Harvesting Costs for

Management Planning for

Ponderosa Pine Plantations

Roger D. Fight, Alex Gicqueau, and

Bruce R. Hartsough

United States 

Department of

Agriculture

Forest Service

Pacific Northwest

Research Station

General Technical

Report

PNW-GTR-467

June 1999
Authors ROGER D. FIGHT is a principal economist, U.S. Department of Agriculture, Forest

Service, Pacific Northwest Research Station, P.O. Box 3890, Portland, OR 97208-

3890; and ALEX GICQUEAU was a graduate student and BRUCE R. HARTSOUGH

is a professor, University of California, Department of Biological and Agricultural

Engineering, Davis, CA 95616-5294. Gicqueau is currently a senior software developer, Axolotl Corp., Cupertino, CA 95014.
Abstract Fight, Roger D.; Gicqueau, Alex; Hartsough, Bruce R. 1999. Harvesting costs for 

management planning for ponderosa pine plantations. Gen. Tech. Rep. PNWGTR-467. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific 

Northwest Research Station. 8 p.

The PPHARVST computer application is Windows-based, public-domain software used

to estimate harvesting costs for management planning for ponderosa pine (Pinus

ponderosa Dougl. ex Laws.) plantations. The equipment production rates were developed from existing studies. Equipment cost rates were based on 1996 prices for new

equipment. Harvesting systems include a cut-to-length harvester-forwarder system, a

whole-tree/log-length skidder system, and a skyline cable system. Harvesting costs

can be estimated for both clearcutting and partial cutting for trees ranging from 3

cubic feet to 250 cubic feet. Cost estimates are in U.S. dollars per 100 cubic feet. 

Keywords: Costs (logging), logging economics, timber management planning, younggrowth stands, ponderosa pine.
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Introduction An important factor in plantation management planning is the effect of silvicultural

decisions on the cost of harvesting. It is generally more costly to harvest smaller

diameter trees than larger diameter trees and more costly to harvest lower volumes

per acre than higher volumes per acre. The cost penalties for low volumes per acre

and small trees differ among types of logging systems; for example, harvesting with a

cable system is typically more expensive than with a mechanized system, and the

incremental penalties of increasing costs also are greater when lower volumes per

acre or smaller trees are harvested. It is therefore appropriate to consider, at the time

the silvicultural prescription is developed, the type of harvesting system likely to be

used in a stand. With that system in mind, harvest costs can be estimated that will

indicate the effect of different management strategies on harvesting costs and total

financial return. If logging cost relations are ignored, prescriptions may be developed

that call for early thinning or frequent light thinning, which will reduce the overall

value of the regime, or cause the cost of the harvest to be more than the timber is

worth. Even on those lands where financial return from timber may not be the primary

goal, it is important to know that the costs of the anticipated regime are such that it is

feasible to implement the prescription. 

The PPHARVST application was specifically developed for use in exploring optimal silvicultural regimes for ponderosa pine (Pinus ponderosa Dougl. ex Laws.) plantations.

Realistic harvesting costs over a wide range of stand conditions are essential for

such an application because optimizing algorithms search more-or-less all possible

combinations of treatments. Some combination that ordinarily would not even be considered practical might be judged optimal if inappropriate costs are used. We have

taken care to develop cost relations that are sensitive to the stand variables that are

directly affected by silvicultural decisions and have a significant impact on harvesting

costs. The two most important variables determined by manipulation of stocking and

harvest age are the number of trees per acre harvested and the average volume per

tree for each harvest entry. 

The purpose of this paper is to describe PPHARVST and how it can be used to estimate

the cost of harvesting ponderosa pine plantations over a wide range of tree sizes and

volumes removed by three types of harvesting systems: a cable yarding system, a

ground-based cut-to-length harvesting system, and a ground-based whole-tree/loglength harvesting system (hereafter referred to as a “whole-tree system”). Enough

information is included to provide a clear understanding of the system configuration

and situation being simulated. It was not our intent to provide the information needed

to determine whether a particular system is appropriate for a particular situation. It is

presumed that the user will get the technical and policy information needed to make

that decision. The PPHARVST software, this document, and related documents can be

accessed from the Internet at http://www.fs.fed.us/pnw.

The production rates on which the model is based are drawn from the existing literature. These sources, resulting equations, and costing approach are described in

detail in Hartsough and others (1998). The capital and operating costs on which the

model is based were developed by use of a standard machine cost approach with

replacement purchase prices for new equivalent equipment. Equipment prices were

for January 1996. Those interested in the detailed assumptions have access to them

through the software and can change them if they wish. 

1
Description of

PPHARVST and

Requirements

Harvesting Systems

and Conditions

The PPHARVST application was developed for a Windows 95 operating system.1 A

PPHARVST exercise typically involves specifying a logging system, whether it is a partial cut or clearcut, the average slope yarding distance, slope, move-in distance, and

the number of acres being harvested at that location. Results are shown for a userspecified range of tree sizes in cubic feet and range of numbers of harvested trees

per acre. The resulting table of costs would then be an appropriate estimate of cost

for a single harvest, a series of harvests that might occur in a stand, or the cost for

alternative harvests or stands. Figure 1 is an abbreviated example of such a table

and the key assumptions on which the table is based. 

The model provides cost estimates for two systems on gentle terrain and one system

on steep terrain for both partial cutting and clearcutting. The following tabulation summarizes the circumstances covered:

Item Harvest parameters 

Terrain Gentle Gentle Steep 

System Whole-tree Cut-to-length Cable 

Tree size (cubic feet) 3-250 3-150 3-250 

Harvest type Partial cut Clearcut Partial cut Clearcut Partial cut Clearcut 

1 The use of trade or firm names in this publication is for reader

information and does not imply endorsement by the U.S. Department of Agriculture of any product or service.

2

Figure 1—Screen showing PPHARVST input values and results.
Gentle Terrain Systems

For the whole-tree and the cut-to-length systems, the equipment components are the

same for partial cutting and clearcutting but differ with tree size. For the yarding system, a smaller yarder is used for partial cutting than for clearcutting. With the exception of the yarding system for partial cutting, each system has one configuration for

small trees and one for large trees. The resulting production relations and costs were

developed by blending the proportions of the two configurations. The blending

process is explained below.

The whole-tree system for smaller trees consists of a feller-buncher, a skidder, a

stroke processor, and a loader; for larger trees, it consists of chainsaw felling and

processing, a skidder, and a loader. For harvests with average tree size of less than

80 cubic feet, the cost is based 100 percent on the feller-buncher system. For harvests with average tree size of greater than 150 cubic feet, the cost is based 100

percent on the chainsaw felling system. If average tree size is between 80 and 150

cubic feet, the cost is a weighted average of the two systems; i.e., if average tree

size is halfway between 80 and 150 cubic feet the cost is a 50:50 weighting of the

two systems. Figure 2 shows how the proportions of the two systems differ with tree

size. (We are not suggesting that these systems be used in combination in any given

harvesting operation.) The logic of this approach is that the two configurations represent but two choices from a continuum of configurations actually used, and this

blending of costs approximates the gradual shift to heavier equipment that tends to

occur as tree size increases. The other systems are blended similarly. Details on the

blending for all systems are found in Hartsough and others (1998).

The cut-to-length system for smaller trees consists of a small harvester, a forwarder,

and a loader; for larger trees, it consists of a feller-buncher, a stroke processor, a 

forwarder, and a loader.

3

Figure 2—Harvesting cost is a weighted average based on proportion

of volume harvested by two configurations going from 0 percent 

chainsaw felling for trees under 80 cubic feet to 100 percent chainsaw

felling for trees over 150 cubic feet.
How To Get Started

With PPHARVST

Installing PPHARVST on 

a Hard Drive

Entering Data Into

PPHARVST

The steep terrain system is a cable yarding system. For partial cutting, it consists 

of chainsaw felling, a small mobile yarder, and a loader. The yarding system for

clearcutting of smaller trees consists of chainsaw felling, an intermediate-sized mobile

yarder, and a loader; for larger trees, it consists of a combination of the same system

as for smaller trees and a system consisting of chainsaw felling, a large tower yarder,

and a loader.

PPHARVST runs under Windows 95/NT/98. It produces a table of harvesting costs in

dollars per 100 cubic feet (US$/cunit) for ponderosa pine plantations, over a range of

tree sizes (cubic feet per tree) and number of trees cut (trees per acre). The harvesting conditions are chosen by the user by selecting options on the program results

screen. The screen resembles a spreadsheet. 

The application was first created as an Excel spreadsheet. It was than converted to a

stand-alone program by use of Visual Basic and Formula One. All the calculation routines are available to the user through the Formula One Workbook Designer (double

right-click within the spreadsheet portion of the program window) or as an Excel

spreadsheet (open any saved spreadsheet in Excel). No software beyond PPHARVST

itself is necessary to use the program. 

Although PPHARVST does not require a spreadsheet program, it requires some dynamic link library files and other files that may not be available on all personal computer

sytems. Some of these are supplied with Visual Basic or Formula One; however, they

may be distributed without charge. To install PPHARVST and the required files, execute

the setupex.exe file that you downloaded from the PPHARVST web page and follow the

instructions in the setup program. The files will be transferred to the appropriate subdirectories on the hard disk, and a PPHARVST program icon will be created.

Double-click on the PPHARVST icon that shows up in Program Manager. The program

results screen will appear (fig. 3). The following four steps are required. 

1. Click on the top left combo box to select the type of harvesting system: whole

tree, cut-to-length, or yarding.

2. In the next box below, select the type of harvest: clearcut or partial cut.

3. In the fifth row in the spreadsheet area, enter an array of tree sizes, each in cubic

feet, beginning in cell C5. Any number of tree sizes may be entered, but no cell

within the range should be left blank because results for entries beyond a blank

cell will not be calculated. Tree sizes must be within the range of 3 to 250 cubic

feet (3 to 150 for the cut-to-length system). The tree sizes can be of any value

within the valid range; they do not have to be evenly spaced. 

4. In the second column, enter an array of removals, in number of trees per acre,

beginning with cell B6. Removals must be 400 trees per acre or less. 

4

Steep Terrain System
Changing Other 

Input Data

These are the minimum data entry requirements for the program to run. The data can

be modified if desired. Clicking the Calculate button will run the program and display

the cost results in the body of the spreadsheet table. You can save the results, modify the input data and resubmit to generate new results, or you can start over again

with a clear spreadsheet by clicking on the Clear button.

Slope, one-way slope skidding/forwarding/yarding distance, and the hourly costs per

productive machine hour (US$/PMH) for each of the different machines can be easily

changed by making entries in the appropriate boxes in the results screen. The number that appears when a change is needed in the hourly costs of one of the machines

is the default value. Once it is changed, the new value becomes the default value for

that session. If the session is saved, the changed value will remain the default value

if that session is reopened.

The average one-way distance is interpreted as either a skidding distance, forwarding distance, or yarding distance, depending on the harvesting system selected. It 

is limited to 1,200 feet for cable systems, which corresponds to an external slope

distance of 2,400 feet for rectangular units with parallel corridors. All yarders have

physical upper bounds on yarding distance, based on the line capacities of their drums.

Move-in costs can be a significant portion of the total cost where total removal volume is low. Move-in costs will be included in the results unless the “include” box,

under move-in costs, is unchecked. Values for the area harvested and the one-way

move-in travel distance for the equipment can be modified as needed. If the results

have been previously calculated, be sure to click Calculate again so that the results

will include the modified move-in costs.

5

Figure 3—Window that appears when PPHARVST is opened.
Saving and Printing

Changing the 

Spreadsheet 

Calculations (for 

Advanced Users)

Description of 

Calculation 

Spreadsheets

Use the Formula One Workbook Designer to save or print. Double-click on the right

button of the mouse while in the spreadsheet portion of the PPHARVST results screen

to activate the Formula One Workbook Designer. This spreadsheet program offers

great flexibility; it is compatible with Excel, and its use is similar to Excel.

To save the results and all the assumptions entered, select Write under the file menu.

Then choose the preferred format for your new file. Type the file name and extension

in the file name box. Choose from the following:

• Formula One format (vts) if it will be used later in the Formula One Workbook

Designer

• Excel spreadsheet (xls) if it will be used with Excel

• Tabbed text (txt) for use with another notepad or another word processor. In this

case, only the spreadsheet from which the command is executed is saved.

The results table can be saved for importation into another program by selecting that

table with the mouse, copying it, then pasting it into a file created by any appropriate

Windows application, such as Notepad, another word processor, or a spreadsheet.

The table can be printed from within the Formula One Workbook Designer by choosing that option under the file menu.

Exit either application by clicking the X in the upper right corner of the screen.

PPHARVST cannot be closed while the Formula One Workbook Designer is active.

If values of internal variables need to be modified, certain harvesting conditions

changed, or calculations of cost or productivity verified, these can be done with

PPHARVST by working in the Excel workbook through Formula One. Double-click on

the right mouse button. Then browse or make changes. Save changes by specifying

a vts format and typing in the file name and the vts extension. 

The changed workbook also can be saved as an Excel file. In this format, the data

entry and tabular calculation features developed with visual basic and Formula One

are not available.

The PPHARVST workbook includes five spreadsheets. Four are calculation routines; the

fifth is used only to display tabular results.

Flat—Flat contains all data and formulas for the whole-tree and cut-to-length systems.

The three most important variables—volume per tree, removals, and yarding distance—

are situated in the following cells: C2, C3, and C4, respectively. The values found in

these cells are the values left from the last calculation performed. Any changes to the

values of these cells will be reflected throughout the spreadsheet. Therefore, if there

is need to change the value of any of those variables, do it only from those cells, and

the productivities of all the machines will correspond to the data entered. The body 

of the spreadsheet includes the productivity relations for each piece of equipment

6
Running a Modified

Version of PPHARVST

Conclusions

included in any of the whole-tree or cut-to-length systems. Beginning on line 48, the

results for the whole-tree systems are summarized, with the productivity of each

machine in 100 cubic feet per hour (ccf/h), its cost per PMH, and finally the cost per

ccf. The summary of the results for the cut-to-length systems begins on line 61.

Steep—Steep contains all data and formulas for the yarding systems, in similar order

to that in “flat.” Beginning on line 60 is the summary of the partial cut yarding system

with the productivity of each machine in ccf/h, the corridor change costs, the cost per

PMH, and finally the cost per ccf. A similar summary for the clearcut yarding system

begins on line 68; one difference is that line and landing shift costs are included

instead of corridor change costs. From line 34 to 55, the corridor change, line, and

landing shift costs are explained.

Machine cost—PPHARVST allows the user to change the cost per PMH directly (and

shows the default value), but through Formula One, any of the assumptions for parameters such as machine life, salvage value, and fuel cost per gallon also can be

changed. The parameters are named in the first column of the spreadsheet, and data

for any one machine are listed in the column under the name of that machine.

Move-in cost—The calculations for each component of move-in cost are displayed in

this spreadsheet.

To reload a modified version of PPHARVST, open PPHARVST and Formula One. 

Then read in the vts file with the version of PPHARVST you want with the File, Read

command. 

The PPHARVST application was developed with machine productivities found in the 

literature. Machine costs were based on 1996 equipment prices. Selection of studies

and adjustment of productivities were done to make PPHARVST as applicable as possible to ponderosa pine plantations. The PPHARVST model is a general model intended

to be used for broad planning applications. It develops estimates for a limited number

of machines across the range of tree sizes; it estimates for intermediate sizes

through an interpolation process. This results in a smooth transition of cost over the

range of tree sizes and volumes per acre for a particular type of machine configuration. It may be necessary to adjust productivity equations or equipment costs to make

a reasonable cost estimate for a particular setting with a particular machine. The

model was not designed for that purpose. The PPHARVST application does not allow

estimating of costs beyond those considered reasonable extrapolations of the data

and beyond reasonable limits imposed by machine performance characteristics. The

ranges allowed, however, should accommodate most any regime that might be contemplated for management of ponderosa pine plantations with a timber production

objective. Because the variability in natural stands of mixed species is much greater

than in ponderosa pine plantations, these cost estimates should not be used for

those types of stands without some corroborating data.

7
Literature Cited

Glossary

Hartsough, Bruce R.; Gicqueau, Alex; Fight, Roger D. 1998. Productivity and cost

relationships for harvesting ponderosa pine plantations. Forest Products Journal. 

48(9): 87-93.

Area harvested—The total area in acres to be harvested by one harvesting system

during one entry.

Ccf—100 cubic feet.

One-way move-in distance—Distance in miles that equipment is transported to

reach the harvest unit.

Operator wage and benefit rate—Total cost per scheduled hour for the operator or

crew.

Skidding/forwarding/yarding distance—This is the skidding distance for the

whole-tree system or the forwarding distance for the cut-to-length system or the yarding distance for the cable yarding system. In all cases, it refers to the average (not

external) one-way distance measured along the slope.

Slope—The average fall-line slope for the harvest unit, measured as a percentage.

Trees/acre—Number of trees per acre being harvested.

Tree volume—Average volume in cubic feet to the merchantable top diameter of

trees being harvested.

Utilization rate—Productive hours divided by scheduled hours.

Vts—Extension applied to Formula One output files.

8
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Fight, Roger D.; Gicqueau, Alex; Hartsough, Bruce R. 1999. Harvesting costs for 

management planning for ponderosa pine plantations. Gen. Tech. Rep. PNW-GTR467. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest 

Research Station. 8 p.

The PPHARVST computer application is Windows-based, public-domain software used to

estimate harvesting costs for management planning for ponderosa pine (Pinus ponderosa Dougl. ex Laws.) plantations. The equipment production rates were developed

from existing studies. Equipment cost rates were based on 1996 prices for new equipment. Harvesting systems include a cut-to-length harvester-forwarder system, a wholetree/log-length skidder system, and a skyline cable system. Harvesting costs can be estimated for both clearcutting and partial cutting for trees ranging from 3 cubic feet to 250

cubic feet. Cost estimates are in U.S. dollars per 100 cubic feet. 

Keywords: Costs (logging), logging economics, timber management planning, younggrowth stands, ponderosa pine.

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