and new technologies technology - southern...

Chapter 15: Forest Operations Technology 341TIMBER

stems must be selectively removedbased on size, species, and spacing;and the soil litter layer should bedisturbed for seed catch, but notcompacted. These requirementsdefine the technology that is neededto meet management objectives. Forestoperations technology is also shapedby the requirements of forest industry.Product form from the woods mustbe compatible with the handling equip-ment at the receiving mill. Minimumspecifications, such as small-enddiameter, define the way trees arecut to length. Developments in forestproducts transportation, mill processes,and products affect the requirementsof forest operations. Changes in theforest products industry may lead tonew constraints or opportunities forwork in the woods.

Available technology defines thepossibilities of forest managementand forest products by limiting thefeasibility of operations. Generally,forest operations are limited byterrain, piece size, productivity,or costs. Increased effort (longerdistances, handling more pieces,steep slopes, wetter ground) translatesinto greater cost per unit of productionor per acre. The fundamental questionfacing the forest manager is whetherthe prescribed operation is bothtechnically and economically feasible.

The current condition of southernforests, in part, reflects forest operationstechnology of the past. The mosaic ofmanaged and unmanaged forested areasis partially a result of the technical andeconomical limits of previous forestoperations. The network of roads andskidtrails on the forested landscaperesulted in part from limitations on

extraction distance and terrain. Standcomposition of regenerated acresreflects the past site preparation andstand establishment techniques.Similarly, future landscapes of southernforests will be an expression of thecapabilities and limitations of today’stechnology. Understanding the role oftechnology in shaping forest conditionswill help predict the future of thesouthern forest resource.

This chapter documents currentsouthern forest operations anddescribes the interaction among forestoperations technology, managementpractices, and forest condition.

Methods

Descriptive data in this chapterwere generally obtained throughstandard literature review methods.The evaluation of logging workforceproductivity, however, involved someadditional data analysis. County-levelemployment data from the 1990Census were merged with 1995 county-level timber products output data. Totallogging employment was assumed to berelatively constant from 1990 to 1995based on employment data from theAnnual Survey of Manufactures (ASM).Timber product output in thousandcubic feet and logging employmentwere aggregated by ecological section.Annual productivity per logger wascalculated at the ecological sectionlevel. The geographic distributionof logging workers was examinedby combining county-level loggingemployment with total county landarea to arrive at logging workers per100 square miles. Finally, analysis ofvariance was used to examine variation

Key Findings

■ A wide range of technologyis available for forest managementin the South.

■ New technology makes forestoperations more productive,cost-effective, and environ-mentally sensitive.

■ Increases in forest operationsproductivity and the loggingworkforce are being used to meetthe increasing demand for fiberand to reduce unit production costs.

■ Southern forests are generallymanaged under economic constraints.Choices of rotation length, systems,and operations technology arefundamentally determined by thecosts and values of a selectedmanagement regime.

Introduction

Forest operations include regener-ation harvests, thinning, pruning,timber stand improvement, sitepreparation, planting, prescribed fire,vegetation control, and fertilization.The methods, materials, and systemsused to transform the forest are thetechnology of forest operations.

Forest operations are designed tomeet management needs. For example,ecological requirements for naturalregeneration in a particular forest typemay include certain light levels, soilconditions, and seed-source spacing.These ecological requirements translateinto the prescription for the forestoperation. For example, the standmust be opened up to a certain density;

Chapter 15:Forest OperationsTechnology

Bob RummerSouthern Research Station, USDA Forest Service

How might existingand new technologies

influence forestoperations and the

resultant conditionsof forests?

Southern Forest Resource Assessment342

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in aggregate logging productivity as afunction of percent pulpwood andpercent hardwood in the section.

Data Sources

While most of the information for thischapter is derived from conventionalliterature sources, online databases wereutilized to estimate workforceand productivity. The primary sourceof county-level timber product output(TPO) data was the Forest Inventoryand Analysis (FIA) TPO DatabaseRetrieval System (Anonymous 2000).This database contains informationabout roundwood products harvestedin each county for calendar year1996, by species and product class.

There are several sources of loggingemployment data. County-level datawere obtained from civilian labor forcedata of the 1990 decennial census(U.S. Census Bureau 2000b), the mostrecent available sample of self-reportedemployment status. A sample of 1990Census respondents described theirindustry and occupation. Based on thisinformation, people were assigned tostandard occupational and industrycodes. Total logging employment wasassumed to consist of both occupations496 (Timber cutting and logging) and494 (Supervisors, forestry, and logging).State-level logging employment data forthe period 1997 to 1999 were derivedfrom the Covered Employment andWages Program (ES-202) of the Bureauof Labor Statistics (U.S. Departmentof Labor, Bureau of Labor Statistics2000a). The ES-202 data are a 100-percent report for all establishmentscovered by unemployment compen-sation insurance. Older state-levelworkforce data were compiled fromthe ASM (U.S. Census Bureau 2000a).ASM data are collected through a mailsurvey of a sample of establishments.Both the ES-202 and ASM were queriedfor total state-level employment inStandard Industrial Classification (SIC)Code 241, Logging. Some years of theASM data are missing for Kentucky,Tennessee, and Oklahoma.

The 1990 Census provides a snapshotof logging employment at the countylevel. Because it is based on self-reported occupation, it may provide amore accurate measure of workforce inan industry with many small firms andself-employed workers. However, it is

also subject to errors in classification,and some nonloggers are likelyincluded in the 494/496 occupationalcodes. The annual data from theES-202 and ASM surveys providean employment time series, but likelyunderestimate the logging workforcebecause they are based on a samplingof establishments. A comparison ofthe 1990 workforce at the countyand state-level highlights the possibledisparity. The ASM data estimate a totalsouthern (less Kentucky, Tennessee,and Oklahoma) logging workforce of36,000. In comparison, the decennialcensus estimates a total of 44,066.Most States are within severalhundred workers. Texas, Virginia,and Mississippi, however, account for6,000 of the 8,066 difference in work-force estimates. For this report, thedecennial census data were considereda reasonable estimate of workforceand the manufacturer survey datawere used to model trends over time.

Results

Description of ForestOperations Technology

Forest management requires a rangeof tools to implement prescriptionsfrom planting, fertilization, burning,and herbicide application, throughthinning and product extraction.International Standard 6814 (ISO1999) provides common definitionsfor individual machines. In manymanagement activities, however,the individual machines are groupedinto systems. A forest operation systemis more than technology representedin equipment design. A systemincludes the technology of methodsand human work. While the capabil-ities of individual machines are ofinterest, the overall productivity andimpacts of operations are the resultof the cumulative effect of systems.

Technology for site preparation andestablishment—Site preparation andstand establish-ment operations mayrequire seedbed preparation, reductionof competition, alteration of soilmoisture or physical properties, ornutrient amendment.The desired management objectivesare to control stocking, speciescomposition, survival, or growth. Giventhe wide range of sites and objectives

in the South, there are many operationsthat can be employed. Since 1952,a periodic survey of southern forestland managers has been conducted toestimate the prevalence and costs offorest management practices (Duboisand others 2001). Fifty-four percentof the responses to the most recentedition of the “Cost Trend Survey”were from forest industry, 32 percentfrom consultants, and 14 percentfrom public agencies.

Prescribed fire is the least expensiveway to prepare the forest floor forregeneration. It provides some controlof herbaceous competition, exposesmineral soil for seed catch, and reduceslogging debris. Prescribed fire is usedin prescriptions for natural regenerationby the seed-tree, single-tree selection,and shelterwood systems, as well asfor artificial regeneration. Waldrop(1997), for example, describes theuse of manual felling combinedwith fire to regenerate pine-hardwoodstands in the Southern Appalachians.Fire often controls hardwood growthenough to allow pines to becomeestablished. While regeneration isan important use of fire, the “CostTrends Survey” found the mostcommon use of fire (about one-thirdof treated acres) is to reduce hazardousaccumulations of fuels at mid-rotation.

Like prescribed fire, chemicaltreatment is used to control vegetativecompetition for light, moisture, andnutrients. Forestry herbicides canbe applied by stem injection, soilapplication, or foliar spray. Busbyand others (1998) compared herbicidetreatment at stand establishmentwith early release applications andfound that herbicide application atstand establishment had the greatesteconomic returns. Groninger andothers (1998) describe the effectivenessof herbicide injection for precom-mercial thinning of oak stump sprouts.The “Cost Trends Survey” found thatabout one-fourth of the treated acreswere by aerial application at the timeof stand establishment. Another thirdwere chemically treated to achieveearly release or herbaceous weedcontrol. The reported costs of herb-icide treatment were about four timesthose for prescribed fire ($68 versus$18 per acre).

Mechanical site preparation isdesigned to modify soil conditions,clear planting sites, and control


ERRA

competing vegetation. Each typeof operation addresses specific siteconditions. Drum chopping, forexample, knocks down standingmaterial and breaks it into piecesusing large rolling cylinders fitted withblades. In shearing, an angled bladeon the front of a crawler tractor splitsstumps, moves debris, and exposesmineral soil. Raking also uses a specialblade on a crawler tractor to move andpile slash. Surface soil can be disked toreduce vegetative competition. Beddingloosens and moves soil to create raisedplanting areas. Finally, subsoiling orripping fractures heavy or compactedsoils. Site preparation prescriptions maycall for a single type of treatment or acombination of treatments. Accordingto the “Cost Trends Survey,” the mostcommon treatment in the Piedmont is acombination of subsoiling, disking, andbedding accomplished in a single passwith a 3-in-1 plow ($121 per acre).This tool was developed around 1990to reduce site preparation costs. Onthe Coastal Plain, a multipass treatmentcombining shearing, raking, and pilingis the most common mechanicaltreatment, averaging $155 per acre.

About 2 million acres were plantedin the South in 1997 (Moulton 1999).The acreage was nearly evenly splitbetween nonindustrial private forest(NIPF) landowners and forest industry.Direct seeding accounted for only 0.4percent of the total. Nearly 1.3 billionseedlings were produced in southernnurseries, and the average plantingdensity was 618 trees per acre. The“Cost Trend Survey” found that mostplanting (79 percent) was done byhand rather than by machine. Machineplanting is slightly more expensive,averaging $45 per acre compared to$39 per acre for manual work. Machineplanting is also more constrained bysite conditions, such as debris, slope,and soil moisture. Seedling costs varyconsiderably, depending on species,genetics, and product form. Onesource, for example, lists containerizedloblolly pine seedlings for $155 perthousand, while similar seedlings inbare-root form are $46 per thousand.Thus, total costs for planting mayrange from $85 to $200 per acre.

With these significant investments insite preparation, improved seedlings,and planting, fertilization is increasinglycommon in the South. Almost 1.6million acres were treated in 1999

(North Carolina State Forest NutritionCooperative 1999). Some applicationsare at stand establishment to promoteinitial growth, but about two-thirdsof the treated acres are in establishedstands (Jokela and Stearns-Smith1993). The most common fertilizers aredry solid forms of urea (for nitrogen) ordiammonium phosphate (for nitrogenand phosphorus). The “Cost TrendsSurvey” found that nearly all fertilizeris applied by airplane or helicopter.

Technology for stand managementand product recovery—Manyprescriptions call for manipulationof vegetation in established stands:thinning, sanitation removals ofdiseased or infested trees, regenerationcuttings in shelterwood or group-selection systems, and harvest of croptrees. All of these treatments involvesome type of felling and, in most cases,processing and extraction. Stokes andWatson (1996) describe a range ofsystems for plantation thinning, andStokes (1991) outlines systems usedin southern timber harvests. Thesesystems are sometimes defined bythe forest product that is produced(pulpwood or sawlog). These distinc-tions, however, are less definitivetoday as multiproduct harvestingbecomes more common. A moreuseful description may be the levelof mechanization, from animallogging systems to helicopters.

Animal logging was replaced bytractor logging in the 1930s to reducecosts. Yet, 60 years later, animal loggingsystems are still found in the southernforest as specialty operations. Varioussurveys indicate a public perceptionthat animal logging is ecologicallyand visually preferred over moremechanized systems. Toms (1999)described current animal loggingsystems used in Alabama. In all ofthese operations, felling, delimbing,and processing are done with chainsaw.Trees are bucked at the stump to loglengths for primary extraction withanimals. Most crews take two animalsto the woods and work them as singlesrather than as a team. Systems vary inextraction and loading. The traditionalanimal logging crew skids logs to aloading point where a self-loading truck(a side-loader or a big-stick loader) canaccess the material. Some crews use afront-end loader or knuckleboomto increase productivity. A final variantis a hybrid system that combines

animal prebunching with subsequentextraction by a conventional skidderor forwarder.

Production is relatively low withanimal logging systems. Toms (1999)found average weekly productionranged from 2,500 cubic feet forthe traditional system to 7,000 cubicfeet for the hybrid variant. Terrain,skidding distance, crew experience,and degree of mechanization arecritical factors affecting the productionrate. Uphill skidding or heavy brushcan significantly reduce output. Tomaximize productivity, animal loggersprefer to work in large timber whereone-log loads approach full capacityand at short extraction distances. Astudy in the Missouri Ozarks (Ficklinand others 1997) observed mulesoperating at skidding distances of1,050 feet, but Toms and others (1996)found an average skidding distance ofless than 200 feet.

The low production rate and minimalmove-in costs make animal loggingoperations most competitive on smallharvest units. As long as total harvestvolume exceeds several loads, there islittle economic penalty associated withsmall tracts. In fact, the smallest unitreported by Toms (1999) was a 1-acretract, and the median tract size wasonly 20 acres.

The primary advantages of animallogging are minimal soil disturbanceand residual tree damage, suitability tosmall tracts and selective cutting, andminimal noise and pollution. Balancingthese advantages, however, are the lowoverall production rate, a significantreduction in productivity with smalldiameter pieces, stand disturbanceassociated with loading and woodsroads, and the need to minimizeskidding distance.

In 1998, an extensive survey ofanimal logging in Alabama identified52 contractors mostly operating in thenorthern half of the State (Toms andothers 1998). Assuming an averageproduction of 4,000 cubic feet perweek, the total output of animalloggers in Alabama represents lessthan 0.5 percent of the statewideroundwood harvest in 1995(Johnson and others 1998).

Mechanizing the extraction functionof an animal logging system leads tothe manual cable skidder system. Inthis operation, trees are manually felled,limbed, and topped. A rubber-tired

Chapter 15: Forest Operations Technology


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cable skidder pulls logs to a landingfor loading. The unique feature of cableskidders is their ability to winch logs.By pulling cable from the skidder to thelog, trees may be pulled into a skid trailwith little soil disturbance. The winchis also useful on wet sites when theskidder loses traction. By slackingthe winch and driving ahead, the loadcan be pulled through the trouble spot.Cable skidder systems are typicallyused in broken, steep, or wet terrain,in large-diameter sawtimber, andin selection harvests.

The feller-buncher and grapple-skidder system has significantlyincreased harvesting productivity.Feller bunchers fell trees with eithera saw or shear and then place the treesin bunches for further handling. Byaccumulating felled trees in piles, thefeller buncher makes the subsequentskidding process more productive.Grapple skidders take advantage of thebunched wood by grasping a full loadwith a large pincer on the back of themachine. Cable skidder operators, incontrast, have to stop and tie a wirerope to each tree. With most feller-buncher systems, the wood is skiddedin tree lengths to either a landing ora processing area for delimbing. Gatedelimbers are large steel grates that areset in the woods at some distance fromthe landing. By backing the load oftrees through the grate with the skidder,most pine limbs can be broken off.A landing sawyer may be employedto clean up the wood prior to loading.Stroke delimbers, loader-mounted,pull-through delimbers, and flaildelimbers (Mooney and others 2000)are gaining acceptance to improvedelimbing quality, reduce waste, andeliminate manual chainsaw work.A typical feller-buncher and grapple-skidder system includes one fellerbuncher, two grapple skidders, a gatedelimber, and a knuckleboom logloader. If products are sorted out,higher value products are bucked fromthe tree-length pieces at the landingeither by chainsaw or slasher. Thesesystems find greatest application ineven-aged stands with trees of uniformsize and high pulpwood volumes.

In-woods chipping is an extension ofthe feller-buncher and grapple-skiddersystem. In these operations, a flail-chipper is added at the landing toproduce pulp-quality chips fromtree-length stems. A spinning chain

flail removes bark and limbs, and theclean stem is chipped and blown intoa waiting van. Watson and others(1991) found that in-woods chippingproduced chips of comparable qualityto mill-produced chips. Flail chippingactually left a higher percentage of totaltree biomass in the stand (31 percent)compared to conventional tree-lengthharvesting (24 percent). The systemis balanced to the productivity of thechipper. Thus, a typical in-woodschipping operation may require twofeller bunchers, three skidders, a loader,and the chipper. High productionis necessary to support the cost ofthe equipment. Munn and others(1998) noted an average productionof about 500 tons per day for in-woods chipping. A similar systemwithout the flail debarker may beused to produce fuel chips.

Cut-to-length (CTL) technologyproduces a different product form atroadside. It is a ground-based systemin which felled trees are processed atthe stump into defined log lengths.Characteristically, the CTL wood istransported to roadside on a forwarder,a machine that carries rather than dragswood. Forwarders were used yearsago in southern shortwood operations.CTL technology has been advancedin Scandinavia, where it is the state-of-the-art system for forest harvesting.Modern harvesters fell trees and processthem through computerized harvesterheads that delimb and buck treesto optimum product lengths. Eight-wheeled forwarders accumulate,sort, transport, and load wood ontohighway trailers. A key advantage ofCTL systems is that they process treesin the woods, leaving a layer of limbsand tops on the ground to drive over.This reduces soil disturbance andcompaction. Lanford and Stokes (1996)compared a CTL system with a feller-buncher and grapple-skidder systemin a pine thinning and found that costsand productivity of the two systemswere practically equivalent.

Several specialized systems have beendeveloped for wet sites (Stokes andRummer 1997). Operations typicallyincorporate modifications to improvedriving on soft soils. Conventional fellerbunchers may be adapted by using awide-tracked feller buncher. Skidderscan be equipped with either widetires or dual tires to reduce groundpressure. Tires up to 72 inches wide

may be used. Large-capacity extractionmachines have also been developed toreduce the need for roads on wet sites.Clambunk skidders may drag up tothree times the load of regular skidders.Tree-length forwarders carry a fulltruckload of wood supported on10 wide tires. Both clambunksand tree-length forwarders canbe combined with tracked fellerbunchers and skidders for fellingand short-distance extraction.

Shovel logging is another adaptationfor wet sites. Originally developed inthe Pacific Northwest, shovel loggingwas modified in the 1990s for southernconditions. The basic system uses atracked feller buncher to fell and piletrees. A second tracked machine, theshovel logger, moves felled trees andaligns them into a solid mat of woodto form a skidtrail. When the skidtrailis complete, dual-tired grapple skiddersstart at the farthest end of the road,picking up the mat of wood as theygo. By traveling on the constructedskidtrail, shovel logging reducesrutting and soil disturbance.

Cable logging is another specializedmethod of extracting material onadverse sites, particularly on slopesgreater than 35 percent. In cablelogging, a long wire rope is suspendedacross the stand. A winch (the yarder)sits at the landing and pulls logs alongthe suspended cable. Depending onterrain and equipment, a cable systemmay simply drag logs from the stump,or it may completely lift them off theground. Units can be relatively large,with extraction distances of one-quartermile. With long extraction distance,it is critical to fully load the systemon each turn. Thus, cable loggingrequires special skills among sawyersand choker setters. Product forms arelimited by the possible load sizes forthe cable. Planning is critical to meetingproduction and cost goals. However,LeDoux and others (1995) estimatethat cable systems make 14 percentof the upland hardwood forest inthe Southern United Stateseconomically operable.

Helicopters also can extract forestproducts where access is limited bysoft soils or steep terrain. Helicoptersare expensive to operate, so high hourlyproductivity is needed to achieveeconomic viability. Material to beremoved is felled and bucked beforethe arrival of the helicopter and


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extraction crew. During extraction,teams of choker setters preset lineson the felled material in optimum load-sized bundles. The helicopter pausesin the woods just long enough for thechoker setters to connect the drop lineto a bundle. After a short flight to thelanding zone, the helicopter releases theload and returns to the woods. Siroisand Stokes (1986) and Jackson andMorris (1986) observed a helicoptercrew operating in cypress swamps incoastal South Carolina. The operationrequired a crew of 14, plus a front-endloader and a knuckleboom loader. Atextraction distances of 900 to 2,900feet, cycle times ranged from 1.74 to5.35 minutes. Average production wasabout 3,100 cubic feet per scheduledhour of operation. Willingham (1989)described the initial configurations ofhelicopter logging with Scott PaperCompany in the Mobile Delta. Theirsystem consisted of manual fellingfollowed by helicopter extraction to ariverbank, where logs were loaded ona barge. The system evolved to includetracked feller bunchers and a purpose-built helicopter to maximize efficiency.

Another application of helicopters isin steep terrain, where roadbuildingcosts are high and ground-basedextraction is difficult. Sloan and others(1994) reported on the use of a K-MAXlogging helicopter for a shelterwoodharvest in the mountains of Virginia.Working at an average extractiondistance of 1,900 feet, the operationwas estimated to produce 1,300cubic feet per hour.

Helicopters are not limited byground conditions; but they are limitedby weather, altitude, and piece size.In order to accumulate full loads,helicopter logging requires a particularminimum volume per acre. Hourlycosts are very high. The reportedoperating costs in 1986 were about$2,000 per hour, including support butnot felling. To avoid delays, the landingzone must be large enough to safelyhandle the loading of 15 to 20 trucksper day. The primary advantages ofhelicopter logging are the reduction ofsoil disturbance associated with roadsand skidtrails and the reduction inroadbuilding costs. With the fast cycletimes, helicopters are also able tooperate economically at longerextraction distances than mostground-based systems.

Operations training—A keycomponent in forest operationstechnology is the skill and expertiseof loggers. For decades, loggers havehad opportunities for continuingeducation through workshops andseminars covering a range of topics.In the late 1980s, the Logger Educationto Advance Professionalism (LEAP)program was initiated in the North-eastern United States to improveloggers’ understanding of basicsilviculture and resource management.Participation in continuing educationwas voluntary until the mid-1990s.When Occupational Safety and HealthAdministration (OSHA) released new

logging safety regulations in 1996, itcreated a regulatory requirement forlogging safety training. The OSHArules closely followed the developmentof the Sustainable Forestry InitiativeKin 1995 by the American Forest &Paper Association. Member companiessupport education programs throughfinancial contributions and byperformance expectations establishedfor their suppliers. In response, all butone Southern State developed someform of logger training and education(Forest Resource Association 2000).Oklahoma sends its people to coursesin Arkansas. Curricula vary, butgenerally include safety and first aid,business management, best manage-ment practices (BMPs), environmentalconsiderations, and forest management.Some courses are for supervisors,while others are for workers. Graduatesreceive formal recognition and maybe required to remain current throughcontinuing education. In 1999, 8,254contractors and employees completedsome form of a logger training andeducation course.

Operations prevalence andproductivity—The 1990 Census(U.S. Census Bureau 2000b) reports51,525 workers engaged in logging(Occupational Codes 494 and 496).Figure 15.1 shows the distribution ofthese logging workers across the South.Note that significant numbers of timbercutters are in counties with no forest

Figure 15.1—Distribution of logging workers in the South, 1990 (loggers per 100 square miles).


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Logg

ing

wor

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45,000

40,000

35,000

30,000

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Year1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

Cor

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eek

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0

Survey year1981 1987 1993

products output. This is particularlyapparent in Texas, Oklahoma, andFlorida, where there are concentrationsof workers in metropolitan areas.These likely represent urban treecutterswho clear land and perform arboristservices. It is probable that othermetropolitan areas have similarnumbers of nonforest timber cutters.The ES-202 Covered Employmentdata suggest a 1999 southern loggingworkforce of 43,234, approximatelya 15-percent increase over the lastdecade (fig. 15.2).

A number of studies documentcharacteristics of these southernloggers. The Southern TechnicalDivisions of the American PulpwoodAssociation conducted a series ofpulpwood producer surveysperiodically from 1976 to 1993. Themost recent report from the 1993 data(Munn and others 1998) located 8,700contractors with 46,580 employees,operating in 11 Southern States (notincluding Kentucky or Oklahoma).Based on workforce estimates andpulpwood production reported, thesurvey sample was a nearly completecensus of pulpwood producers. Themost common harvesting configurationwas a rubber-tired feller buncherworking with grapple skidders toextract wood for tree-length transport.Most delimbing and topping weredone with chainsaws, but delimbinggates were used in about half of theoperations. Less than 3 percent ofcrews used in-woods chippers. Fromthe receiving mills’ perspective, about78 percent of the wood volume wasproduced by only 28 percent of thecrews. Almost half of the pulpwoodlogging crews sampled produced less

Figure 15.2—Changes in the logging workforcein the South, 1987 to 1999.

Figure 15.3—Average weekly crew productionfrom pulpwood producer surveys, 1981 to 1993.

than 70 tons per week. The periodicsampling of pulpwood producers showsa clear increase in crew productivityover the last 20 years (fig. 15.3).

In their analysis of successful loggingcontractors, Stuart and Grace (1999)reported that productivity increasedby about 12 percent between 1994and 1997. In the sample of the upperquartile of loggers, productivityaveraged about 60,000 tons per year.Greene and others (2001) found thatweekly production of Georgia loggersnearly doubled from 1987 to 1997.Capital investment per cord remainednearly constant over the decade,while labor productivity increasedby 79 percent.

Combining the logging populationdata with TPO production figuresprovides an overview of loggingproductivity variations across theSouth (fig. 15.4). Productivity wasnegatively related to percent hardwoodproduction. Productivity was higheston the Coastal Plains and decreasedthrough the Piedmont to theAppalachians and Interior Highlands.

The various assessments of thelogging workforce show a diverse rangeof forest operations in the southernforest. The majority of fiber is producedwith high-production, ground-basedsystems. However, the majority offorest operators are small contractorswith relatively low productivity. Tech-nology has been developed to meetmost conceivable forest conditionsin the South. However economicviability limits the options of loggersand landowners.

Technology Impactson Productivity andManagement Choices

Rational selection of a managementregime (rotation length, timing andtype of intermediate treatments, etc.)should be based on landownerobjectives, scientific managementprinciples, and economic analysis.For any management prescription,there may be a range of alternativetechnologies that vary in objectiveattainment and cost. The managermust select a system that providesthe greatest benefits at the least cost.

An economic analysis to determinethe optimal rotation age will includethe costs and timing of all managementactivities and the estimated returns. Inthe traditional (Faustmann) economicmodel, increasing harvesting costsextend the economically optimumrotation age. Prestemon and others(2000) analyzed data from the SouthernAppalachians of North Carolina andVirginia to determine whether forestmanagement decisions were consistentwith economic viability. Resultsindicated that stand age increaseswith distance to markets, increasingslope, and decreasing site class. Thesefindings would be expected under thetraditional economic model and wereobserved across all ownership types(NIPF, industry, and government).Similarly, Brown (1990) analyzedharvesting activity on both wet andsteep sites in the South. About 10percent of southern forest sites wereclassified as adverse, mostly due toslopes over 40 percent. Harvesting rateson difficult sites were one-fifth of thoseon easily accessible sites. As a result,


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stands on difficult sites are olderand have higher timber volumes.Barlow and others (1998) also founddecreasing harvest rates with increasingslope and distance to roads; bothfactors increase harvesting costs.

While high harvesting costs increaserotation length, high site-preparationand establishment costs tend to reducerotation length. The objective ofintensive regeneration practices is toincrease survival and growth, leadingto economic maturity at an earlier age.The economic consequence is a shorterrotation to recover these costs earlier.

Haight (1993) added considerationof variation in future product pricesto the traditional economic model.He based the timing of the final harveston a comparison of current prices witha calculated reservation price. Whenprices exceed the reservation price,harvest is indicated. Plantinga (1998)notes that the reservation price modelgenerally leads to longer rotationsthan the fixed rotation age calculation.Haight modeled a range of site prepar-ation alternatives and found that themoderate treatment (chopping,burning, plant) had a higher expectedpresent value than either an intensiveor a natural regeneration option. Inaddition, this analysis found nearlya 20-percent increase in return dueto timing the final harvest based onprice expectations.

While an economic analysis mayaffect the selection of rotation length,in some cases the total costs may render

any forest management uneconomical.May and LeDoux (1992) analyzed FIAplot data for Tennessee and estimatedharvesting and stumpage prices fortimberland. At medium stumpageprices, 51 percent of timberland wasestimated to be profitable to harvest. Atlow stumpage prices, only 72 percent ofthe total timberland acreage could beeconomically managed. A similarapproach was used in western Virginia(Worthington and others 1996). Undercurrent market conditions, about one-third of the timberland in the study areawould be unprofitable to manage.

Technology is being sought to reducecosts of forest operations. Such savings,however, cannot alter land managementpractices unless they are passed on tothe landowner in the form of stumpageprice increases. Most cost-savingtechnology now is being directed tocontrolling rising operational costs.Stuart and Grace (1999) noted thataverage logging costs per ton increased16 percent between 1994 and 1997.During the same period, the ProducerPrice Index (PPI) for contract loggingservices only increased 4 percent (U.S.Department of Labor, Bureau of LaborStatistics 2000b). For the entire decade1990 to 2000, the PPI for contractlogging increased only 9 percent.Clearly, there is significant cost pressureon logging contractors. Costs of somesite preparation treatments are alsorising faster than inflation. Costs ofprescribed fire nearly doubled in the

last decade (Dubois and others2001). Precommercial thinning andmechanical site preparation costsincreased 30 percent. Costs forchemical treatments were up 20percent, and those for hand plantingrose 25 percent. Labor costs haveincreased with rising workers’compensation rates. With these pricepressures, much of the technology toreduce costs is focused on maintainingprofitability of logging contractors orfor controlling wood costs at thereceiving mill. Larger skidders andbetter delimbers are examples ofdevelopments to reduce costs throughelimination of labor. It is unlikelythat these cost savings will be passedback to landowners. The increasein mechanization as an approachto controlling logging costs has alsoresulted in more highly capitalizedsystems that derive efficiency fromhigh volume production.

Impacts of ForestOperations

Forest operations alter theenvironment. Some of these effectsare intended; others are undesirableconsequences. Most impacts areassociated with driving equipmentand moving material in the forest. Soil,water, and residual vegetation can beaffected. Effects must be consideredin terms of their quantity, severity,persistence and location within the

Figure 15.4—Annual logging productivityaggregated to ecological subregions in theSouth (thousand cubic feet per logger).


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landscape. Some impacts are short-lived, while others may affect thelong-term productivity of the forest.Impacts that are concentrated maybe significant, while the same impactsspread across a stand may not beecologically important. Chapters 21,22, and 18 provide more informationabout the effects of forest managementon water and soil.

The principal impact of most forestoperations is soil disturbance. Soildisturbance results from road or trailconstruction, equipment traffic, and thedragging of material. Soil disturbanceincludes physical dislocation andloosening, compaction, or puddling.Disturbance effects are the cumulativeresult of all operations in a silviculturalsystem. Soil disturbance from fellingis covered by soil disturbance fromskidding, which is subsequentlyameliorated by the soil disturbanceassociated with site preparation.

Conventional clearcut skidderharvesting systems cover about15 percent of the stand in trails andlandings. The most heavily impactedareas are the primary skid trails, gatedelimbing areas, and landings. Detailedtracking of total soil disturbance ona Piedmont clearcut showed about22 percent of the stand affected bymore than five passes of machinery(McDonald and others 1998). Atleast 30 percent of the stand remainsundisturbed, even in clearcuts.Reisinger and others (1988) summa-rized studies from the South and notedthat 63 to 99 percent of the standareas were undisturbed, dependingon the system used.

More difficult sites tend to have agreater amount of undisturbed areathan more easily accessible areas. Stuartand Carr (1991) and Stokes and others(1998) observed that disturbed areadecreased with increasing slope. Onslopes greater than 35 percent in centralVirginia, skidtrail disturbance rangedfrom 3 to 10 percent of the stand.In contrast, Aust and others (1993)found 34 percent of a wet flat rutted.

Harvest intensity also affects theamount of soil disturbance. Kluenderand others (1994) and Carter andothers (1997) found that clearcuts andshelterwood cuts had similar amountsof skidtrail disturbance (about 15percent of the stand). Shelterwoods,however, had more area in undisturbedcondition. Single-tree selection had the

least amount of soil disturbance,but that prescription calls for morefrequent entries with additionalimpacts over time.

CTL systems carry wood rather thandragging it over the soil. The resultis less soil disturbance. Vidrine andothers (1999) and Lanford and Stokes(1995) found that seventh and fifthrow thinning in pine plantations witha harvester/forwarder combinationresulted in 11 to 30 percent of the totalstand area disturbed by traffic. Bothof these studies were on Coastal Plainsites in winter. Seixas and others (1995)compared five CTL configurations invarious prescriptions and found theleast disturbance occurred with a fellerbuncher, manual processing, forwardersystem. About 26 percent of the standarea was disturbed. A system with adrive-to-tree harvester and forwarderdisturbed 39 percent, and a horselogging crew disturbed 42 percentof the stands.

Cable logging reduces soil disturbancebecause wheeled traffic is eliminatedin the stand. Disturbance still occursfrom dragging logs, however, Millerand Sirois (1986) compared skidderand cable logging in southwesternMississippi. About 16 percent of thecable units were disturbed, mostly incable corridors. Skidders disturbedabout twice as much area. Cablelogging disturbance tended to beoriented up-and-down slope, whileskidder disturbance was more irregular.

Forestry tires have gotten largerto provide better flotation and reducerutting and disturbance. Wider tirestypically reduce rut depth but increasetrack width (McDonald and others1995). Thus, the primary applicationof wide tires appears to be on very softsoils where sinking and rutting areconcerns. Carruth and Brown (1996),for example, noted that when moisturecontent exceeds 40 percent on lowerCoastal Plain sites, the only systemsthat can operate are tracked fellerbunchers and wide-tired skiddersoperating on trees and mats. On driersoils in eastern North Carolina, Seixasand McDonald (1997) observed thatthe least rutting developed withnarrower tires on a forwarder ratherthan wider tires or tires with tracks.Rummer and Sirois (1984) observedthat carrying larger loads on widertires probably offset any reduction insoil loading.

Operational configurations that carry,rather than drag, materials generallyproduce less soil disturbance. Fellerbunchers generate less disturbancethan manual felling because trees arecarried from the stump to the bunchinglocation. Forwarders generate lessdisturbance during extraction thanskidders because the load is off theground. Swing machines have arms androtating upper structures; they causeless disturbance than drive-to-treedesigns. Swing machines can oftenreach into the stand to perform workwithout driving over every area.

Operating methods can also reducesoil disturbance. Designating skid trailscan manage and minimize the amountof area impacted. Shovel logging is amethod of logging that limits heavytraffic to a road of felled trees. Whenthe trees are picked up, the underlyingsoil is minimally affected. Similarly,CTL operations can process treesin front of the machines, buildinga trail mat of limbs and tops. Seixasand others (1995) found that soilcompaction was reduced under theheavier layers of the slash mat.

Cumulative soil disturbance can alsobe reduced by follow-up treatmentsto ameliorate adverse effects. BMPstypically call for vegetative stabilizationof exposed soil that may be a sedimen-tation risk. Compacted areas may besubsoiled, ripped, or disked duringsite preparation to improve physicalproperties. On well-drained sites,survival and growth of loblolly pinehave been positively affected bysubsoiling treatments. On wet sites,bedding can create drier planting siteswhere harvesting has resulted in raisedwater tables (Aust and others 1998).

Accessibility to VariousOwnership Groups

Forest operations accessibilitydepends primarily on economicviability. Economic viability, in turn,depends on whether the perceivedvalue of the treatment exceeds thecosts of implementation. A thinning,for example, may not have a short-runpositive cash flow, but the increasedvalue of the residual stand is expectedto yield a profit over the rotation.Similarly, a landowner may realize notangible return from creating a wildlifeopening, but the intangible benefit ofviewing wildlife may be deemed greaterthan the incurred costs. A prescription


Dol

lars

per

ton

$35.00

$30.00

$25.00

$20.00

$15.00

$10.00

Tract size (acres)0 20 40 60 80 100

CTL partialSkidder partialSkidder clearcut

Many studies have examined theeffect of removal intensity on harvestingcosts (Brummel 1993, Kluender andothers 1998, Rummer 1998). Generally,there is little reduction in systemproductivity for prescriptions that leavea moderate residual stand, such as aseed-tree or shelterwood. However,when harvesting in small blocks, aswith group selection or single-treeselection, productivity declines andcosts increase. In selection harvests,other factors, such as the effect ofselection criteria on average tree size,may be more important than tract sizein determining economic operability.

Discussion andConclusions

Forest operations technology ischanging in the South. Tree-lengthlogging and hauling have largelyreplaced shortwood operations.Labor-intensive bobtail crews, oncethe mainstay of pulpwood logging,are becoming harder to find.

The primary driver of change iseconomic viability. Labor costs havegone up, and the pool of ableemployees has been shrinking. Theresult has been a shift towards moremechanized operations with higherproductivity per person. Sitepreparation and establishment costshave increased sharply. While newtechnology, such as fertilization, canincrease yields, its costs must be closelyexamined to make sure the net financialreturn is positive. Rosenberg and others(1990) discuss the development andadoption of new technology in theforest products industry. They notethat the adoption of new panelproducts in the 1970s and 1980s wasnot due to breakthrough technology(the basic technology had beendeveloped 20 years previously), butrather to significant shifts in the priceof veneer logs, which were the rawmaterials for conventional plywood.Relatively suddenly, the economicenvironment had changed.

A secondary driver of change hasbeen the development of ecologicalissues. Water-quality concerns led tothe development and promulgationof BMPs and logger training initiatives.Aesthetic values have become betterdefined and guidelines for minimizingvisual impacts have been developed.

Figure 15.5—Predicted costs of harvesting 40 tons peracre in trees averaging 9 inches diameter at breast height.

to achieve a given managementobjective establishes a set of operatingconditions, such as extraction distance,volume per acre handled, seasonalrestrictions, and slope, which willdetermine the operating costs for aparticular forest operations technology.The prescription also determines thetime frame over which expenses mustbe amortized and the values of theanticipated outcomes.

In the context of differences amongvarious ownership groups, economicviability of forest management isprimarily affected by the selection ofmanagement regimes and variationsin tract size. Thompson and Johnson(1996) profiled NIPF landowners inVirginia and identified three subgroups:(1) farmer-owned, (2) other corporate,and (3) other private individual. Blissand others (1997) surveyed NIPFowners in the Tennessee Valley andexamined differences among income,ownership size, and managementactivity. Differences in accessibility offorest operations technology to any ofthese forest ownership groups dependson whether they fundamentally differin their management objectives or inthe size and composition of their forestholdings. See chapter 9 for additionalinformation on the managementobjectives of various ownership groups.

Tract size may be the most importantfactor affecting economic viability ofmanagement activities. Row (1978)

notes that the diseconomies of smalltract size may reduce the willingnessof landowners to invest in forestmanagement. In the Virginia survey(Thompson and Johnson 1996),about 11 percent of the NIPF holdingswere in tracts less than 10 acres; and40 percent were in tracts less than50 acres. The smallest average tractsize was in the natural pinemanagement type.

Generally, an economy of scale isrealized by spreading fixed costs ofownership and management over moreunits of output (Cubbage 1983). Inforest management, many costs must berecovered through value generation atsome point in the management regime.For example, fire protection, boundarymaintenance, and administration andplanning are costs that vary little withtract size. In harvesting, costs formoving and planning accrue withoutrespect to tract size. Greene and others(1997) analyzed the effect of tract sizeon harvesting costs. Their assumptionswere based on a survey of recent timbersale volumes and tract sizes in Georgia.Figure 15.5 illustrates estimatedproduction costs for three alternativesystems using cost equations derivedfrom the simulation analysis. Notethat above 20 acres, all of the systemshave relatively flat cost curves.Conversely, below 10 acres all of thesystems demonstrate significantlyincreasing costs.


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Our growing understanding of nutrientcycling and global carbon sequestrationis leading to new technologies andopportunities in southern forests.

Neither economics nor ecology areoptional. Southern forest managementis not feasible if it cannot offer positiveeconomic returns. Similarly, forestmanagement is not tenable if it cannotmaintain or enhance ecologicalfunctions. New technology mustbe constantly pursued to meet thesecontinuing challenges. Yet Rosenbergand others (1990) observe that newtechnology is seldom the perfectsolution to a problem. Innovationsoften have undesirable as well asdesirable traits. The adoption processproceeds over time to reduce theadverse effects while optimizing thebenefits. CTL is probably an exampleof this process. Modern CTL systemswere developed and optimized inScandinavia with very different labor,product, and cost structures. WhileCTL has some very good attributes,there are significant reservationsabout widespread adoption in theSouth at this time.

Another barrier to the adoptionof new technology is the integrationof forest operations. All parts of anoperations system must be compatiblewith one another. Wood is hauledtree-length because the mills are setup to receive that form. Heavy trafficfrom ground-based systems definesthe need for subsoiling. Changes intechnology have to fit the existingframework of silviculture, products,processes, and culture.

Developments in informationtechnology will be a central factorin all future management. GeographicInformation Systems (GIS) permitthe presentation, manipulation, andtransfer and storage of map-type data.Increasingly, resource managers utilizeGIS to develop and design prescriptionsthat better address the variation ofconditions across the landscape.Geographic Positioning Systems (GPS)will allow operations technology toimplement more complex treatmentplans that are better adapted to site-specific ecological features.

Variation in the southern forest isa key factor that works both for andagainst innovation and new technology.Given the wide range of operatingconditions from Virginia to Texas,it is unlikely that many new forest

operations will find widespreadapplication. New technology has tofind its niche, and that niche must belarge enough to warrant the necessarydevelopment costs. The variety of forestconditions, however, also supportsinnovation. Shovel logging, forexample, was a niche system designedfor upland sites in the Northwest.That concept, however, sparkednew thinking about how to workin wet sites of the South.

Technology is developed in responseto needs. Forest management definesa need, and technology delivers asolution. Forest industry definesa need for fiber in a specific form, andlogging systems are modified to providethat form. The process of technologicalprogress can be slow. Yet progress—both economic and ecologic—isevident in southern forest management.Even more new technology is waitingin the wings for the right need, theright place, and the right time.

Needs for AdditionalResearch

Little specific information is availableon the distribution and characteristicsof niche technologies. Shovel loggingsystems, animal logging, CTL, andmodern cable skidding are not welldocumented in the South. Landmanagers and contractors have littlequantitative basis for the selectionof appropriate technology on sometracts. This information will becomemore important as more site-specificprescriptions evolve. If timber marketsexpand, niche systems will also besought for application on adversesites, such as wet or steep terrain.

There is also a critical need fortechnology to manage smaller tracts,smaller diameters, and lower volumesper acre. Chapter 6 describes trendsin ownership patterns, tract size, andfragmentation. It is an open questionwhether there are realistic silviculturalprescriptions for many small NIPFholdings, but the lack of mechanizedoperations that can operate eco-nomically where volumes are smallaffects many forest owners in the South.

The conventional ground-basedoperations that are used to producethe majority of timber in the Southwill continue to be refined by producersand equipment manufacturers through

product development. However,research into the effects of planningand work organization may be ableto generate cost savings and reduceadverse impacts.

Acknowledgments

Tom Bailey, Soil Scientist, USDAForest Service, provided backgroundinformation and reviewed the literatureon operations impacts. Mark Duboisassisted with the presentation of“Cost Trend Survey” data.

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The USDA prohibits discrimination in all its programsand activities on the basis of race, color, national origin,sex, religion, political beliefs, sexual orientation, ormarital or familial status (Not all prohibited bases applyto all programs). Persons with disabilities who requirealternative means for communication of programinformation (Braille, large print, audiotape, etc.) shouldcontact the 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, WhittenBuilding, 1400 Independence Avenue, SW, Washington,DC 20250-9410 or call 202-720-5964 (voice and TDD).USDA is an equal opportunity employer.

In: Wear, David N.; Greis, John G., eds. 2002. Southern forest resourceassessment. Gen. Tech. Rep. SRS-53. Asheville, NC: U.S. Departmentof Agriculture, Forest Service, Southern Research Station. 635 p.

The southern forest resource assessment provides a comprehensiveanalysis of the history, status, and likely future of forests in the SouthernUnited States. Twenty-three chapters address questions regarding social/economic systems, terrestrial ecosystems, water and aquatic ecosystems,forest health, and timber management; 2 additional chapters provide abackground on history and fire. Each chapter surveys pertinent literatureand data, assesses conditions, identifies research needs, and examinesthe implications for southern forests and the benefits that they provide.

Keywords: Conservation, forest sustainability, integrated assessment.

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