ABSTRACT

In-woods utilization

Once an active harvest site was chosen, the field crews met with the logging supervisor before fieldwork commenced. A survey was used to collect general harvest information including the following:

• Global positioning system coordinates of landing

• Type and log size and quality specifications of all product markets

• Number of loggers on logging crew

• Average number of truckloads leaving site each day

• Location of all product markets

• Type of logging operation (contract, independent, company owned)

• Degree of mechanization (fully mechanized having mechanical harvester, grapple skidder, and sawbuck vs. not fully mechanized)

The field crew then noted the current location of harvesting within the tract and the general direction of harvest progression. With this information, field crew members were positioned a safe distance from harvesting while the logging crew felled several trees in a given area. Once the trees were felled and topped, the field crew collected the following information for each tree:

• Species

• Stump height

• Stump diameter

• Diameter at 12-inch stump

• Diameter at breast height (DBH)

• Diameter at 16-foot log

• Diameter and distance to topping point in woods

• Diameter and distance to 9-inch top of main stem (limit of hardwood sawlog portion as per USDA Forest Service FIA definition)

• Diameter and distance to 4-inch top of main stem (limit of growing-stock portion as per USDA Forest Service FIA definition)

• Large and small end diameters for each portion of the felled tree remaining as long as they met a 4-inch diameter and 8-foot length minimum

• Utilization (binary) of each measured piece

Details of the measurement points and adjustments that were made for branched trees and trees with other types of form abnormalities are available in Bentley and Johnson (2006, 2009). All diameters were based on outside-bark measurements taken with calipers.

Landing utilization

The felled trees were sequentially numbered by painting on the large and small ends of the log sections that were bucked out in the woods. In some cases these sections were essentially tree-length logs while at other logging operations these sections were the final log products (depending on whether the logging operation was running a sawbuck at the landing or manually bucking). The logs were then skidded to the landing by the logging crews. Once the tree stem portions arrived at the log landing, another field crew member recorded the following information for each bucked stem:

• Tree number (from the woods)

• Large and small end diameter

• Total log length

• Product category for each log (based on specification provided in conversation with harvest supervisor)

• Large and small end diameter for any unutilized piece

Analyses

Upon returning from field visits, data were entered into the computer. Since this project produced a tremendous amount of data, significant attention was given to data checking and resolving discrepancies before analyses could proceed. All markets were geospatially identified, and the over-the-road travel distance from each landing to each product market was determined using a Web-based travel network algorithm.

With these data, a number of useful metrics were calculated. These included growing- and nongrowing-stock volume as well as percent underutilization and percent overutilization. Growing-stock volume, as defined by FIA merchantability standards, is the volume in the main stem of a tree from a 1-foot stump to a 4-inch top. Volume merchandised outside of these parameters is considered nongrowing-stock volume. All volume in the 1-foot stump, the tree stem above the 4-inch top to the growing tip of the tree, and in all limbs 4 inches and larger and at least 5 feet long are considered nongrowing stock according to FIA protocol.

Most of the time trees are not cut exactly at a 1-foot stump, nor are they cut off at exactly 4 inches. Trees cut above a 1-foot stump and below 4 inches would be considered underutilized, and that volume not utilized would be considered growing-stock residue. On the other hand, by FIA standards, trees cut below a 1-foot stump and above a 4-inch top are considered 100 percent utilized, and those portions below and above are considered overutilization. A myriad of combinations actually occur on active harvest operations. The aggregated volume from measured trees has provided overutilization and underutilization factors that can be applied to statewide inventory results for an estimate of growing-stock and nongrowing-stock logging residues (Bentley and Johnson 2009). The tops of the sawtimber portion of each stem (7 in. in softwoods and 9 in. in hardwoods) also were recorded so that both sawtimber and poletimber portions of the growing-stock section could be determined.

Landing utilization was calculated for each numbered tree that was skidded to the landing. A few numbered trees were not measured on the landing because they were (1) not skidded from the field, (2) dropped by the skidder along the way, or (3) had illegible tags/numbering as a result of environmental conditions. The information collected on these trees was used for calculating in-woods utilization rate but not landing utilization rate.

An overall utilization rate was calculated by dividing the cubic-foot volume of all products produced at the landing by the total cubic-foot volume for each measured tree. The overall utilization is roughly equivalent to the product of in-woods total tree utilization and landing utilization. Differences are due to minor differences in measurements and the fact that some stem sections were included in the in-woods calculation but not in the landing calculation because of tracking issues.

The influence of market distance on utilization rates was investigated using Pearson correlation. Actual distances to current markets as well as calculated distances to all major pulpwood and oriented strandboard (OSB) markets in West Virginia and surrounding states (even if they were not being used) were developed for each site. The relationship between overall utilization rate and other site factors including forester involvement, type of logger (contract, independent, and company), number of product markets, mechanization (fully or nonfully mechanized), and number of employees (full-time equivalent) was tested using analysis of variance (ANOVA) with . The following general model was used for all tests:

where Y_ij is the overall utilization rate over all 30 sites, μ is the overall mean, α_i is the effect of the ith treatment, and ɛ_ij is the unexplained variability. The Tukey Studentized Range Test was used for multiple comparison testing. For both number of product markets and number of employees, data were recoded into two categories—“high” and “low.” High represented measurements equal to or greater than the mean response for that particular indicator. Low represented all other measurements. Rounding was performed to the nearest integer value.

To meet assumptions of the parametric statistical tests used in the overall analysis, the total utilization rate was tested for normality. The Shapiro-Wilk hypothesis that total utilization was normally distributed was accepted (P < 0.06). Therefore, we assumed that the calculated utilization rate was representative of a normal distribution.

Sites

Presampling harvest characteristics based on West Virginia DOF notification data for each of the three West Virginia DOF regions is shown in Table 1 along with harvest site information for the sample sites. A total of 10 harvests from each of the three West Virginia DOF regions were sampled during the summer and fall of 2008. Region 2, which encompasses the southern portion and central mountain counties, had the highest level of active harvests during the sampling period. Region 3, the northwestern portion of the state, had the largest average harvest size on record for the sites scheduled for harvest during 2008 (99 acres per site). As it turned out, the 10 sites sampled in Region 1 in the northeastern part of the state were, on average, larger than the sites in the other two regions (Table 1).

Table 1. Presampling data collected from West Virginia Division of Forestry Harvest Notification forms for each region sampled during a 2008 roundwood utilization study in West Virginia.

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Logging crew characteristics

The majority of the loggers sampled were contract or independent loggers (logging operators that bought the stumpage). Company crews composed only 13 percent of the sample (Table 2). Twenty percent of the loggers used a mechanical felling machine, and 27 percent used a grapple skidder. On the landing, 70 percent of the loggers sampled used a mechanical bucking loader/saw (sawbuck). Of the 30 harvests sampled, 5 (17%) used a mechanical harvester, grapple skidder, and sawbuck, and thus could be considered fully mechanized (Table 2). The majority of the harvest operations that we sampled were on private land (93%) and had a professional forester involved in the harvest (73%). All of the fully mechanized harvests had professional forester involvement. On average, contract loggers had forester involvement on 78 percent of the harvests sampled, followed by 75 percent for company crews, and 67 percent for independents.

Table 2. Characteristics of loggers and logging sites sampled during a 2008 roundwood utilization study of 30 active timber harvests in West Virginia.

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The number of employees working on each site ranged from two to nine. The mean number of employees for all 30 harvests was 4.4. Mechanized harvests averaged more employees than nonmechanized harvests (6.0 vs. 4.0). Contract loggers averaged 4.9 employees, independents averaged 3.6, and company crews averaged 4.8 employees on site. Four of the five fully mechanized harvests were contract logging crews.

The reported number of product truckloads produced per day ranged from one to nine. The mean number of daily truckloads was 3.3. Fully mechanized harvests produced 5.2 loads per day compared with an average of 3.0 for nonmechanized crews. Contract loggers produced the greatest number of loads per day (3.6), followed by company crews (3.2), and independents (3.0). While a variety of truck types and configurations were used, the average truck payload ranged from 20 to 25 tons per load.

Markets

Seven primary markets were identified during the sampling of the 30 harvest operations (Table 3), as well as one additional output that was termed “waste.” As expected, each of the harvest sites produced sawlogs (Table 3). Following sawlogs, the next most common market was OSB pulp and pulpwood for paper production and yellow poplar (Liriodendron tulipifera) peeler materials (Table 3). Each of the harvests visited left waste material on the landing that was not merchandised.

Table 3. Percentage of sites and trees producing different roundwood products and the percentage of total volume merchandised by product class at the landings of 30 active timber harvests in West Virginia during 2008.

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The number of markets used ranged from one to six and averaged 3.6 across the 30 sample sites. Markets used by contract, independent, and company loggers did not differ greatly, with calculated means of 3.5, 3.7, and 3.5 markets, respectively. Harvests that had a forester averaged 3.8 product markets, and those without averaged 3.0.

Forty-seven percent of the sites delivered to sawlog as well as pulpwood and OSB pulp markets. Fifty percent of sites with a forester delivered to both sawlog and OSB and pulp markets, whereas 38 percent of sites without a forester used these markets. Half of both contract and company crews delivered to both sawlog and OSB and pulp markets, whereas 42 percent of independents did the same.

When looking at all major sawlog, pulp, and peeler markets, 33 percent of the loggers sampled delivered to each. Again, half of company loggers delivered to sawlog, peeler, and pulpwood markets, followed by 36 percent of contract loggers, and 25 percent of independents. Forester involvement also affected delivery to major sawlog, peeler, and pulp markets. Thirty-six percent of harvests with a forester delivered to all of these markets compared with 25 percent of those without a forester. Distances between individual markets ranged from 23.3 miles for those that delivered to scragg markets to 138.7 miles for a high-quality sawlog market (Fig. 1).

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Sawlog market transport distance averaged 38 miles (standard deviation [SD] = 27.7). Distances to pulpwood, peeler, and OSB pulp were relatively consistent, averaging 68.1, 71.3, and 71.8 miles, respectively. The average distance to the closest pulpwood and OSB pulp facilities for those sites that did not include them as markets averaged 85.2 and 84.3 miles, respectively. The minimum distance to a wood products facility that was not delivered to was 34.4 miles for pulpwood and 44 miles for OSB pulp.

In-woods utilization

A total of 816 felled trees were sampled during this study, 84 less than our goal of 900 trees. A sample size of 900 was not achieved as a result of loggers finishing work before all trees were measured or the harvest being completed before sampling was finished. Twenty-three unique species were represented by the samples taken on the 30 harvests. Yellow poplar had the highest frequency of occurrence, followed by red maple (Acer rubrum), black oak (Quercus velutina), and red oak (Quercus rubra).

When species were grouped by specific physical and market characteristics, the yellow poplar group was the most prevalent (Table 4). This was followed by the white oak (white and chestnut oak [Quercus alba and Quercus prinus]), soft maple (red maple), and red oak (red and black oak) groups.

Table 4. Number of sample trees in each of 10 species groups measured on 30 active timber harvests in West Virginia during 2008.^a

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The average DBH for the 816 trees measured was 16.9 inches (SD = 4.5 in.), the average stump height was 9.8 inches (SD = 7 in.), and the average stump diameter was 20.6 inches (SD = 5.6 in.; Table 5). The soft maple species group had the smallest DBH and stump diameter. The red oak species group had the largest DBH and stump diameter, followed by the hard maple (Acer saccharum) and black cherry (Prunus serotina) species groups. Hickory species and pine species had the lowest average stump heights. White oak and hard maple had the highest average stump heights, although both were below 12 inches (the assumed stump height used in TPO utilization studies in the eastern United States).

Table 5. Mean diameter at breast height (DBH), stump height, and stump diameter of trees in each of 10 species groups measured on 30 active timber harvests in West Virginia during 2008.^a

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The mean tree bole length to a 9-inch merchantable top was 49.8 feet (SD = 24.2 ft). Not all stems had a merchantable height that was exactly 9 inches due to branching and other stem form inconsistencies. The mean diameter at the 9-inch merchantability point was 9.3 inches (SD = 0.8 in.) for all stems measured. The average bole length to at least a 4-inch merchantable top was 69.4 feet (SD = 4.5 ft). Again, not all stems had a merchantable height that was exactly 4 inches. The average diameter at the 4-inch merchantability point was 4.3 inches (SD = 0.6 in.). Yellow poplar stems had the largest bole length to a 9- and 4-inch top at 60.3 and 80.3 feet, respectively. The mixed-hardwood species group had the shortest length to a 9- and 4-inch top (Table 6).

Table 6. Mean bole lengths to a 9- and 4-inch merchantable top and mean end of utilization (top) diameter of harvested stems for each of 10 species groups from data collected on 30 active timber harvests in West Virginia during 2008.^a

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The mean in-woods bucking diameter or end of utilization along the main stem for all trees sampled was 9.4 inches (SD = 3.9 in.). This represents the diameter at which the loggers bucked the main stem in the woods. The red oak species group had the largest diameter at the end of utilization at 11.5 inches, followed by hard maple at 11.3 inches (Table 6). The pine group and soft maple had the smallest diameter at the end of utilization point of 5.9 and 8.3 inches, respectively.

A total of 74,972 ft³ of harvested trees were sampled during the 30 site visits. Total tree utilization ranged from 75.4 to 99.1 percent. Average whole-tree utilization was 87.8 percent (Table 7). Sawlog-sized material measured totaled 65,823 ft³ and had a mean utilization rate of 94.1 percent. Sawlog utilization ranged from 82.1 to 99.9 percent. More than 9,000 ft³ of pulp-sized material was measured, of which 42.5 percent was utilized. Pulp utilization ranged from 0 to 95 percent on the 30 sites.

Table 7. Total volume and in-woods utilization percentage for trees harvested on 30 active harvest sites in West Virginia during 2008.

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The pine species group had the highest overall in-woods utilization rate (96.3%), followed by the yellow poplar and black cherry groups (Table 8). The soft-hardwood group had the lowest in-woods utilization rate (79.0%), followed by the hard maple and mixed-hardwood groups. Sawlog utilization among species groups followed similar patterns as total tree utilization—the pine species group (98.7%) had the highest sawlog percentage and the soft-hardwood group had the lowest (88.1%).

Table 8. Average overall utilization rate for species groups sampled on 30 timber harvests in West Virginia during 2008.^a

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Landing utilization

A total of 796 trees were measured on the landing during this study. This is less than the 816 trees measured in the woods because several trees were lost between the woods and the landing. These trees do not represent unutilized stems, rather they were not skidded to the landing during the study period or the numbers written on the logs had become illegible during transport and thus were not used in the calculations for landing utilization rate.

The mean utilization rate found on the landings sampled was 97.9 percent (SD = 5.6%). Variation among species groups was not pronounced, ranging from 96.3 percent for soft hardwoods to 99.4 percent for the hard maple species group (Table 8).

Approximately 66.8 percent of all trees had a sawlog merchandised from them on the landing (Table 3). Pulpwood was merchandised from 56.3 percent of the stems. Of those trees from which a sawlog was merchandised, 50.6 percent also contained pulp material, but only 8.7 percent produced a peeler log. Furthermore, of those stems where a sawlog was not merchandised, peelers made up 22.4 percent and pulpwood 67.8 percent of the products, respectively.

In terms of tree volume utilization, 58 percent of the total tree volume that was measured on the landing was merchandised as a sawlog (Table 3). Pulpwood was the next highest product category produced on the landing, with 20 percent of the total volume. The least merchandised product on the landing was rail and scragg material at 1 percent.

The interaction between product merchandising and species showed that on average the red oak species group had the highest proportion of its volume being merchandised as sawlogs (79.8%, Table 9). This was followed by black cherry (74.1%) and white oak (71.6%). Only 45.6 percent of the yellow poplar group was merchandised as sawlogs; however, an additional 26.2 percent was devoted to peeler markets.

Table 9. Product class–based breakdown of merchandised volume for each species group based on a 2008 harvest utilization study in West Virginia.

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Overall utilization

When the in-woods and landing utilization rates are combined, an overall utilization rate can be calculated for the harvests sampled. The overall utilization rate for the 30 harvest sites was 86.9 percent (SD = 11.8%). Again, the soft-hardwood species group had the lowest overall utilization rate followed by white oak (Table 8). The pine group had the highest overall utilization rate and yellow poplar had the second highest.

Pearson correlation test results found no relationship between the distance to individual markets and overall utilization on harvested sites. Similarly, no relationship was detected between distance to pulpwood market and overall utilization for those cases in which a proximally located pulpwood market was not exploited.

Utilization rates on sites that had a forester involved versus those sites that did not were not significantly different (P = 0.5850). Sites with a forester involved averaged 86.6 percent utilization versus 88.2 percent on sites without. There was a significant difference in utilization rate among logger types (P = 0.0112). Both independent (88.5%) and contract (88.3%) loggers had higher average utilization rates than company loggers (77.5%).

The utilization rate for companies that were fully mechanized versus those that were not did not differ (P = 0.1789). Likewise, no difference in overall utilization was found for those loggers with a high number of markets (P = 0. 6320) or a high number of employees (0.9412) compared with those with a lower number.