexibility to mark for harvest some small,defective, and poor vigor trees, and to leave some large,healthy trees in the forest, in order to maintain and evenimprove the health and productivity of the forest. Manydiameter-limit cuts result in a forest consisting of treesthat were formerly overtopped, stunted, and slowgrowing. Because of poor vigor, many never increasetheir growth rate in response to the additional sunlight,water, nutrients, and space suddenly available. Some areso distorted after decades of unsuccessfully trying togrow toward some little opening of light that they nevercan straighten out. Other trees have significant decayand continue to decline in health and value.

Unfortunately, the damage caused by high grading anddiameter-limit cutting to long-term forest health andproductivity extends beyond the poor, rag-tag trees left.These remaining trees still occupy space and cast shadeon the forest floor. This inhibits the growth of new treesthat have a much better chance of growing into valuabletimber trees and wildlife food producers. In addition, thepoor-vigor trees left are most likely of poorer geneticquality. Thus, the seed source and the resulting regenera-tion is degraded genetic stock. High grading and

diameter-limit cutting methods have no place in

sustainably managed forests.

Ironically, the best management practice for foreststhat have been severely high-graded or subjected to adiameter-limit cut may be a clearcut. This allows theforest to start over again without the young trees havingto compete with the “junk” residue left from the previouscut. If you have a high-graded forest, ask a forester howyou can restore it to greater health and productivity.

The best protection against high grading and diameter-limit cutting is learning how to properly market timbermarked for sale using sustainability guidelines. Aforester can help ensure the right trees are harvested inorder to regenerate the forest and meet your otherobjectives. Additionally, a forester can provide timber

Foresters need the flexibility to mark for harvestsome small, defective, poor vigor trees, and toleave some large, healthy trees in the forest.

Diameter limit cutting often results in a forest of stunted,slow growing, low vigor, poorly formed trees.

What Do Hogs and Trees Have

in Common?High-grading and diameter-limit cutting are

analogous to the hog farmer who sells off hisfastest growing, most robust pigs and saves thesickly runts to breed. You don’t need to be afarmer to understand how herd, profits, and hogfarm might plunge into failure and bankruptcy.Likewise, high grading and diameter-limit cuttingthreaten to “bankrupt” Indiana’s forests.

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marketing assistance to help you get a fair price andensure your forest is logged in a manner that protects itslong-term health and productivity. Purdue CooperativeExtension Publication FNR-111, Marketing Timber,provides more information on how to go about sellingtimber.

Additional InformationBeattie, M., C. Thompson, and L. Levine. 1993. Working

with Your Woodland, A Landowner’s Guide. Univer-sity Press of New England, Hanover, New Hampshire.279 p. ISBN 0-87451-622-6

Clark, F.B. and J.G. Hutchinson (eds.). 1989. Central

Hardwood Notes. USDA Forest Service, North CentralExperiment Station.

Fazio, J.R. 1994. The Woodland Steward. The WoodlandPress, Moscow, Idaho. 211 p. ISBN#: 0-9615031-1-4.

Fischer, B.C. 1991. Marketing Timber. Purdue UniversityCooperative Extension Service, FNR-111. 11 p.

Miller, B.K. 1992. Woodland Wildlife Management.Purdue University Cooperative Extension Service,FNR-102. 12 p.

Myers, R.K. and J.R. Seifert. 1993. Tips on How to Get

the Most From Your Timber Harvest. Purdue Univer-sity Cooperative Extension Service, FNR-138. 4 p.

Pope, P.E., B.C. Fischer, and D.L. Cassens. 1980. Timber

Harvesting and Logging Practices for Private Wood-

lands. Purdue University Cooperative ExtensionService, FNR-101. 7 p.

Sadof, C.S., G.R. Jansen, and R.D. Waltz. 2000. The

Gypsy Moth in Indiana. Purdue University Coopera-tive Extension Service, GM-1. 4 p.

Walker, E.P. and M. Leahy. 1998. Forest Improvement

Handbook: Stewardship for Tomorrow. IndianaDepartment of Natural Resources Division of Forestry.8 p.

Rathfon, R. 2002. Planting Forest Trees and Shrubs in

Indiana. Purdue University Cooperative ExtensionService, FNR-36.

12

It is the policy of the Purdue University Cooperative Extension Service, David C. Petritz, Director,that all persons shall have equal opportunity and access to the programs and facilities without regard to race, color, sex, religion, national

origin, age, marital status, parental status, sexual orientation, or disability.Purdue University is an Affirmative Action employer.This material may be available in alternative formats.

1-888-EXT-INFO

http://www.ces.purdue.edu/extmedia/

1/2002

Part 1. Sustainable Forestry - What Does It Mean for

Indiana?—FNR-180

• Sustainable Forestry Described• Historical Perspective• Indiana’s Forests Today• How This Series Is Organized

Part 2. Planning for the Future—FNR-181

• The First Step - Who Can Help You?• Your Objectives• Gathering Information• Planning Your Management Activities• Using Legal Contracts

Part 3. Keeping Your Forest Healthy and Productive

—FNR-182

• Maintaining and Enhancing Site Productivity• Improving Tree Growth and Protecting Timber

Quality• Regenerating the Forest

Part 4. Conserving Nature—FNR-183

• Providing Wildlife Habitat• Unusual Habitats• Endangered Species• Invaders! Harmful Exotic Species• Forest Fire - Not Always as Bad as It Sounds• Fragments of Forests

Part 5. Forests and Water—FNR-184

• Livestock• Reforestation Benefits Water Resources• Avoid Clearing Forest• Forest Roads and Trails• Best Management Practices (BMPs) for Timber

Harvesting• Pesticides• Protecting Sensitive Water Resources

Part 6. Maintaining the Beauty and Enhancing the

Recreational and Cultural Values of Your

Forest—FNR-185

• Maintain Visual Buffers Next to Public Places• Maintain Important Scenic Views• Tips for a Better-Looking Logging Job• Developing the Recreation Potential of Your Forest• Protecting and Enhancing Cultural and Historic

Values

Part 7. Managing for a Diversity of Value-Added

Forest Products—FNR-186

• Forest Herbs• Mushrooms• Nature-based Tourism• Christmas Trees and Greenery• Maple Syrup• Value-added Wood• Do Your Homework!

Part 8. Help!—FNR-187

• Cost Share Grants• Classified Forest and Wildlife Habitat Programs• Leaving a Forest Legacy - Permanent Forest

Protection Through Conservation Easements• Tax Incentives and Estate Planning• Forest Bank• Forest Cooperatives• Carbon Sequestration• Forest Certification• Education and Technical Assistance

A Landowner’s Guide to Sustainable Forestry in Indiana