United States Department of Agriculture

Forest 

Service

General Technical 

Report NRS-128

Northern 

Research Station April 2014

User’s 

Guide to 

SILVAH

A Stand Analysis, Prescription, and 

Management Simulator Program for 

Hardwood Stands of the Alleghenies

Peter D. Knopp and Susan L. Stout
Visit our Web site: www.nrs.fs.fed.us

Published by: For additional copies:

U.S. Forest Service U.S. Forest Service

Northern Research Station Publication Distribution

11 Campus Blvd, Suite 200 359 Main Road

Newtown Square, Pa 19073-3294 Delaware, OH 43015-8640

Fax: 740-368-0152

April 2014 Email: nrspubs@fs.fed.us

Abstract

This user’s guide for the SILVAH computer program, version 6.2, supersedes the 1992 

user’s guide (Gen. Tech. Rep. NE-162). Designed for stand-alone Windows-based 

personal computers, SILVAH recommends a silvicultural prescription for a forest stand 

based on a summary and analysis of field inventory data. The program also includes a 

simulator that can be used to project stand growth and development, estimating yields 

from either prescribed or user-defined treatments. The software is distributed with an 

online help system and this printed user’s manual. The computer program described in 

this publication is available on the Internet at http://nrs.fs.fed.us/tools/silvah

The Authors

PETER D. KNOPP is a former information technology specialist affiliated with two 

research units of the Northern Research Station.

SUSAN L. STOUT is Project Leader and research forester of the Northern Research 

Station’s Unit for Sustaining Forests in a Changing Environment and is located in 

Irvine, Pennsylvania.

The computer program described in this publication is available on request with the 

understanding that the U.S. Department of Agriculture, the Forest Service, or the authors 

cannot assure its accuracy, completeness, reliability, or suitability for any other purpose 

than that reported. The recipient may not assert any proprietary rights thereto nor 

represent it to anyone as other than a Government-produced computer program. 
Contents

Introduction.................................................................................................................................. 1

Chapter 1 - SILVAH Overview...................................................................................................... 5

Chapter 2 - Installing SILVAH On Your Computer..................................................................... 10

Chapter 3 - Data Entry and Manipulation................................................................................... 12

Working with Grid Tables......................................................................................................... 17

Entering Overstory Data........................................................................................................... 20

Entering Understory Data........................................................................................................ 26

Entering Nonnative Invasive Species......................................................................................... 29

Importing Data........................................................................................................................ 32

Chapter 4 - Setting up a Defaults File.......................................................................................... 38

Calculation Settings.................................................................................................................. 41

Plant Species Information......................................................................................................... 44

Chapter 5 - Analysis and Prescription.......................................................................................... 48

Establishing a List of Stands to Run.......................................................................................... 49

Script Files................................................................................................................................ 51

Reports..................................................................................................................................... 52

Silvicultural Prescriptions.......................................................................................................... 56

Stand Growth Projection.......................................................................................................... 63

Database Output...................................................................................................................... 64

Running Stands........................................................................................................................ 65

Chapter 6 - TreeCalc, A Volume and Value Calculator................................................................. 67

Chapter 7 - SILVAH Calculations................................................................................................. 70

Volume and Value Calculations................................................................................................ 72

Chapter 8 - Data File Format........................................................................................................ 76

Appendix A - Codes and Input Definitions.................................................................................. 81

Appendix B - Sample Output........................................................................................................ 90

Appendix C - Troubleshooting......................................................................................................106

Appendix D - Tally Sheets.............................................................................................................107

Glossary.........................................................................................................................................111

References......................................................................................................................................118

Index ..........................................................................................................................................121
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1

Introduction

This user’s guide describes how to use SILVAH, a computer program that recommends a silvicultural

prescription for a forest stand, based on a summary and analysis of field inventory data. As such, it is

an “expert” system. The program also includes a simulator that can be used to project stand growth

and development, estimating yields from either prescribed or user-defined treatments. The program’s

acronym—SILVAH—stands for Silviculture of Allegheny Hardwoods, although it has been updated

to include guidelines for mixed oak forests in the Mid-Atlantic region. Thus, SILVAH incorporates

the current knowledge about silvicultural treatments in cherry-maple, beech-birch-maple, and mixed

oak forests in the Alleghenies, and packages all the decisionmaking criteria that have been developed

through research into a form that is easily used by practicing foresters.

The SILVAH computer program was first developed in 1985 and was thoroughly tested on lands of the

Hammermill Paper Company (later International Paper Company). Revisions based on their experience

resulted in version 2 of the program—the first version made available for public distribution in 1986.

Periodic revisions and improvements were made since then. The most significant improvements resulted

from development of guidelines for mixed oak forests, work completed through a partnership among

the U.S. Forest Service Northern Research Station, the Pennsylvania Department of Conservation and

National Resources (DCNR) Bureau of Forestry, the Pennsylvania State University, and others. The

current version (6.2) is described in this user’s guide.

The user’s guide is divided into the following chapters: Chapter 1 describes the purpose and function of

the program in general terms, Chapters 2 through 6 provide detailed instructions on use of the program,

Chapters 7, 8, and Appendix A provide information on program organization and data formats.

Proper use of the SILVAH program requires some knowledge of silvicultural principles in Allegheny

forests. A summary of the silvicultural information on which SILVAH is based is presented in the 1992

U.S. Forest Service General Technical Report NE-96 (revised), “Prescribing Silvicultural Treatments

in Hardwood Stands of the Alleghenies,” by David A. Marquis, Richard L. Ernst, and Susan L.

Stout, and the 2008 General Technical Report NRS-33, “Prescribing Regeneration Treatments for

Mixed Oak Forests,” by Brose et al. Separate 4-day training courses based on silviculture in Allegheny

hardwoods and silviculture in mixed oak forests are given each year by the Northern Research Station in

cooperation with the extension service of The Pennsylvania State University, the Pennsylvania DCNR

Bureau of Forestry, and the Jefferson County Conservation District. A 1-day course on the use of the

SILVAH computer programs is also given periodically. A nominal fee exists for both courses. Further

information may be obtained from the Warren Forestry Sciences Laboratory, Northern Research

Station, PO Box 267, Irvine, PA 16329; telephone: 814-563-1040.

Every effort is made to provide accurate and useful information. However, the U.S. Department of

Agriculture, the U.S. Forest Service, and their employees and contractors assume no legal liability for

the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed

herein. Neither the U.S. Forest Service, nor their employees and contractors makes any warranty,

express or implied, including the warranties of merchantability and fitness for a particular purpose with

respect to SILVAH software or documentation.
2

About Forest Management Decision Support

Our knowledge of the factors affecting regeneration, growth and yield, and proper management of

forest stands has improved dramatically, especially during the past 30 years. In spite of this vast amount

of scientific information, the practice of silviculture is still more of an art than a science. Subjectivity

and intuitive judgment are required to determine the most appropriate silvicultural treatment and to

apply that treatment in individual stands. For example, we know that successful regeneration after

clearcutting in many eastern hardwoods is highly dependent upon advance seedlings. But how many

advance seedlings are needed? How does the number vary with size of seedling, with site, and with deerbrowsing pressure? How can one evaluate seedling numbers without tedious and costly surveys? What

levels of advance reproduction will permit overstory removal, and what levels require other methods to

establish and culture adequate regeneration?

The thrust of silvicultural research by the Northern Research Station units in Warren, PA; Morgantown,

WV; and Delaware, OH, has not been only to identify important factors and discover how they

function in regulating regeneration or stand growth, but also to develop objective guidelines on how

much is enough or too much in particular circumstances. These guidelines have been integrated into

a complete stand analysis and prescription procedure that provides a systematic way of measuring and

evaluating critical stand conditions and using that data to arrive at a recommended treatment.

This “system” involves a stand inventory of basic overstory, understory, and site factors that are

then summarized and analyzed to evaluate the stand’s potential for growth and regeneration. The

necessary calculations can be done by hand, but we recommend use of the computer program for

increased precision and efficiency. Then, decision tables are used to determine the proper prescription

based on critical levels of the various site, overstory, and understory variables in combination with

landowner objectives.

Since all steps of this process are based on stand and site parameters that have been measured during

a sample inventory, the entire process can be handled by a computer. SILVAH was written for

this purpose.

After field data are entered into the computer, SILVAH performs a data summary, outputting all of

the tabular data that one normally expects from a stand inventory. In addition to the tabular data,

SILVAH prints an analysis of the stand, rationale for stand treatment, and a specific recommendation

or prescription in an easily understood, narrative form. Details on application of the recommended

treatment are also provided. If that treatment is a partial cutting of any kind, SILVAH provides specific

marking instructions on which sizes, qualities, and species of trees to cut; the volumes involved; and

information on the desired residual stand.

Once an inventory is made, SILVAH does the entire job of analysis, prescription, and marking

instruction preparation. It even assists with report writing, providing text files that can be incorporated

directly into such reports as the Environmental Analysis Report in the National Forest System, or the

Landowner Management Plan prepared by most service foresters and consultants. In fact, we have

found the narrative to be especially valuable in dealing with nonindustrial private landowners, who are

more likely to accept a forester’s recommendations when they are backed by documentation that they

can read and understand. Thus, SILVAH greatly reduces the amount of time required for all aspects of

silvicultural decisionmaking and ensures consistency across all areas and among all individuals.
3

Obviously, no system of this sort can substitute for professional judgment, nor is it intended to do

so. The prescriptions are based on average or usual situations. Circumstances not evaluated may often

dictate that the recommendations be modified, or landowner objectives may deviate from those

assumed, or the guides just may not work in every situation. So the system provides a starting point

or standard that must be verified by professional judgment. Nevertheless, it greatly reduces the work

involved and generally improves the quality of decisions made by professional silviculturists.

Several additional features of SILVAH greatly expand its capabilities beyond those already described.

SILVAH also optionally outputs stand summaries into a format that can be incorporated into a

database, using key information from the original stand plus data on any cut and residual stands

that may result. Output data from individual stands can be combined into a single file which

facilitates the development of a forest-wide inventory database that provides a powerful tool for forest

management planning.

If a cruise is completed in each stand before treatment, a complete inventory can be built up even

on large properties over a 10- or 15-year period. With such a complete database, extremely accurate

information is available. Managers can query the database to find out virtually anything they need to

know about the property. For all properties, selected forest districts, or individual properties, managers

can quickly determine how much volume they have in any or all stand classes, how many areas are ready

for harvest, how many are in need of herbicide treatment, and so forth. Unlike many similar sorts of

inventory systems, the database output from SILVAH permits users to identify each of these stands on

the ground. For example, managers can not only determine that there are X acres needing herbicide

treatment, but also can get a listing of the stand, property, and district where every one of those acres

is located.

SILVAH also makes it easy to test treatments other than the recommended one. Users can choose

one of the many standard cuttings built into SILVAH, or they can modify these standard cuttings to

fit particular needs. Each of these standard cutting methods provides a specific formula for control of

residual stand density, structure, species composition, and quality. As a result, it is very easy to specify

common types of cuts with just a few instructions. The ability to specify individual species, diameters,

and quality classes of trees to cut is also provided. After each treatment used, printouts showing the

effect of that treatment on cut volumes and residual stand parameters may be obtained. It is easy to test

the immediate effect of alternative treatments.

Another feature of SILVAH is a stand growth simulator. Individual stand projections can be made and

the expected yield can be estimated under virtually any treatment one desires. If the projections are

made using SILVAH expert-recommended prescriptions, SILVAH will recommend a treatment at the

end of each 5-year projection interval. When this is done, the end result is a recommended schedule

of silvicultural treatments for that stand from the present to the end of the rotation. A typical output

for such a run might include the recommendations that the stand be thinned now, thinned again in

15 years, then clearcut 35 years from now. If the projections are made with modifications to standard

treatments or custom, user-specified treatments, SILVAH will attempt to implement the treatment at

the end of each 5-year projection interval. Either way, detailed estimates of the yields (in volume and

value) from each cut and for the entire period are included.

However, we do not visualize most stands being analyzed by time-consuming trial and error simulation.

Simulators should not be used extensively by practicing foresters for routine stand prescription.
4

It would be time consuming and costly to do this for any large number of stands, and subject to many

erroneous conclusions by individuals unfamiliar with the simulator’s function and limitations. The

recommendations that are incorporated into SILVAH are themselves the result of many simulation runs

to determine treatments that maximize particular products under particular conditions. Expert system

programs such as SILVAH, which make definite recommendations based upon usual responses of

similar stands, are likely to be the most useful approach to daily silvicultural decisionmaking.

However, we do see another major use for simulators in connection with the database generated

by SILVAH. As that database is built, it is possible to project each stand, and to accumulate these

projections and prescriptions in the database, thereby incorporating the expected inventory at any time

in the future. Such projections could drastically reduce the amount of field work needed by permitting

computer updating of the database and by eliminating the need for field work during future inventories

in stands that will not require treatment. Furthermore, the database can be queried to quickly estimate

how much volume there will be or how many stands (or acres) will be ready for final harvest in

the future.

The stand analysis and prescription system on which SILVAH is based was originally developed for

Allegheny hardwoods— a variation of the northern hardwood type in which black cherry is a major

component. As a result of some recent research advances in evaluation of stand density that can be

applied in eastern hardwoods of almost any species composition, by adopting more general data

collection procedures and by incorporating research information on oaks, we have broadened the

application of the procedure to beech-birch-maple, cherry-maple, oak-hickory and transition forest

types. Many of the critical factors affecting prescriptions are the result of localized conditions, so

the stand analysis system and program SILVAH should not be applied unquestioningly outside of

the Allegheny Plateau and Allegheny Mountain provinces of Pennsylvania, New York, Ohio, West

Virginia, Maryland, and New Jersey. Nevertheless, the basic procedures could easily be adapted to

other forest regions by incorporating decision criteria and critical levels appropriate to the type and

geographic area.

SILVAH operates on individual stands without consideration of the landscape context in which

they occur. Many forest management considerations, such as wildlife habitat or aesthetics, are better

assessed on larger landscapes. NED-2, another Northern Research Station decision-support tool,

downloadable from their website (located at www.nrs.fs.fed.us/tools/ned, as of the time of this

printing), can interpret SILVAH data files and provide this type of landscape assessment.
Chapter 1 - SILVAH Overview

Getting Started

This chapter provides an overview of the SILVAH system and briefly describes the major features.

Follow these steps to get started with SILVAH:

1. Review this chapter.

2. Browse the table of contents, index, and reference material in the appendices, so you can

quickly find answers to any questions that arise as you use SILVAH.

3. Install SILVAH on your computer. See Chapter 2 on installation for further instructions.

4. Run SILVAH using the sample data file included in the installation. This will help you

become familiar with SILVAH and will also assure you that SILVAH is working properly on

your machine. Refer to Chapter 5 on running analysis and prescription to become familiar

with the software.

5. Refer to Appendix C on troubleshooting for coverage of some issues and their solutions. If all

else fails, feel free to contact us using the information below.

The computer program described in this publication is available on request, as well as on the Internet

at http://nrs.fs.fed.us/tools/silvah, with the understanding that the U.S. Department of Agriculture

cannot assure its accuracy, completeness, reliability, or suitability for any other purpose than that

reported. The recipient may not assert any proprietary rights thereto nor represent it to anyone as

other than a government-produced computer program.

We welcome your suggestions on how to improve SILVAH. If you need help or have comments,

please write to:

Northern Research Station

USDA Forest Service

Forestry Sciences Laboratory

PO Box 267

Irvine, PA 16329

(814) 563-1040
6 User’s Guide to SILVAH: Chapter 1 - SILVAH Overview

Getting Help with SILVAH

Online help is available for many SILVAH6 features.

Quick access to help within SILVAH6 can be achieved by the following actions:

• Press F1 for information on the active SILVAH6 window or dialog.

• Double-click a column or row header for help with a particular variable.

To launch the help system within SILVAH6, from the Help menu, click Help with SILVAH6, or

outside SILVAH6, from the Start menu, select Programs - Silvah6 - Help on Silvah6.

When a topic is displayed in the help system, click the Contents tab to see where the given topic fits

within the organization of the help system.

In the help system, click the Index tab to find topics of interest. Click the Search tab to find all

topics that reference a word or phrase.

SILVAH Layout

SILVAH consists of four main components. Through these components, you will find the features

that enable you to input and analyze forest stand data and perform calculations on individual trees

in a stand. To access these features, click on the large buttons at the top of the SILVAH window as

shown in Figure 1 described below.

Figure 1.—The SILVAH6 program showing a list of tree records in Inventory Entry.
User’s Guide to SILVAH: Chapter 1 - SILVAH Overview 7

Calc Settings and Species

This component provides settings that allow for customization of timber pricing and volume

estimations. In addition, you can establish the minimum amount of volume required for SILVAH to

prescribe intermediate commercial cuts (thinnings). You can indicate which species are desirable or

undesirable, exotic or native, and SILVAH will use this information in evaluating stand conditions.

You can also create custom species identification codes (mnemonic codes) for use in your field

inventory. See Chapter 4 for more detail on these functions.

Inventory Entry

In this component, you can enter data, save it to a file, edit an existing file, and convert older data

formats to the current up-to-date format. You can also import data from other sources. See Chapter 3

for more detail on these functions.

Analysis and Prescription

This is the component in which SILVAH analyzes forest stands and generates reports of the results.

SILVAH can summarize inventory data regarding stand volume and value, structure, and species

composition, understory regeneration data, and site conditions. You can write your own prescriptions

or ask SILVAH to recommend one. You can simulate stand growth and develop prescriptions for

projected stand conditions in the future. All SILVAH output is produced in text report files that can

be opened in any word processor. You can also create database output that allows you to compile

information into a single table that can be used in a database. SILVAH can analyze the current

inventory data loaded into memory, as well as any number of stands all during the same run. See

Chapter 5 for more detail on these functions.

Tree Calc

This component (hereafter referred to as TREECALC) provides a way to calculate the volume

and value of individual trees. It is an electronic volume table. TREECALC uses the same volume,

density, grade distribution, and value equations used in SILVAH when it analyzes stands and writes

prescriptions, so it gives you a convenient way to check on answers produced during analysis of forest

stands. TREECALC can also be educational; by examining the volumes and values of a few trees with

this feature, you will have a much better understanding of the procedures that SILVAH uses in its

inventory processing. TREECALC is also useful any time you want to calculate and sum values on a

small number of individual trees. See Chapter 6 for more detail about this SILVAH feature.

System Requirements

SILVAH will run on any Microsoft Windows computer. On early versions of SILVAH (early 1990s),

when systems were much slower, hardware made a significant difference in the performance of

SILVAH. Currently, any personal computer should be able to process your data quickly (in seconds)

without any noticeable delays.

Earlier versions of SILVAH ran on DOS (the predecessor of Windows), and therefore required a file

called “ansi.sys” to provide user interface features. SILVAH no longer runs on DOS nor does it use

screens that resemble the old DOS interface of previous versions (prior to version 6.0).
8 User’s Guide to SILVAH: Chapter 1 - SILVAH Overview

A minimum of 5 megabytes (MB) of disk space is required for the installation of the software. A

monitor with 800x600 resolution or higher is recommended.

An important software requirement should be noted. In order to take advantage of new installation

technologies for improved system security and to enhance deployment over the internet, SILVAH

uses the Microsoft Windows Installer technology (version 3.1 or newer), which requires relatively

recent versions of Windows in order to run the installation. The installation requires Windows 2000

service pack 4 or newer versions of Windows.

No other software is required to run SILVAH. All of the output is generated as plain text files that can

be opened in Notepad or WordPad—applications that are packaged with Windows.

Discontinued Features

SILVAH 6 provides a major redevelopment of the traditional SILVAH user interface. The use of

DOS-like screens for stand processing has been replaced by Windows interface tools. As a result of

the new SILVAH interface design, the following features have been discontinued in SILVAH 6.

Analysis and Prescription Operating Mode

Formerly there were three operating modes when analyzing stands: Interactive, Script, and Batch.

You had to tell SILVAH which mode you were using during a run. In the current version of SILVAH,

there is no operating mode. Instead, how you use the program will directly control what it does. You

can still work interactively on a single stand, using the mouse to select options, and asking SILVAH

to provide reports and prescriptions as desired. You can go one step further to save your processing

options in a script file to reuse the same set of options repeatedly.

Batch Processing

There is no longer a utility for processing separate lists of stands against multiple script files all in one

run. Batch processing of stands has been replaced with a new capability of using the mouse to browse

and select multiple stands for processing. You can process as many stands as you want, regardless of

whether you are working interactively or with a script file. You can store the list of stands for future

use if desired.

Simulation Output (.syy) and Database Output (.dyy) Files

Simulated stand data was formerly output into files ending with the .yy extension. The ‘yy’ indicated

the projection year for a simulated stand. Thus, if you started with a file called MYSTAND.sil which

was tallied in 2008, and projected that stand for 20 years, the simulated output file would have been

called MYSTAND.S28. In older SILVAH versions (pre-version 5.5) this data could be re-entered into

SILVAH for further processing if desired. Similarly, if you had asked for database output at the end

of the projection period, a file called MYSTAND.D28 would have been created. Database output

files of this naming convention have been discontinued. However, database output remains and has

been enhanced in the current version of SILVAH. Database output now goes into a user-selected file

name, and if you are processing multiple stands, data from all stands will be output into the file that

you specify.
User’s Guide to SILVAH: Chapter 1 - SILVAH Overview 9

Data, Output, and Script-batch File Directories

SILVAH no longer maintains any directories for your files. Furthermore, these directories are no

longer stored in the defaults (.def ) file. For each stand that you select for processing, all output

associated with that stand will be created in the same folder in which the stand originated. Database

output is generated into a folder and file that you specify.

Adding Stands Together

Formerly SILVAH would let you add (combine) stands into one printout, giving you the average

or total volume or value of a tract. This feature has been discontinued. To achieve similar results,

use the database output feature of SILVAH6 to accumulate summaries of multiple stands, and use a

spreadsheet program to open the database output and summarize the columns with headings such

as “[net cd vol],” “[net bdft vol],” and “[value].” Alternatively, you can import SILVAH stands into

NED-2 software, or manually input table results into a spreadsheet to produce averages or totals.
Chapter 2 - Installing SILVAH On Your Computer

Installation Procedure

The SILVAH installation requires Administrative privileges.

The installation and setup of SILVAH requires the Microsoft Windows Installer engine, version 3.1

or newer. You may already have Windows Installer 3.1 if you have Windows XP service pack 2 or

newer. The SILVAH setup will automatically determine whether or not you need to upgrade the

Windows Installer on your machine. If the SILVAH setup does not find the correct version of the

Windows Installer, the setup will stop and inform you that it cannot proceed until you upgrade the

Windows Installer on your computer. If you do not have the proper version of the Windows Installer

engine, you can download it for free from Microsoft Corporation. NOTE: You will need to have

administrator privileges to upgrade the Windows Installer engine, and a system reboot is required

after the Windows Installer upgrade.

Follow the prompts on the SILVAH setup to install SILVAH on your computer.

Whether you install from a CD or from the web, we encourage you to visit the SILVAH

website (http://nrs.fs.fed.us/tools/silvah/) to check for updates that are newer than your full

installation package.

Installing from CD

To begin the installation, insert the SILVAH CD into the CD-ROM drive. If auto-play is enabled on

your computer, the installation program will launch automatically. If the CD does not start within

5-10 seconds, follow these steps below to start the setup manually:

1. From the Start menu, click Run, and from the Run dialog box, enter “d:\silvah6setup.exe,”

where “d:” is the name of your CD-ROM drive.

2. Click OK.

3. Follow the installation instructions on the screen.

Installing from the web

You may download the installation from the SILVAH website, as of the time of this printing, at

http://nrs.fs.fed.us/tools/silvah/. Do not click Run from the pop-up window. Instead, click Save to

download the SILVAH setup, then run it. The SILVAH setup is called “silvah6setup.exe.”

Starting up SILVAH after a successful installation

Immediately after the installation has finished successfully, you may start the SILVAH program

as follows:
User’s Guide to SILVAH: Chapter 2 - Installing SILVAH On Your Computer 11

1. From the Start menu, click Programs (“All Programs” in Windows XP).

2. Click Silvah6 from the list of installed programs.

3. From the pop-up list of options, click Silvah6.

Creating a desktop shortcut to the SILVAH program

1. From the Start menu, click Programs (“All Programs” in Windows XP).

2. From the list of installed programs, click SILVAH6.

3. From the pop-up list of options, right-click SILVAH6.

4. From the pop-up menu, click Copy.

5. Move the cursor to your desktop.

6. Right-click anywhere in the open space on your desktop.

7. From the pop-up menu, click Paste Shortcut. You can use this shortcut to launch SILVAH

from the desktop.
About Inventory Entry

Inventory Entry is where you create and edit data files (.sil). Proceed with the steps below to learn

about Inventory Entry using the sample file distributed with SILVAH.

To start SILVAH 6 and open the sample file:

1. Click the Windows Start menu button. Click Programs (“All Programs” in Windows XP),

then click Silvah6 from the list of programs. Click Silvah6 from the SILVAH6 program

options. When it starts up, SILVAH6 automatically selects the Inventory Entry component.

2. On the menu at the top of SILVAH6, click File.

3. From the File menu, click Open SIL file.

4. Browse to the SILVAH6 installation folder (default = C:\USFS-NRS\SILVAH6) and select the

newdemo.sil file.

5. Click Open. 

NOTE: Data that uses species identification codes other than the default codes known internally

by SILVAH require the use of a defaults (.def ) file to properly interpret species. See the topic “About

SILVAH defaults” in Chapter 4 for more information. The newdemo.sil file opened in step 4 above

uses default species codes, allowing it to be viewed successfully without opening a defaults file. 

• Click the Inventory Settings tab to review the inventory settings for the stand. Inventory settings

are stored with your data and can be edited once you have opened the data file. Inventory settings

can be retained as a set of defaults and applied to all of your new stands if you intend on following

the same inventory procedures (see the topic on entering stand inventory settings for more details).

You should specify your inventory settings before you begin entering data.

• Click the Stand tab to examine stand detail which identifies the stand and includes management

guidelines that are used by SILVAH when writing a prescription for the stand. You will see separate

blocks for management information, identification, and physiography and site data for the stand.

• Click the Trees tab to examine the overstory (tree) data. All of the plots and trees will appear

together in a large matrix, with each row pertaining to a single tree, and columns containing data

about the tree. The plot and tree number appear off to the far left in dark gray columns to signify

that they cannot be edited. To help your eye distinguish data from each plot at a glance, rows of

trees of every other plot are colored in light gray—this data is editable.

Chapter 3 - Data Entry and Manipulation
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 13

• Click the Understory Plots tab to examine the understory data. Each column represents a plot.

Desirable regeneration (collected in the 6 foot or milacre regeneration plot) is represented by the

upper rows which contain desirable tree regeneration, saplings, and residuals. The lower rows

contain data that is collected in the interference plot, such as tall woody interference, percent fern

cover, and site limitations.

• Click the NNIS Observations tab to examine the nonnative invasive species (NNIS) data. In the

left side of the screen, rows represent the presence of NNIS in the regeneration plots. In the right

side of the screen, check boxes indicate the presence of NNIS outside of the regeneration plots

within the stand or near the stand.

Starting a New Stand

You can edit one stand at a time. When you are ready to start a new stand (a new data file), follow

these steps:

1. Click the Inventory Entry button.

2. From the top menu, click File, then click New SIL File. You may also try the shortcut, [Ctrl] 

+ [N] (press and hold the Control [Ctrl] key and then press the letter “N”), to start a new

file. If you have previously been editing data, SILVAH will prompt you to save the changes

before starting a new file.

3. Click the Stand tab to enter appropriate information about the stand.

4. Click the Inventory Settings tab to enter the inventory settings for the stand.

5. Click the other tabs to enter plot data.

6. Be sure to save your work. Your stand will be stored in a new data (.sil) file. You may continue

to enter overstory and understory data if necessary.

See Chapter 5 to learn about analyzing a stand and about prescription and report options.

Saving Your Data

To save the current inventory data to a file:

1. Click the Inventory Entry button.

2. From the top menu, click File, then click Save SIL File. You may also try the shortcut, [Ctrl] 

+ [S] (press and hold the Control [Ctrl] key and then press the letter “S”), to save a file. The

file will contain the data for one stand only.

3. If you are saving the data for the first time, enter a file name, and be sure you are aware of the

folder where the file is being created.
14 User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation

Generating Raw Screen Output

You can create raw output of the data that appears on the screen. This may be useful in proofreading

data, plant species codes, and other items in SILVAH.

Raw output can be generated for any of the SILVAH screens. The output is formatted in HTML and

is automatically opened in your default web browser.

To generate raw output from any screen:

1. Click the View menu at the top of the SILVAH window.

2. From the View menu, click Raw Output of Current Screen. You may also try the shortcut,

[Ctrl] + [h] (press and hold the Control [Ctrl] key and then press the letter “h”), to generate

raw output of the current screen in HTML format.

Opening an Existing Data File

To open an existing data file:

1. Click the Inventory Entry button.

2. From the top menu, click File, then click Open SIL File. You may also try the shortcut,

[Ctrl] + [O] (press and hold the Control [Ctrl] key and then press the letter “O”), to open

a file.

Converting Data from Older Versions

SILVAH has existed since the 1980s. As it evolved, additional capabilities were added. Along with

those additions came format changes in the data. To accommodate older formats, SILVAH can

convert files going back to version 4.0. The program attempts to read the old formats directly, and

when you save the file, the data will be saved in the current format.

It is recommended that you back up your older files before converting them to the current format.

Converting older data requires a few simple steps. You must also review the data to ensure it was

correctly interpreted.

1. Click the Inventory Entry button.

2. Open the data (.sil) file that contains data with an older format.

3. Once the data has been loaded, review the data to be sure it is accurate. Pay close attention

to inventory settings, management information, and understory woody interference, as these

items have gone through several revisions over the years.
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 15

4. If you are working with a file that has already been backed up, save the file. If you are not sure,

then click File, click Save As..., and use a slightly different file name in order to preserve the

contents of the original data file.

5. Data processed in this way will be saved in the current SILVAH6 file format.

Entering Stand Inventory Settings

It is important to provide information on how your stand data was collected in order for SILVAH to

be able to analyze your data and properly assess your stand. Inventory settings are stored with your

data, in the .sil file, so they can be readily available to SILVAH.

1. Click the Inventory Entry button.

2. Click the Inventory Settings tab.

3. Enter your settings. See below if you want to establish these settings as defaults.

Establishing Default Inventory Settings

If you think you will sample your stands the same way repeatedly, you can establish a set of default

inventory settings that will be applied each time to you start a new stand.

To establish defaults that match the current settings you have entered in the Inventory Settings tab:

1. Click the Make these your default inventory settings button.

2. The next time you create a new stand, it will inherit the default settings. Of course, you can

modify the settings for a stand at any time.

Entering Stand Management Information

In writing a prescription for your stand, SILVAH requires information on management policies,

goals, and other factors that may affect the treatment options for the stand.

These questions are of vital importance because they influence the kind of prescription generated by

SILVAH. To record your management information, such as deer impact, restrictions on silviculture

systems, whether to start regenerating the stand now, etc.:

1. Click the Inventory Entry button.

2. Click the Stand tab.

3. Provide your answers in the upper section labeled “Management.”
16 User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation

Establishing Default Management Guidelines

If you think that the same management policies, goals, deer impact, etc. will apply to most of

your stands, you can establish a set of default answers that will be applied each time to you start a

new stand.

To establish defaults that match the current settings you have entered on the Stand tab:

1. Click the Make these your default mgmt settings button.

2. The next time you create a new stand, it will inherit the default settings. Of course, you can

modify the settings for a stand at any time.

Entering Stand Identification Data

Identification data helps identify the stand when you examine reports. Currently, this information is

not used in writing a prescription.

To provide a unique stand ID, county, land cover type, comments, etc.:

1. Click the Inventory Entry button.

2. Click the Stand tab.

3. Provide your answers in the upper section labeled “Identification.”

Entering Stand Physiography and Site Data

The sum total of all factors in a stand, such as climate, physiography, soil, and vegetation results in a

site with specific characteristics important to tree growth and forest management. As an expression of

site quality (productivity), you can record site index and species, or site class.

Stand area and site index or class are used by SILVAH in determining a prescription. If you elect to

follow the prescription charts for oak, you are required to provide information about site quality.

Site class can be used as an alternative to site index. You do not need to record both site index and

site class.

If you are not recording heights, you may use a merchantable height adjustment if the SILVAHestimated heights are not representative for your site. 

Valid merchantable height adjustment values

range from 0.5 to 1.5. The merchantable height adjustment is applied to the estimated sawtimber

and total merchantable height of each tree.

Other physiographic features such as slope and aspect are not currently used but may be used in the

future, and may be useful to you if you are using SILVAH to create a database of stand information.
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 17

Working with Grid Tables

About Grid Tables

Tabular data, such as overstory and understory data, is entered on a grid table, hereafter referred to

as a grid. It resembles a worksheet in Microsoft Excel and has some similarities. There are a series of

rows and columns each with appropriate labels for guidance. Anything that appears in a dark gray

background color is fixed and cannot be edited or altered in any way.

Overstory data is entered in rows, with each column representing a particular field or tree variable

such as species or diameter. Each row is a separate tree observation.

Understory data is entered in columns, with each column representing a plot. Each row represents a

particular regeneration variable, such as the count of black cherry seedlings, or percent fern cover.

A grid is also used in setting plant species codes and default parameters.

Data cannot be copied into the grid. However, data may be copied from the grid and pasted into

another application for other purposes. If you are interested in importing data from other sources, see

the section on importing data at the end of this chapter.

Moving Through the Grid

To move between the cells on the grid, use the Tab key, the arrow keys, or the mouse cursor. When

you move to a cell, it becomes active and is ready to accept input. When you press the Enter key, you

will be moved to the next cell of the current observation.

Data Entry Shortcuts for the Grid

There are a variety of keystrokes or key combinations that provide quick shortcuts to oft-repeated

actions during data entry, such as creating records, copying fields, and looking up values. All of these

grid shortcuts apply to the overstory and the understory grids.

[Enter] Move to next cell - The Enter key exits the current cell and moves to the next cell, or into

the first nonfixed column in the next row if currently in the last column. If you are in the very last

column of the very last row, it will add an observation to the current (last) plot.

[Ctrl] + [Enter] Add new obs to plot - Press and hold the Control [Ctrl] key and then press Enter,

and a new observation is inserted below the current row. Example: if you have five plots and are

currently positioned on the second observation in plot 3, it will add a new observation to plot 3, as

the third observation—below the second observation. What used to be the third observation will now

be the fourth observation.
18 User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation

[Ctrl][Shift][Enter] Add new obs to next plot - Press three keys at once, [Ctrl][Shift][Enter], and a

new observation is inserted into the next plot. If that plot does not have an observation, it will create

one. If you are in the last plot, it will create a new plot. Example: If you have five plots, and you are in

plot 3, it will add the observation to the “bottom” of plot 4. If there is no observation in plot 4, it will

create one. If you are in plot 5, it will add a sixth plot and a new observation in that plot.

[Ctrl] + [Q] Query - Press and hold the Control [Ctrl] key and then press the letter Q key to look

up the possible values for a given field. You can make a selection from the list of choices. Example:

If you don’t know the species code for black cherry, press [Ctrl] + [Q] to view all species. Above

the choices, indicate the type of code you are interested in viewing. Choose a species from the list

if desired.

[Ctrl] + [D] Copy content from cell above - Press and hold the Control [Ctrl] key and then press

the letter D key to copy the contents of the cell above. D stands for “ditto” and not delete! Example:

You are working in a pure black cherry stand and you want to save a few key strokes by repeating

some information from row to row. The next time you need to enter the species, press [Ctrl] + [D] to

copy the species from the cell above.

[Ctrl] + [Del] Delete current row - Press and hold the Control [Ctrl] key and then press the Delete 

[Del] key to delete the current row. Existing rows will be renumbered.

Configuring Data Fields on the Grid

You can arrange the data fields of a grid in any order that you prefer, and you can turn off fields that

you do not need. Turning off a field doesn’t cause a loss of data, nor does it eliminate the field—

it only tells the program not to display it. SILVAH will remember these settings after you close

the program.

When you click the Configure button that typically appears in the upper-right corner above the

grid, the Select variables dialog appears. Fields currently being displayed are shown on the righthand side, and they are arranged from top to bottom to reflect their display from left to right during

data entry.

Turning off a field

1. Click the Configure button to launch the Select variables dialog.

2. Click on the field that you wish to remove from display on the right hand side.

3. Click the left-pointing arrow to remove the field from the list of items displayed.

Alternatively, you can double-click the item you wish to remove from the display.

4. If desired, click the double left-pointing arrow to remove all fields from the right hand side

at the same time.

5. Click OK.
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 19

Turning on a field

1. Click the Configure button to launch the Select variables dialog.

2. Click on the field on the lefthand side that you wish to display.

3. Click the right-pointing arrow to add the field to the list of items displayed. Alternatively,

you can double-click the item you wish to add to the display.

4. If desired, click the double right-pointing arrow to add all fields on the left hand side at the

same time.

5. Click OK.

Changing the order that fields appear during data entry

1. Click the Configure button to launch the Select variables dialog.

2. From the list of items to be displayed, use the mouse to drag-and-drop a field up or down

the list until the order from top to bottom reflects the desired order from left to right during

data entry.

3. Click OK.

Toggle fields displayed or not displayed

1. Click the Configure button to launch the Select variables dialog.

2. Click the cycling arrows to exchange displayed fields with nondisplayed fields. This option

swaps fields in the left list with fields in the right, and vice-versa.

3. Click OK.

Copying Data from the Grid

Data can be copied from most of the grid tables displayed throughout SILVAH, with the exception

of the plant species grid. Copying the information in the grid may be useful if you want to obtain

a printout of your data for proofreading or to perform additional analyses outside of SILVAH.

Remember that data cannot be pasted into a grid.

1. Click anywhere in the data entry grid.

2. Select the cells you wish to copy. If you click once in the header cell of the dark gray columns

to the left side of the grid, all cells will be selected.

3. Press [Ctrl] + [C] - Press and hold the Control [Ctrl] key and then press the letter “C” key to

copy to the clipboard. Then paste the contents into other software as desired.
20 User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation

Entering Overstory Data

About Tree and Plot Records

Overstory data consists of a hierarchy of plot and tree records. Plot records are used solely to identify

the trees that were sampled in specific plots. Currently, there are no plot-specific attributes and thus

there are no tools for editing plot attributes such as plot identification, comments, etc. To enter data

on a tree observation, you must first establish a new tree record, and then enter the data. However,

tree records must be associated with at least one plot record, which means you must first create a plot

record before you can create tree records. You can establish all of your plot records ahead of time or

you can establish plot records as you need them. The latter approach tends to work well and is most

commonly used. There are buttons for adding tree and plot records, but these are not always necessary

and faster ways of creating records are available. See the topic on data entry keyboard shortcuts for

the grid in the section on working with grid tables to learn how to create tree records and plot records

most efficiently.

SILVAH displays all tree records in a stand concurrently in a grid. Each tree record is assigned a

sequential tree number, which is always in display. The plot number of each tree record is displayed

in the column to the left of the tree number. Plot numbers and tree numbers are fixed and cannot

be reconfigured.

Adding Tree Observations

Tree observations can be added or inserted at any time, or you can add trees as you proceed through

your tally sheets during data entry. See the topic “Entering Tree Data” in this chapter for information

on specific fields, and be sure to review the data entry shortcut topics for helpful tips on data entry.

The steps below will always apply, but you may find the shortcuts more efficient.

Adding the First (Initial) Tree of the Stand

1. Click the Inventory Entry button.

2. Click the Trees tab.

3. Click the Add button or click anywhere in the space that includes the caption, Click here 

to begin data entry. The tree will be added as the first record of the first plot. SILVAH will

create the first plot automatically and add the new tree record to that plot, then the new tree

record will appear in the display.

Adding More Trees

1. Click the Inventory Entry button.

2. Click the Trees tab.

3. Click the Add button.
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 21

4. If you want the new tree to be added as the last tree in an existing plot, click the desired plot

number from the list box in the Choose a plot dialog. Then, click OK.

5. Click Add a new plot from the Choose a plot dialog if you want the new tree record to be

added as the first record in a new plot. SILVAH will immediately create a new tree record in a

new plot that follows the existing plots.

Inserting a Tree Record

1. Click the Inventory Entry button.

2. Click the Trees tab.

3. Click anywhere in the row of an existing tree record.

4. Press [Ctrl] + [Enter] (press and hold the Control [Ctrl] key and then press the Enter key) to

insert a new tree record below the existing one.

Default values for new tree records

There are a limited number of fixed default values that appear every time you create a tree record.

Timber quality is Acceptable Growing Stock (AGS) and diameter at breast height (dbh) is 0.6 inches.

The number of trees represented by this observation (the count) is 1, and defect is assumed to be zero.

Entering Tree Data

These instructions assume the fields are configured on the grid in the order as presented below. If your

fields are arranged in a different order, the information about each field is the same.

The species code, diameter, and quality fields should be completed for each tree in order to obtain the

most appropriate silvicultural prescription for your stand. The remaining fields are optional and may

be left blank if desired. See Marquis et al. (1992) and Brose et al. (2008) for silvicultural details of

recommended inventory procedures.

All units are in English. Currently, metric units are not supported in SILVAH.

Entering Species Codes

After you enter the species code of a tree record, press either the Tab, Enter, or right arrow key to

move to the next field. Species entries are not case sensitive but will be displayed in upper case. If you

type in a species code that does not exist, you will be presented with a pop-up list. The list is initially

sorted by the species code specified under Inventory Settings. Select a species from the list and click

OK. If you click Cancel, the species cell is returned to the previous value.

To learn more about how to identify species during data entry—see the topic “About Species Codes”

in the Plant Species Information section of Chapter 4 on setting up defaults.
22 User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation

Entering the Diameter

When the species code is accepted, the next field to the right will become active, which is the

diameter field. Enter the diameter of the observed tree. SILVAH works only with whole numbers,

and if you enter more precise values, the display will retain them, but only rounded values will be

stored in the data (.sil) file. If applicable, you may only need to record even numbers if your cruise is

by 2-inch size classes. If you are using broad size classes, then use only the midpoints of the diameter

classes. You will not be able to enter a diameter larger than 40 inches.

Entering the Quality

The quality field is the next one to be filled in. You may record AGS, Unacceptable Growing Stock

(UGS), or dead. If you are using a prism cruise, you may also record borderline AGS, borderline

UGS, or borderline dead. You may enter the first letter of the quality, such as “a” for AGS, or the

equivalent numeric code (“1” for AGS). If you prefer to display numeric codes instead of alphabetic

codes, check the Display codes for coded values box in the space above the tree grid. If you are not

sure what codes are available, press [Ctrl] + [Q] (press and hold the Control [Ctrl] key and then

press the letter “Q” key) to look up the possible values for timber quality.

Entering Merchantable Height or A Tree Count

The Tree observations include an option under the Inventory Settings tab determines which value is

entered in the next field. Specifically, if you indicate that your tree observations contain counts, then

SILVAH will display a count field. If you indicate that your tree observations contain heights, then

you will see a M. Height field for merchantable height. There are actually two separate variables, one

for counts, and another for merchantable heights, but the program will not allow both to be used at

the same time—only one of them will be available. You can switch back and forth and SILVAH will

redisplay the values previously entered, but only while the file is open. Once the file is closed (and

saved), the most recent value displayed is the one that will be saved with the data.

Entering Grade, Defect, Crown, and Wildlife Codes

The remaining four fields, grade, defect, crown condition, and wildlife code, are entered similarly as

the fields above. All four of these fields are optional, and need not be filled in. The grade, crown, and

wildlife fields are all coded values. The codes and meanings can be found in Appendix A. Defect is a

percentage recorded as tens of percent; that is, 1 for 10 percent, 2 for 20 percent, and so on.

Proceeding to the next tree observation

When you reach the end of a row, if you press the Enter key after editing the last field, and this is the

last observation in the current plot, SILVAH will add a new tree to the plot, otherwise, you will jump

to the next row below if an existing record occurs after the current one. When you are ready to add a

new observation that begins in the next plot, instead of pressing the Enter key, press [Ctrl][Shift] + 

[Enter]—that is, press and hold down the Control [Ctrl] key and the Shift key at the same time and

then press the Enter key. Refer to the topic “Data Entry Shortcuts for the Grid” earlier in this chapter

for more information.

You should periodically save your work while you are entering data to avoid losing information and

having to start over.
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 23

Working with Empty Plots

When a plot is empty (i.e., when the inventory found no trees on that plot), it is very important to

record it in SILVAH. Failure to do so may result in inaccurate, biased assessments of your stand, with

potentially inappropriate prescriptions from SILVAH.

An empty plot can be entered in SILVAH in the order it was encountered in the field. Note that

empty plots are handled differently for the overstory and understory.

In the overstory, the empty plot will not appear in the grid. The example in Figure 2 shows trees from

plots 1, 3, and 4, but not plot 2. When a plot is not shown in the grid, as in Figure 2, it signifies that

an empty plot was entered without any tree observations. An exception would be if the last plot in the

inventory was empty. In this case, there is no way to tell by looking at the grid whether the last plot

in the field was empty, or whether the inventory simply stopped with the last plot shown in the grid.

The only way to be sure is to click Plots button (located immediately above the grid) to view the list

of plots and see if another plot exists beyond the last plot shown in the grid.

Figure 2.—Sample tree data in SILVAH where plot 2 is empty 

and not shown in the grid. 

To add an empty plot in the overstory

1. Click the Plots button near the top of the grid.

2. Click the Add button on the Manipulate plots dialog.

3. Click OK.

4. Click the Add button near the top of the grid.

5. At the top of the Choose a plot dialog, click the Add new plot button. A new tree record will

be added to the grid in the plot after the empty plot, and you may resume entering data.
24 User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation

To add an empty plot in the understory

When a new understory plot is added in SILVAH, items that require counts or percent cover data are

given zero values by default. Thus, the way to enter an empty plot is to add it and then leave it alone.

Be sure that no values are entered in the column for the empty plot, and that zeros appear where

appropriate. In the understory, empty plots will appear in the grid.

1. Click the Add button near the top of the grid.

2. If there are additional plots beyond the empty plot, repeat step 1 and then enter appropriate

inventory values in the new plot.

3. Be sure that no values (i.e., only zeros) are entered in the column that represents the

empty plot.

Manipulating Plots

If the need arises, you can rearrange plots even after you have entered data. This would result in a

renumbering of all plots according to the order you want. You can also insert a plot at any time, and

this may be important if order is critical and you discover later that you inadvertently skipped a plot

or entered data out of order.

Change Plot Order

1. Click the Inventory Entry button if you aren’t already there.

2. Click the Trees tab.

3. Click the Plots button at the top of the trees grid to launch the Manipulate plots dialog as

shown in Figure 3.

4. In the list of existing plots, drag-and-drop the plot to its appropriate place on the list.

5. Click OK when you are finished.

Figure 3.—Manipulating overstory plots.
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 25

Add a Plot

1. Click the Inventory Entry button.

2. Click the Trees tab.

3. Click the Plots button at the top of the trees grid to launch the Manipulate plots dialog as

shown in Figure 3.

4. Click the Add button, and you will see New Plot 1 appear at the bottom of the list.

5. Drag-and-drop the plot to its appropriate place in the list if you don’t want it to be the last

plot in the group.

6. Click OK.

Insert a Plot

1. Click the Inventory Entry button.

2. Click the Trees tab.

3. Click the Plots button at the top of the trees grid to launch the Manipulate plots dialog as

shown in Figure 3.

4. Click on one of the existing plots where you wish to insert a plot.

5. Click the Insert button.

6. Choose whether to insert the plot before or after the highlighted plot.

7. Click OK.

Delete a Plot

1. Click the Inventory Entry button.

2. Click the Trees tab.

3. Click the Plots button at the top of the trees grid to launch the Manipulate plots dialog as

shown in Figure 3.

4. In the list of existing plots, click on the one you wish to delete. Note: All tree observations in

the plot will also be deleted.

5. Click Delete button.

6. Click OK. If you accidentally deleted the wrong plot, click Cancel and try again.
26 User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation

Entering Understory Data

About Understory Data

Understory data is recorded by plot. Unlike overstory data, SILVAH does not maintain records below

the plot level.

There are two ways that understory data can be collected, and what you see on the Understory Plots

tab in SILVAH will depend on your choice of understory cruise type under the Inventory Settings

tab. The first, and substantially most common, is what is known as Extended regeneration data, where

you enter seedling counts, percent cover of interfering vegetation, and site characteristics for each

plot. The second, less common and older method is known as Checkmark data. With Checkmark

data, you enter the number of plots stocked with each category of commercial seedling regeneration,

interfering vegetation, and site limitations. If you select Checkmark for the Understory cruise under

the Inventory Settings tab, you must also enter the total number of checkmark plots assessed in the

field before completing the Inventory Settings.

The presence of nonnative invasive species may be recorded while sampling. For further information,

see the section “About Nonnative Species Data” later in this chapter.

See Marquis et al. (1992) and Brose et al. (2008) for silvicultural details of recommended understory

inventory procedures.

Entering Extended Regeneration Data

This is the preferred and most beneficial of the methods for collecting understory data because

you are collecting and retaining quantitative data that can be analyzed against known criteria in an

objective manner, and it allows for a more meaningful comparison with data in the future. You can

begin an extended regeneration tally by following the steps below:

Adding the First (Initial) Understory Plot of the Stand

1. Click the Inventory Entry button.

2. Click the Understory Plots tab.

3. Click the Add button or click anywhere in space that includes the caption, Click here to 

begin data entry. SILVAH will create the first plot and then display it in the Understory

data grid.

Adding More Understory Plots

1. Click the Inventory Entry button.

2. Click the Understory Plots tab.

3. If you want the new plot to be added as the next or last plot, click the Add button.
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 27

Inserting an Understory Plot

1. Click the Inventory Entry button.

2. Click the Understory Plots tab.

3. Click anywhere in the column of an existing understory plot column.

4. Click the Add button to insert a new understory plot after the existing plot selected in Step 3.

Refer to the topic “Data Entry Shortcuts for the Grid” in the Working with Grid Tables section in

this chapter for tips on how to add or insert plots without using the mouse.

Behavior of the Enter Key on the Understory Plot Grid

If only one plot has been entered, after you enter a value, when you press the Enter key, you will

move down to the next row in the plot. However, when several plots have been added, the Enter key

will move over to the next column within the same row. At the end of a row (in the last understory

plot), the Enter key will move down to the first column of the next row.

Use the down and up arrow keys to move within the same plot if you prefer to enter data for each

item in a plot before moving on to the next plot.

Desirable regeneration data is displayed in the upper half of the rows in the understory data grid.

Lower rows contain interfering vegetation and site limitations.

Desirable Regeneration

Enter the weighted counts of black cherry, yellow-poplar, new oak, established oak, competitive oak,

other desirable species, and conifers.

Items with Species

Enter the appropriate species code when applicable. Species entries are not case sensitive but will be

displayed in upper case. If you type in a species code that does not exist, you will be presented with

a pop-up list to choose from. The list is initially sorted by the species code specified under Inventory

Settings. Select a species from the list and click OK. If you click Cancel, the species cell is returned

to the previous value. See the topic “About Species Codes” in the Plant Species Information section of

Chapter 4 for more information on how to identify species during data entry.

Percent Cover

For these items, enter the percent cover using whole numbers such as 15 percent, 70 percent, and

so on.

Total Height of Oak Seedlings

This data is an optional prerequisite for running the Pennsylvania State University Appalachian

Oak Guide (Steiner et al. 2008). It represents, to the nearest 0.5 feet, the total combined height of

all oak seedlings in the central milacre of the regeneration plot. If you do not collect data on the

height of oak seedlings, but you collect extended regeneration data, SILVAH will estimate the total
28 User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation

height of oak seedlings based on conservative assumptions regarding the height of the different

classes of oak regeneration. SILVAH uses 0.25, 0.5, and 3 feet for new, established, and competitive

oak, respectively.

Grapevines

This is the total count of grapevines that have ascended into the overstory.

Thick Duff, Rocky Surface, Poor Drainage

Answer yes or no for these items as found during the inventory of the interference plot.

Deleting an Understory Plot

To delete an existing plot, click anywhere inside the column of the plot you wish to delete, and then

click the Delete button above the understory plot grid.

You should periodically save your work while you are entering data to avoid losing information and

having to start over.

Entering Checkmark Regeneration Data

Checkmark data is quick but rather inflexible, and is based on field judgment at the time of

sampling. During inventory, the data collector compares the observed weighted count of seedlings

or interference on the sample plot against the stocking criteria for the ambient deer impact level, and

records whether or not the observation met or exceeded the criteria. These data cannot be reassessed

at a different deer impact level. You can begin a checkmark tally by following the steps below:

1. Click the Inventory Entry button.

2. Be sure you have specified Checkmark for the Understory cruise on the Inventory Settings tab.

3. Click the Understory Plots tab.

Enter the number of plots stocked with each category of regeneration, interfering vegetation, and

site limitations.

Several rules apply as follows:

• The maximum value for any category must not exceed the total number of plots taken.

• The established and competitive desirables subtotal fields must be at least as much as any of the

individual regeneration fields.

• The total oak field must be at least as much as any of the individual oak regeneration fields.

• The established oak field must be less than or equal to the established desirables subtotal field.

• The any interference field must be at least as much as any of the individual interference fields.

Validations of the rules above are typically postponed until you try to select a different tab. If there are

errors, you will get an appropriate message and the opportunity to make corrections.

When you are finished, be sure to save your work to avoid losing information and having to start over.
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 29

Entering Nonnative Invasive Species

About Nonnative Invasive Species Data

NNIS may be present in or adjacent to the stand. Without being aware of their presence, any

disturbance that reduces competition, increases light, or disturbs the soil may result in a rapid

and near-complete dominance of the ground cover and the understory by aggressive nonnative

species, which will likely displace most native herbaceous and shrub species and eliminate desirable

tree regeneration.

While there are dozens of problematic invasive species in the eastern United States, SILVAH

includes about 14 of the more common species in the Allegheny Plateau. This number was arrived

at through consultation with U.S. Forest Service research scientists and practicing foresters in Ohio,

Pennsylvania, and West Virginia.

Knowing what to look for, and knowing their whereabouts, is the first step in determining the

severity of this issue and whether NNIS require additional sampling, or specific treatment prior to or

in conjunction with other forestry practices.

SILVAH provides for the collection of presence-absence data, provides reports on which species were

observed, and provides information about the ecology of each species. While percent cover or other

quantitative sampling of NNIS would be provide the most useful information, there is currently an

insufficient amount of evidence to suggest appropriate levels of NNIS that would require treatment,

as well as which treatments are the most effective according to soil, climate, vegetation, management

practices, land use, etc. Until we develop more understanding about the science and management of

NNIS, a useful alternative is to note the presence of NNIS while sampling.

There are two ways to record information on NNIS in SILVAH. During understory sampling, you

can record the presence of one or more NNIS that occur anywhere within the interference plot.

NNIS can also be observed “off-plot” within the stand, or near the stand, such as across the road, in

adjacent stands, etc.

NNIS data entry is split into two sides of the NNIS Observations tab. The left side is for recording

observations made within plots. The right side is for recording the presence of NNIS “off-plot” within

or near the stand.

Entering Plot-based NNIS Observations

NNIS observations observed within interference plots are entered in a manner similar to tree data,

using understory plots as the basis. If you have already entered understory data, then you do not need

to establish understory plots again—you will use the same plots for recording NNIS observations.

To enter data on an NNIS observation, you must first establish a new NNIS observation record, and

then enter the data. NNIS records must be associated with at least one plot record. You will need

to choose from the list of existing understory plots (or create new plots if necessary) before you can

create NNIS records.
30 User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation

Getting Started after Entering Other Understory Data

1. Click the Inventory Entry button.

2. Click the NNIS Observations tab.

3. Click the Add button in the upper left corner of the tab.

4. From the pop-up Choose a plot dialog, click on the plot that contains the NNIS observation

you wish to record. Alternatively, you can double-click on a given plot, and step 5 is omitted.

5. Click OK.

Getting Started without Existing Understory Data (No Understory Plots Created Yet)

1. Click the Inventory Entry button.

2. Click the NNIS Observations tab.

3. Click the Add button in the upper left corner of the tab. This step will automatically create

the first understory plot record and also establish the first NNIS observation record for you.

Entering the data

Currently, only the identification of species is required. No other data can be recorded. Species entries

are not case sensitive but will be displayed in upper case. If you type in a species code that does not

exist, you will be presented with a pop-up list to choose from. The list is initially sorted by the species

code specified under Inventory Settings. Select a species from the list and click OK. If you click

Cancel, the species cell is returned to the previous value. Be aware that Forest Inventory and Analysis

(FIA) codes may not have existed for many of the nonnative herbaceous species, as early FIA data was

targeted mainly at trees and other frequently observed woody shrubs. The FIA codes displayed for

NNIS were arbitrary assigned but can be used throughout the program to recognize the species.

If you enter a native species that is “invasive,” or any species that is not marked as exotic under Plant

Species information, the species cell will be highlighted in yellow to distinguish native species from

nonnative ones.

Adding new understory plots

If you need to add additional understory plots, you may create them during understory data entry, or

while entering NNIS observations.

1. Click the Inventory Entry button.

2. Click the NNIS Observations tab.

3. Click the Add button in the upper left corner of the tab.

4. From the pop-up Choose a plot dialog, click the Add new plot button.
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 31

Deleting understory plots

If you need to delete an understory plot, it must be done through understory data entry. Please see

the instructions for deleting an understory plot in the topic “Entering Extended Regeneration Data.”

You can, however, remove any row that contains an NNIS observation within a plot. Click anywhere

inside the row, then click Delete to remove the observation.

Proceeding to the next NNIS observation

When you reach the end of a row, if you press the Enter key after editing the last field, and this is the

last observation in the current plot, a new NNIS observation will be added automatically, otherwise,

you will jump to the next row below. When you are ready to add a new observation that begins in

the next plot, instead of pressing the Enter key, press [Ctrl][Shift] + [Enter] (press and hold down

the Control [Ctrl] key and the Shift key at the same time and then press the Enter key). Refer to the

topic “Data Entry Shortcuts for the Grid” for other related shortcuts. You can use the arrow keys to

move between observations without adding new rows.

Entering Off-plot NNIS Observations

Off-plot NNIS observations are recorded on a list of known exotic invasives in your sampling area.

Before you can record your off-plot observations, you must first establish a list of exotic species. This

list is used for species observed within the stand and near the stand, and is displayed on the righthand side of the NNIS Observations tab. Your observations are made by checking species on the list.

Establishing a list of exotic species

1. At the top of the SILVAH6 window, click the Calc Settings and Species button.

2. Click the Plant Species Information tab to modify plant species attributes.

3. Make sure the Exotic column is in display. If it is not, try scrolling to the right or left, or

click Configure button to add or rearrange the plant species fields in the grid. See the topic

“Configuring Data Fields on the Grid” in Chapter 3 for further information.

4. In the species row, enter yes (or the press the letter “y”) in the exotic field. Repeat this process

for all species that should be considered exotic in your area.

To see all of the exotic species together, try sorting by the exotic field: click once in the header of the

exotic column to sort in ascending order, and click again to sort in the opposite order.

Entering the data

When you are ready to record your off-plot NNIS observations, follow these steps:

1. Click the Inventory Entry button.

2. Click the NNIS Observations tab.

3. If you do not see any species to the far right-hand side, that probably means there are

currently no species marked as exotic in the list of plant species. Refer to the instructions

above on establishing a list of exotic species.
32 User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation

4. For off-plot observations made within the stand, check the appropriate species under the

within stand column on the right-hand side of the NNIS Observations tab.

5. For off-plot observations made outside the stand, check the appropriate species under the near

stand column on the right-hand side of the NNIS Observations tab.

Importing Data

About Importing Data

The process of importing data involves reading in “foreign” data, interpreting it, and converting it so

it can be viewed and analyzed by SILVAH.

The following are two formats that you can import:

Text

If you have data from commercially available tools for recording inventory data, or from generic word

processing or spreadsheet tools (such as Microsoft Excel), you can import it into SILVAH—provided

that these programs have a mechanism for converting or exporting their data into text format (.txt,

.csv, etc.). Please read the topic on preparing text data before you begin.

NED-2

NED-2 is forest ecosystem decision-support software developed by the U.S. Forest Service, Northern

Research Station. NED-2 is designed to improve project-level planning and decisionmaking by

providing useful and scientifically sound information to natural resource managers. Resources

currently addressed include visual quality, ecology, forest health, timber, water, and wildlife. NED-2

expands on previous versions of NED applications by integrating treatment prescriptions, growth

simulation, and alternative treatment comparisons with evaluations of multiple resources across a

management unit.

NED-2 data is stored in a Microsoft Access database.

Preparing Text Data for Import

Before your text data can be imported into SILVAH, a considerable amount of cleanup may be

necessary in order for the import to be successful.

Your data must be organized into distinct columns (one per variable), and each column should

contain values and formats that closely match SILVAH. For instance, if you maintain “live or dead”

status separate from timber quality, these items are represented by a single variable in SILVAH

(timber quality). So you would need to understand the quality codes used by SILVAH (e.g., 1= “live

AGS,” 2=”live UGS,” 3=”dead,” etc.) and perhaps invent a new column in your raw data that reflects

live or dead and timber quality simultaneously as shown here.
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 33

It is helpful if the first row in your data contains column headers, as these will help you map your

variables with ones in SILVAH.

SILVAH data (.sil) files only contain information for a single stand, and if your data contains multiple

stands, you will need to split them into separate files unless you are importing data from NED-2.

If your data is in metric, you must convert to English units before importing the data.

If you collected overstory and understory data, they must be split into separate files and imported in

separate steps.

Order of your columns (variables) is not important, and you do not need to remove variables unless

you prefer to work with a smaller set of variables.

Once all of this work has been completed, save your data in text format (.txt, .csv, etc.).

How to Import Text data

Once you have organized and prepared the text data for import, importing involves two phases—

opening your raw data, and mapping your variables to SILVAH variables.

Opening Your Raw Data

1. From the File menu, click Import Data.

2. From the pop-up Import SIL dialog, click File to browse and select the text data you wish

to import.

3. From the Open dialog, be sure to click Files of Type at the bottom center of the dialog and

select ASCII files (*.txt) or All files (*.*) if .csv or other.

4. Select the file that contains your data and click Open.

5. At the top of the Import ASCII data dialog, specify whether you are importing TREE data

or UNDERSTORY data. If you have both kinds of data, they must be imported in separate

steps, using these same instructions.

6. Below the upper window that displays your raw data within the Import ASCII data dialog,

select the delimiter that separates your variables (tab, comma, semicolon, other).

7. If your data contains column headers, be sure to check the box that says first line contains 

column headings.

Your data is displayed in the bottom window of the Import ASCII data dialog. If you applied column

headings, you should see them near the top of your columns. If the data looks correct, you are ready

to map the variables to SILVAH variables, as described below.
34 User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation

Mapping Your Variables

1. To map your variables to SILVAH variables, double-click in the top cell of one of the columns

in your raw data in the bottom window of the Import ASCII data dialog. This will launch the

Pick a variable for column dialog that lists the possible SILVAH variables that you can match

with your variable.

2. By default, ignore column is selected. This allows you to skip variables that you do not wish

to import.

3. To make a selection, uncheck ignore column.

4. Click an item on the list.

5. Click OK. The column you just matched will be shaded in white to let you know that it has

been mapped (selected). Any data values that are out of bounds or invalid will be highlighted

in red. Once a SILVAH variable has been mapped, it will disappear from the list of available

variables when you continue mapping other data.

6. If you change your mind or want to unselect a previous match, repeat these steps and instead

check ignore column to reset or undo the match.

7. Proceed through each of the variables that you intend to match.

8. When you are finished, click OK on the Import ASCII data dialog.

9. The program will examine the data and report errors, if any. Click Yes to attempt the import

anyway, or click No if you want to fix any problems that were found.

How to Import NED-2 Data

1. From the File menu, click Import Data.

2. From the pop-up Import SIL dialog, click File to browse and select the text data you wish

to import.

3. From the Open dialog, be sure to click Files of Type at the bottom center of the dialog and

select NED-2 database files (*.mdb).

4. Select the file that contains your data and click Open.

5. Click only one stand from the list.

6. Click OK.

NED-2 has many more variables than exist in SILVAH. For those NED-2 variables that have a

counterpart in SILVAH, some require special handling to most accurately represent NED-2 data in

SILVAH, as described below. Not all SILVAH variables are described here. In such cases, there is a

direct match between NED-2 and SILVAH and no special handling is necessary.
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 35

Overstory Variables

Merchantable Height

If the NED-2 data contains user-entered sawtimber height or individual sawlog lengths (i.e., not

calculated but entered by user) then the SILVAH setting for Tree observations include under the

Inventory Settings tab will be set to heights instead of stem counts. Either the sawtimber height or the

total length of sawlogs from the logs table will be divided by 8.0 to get the number of 8-foot bolts for

SILVAH. Since SILVAH will only accept an integer, the value will be rounded down to the nearest

integer. If the NED-2 overstory observation also contains a stem count greater than 1, SILVAH

will have multiple tree records to match the number of stems in NED. That is, each tree record in

SILVAH will have the same species, diameter, and number of 8-foot bolts calculated as described

above. NED-2 pulpwood heights are not imported into SILVAH, since there is no equivalent variable

for pulpwood height in SILVAH.

Live or Dead Tree

Live trees in NED-2 are brought over to SILVAH without any special considerations. If the tree is

DEAD, then the SILVAH timber quality will be set to DEAD.

Timber Quality

Any NED-2 tree recorded as a CROP tree will be recorded as AGS in SILVAH. Trees recorded as

AGS and UGS can be imported without modification (unless the tree is dead, in which case the

timber quality in SILVAH will be set to DEAD).

Timber Product 

The NED-2 most valuable product, if entered, will be used as the product in SILVAH. If any

sawtimber grade (i.e., any product that is not related to pulpwood) is found in NED-2, then the

SILVAH Tree grading procedure under the Inventory Settings tab will be set to Grade every tree.

If only pulpwood products and culls are found in NED-2, then it will be assumed that the set the

SILVAH Tree grading procedure will be set to Grade only culls and large pulp.

Defect

Only the NED-2 sawlog defect will be used, and it will be divided by 10 for SILVAH. This value will

be recorded as the SILVAH tree defect.

Crown Condition

The NED-2 crown condition is recorded as percent of crown living, which would be converted into

the SILVAH crown categories as shown below:

Category 1 - Healthy - Living Crown ≥ 90 percent

Category 2 - Good - Living Crown ≥ 75 percent and < 90 percent

Category 3 - Fair - Living Crown ≥ 50 percent and < 75 percent

Category 4 - Poor - Living Crown < 50 percent
36 User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation

Understory Variables

Oak Seedlings

If there were NED-2 oak seedlings in the ground plot, and height classes were not used, or they did

not match well with SILVAH oak seedling classes, then all NED-2 oak seedlings will be recorded

as new oak in SILVAH. If the NED-2 data has ground plot observations using the NED default

height classes, then any oak seedling in the 0- to 3-foot height class would be recorded as new oak in

SILVAH. Any oak seedling taller than 3 feet would be recorded as competitive oak.

Conifers

The total number of seedlings for all coniferous species identified in the NED-2 ground plot will be

recorded in SILVAH as the total count of coniferous seedlings in the understory plot.

Other Desirables

In NED-2, desirable species should be identified with a growth form = tree and a timber value

class = 1 (high value) in the Plant Species module. Thus, all species not specifically counted already

(black cherry, yellow-poplar, oaks, and conifers) and marked as high value will be added together to

get a total count of other desirables for SILVAH.

Tall Woody Interfering Vegetation

For species in the NED-2 ground plot, they must be designated with a height or height class taller

than 15 feet (despite that the practical cut-off height in SILVAH is the eye level of the observer) and

must not considered high value and must not be one of the species singled out in SILVAH (e.g., black

cherry, yellow-poplar, etc.) in order to be counted as tall woody interference in SILVAH. If more than

one tall woody interfering species is detected in NED, the most abundant woody interfering species

will be recorded in SILVAH. However, where there is a tie in species abundances, then the only the

first tall woody interfering species found will be recorded in SILVAH.

Low Woody Interfering Vegetation

For species in the NED-2 ground plot, they must be designated with actual stem height or a height

class lower than 15 feet (despite that the practical cut-off height in SILVAH is the eye level of the

observer) and must not considered high value and must not be one of the species singled out in

SILVAH (e.g., black cherry, yellow-poplar, etc.) in order to be counted as low woody interference in

SILVAH. If no height information is entered by the user in the NED-2 ground plot, a species will not

be included as low woody interference. If more than one tall woody interfering species is detected in

NED, the most abundant woody interfering species (by percent cover only—not by stem count) will

be recorded in SILVAH. However, where there is a tie in species abundances, then the only the first

low woody interfering species found will be recorded in SILVAH. Furthermore, if the NED-2 ground

cover species are not recorded with percent cover data, all species would be considered to have equal

abundance, and the first species that met the criteria as low woody interference would be recorded in

SILVAH but without any percent cover data.
User’s Guide to SILVAH: Chapter 3 - Data Entry and Manipulation 37

Percent Grass and Sedge

If the NED-2 data contains percent grass and sedge recorded as a separate ground plot variable, that

value will be recorded into SILVAH without further modification. Otherwise, the total combined

cover of all grass and sedge species in the NED-2 ground cover plot observations will be recorded as

the total percent cover of grass and sedge in SILVAH.

Percent Fern

If the NED-2 data contains percent inhibiting fern or percent other fern recorded as separate ground

plot variables, then the value recorded in SILVAH would be the sum of the percent inhibiting fern

plus half the value of percent other fern. Otherwise, the total combined cover of hay scented and

New York fern, plus half of the combined percentages of all other fern species in the NED-2 ground

cover plot observations will be recorded as the total percent fern in SILVAH.

Thick Duff

There is no equivalent in NED-2 for this variable.

Rocky Surface

The value of the NED-2 ground plot variable, Rockiness barrier to regen (“too rocky”), will be

recorded in SILVAH without modification.

Poor Drainage

The value of the NED-2 ground plot variable, Wetness barrier to regen (“too wet”), will be recorded

in SILVAH without modification.
About SILVAH defaults

SILVAH uses defaults files (.def ) to maintain information on local stumpage prices, the log rule you

want to use, a list of your own species codes (if you do not like ours), and other parameters. Every

time you analyze stands in SILVAH, or perform calculations using TREECALC, you will have the

opportunity to specify the name of the defaults file you want to use.

SILVAH supplies default values for all parameters in the program, so you do not absolutely have

to have a defaults file. The default values in the program are ones that we find convenient for our

computers and our forest conditions in northwestern Pennsylvania. For example, some species such

as red maple are listed as undesirable, but they may be desirable in other regions. You can change the

default values to suit your situation, resulting in a defaults file that suit your needs.

Some users will find it convenient to create more than one defaults file, especially if you work in

several different geographic areas where stumpage prices vary, for example. Thus, you could create a

defaults file for each area, and then read the appropriate one when running SILVAH.

A sample defaults file (silvah.def ) is installed with the program into the SILVAH6 installation folder

(default = C:\USFS-NRS\SILVAH6). You may want to open this file to examine the defaults, and if

desired, modify the defaults as necessary.

To open the sample defaults file:

1. At the top of the SILVAH6 window, click the Calc Settings and Species button.

2. Click the Calculation Parameters tab to modify commercial sale breakpoints that are used by

SILVAH in determining if you have enough volume to make a commercial sale. You can also

specify the log rule for board-foot volume, and other settings that effect calculations. These

settings are stored in the defaults (.def ) file.

3. Click the Plant Species Information tab to modify plant species attributes. Each row pertains

to a single species, and each column contains information about the species. This is where

you would record your species codes so that SILVAH can interpret your species, and you can

also set volume correction factors and timber prices (i.e., sawtimber 1,000 board foot (MBF)

pricing and pulpwood pricing per cord). Other traits such as whether a species is exotic

(nonnative) and desirable are also set here. These settings are stored in the defaults (.def ) file.

Chapter 4 - Setting up a Defaults File
User’s Guide to SILVAH: Chapter 4 - Setting up a Defaults File 39

Starting a New Defaults File

You may store and use multiple defaults files. To start a new defaults file, follow these steps:

1. Click the Calc Settings and Species button.

2. From the top menu, click File, then click New DEF File. You may also try the shortcut,

[Ctrl] + [N] (press and hold the Control [Ctrl] key and then press the letter “N”), to start a

new file.

3. Click the Calculation Parameters tab to review and modify the calculation settings

as necessary.

4. Click the Plant Species Information tab to review and modify and plant species

characteristics as appropriate.

5. Be sure to save your work. Your defaults will be stored in a new defaults (.def ) file.

Opening an Existing Defaults File

To open an existing file:

1. Click the Calc Settings and Species button.

2. From the top menu, click File, then click Open DEF File. You may also try the shortcut,

[Ctrl] + [O] (press and hold the Control [Ctrl] key and then press the letter “O”), to open

a file.

Saving Your Defaults

To save the current defaults to a file:

1. Click the Calc Settings and Species button.

2. From the top menu, click File, then click Save DEF File. You may also try the shortcut,

[Ctrl] + [S] (press and hold the Control [Ctrl] key and then press the letter “S”), to save

the file.

3. If you are saving the defaults file for the first time, enter a file name, and be sure you are aware

of the folder where the file is being created.
40 User’s Guide to SILVAH: Chapter 4 - Setting up a Defaults File

Converting Older Defaults Files

SILVAH has been around since the 1980s. As it evolved, additional capabilities were added. Along

with those additions came format changes in the data. To accommodate older formats, SILVAH can

convert files going back to version 4.0. The program attempts to read the old formats directly, and

when you save the file, the defaults file will be saved in the current format.

It is recommended that you back up your older defaults files before converting them to the

current format.

Converting older defaults files requires a few simple steps. You must also review the defaults to ensure

they were correctly interpreted.

1. Click the Calc Settings and Species button.

2. Open the defaults (.def ) file with the older format.

3. Once the defaults have been loaded, review the data to be sure it is accurate. Pay close

attention to plant species information.

4. If you are working with a file that has already been backed up, save the file. If you aren’t sure,

then click File, then click Save As... and use a slightly different file name in order to preserve

the contents of the original data file.

Importing Defaults Files

SILVAH allows you to import portions of information from other defaults files. With this feature,

you can import only the plant species information, or only the calculation parameters, or both. This

allows you to reuse portions of a defaults file while preserving what you do not want changed.

1. Click the Calc Settings and Species button.

2. From the File menu, click Import DEF file.

3. From the pop-up Import DEF file dialog, click File to browse and select the defaults file that

contains information you wish to import.

4. Check Calculation parameters to import calculation parameters. If you do not wish

to import plant species information at the same time, be sure to uncheck Plant species 

information, and then click OK.

5. Check Plant species information to import plant species characteristics including codes,

prices, and other species traits. If you do not wish to import calculation parameters at the

same time, be sure to uncheck Calculation parameters, and then click OK.
User’s Guide to SILVAH: Chapter 4 - Setting up a Defaults File 41

Calculation Settings

Default Commercial Sale Breakpoints

These values specify how much volume per acre must be available for SILVAH to prescribe a

commercial cutting. For example, the default breakpoints supplied by SILVAH require a minimum

of 2,000 board feet to be removed during a sawtimber only sale. If there is insufficient volume

available for such a sale, SILVAH will check if sufficient volume is available for an integrated sale,

using default values of 1,500 board feet and 5 cords as breakpoints. If there is not enough volume

for an integrated sale, SILVAH will check to see if 7 cords (the default) are available for cutting in a

pulpwood only sale. If the volume is inadequate to support any of these commercial sale minimums,

the recommended prescription from SILVAH will be “DEFER CUT - VOLUME < THRESHOLD.”

1. Click the Calc Settings and Species button.

2. Click the Calculation Parameters tab.

3. Enter the desired commercial sale breakpoints.

4. Remember to save your work. Doing so will place your values into a defaults (.def ) file that

you can use with SILVAH.

Minimum Diameters for Volume Estimates

These are the threshold diameters for calculating volumes. For example, hardwood sawtimber volumes

will be calculated for trees larger than 10.5 inches (11-inch class if you use 1-inch classes, or 12-inch

class if you use 2-inch classes). You can set any threshold diameter you wish for these calculations.

Setting the threshold diameter to 41 inches will prevent any calculation of volumes. Thus, you could

prevent pulpwood volume from being calculated (if you have no pulpwood market, for example) by

setting minimum diameter for pulpwood to 41 inches.

1. Click the Calc Settings and Species button.

2. Click the Calculation Parameters tab.

3. Enter the desired minimum diameters.

4. Remember to save your work. Doing so will place your values into a defaults (.def ) file that

you can use with SILVAH and TREECALC.
42 User’s Guide to SILVAH: Chapter 4 - Setting up a Defaults File

Log Rule, Trees to Include, and Other Values

These values effect calculations by SILVAH and TREECALC.

To set calculation parameters:

1. Click the Calc Settings and Species button.

2. Click the Calculation Parameters tab.

3. Remember to save your work. Doing so will place your values into a defaults (.def ) file that

you can use with SILVAH and TREECALC.

Log Rule

You can select a board foot log rule to use: International 1/4 inch, Doyle, or Scribner.

Trees Included

Specify whether to include live trees only, live and dead, or only dead trees in your calculations.

Name of local log and boltwood product

You can specify the names you want to use on reports for a bulk and local sawlog product. For

example, if you have a pallet log market or a railroad tie market, you can define that product name

here. Note that you must grade appropriate trees as “local log” or “local bulk” in your inventory to

obtain volumes for local products.

Sugar maple site condition

Sugar maple growth and seed production are affected by site quality. The seed source calculation of

SILVAH utilizes this value. If you know that your site is rich in nutrients (high base cation levels),

choose “good” as the sugar maple site condition. If your site is low in base cation levels, such as on

upper slopes and ridge tops in the unglaciated Allegheny Plateau, choose “poor.” The default sugar

maple site condition is “poor.”

Use NY relative density equation

If you are in New York or New England, you can use a relative density equation that accounts for

site differences there. Relative density is a measure of crowding in forests, and is influenced by species

composition and stand structure. The default relative density equation was developed in stands with

little white ash. Most of the sugar maple occurred in lower canopy positions. Use the New York

equation if your stand has healthy sugar maple in the dominant and codominant positions and/or a

high proportion of dominant and codominant white ash.

Species codes (TREECALC)

Specify the species codes you prefer to use when running TREECALC (see Chapter 6). This setting is

not used elsewhere.
User’s Guide to SILVAH: Chapter 4 - Setting up a Defaults File 43

Default Management Values

For convenience, you can establish default management values, saving you the effort of reentering

these values for each stand.

The following are management-oriented values:

Owner

Management Value

Restrictions on Silvicultural System

Prescription Charts to Follow

Intend to Regenerate

Increase Oak

Residuals Desired

Operability

Accessibility

Deer Impact

Management values have always been stored in the data files (.sil), and they are no longer stored as

part of the defaults (.def ) file. However, you can still specify default management values in the Stand

tab under Inventory Entry. To establish default management values, refer to the topic “Establishing

Default Management Guidelines” in Chapter 3 for further information.

Default Inventory Settings

You can specify default inventory settings that you can use repeatedly whenever you start a new stand.

The following are inventory-related values:

Overstory Cruise Type

BAF or Fixed Overstory Plot Size

Observations Include Counts or Merchantable Heights

Tree Grading Procedure

Understory Cruise Type

Understory Plot Size

Species Code Type Used in Data

DBH Size Classes Used in Data

Tally Month and Year

Inventory settings have always been stored in the data files (.sil), and they are no longer stored as part

of the defaults (.def ) file. However, you can still specify default inventory settings in the Inventory

Settings tab under Inventory Entry. To establish default inventory settings, refer to the topic

“Establishing Default Inventory Settings” in Chapter 3 for further information.
44 User’s Guide to SILVAH: Chapter 4 - Setting up a Defaults File

Plant Species Information

About Species Codes

SILVAH will only use one of three possible codes, either the FIA, Mnemonic, or User code, to display

your species entries and to store species in your data. However, there are additional ways to enter a

species, according to any of several possible species identifiers shown below. This may be advantageous

if you remember one identifier but not the one that belongs to the set of codes you have specified

on the Inventory Settings tab. For example, if you have chosen the Mnemonic species code and you

enter “318”—the FIA code for sugar maple, the program will recognize the species and display “SM”

in the species field because “SM” is the mnemonic code. If you could not remember either of these

codes, you could try entering the common name, such as “sugar maple,” and the program would

display “SM.” The code “SM” would be stored in the data file (*.sil).

Types of species codes

• FIA - The original U.S. Forest Service Forest Inventory and Analysis (FIA) codes. A three-digit

numeric code that was formerly used throughout the United States. Almost exclusively used for

woody species only.

• USDA Plants Symbol - This is a relatively new identifier that replaced the FIA codes. It is the

first two letters of the genus and the first two letters of the species, followed by a number if there

are other plants that have similar genus and species abbreviations. You cannot change this code

because it is maintained in the PLANTS database developed by the USDA Natural Resources

Conservation Service for every species found in North America (native or exotic). SILVAH will

readily interpret these codes, but they will never show up in the display, nor will they appear in the

data (.sil) file.

• Mnemonic - A user-defined code, typically two or three letters that abbreviate the common name.

Used on all reports, regardless of what code occurs in the data. Based on the first letter of the

common name to represent individual species (thus, “SM” for sugar maple), and the first letters of

the common genus name to represent an entire genus (thus, “B” for birch). You can change these

abbreviations to meet your own needs, if desired.

• User Defined (Local) - Another user-defined code, allowing only numeric values. Often used to

represent multiple species of a genus or family, such as “pine,” “conifers,” and so on.

• Common Name - The common name of the species. SILVAH will readily interpret the common

name, but it will never show up in the display, nor will it appear in the data (.sil) file.

Number of species

Currently there are 148 species included in the program, mostly trees, some woody shrubs, and a few

nonnative invasive herbaceous species. This is a fixed list of species, representing those most likely

to be encountered in the Allegheny Plateau of Pennsylvania, New York, Ohio, Pennsylvania, and

Maryland. You may not change the species that are included.

Sorting the display of species

You can sort the display of species by any of the species attributes. This is very useful in searching for

species as well as examining prices or other attributes.
User’s Guide to SILVAH: Chapter 4 - Setting up a Defaults File 45

To sort by an attribute, click once in the header of the column that contains the attribute. The first

click will toggle the sort in descending order, and second click will sort in ascending order.

Configuring the display of species attributes in the grid

You can rearrange the order of the columns of species attributes, or turn on or off attributes that

you do not intend to use. See the topic “Configuring Data Fields on the Grid” in Chapter 3 for

further instructions.

Editing Species Codes

You may edit the mnemonic and user-defined (local) species codes. Other identification codes

displayed in the gray columns cannot be changed.

Warning!

If you want to change species codes that you have already used in the past, be careful! When you run

the old data files (*.sil) with the original species codes through SILVAH, you will need to load and use

the old defaults file so that species codes are interpreted properly. Therefore, you should retain a copy

of the original defaults file that contains the older codes before you alter the species codes. Be sure not

to replace or edit the original defaults (*.def ) file.

To edit species codes:

1. Click the Calc Settings and Species button.

2. Click the Plant Species Information tab.

3. Edit the species codes.

4. See the warning above about maintaining a copy of the original species codes. When you are

ready, remember to save your changes.

Perhaps a better solution is to convert the species codes in your old data files to the new codes.

That way, you will need to maintain only one defaults file for species codes. SILVAH will make the

conversions automatically for you, but you must do this in the proper sequence to avoid loss of data.

To update species codes in older data files (*.sil), proceed as follows:

1. Make backup copies of all data files to be converted to the new codes, in case something

goes wrong.

2. Make certain that you have available your old defaults file (containing the old species codes),

and your new defaults file containing new species codes.

3. Click the Calc Settings and Species button.

4. Open the original defaults file (*.def ) containing the old species codes.

5. Click the Inventory Entry button.
46 User’s Guide to SILVAH: Chapter 4 - Setting up a Defaults File

6. Open the data file (*.sil) containing the old codes that you want to update with new codes.

7. Click the Calc Settings and Species button.

8. Then open the new defaults file (*.def ) that contains your new species codes.

9. Click the Inventory Entry button.

10. Click the Trees tab to review the updated codes in the overstory data.

11. Click Understory Plots tab to review the updated codes in the understory data. The old

codes should now be replaced by the new codes.

12. Save the data file by choosing File Save As... to create a new copy. Be sure not to overwrite

the original version that had the original species codes.

Editing Species Parameters

SILVAH maintains several species parameters that effect the calculation of volume and value. Other

attributes help SILVAH determine the stocking of undesirable and exotic species.

To edit species parameters:

1. Click the Calc Settings and Species button.

2. Click the Plant Species Information tab.

3. Enter the desired values for the parameters you wish to modify.

4. Remember to save your work. Doing so will place your values into a defaults (.def ) file that

you can use with SILVAH and TREECALC.

Form

This is the Girard Form Class that will be used in calculating volumes.

Cubic VC, Bdft VC

These are volume correction factors that may be used to adjust the volumes, both board-foot and

cubic-foot. If you find that the program consistently gives high or low volumes for a species, then you

may change these factors to more reasonably reflect your volumes.

Exotic

This determines whether a species is not native to your area. If you wish to obtain reports on off-plot

nonnative species in your data, you must identify exotic species as appropriate. SILVAH identifies

several species by default.
User’s Guide to SILVAH: Chapter 4 - Setting up a Defaults File 47

Desirable

This determines whether a species is desirable for your management objectives. This attribute is

currently used in two ways. During data entry, if you try to record a sapling of undesirable species,

you will be warned that the regeneration plot will not be considered stocked with saplings since you

recorded an undesirable species. SILVAH also checks the basal area per acre of saplings of undesirable

species detected in the overstory inventory. If this value is at least 10 square feet per acre or greater,

SILVAH will increase the understory inventory stocking value for tall woody interference to 70

percent. If the understory inventory stocking value was already 70 percent or greater, the undesirable

sapling basal area will be reported in the understory inventory, but the stocking value will not

be changed.

Prices

There are several columns that provide the stumpage values for sawtimber, veneer, pulp, local bulk,

and local sawlog products.
About Analysis and Prescription

Once you have completed a stand inventory and entered it into a SILVAH data file (.sil), use the

analysis and prescription component of SILVAH to summarize the data and develop prescriptions

that will help meet your forest management objectives.

Proceed with the steps below in your first attempts to learn about SILVAH’s analysis and

prescription capabilities:

Start SILVAH6 and open the sample file:

1. Click the Windows Start menu button.

2. Click Programs (“All Programs” in Windows XP), then click Silvah6 from the list

of programs.

3. Click Silvah6 from the SILVAH6 program options. When it starts up, SILVAH6

automatically selects the Inventory Entry component.

4. On the menu at the top of SILVAH6, click File.

5. From the File menu, click Open SIL file.

6. Browse to the SILVAH6 installation folder and select the file, newdemo.sil.

7. Click Open. 

Select the stands to analyze and find the defaults file that has your specific calculation settings and

species attributes:

1. Click the Analysis and Prescription button.

2. Click the Pick Stands tab.

3. To analyze the sample file that you opened above, click the Add current SIL file button.

4. Click the DEF file button.

5. Browse to the SILVAH6 installation folder and select the file: silvah.def. The calculation

parameters and species attributes stored in silvah.def will be used when you analyze the sample

file (newdemo.sil) in SILVAH.

Chapter 5 - Analysis and Prescription
User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription 49

Select the desired reports:

1. Click the Reports tab.

2. A set of standard reports are available for analyzing the original stand inventory data. Rightclick once on the header of the Initial stand column.

3. From the pop-up context menu, click Standard reports to select a set of reports that are

generated during the analysis.

4. Other reports are available for analyzing prescribed treatments on the original stand. Rightclick once on the header of the Current Rx column.

5. From the pop-up context menu, click Standard reports to select a set of reports that will

describe the recommended treatment and display the effects of the recommended treatment

by showing the original, cut, and residual stand data.

Ask SILVAH to recommend a prescription:

1. Click the Current Rx tab.

2. Make sure to select SILVAH expert-recommended prescription.

Run the Analysis:

1. Click the Run tab.

2. On the Run tab, click the Run button.

3. All of the output from the analysis will be placed into an output file (.prn) that matches the

name of the stand (e.g., newdemo.prn). SILVAH will display the results on the Run tab for

quick viewing. If you prefer to open the file in Notepad, click the Open button.

4. Compare the output you get (newdemo.prn) with those in Appendix B. They should be

identical. If they are not, you may have specified a different parameter file or selected different

reports, or something may be wrong. See the section “Solution to Common Problems” in

Appendix C, or feel free to contact us.

Establishing a List of Stands to Run

Adding Stands to the List

Before SILVAH can provide results, you must supply the names of the stands you wish to run.

SILVAH can just as easily process one stand at a time as it can many stands.

1. Click the Analysis and Prescription button.

2. Click the Pick Stands tab.

3. Click the DEF file button to browse to and select a defaults file (*.def ). If you do not select a

defaults file, SILVAH will supply the default parameter values during the run.
50 User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription

4. Click the Add current SIL file button if you want to run the stand currently opened in the

Inventory Entry component. This is convenient in situations where you opened a stand,

edited the data, and are now ready to analyze it.

5. Click the Add button to browse to and select one or more SILVAH data files (*.sil). Within

a folder, use the Control [Ctrl] and Shift keys as in other Windows applications to select

multiple files. You also may add as many files from other folders as desired.

Removing Stands from the List

If you have more stands than you need, you can remove individual stands. You can also empty the list

if you want to start over.

1. Click the Analysis and Prescription button.

2. Click the Pick Stands tab.

3. To remove one stand at a time, click once on the stand and then click the Remove button.

4. To empty the list of stands to run, click the Remove all button.

Changing the Stand Order

Once you have a list of stands to run, you can modify the stand order if desired. The order that stands

appear in the list is the order in which they will be processed.

1. Click the Analysis and Prescription button.

2. Click the Pick Stands tab.

3. To change the order of a stand, click the stand and then drag it to its desired location in the

list. A stand cannot be dragged to the bottom of the list. Instead, it must be dragged to the

2nd-to-last position and the last item must be moved up one position.

Saving and Retrieving the List

You can store the list of stands if you intend to use it repeatedly.

Storing a list

1. Click the Analysis and Prescription button.

2. Click the Pick Stands tab.

3. Click the Store this list of files button to save the list into a text file.

4. Browse to the desired folder and enter a file name in the Save As dialog.

5. Click the Save button when you are finished.
User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription 51

Retrieving a list

1. Click the Analysis and Prescription button.

2. Click the Pick Stands tab.

3. Click the Read a list from a file button to retrieve a previous list of stands.

4. Browse to and select the desired file name.

5. Click the Open button when you are ready.

Script Files

About Script Files

A script file contains a list of all of the processing options for your reports, prescriptions, stand growth

and yield, and database output. To save time, you can save your options in a script file and reuse them

when processing stands.

Script files from older versions of SILVAH also can be used. However, it is recommended that you

review the options after opening older script files.

The list of selected stands on the Pick Stands tab also can be stored and retrieved, but it is saved in its

own file and not with script files.

Creating a Script File

To create a new script file:

1. Click the Analysis and Prescription button.

2. From the top menu, click File, then click New SCR File. You may also try the shortcut,

[Ctrl] + [N] (press and hold the Control [Ctrl] key and then press the letter “N”), to start a

new file.

3. Begin selecting options for reports, prescriptions, stand growth and yield, and

database output.

Saving a Script File

To save the current processing options to a file:

1. Click the Analysis and Prescription button.

2. From the top menu, click File, then click Save SCR File. You may also try the shortcut,

[Ctrl] + [S] (press and hold the Control [Ctrl] key and then press the letter “S”), to save a

file. The file will contain all of your selections for reports, growth and yield, prescriptions, and

database output.

3. If you are saving the options for the first time, enter a file name, and be sure you are aware of

the folder where the file is being created.
52 User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription

Opening an Existing Script File

After you have selected one or more stands, if you have previously saved a script file, you can process

your stands quickly by opening the script file that contains your desired processing options.

To open an existing script file:

1. Click the Analysis and Prescription button.

2. From the top menu, click File, then click Open SCR File. You may also try the shortcut,

[Ctrl] + [O] (press and hold the Control [Ctrl] key and then press the letter “O”), to open

a file.

3. View or modify the options if necessary for the current run.

4. If the options are okay, you are ready to proceed with selecting stands or running them.

Reports

About Reports

Reports provide concise summaries of stand conditions which include information on all of the

factors that affect silvicultural prescription recommendations. If prescriptions involve cutting, you can

generate reports to compare the before and after effects on stand structure, species composition, and

stand volume and value.

Reports are managed under the Analysis and Prescription component of SILVAH, on the Reports

tab. A variety of reports are available. You decide which reports to use. For convenience, in one step

you can select a standard set of reports that collectively provide pertinent information on important

management criteria such as how much volume is available in your stand, whether the stand is ready

for harvest, and how to mark the stand for intermediate treatments. Most reports are available at any

stage in the planning cycle. The reports you select for initial stand conditions and prescriptions may

also be selected over the course of simulating future conditions.

The output from reports is written into a single text file. The output file will be created in the same

folder as the source data file (*.sil), with an identical file name except for a .prn suffix to identify it as

a reports file. Existing reports files will always be replaced (overwritten) by new output. If you wish to

preserve older reports files, consider archiving them so that multiple versions can be identified in the

future. Report output can be opened readily in Notepad. You can copy portions of the output into

other word processors as desired.

In the reports file (.prn), reports will appear in a predetermined order regardless of the manner in

which they were selected. If you have selected reports over the course of simulation, the same order

will be followed at each time-step. Each report is uniquely identified with an underlined, uppercase

title. Below the report title is the date and name of the source data file (*.sil). At the top of the file

(first page only), SILVAH outputs a header that identifies the stand name, forest type, acres, and

so on.

Some of the values in SILVAH reports have definitions specific to SILVAH and are based on research.

To better understand these definitions, see Marquis et al. (1992) and Brose et al. (2008).
User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription 53

Report Descriptions

There are nine categories of SILVAH reports. Categories are highlighted in bold to help you

distinguish them. Some categories contain only one report, in which case the highlighted category is

the report. Use the following descriptions to learn about each report offered in SILVAH.

Cruise Information - This is a report that describes the inventory settings and sampling statistics

for the stand. Information on overstory sampling error includes the number of plots required to

be within 10 percent and 15 percent of the mean. For the understory, the report determines the

minimum number of plots that should have been collected, based on the number of acres in the

stand. If the actual number of understory plots is less than the desired number, the report will list

how many additional understory plots are necessary to meet SILVAH standards.

Site Characteristics and Regeneration Summary - This is a key report that describes conditions

affecting forest regeneration. Regeneration of desired tree species is assessed according to the percent

of plots stocked with adequate numbers of seedlings under current deer browsing impact. An

additional regeneration stocking assessment is performed against standards for fenced stands (no deer

impact) if extended regeneration data were collected. The average number of desirable tree seedlings

per acre also is reported. Factors affecting regeneration difficulty such as rocky or wet soils, thick duff,

deer impact, seed supply, the presence of nonnative invasive species, and interfering vegetation are

also described. The report concludes with a table of general site characteristics of the stand.

Exotic Species Present—This report lists the nonnative invasive species present in the overstory and

understory, on or between sample plots as well as adjacent to the stand.

Narrative Descriptions for Nonnative Invasive Species—This report provides detailed, narrative

descriptions of the identification characteristics, ecology, and response to management or disturbance

for the nonnative invasive species found in the stand. Due to the potential length of this report,

unlike other reports it is output in a separate file, in the same folder as the source data file (*.sil),

with an identical file name except for a .nns suffix to identify it as narrative output for nonnative

invasive species.

Narrative Summary and Analysis of Stand—This report summarizes the stand in a series of

descriptive paragraphs. The forest type and the dominant overstory species comprising 85 percent

of the stand basal area are identified. An assessment of average diameter, timber volume, and quality

is included. The report describes the impact of relative density on tree growth, and the need for

thinning. It includes the effective age and number of years to maturity for the stand. The narrative

concludes with an assessment of desirable seedling regeneration, and possible factors such deer

impact, site limitations, and other vegetation that could interfere with regeneration after a final

harvest. This report may be particularly valuable for communicating with private landowners or

public land stakeholders unfamiliar with forestry data tables.

Central Appalachian Oak Guide—This report uses overstory and understory data to project the

proportion of oak that would be found in thirty years if a final overstory removal took place now.

It can use standard SILVAH data or, if collected, the total height of all oak seedlings on the interior

milacre of each regeneration plot. This report was developed in the Ridge and Valley region of central

Pennsylvania by researchers at Pennsylvania State University (Steiner et al. 2008). It provides an

additional assessment of oak regeneration in case you are unsure whether you already have sufficient
54 User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription

oak regeneration. The report provides a table of expected contributions (percent stocking) from

stump sprouts of five oak species plus the total expected contribution (percent stocking) from all oak

seedlings. It is most applicable to the conditions of the Central Pennsylvania Ridge and Valley.

Information on Silvicultural Systems and Wildlife Habitat—This report lists any user-specified

restrictions on silvicultural systems along with the relative value of this stand in fulfilling whatever

management objectives may have been planned. This is followed by an assessment of stand

characteristics that may benefit wildlife, such as the number of trees per acre of existing and potential

den trees, and the number of stems per acre of snags with existing and potential cavities. Aquatic

features within the stand are noted, as are other habitat conditions that are within 1 mile of the stand.

The wildlife portions of this report are only useful if the overstory inventory included information on

den trees and snag potential, and landscape context variables are only available if users provide them.

Treatment Description with Marking Instructions—This is a key report that provides a description

of the treatment prescribed in SILVAH, along with the reasons for that prescription if it was provided

by SILVAH (i.e., an expert prescription). The report outlines treatment steps along with special

considerations. For prescribed cuts, the report estimates the amount of volume available. Marking

instructions detail the amount of trees to retain (leave) in each size class, followed by information

on removals, such as the target relative density and the proportion of trees to cut in each size class.

A companion report is automatically generated along with this report, and is output in a separate file

in the same folder as the source data file (*.sil), with an identical file name except for a .prx suffix to

identify it as a prescription history file. It contains a history of the prescription chart decisions leading

up to the treatment prescribed by SILVAH.

Comparison of Residual, Cut, Residual Stand Data—This report provides tables that show the

effects of a treatment on basal area, number of trees, average diameter, relative density, volume, timber

quality, and species composition. These characteristics are displayed in three columns to allow you to

compare values for the original, cut, and residual stand.

Timber Volume and Value by Species—This report is available only for the initial stand. It provides

net sawtimber and pulpwood volume and value by major timber product (veneer, grades 1-3, pallet,

boltwood, pulpwood, and firewood) and species. The breakdown of timber products will follow the

grading in the data. If trees were not graded, then SILVAH calculates the proportion of trees in each

factory sawlog grade plus veneer (see Chapter 7 for details about volume and value calculations).

Two versions of this report are available—one produces per acre values, and the other produces total

stand values.

Overstory Summary—This is a key report that provides tables on stand composition, timber quality,

average diameter, structure (Q factor), relative density, volume, and value. Species are listed to the

right in descending order of basal area per acre, along with number of trees, and relative percent basal

area for each species. Succeeding tables maintain this species order, and you may notice in some tables

that the values across species do not always proceed in descending order.

Overstory Species X Diameter Tables—These are a series of reports that produce two species by

diameter tables. In the first table, diameter classes are established in rows according to the dbh size

class specified in the inventory settings for the stand. Thus, if you specified the 2-inch size class, those

are the diameter classes shown in the table. If you specified the 1-inch size class for your inventory
User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription 55

settings, but recorded dbh using 2-inch diameter classes in the data, the table will contain 1-inch

diameter classes, and you will notice a lot of zeros for the ranges where no diameters were entered. On

the other hand, if you specified the 2-inch size class but recorded dbh using 1-inch diameter classes,

SILVAH will adjust the diameters to fit the 2-inch size classes. This is followed by a second table of

species by major size classes (saplings, poles, sawtimber, etc.) for AGS only.

Selecting Reports

SILVAH provides several scenarios for which you can obtain reports as you analyze a stand and

consider various treatment alternatives.

1. Click the Analysis and Prescription button.

2. Click the Reports tab. Reports are listed in the first column of the table.

3. Select one or more reports by checking the corresponding boxes under the column that

indicates when the report will be generated. Review the column descriptions for further

information below.

Scenarios under Which You may Select Reports

The following are the columns that represent specific stages or events during which SILVAH will

generate the reports you have selected.

Initial stand—Report on stand characteristics prior to any simulation or treatment implementation.

These are summaries of the inventory data entered in SILVAH.

Every cycle—Report on stand characteristics throughout a simulation period. If you are projecting

stand growth into the future, SILVAH projects growth in 5-year increments. A cycle represents one

5-year increment. Reports will be generated at the end of each 5-year increment.

Final results—Report on final stand characteristics at the end of a simulation period.

Current Rx—Report on the details of a treatment prescribed for the initial (current) stand.

Future Rx—Report on the details of a treatment prescribed at the end of each 5-year increment

within a simulation period.

Standard Reports

For your convenience, a set of standard reports can be selected under each scenario. In most cases,

standard reports will be satisfactory in providing all of the information you need for analyzing

your stands.

1. Click the Standard reports button if you want to select the standard reports in every scenario.

2. To select standard reports only for a single scenario, right-click once in the header cell at the

top of the scenario column. Click Standard reports.
56 User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription

Short Reports

For the Initial stand, Every cycle, and Final results scenarios, a reduced set of standard reports can be

selected, known as short reports.

1. To select short reports, right-click once in the header cell at the top of the scenario column.

Click Short reports.

Clearing Report Selections

1. Click the Clear selections button if you want to wipe out all report selections quickly.

2. If you want to clear the selections only for a single scenario, right-click once in the header cell

at the top of the scenario column. Click Clear selections.

3. For individual report selections, uncheck the box of a selected report to remove the selection.

Silvicultural Prescriptions

About Prescriptions

SILVAH offers four flexible options for prescriptions of management activities designed to move

stands toward their desired future condition. SILVAH’s expert prescriptions are based on years of

experience and research (Marquis et al. 1992, Brose et al. 2008) into silvicultural prescriptions

that should produce consistent results among stands of similar characteristics within the Allegheny

hardwood and mixed oak forests of the Allegheny Plateau and Allegheny Mountain sections of

Pennsylvania, Ohio, New York, West Virginia, and Maryland. Even if you decide not to follow them,

the treatments recommended by SILVAH will provide a starting point for selecting and documenting

your management actions.

SILVAH will apply your prescription choice (below) for all stands in the same run. After reviewing

the results, you may want to design a different treatment for one or more stands. If you need to tailor

treatments for specific stands, you may need to run those stands separately.

If you are projecting forest growth and yield, you may implement prescriptions on future stands. If

desired, your prescription choice for simulated stands may be different than the initial (current) stand.

SILVAH provides the following choices for implementing prescriptions:

No treatment—If you make this selection, SILVAH will not recommend or implement any treatment.

Silvah expert-recommended prescription—SILVAH will evaluate stand conditions and recommend

a silvicultural treatment for you. SILVAH will implement any treatment it recommends, allowing

you to compare the original, cut, and residual stands. Thinnings in merchantable tree size classes are

implemented only if timber volume is adequate for a sale. Harvest cuttings are implemented only if

the stand is adequately stocked with desirable tree regeneration.
User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription 57

Modify a standard prescription (semi-custom)—Select this option if you would like to implement

your own treatment using a standard SILVAH prescription as a template. You may adjust parameters

such as residual relative density, proportion of stocking removed to come from different diameter

classes, etc. A treatment you design will be implemented without evaluating stand conditions and

there are no checks against minimum sale quantities in timber volume.

Develop a prescription of user’s own design (custom)—This option allows you to specify almost

any kind of cut you desire. You will need to specify the target relative density (minimum residual

density) and maximum density (percent) to be removed at one time. You will also need to specify the

proportion of each species to be cut by diameter and quality—for each of three cutting priorities. A

completely custom treatment will be implemented without evaluating stand conditions and there are

no checks against minimum sale quantities in timber volume.

Major Prescription Variables

SILVAH summarizes a stand inventory into major factors that form the basis for writing a

prescription. These are the prescription variables described below, which are described in further

detail in Marquis et al. (1992) and Brose et al. (2008).

Site and Environmental Prescription Variables

• Silvicultural systems permitted or desired by manager

• Manager’s intentions for regenerating the stand (final harvest)

• Manager’s desire to increase oak in the stand

• Prescription charts manager wants to use (oak or northern/Allegheny hardwoods)

• Manager’s desire to retain post-harvest overstory residuals (legacy trees)

• Seed source index (seed-producing capacity of overstory)

• Deer impact

• Oak site quality (oak species are easier to regenerate on poor-quality sites)

• Thick duff on the forest floor1

• Soils that are very poorly drained or too wet1

• Rocky surface that would inhibit seedling establishment1

Overstory Prescription Variables

• Basal area of saplings

• Basal area of shade tolerant species

• Basal area of black cherry, white ash, and yellow-poplar combined

• Basal area of oak sawtimber

• Relative stand density

• Relative stand density of AGS

• Stand diameter

• Years to maturity

• Amount of timber volume available for a commercial sale

1Denotes variables that are summarized and evaluated against stocking criteria as described for understory prescription variables.
58 User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription

Understory Prescription Variables

In the understory tally, several vegetation and site variables are evaluated against predetermined

stocking thresholds, such as the number of seedlings or the presence or absence of site conditions that

would inhibit seedling establishment. Each variable is represented as the number of plots (percent)

that satisfy the threshold requirements for that variable. Variables evaluated against stocking criteria

are as follows:

• Established seedlings2

• Competitive seedlings2

• New oak seedlings2

• Established oak seedlings

• Competitive oak seedlings

• All sizes of oak seedlings combined2

• Desirable sapling species

• Oak stump sprouts3

• Any competitive seedlings supplemented with overstory residuals2

• Any interfering vegetation (tall woody plants, cover of shrubs, fern, grass)

Initial Stand Prescription

To implement a silvicultural prescription on the initial (current) stand:

1. Click the Analysis and Prescription button.

2. Click the Current Rx tab.

3. Choose how to implement a prescription.

4. If you choose No treatment or Silvah expert-recommended prescription, no further

treatment specifications are necessary.

5. If you choose Modify a standard treatment (semi-custom) or Develop a prescription of 

user’s own design (custom), review and modify the treatment parameters as necessary.

If you want to experiment with different treatments on the initial stand, you will need to accomplish

this through multiple runs. SILVAH will not prompt you for an alternate cut when the run is

finished. Therefore, you will need to establish a different prescription for each run in order to

compare the effects of different treatments on the current stand. Be sure to manage file names or

folders to avoid overwriting a file you will need for comparison.

Future Stand Prescription

You may implement treatments on stands during the simulation of stand growth and yield. SILVAH

will apply your prescription choice at the end of each 5-year increment during the simulation cycle.

2 Denotes variables that are evaluated a second time, under different stocking criteria based on the assumption that deer impact is very

low or absent (such as behind a fence). If a variable meets the stocking requirement only when deer impact is very low, then a fencing

prescription is included in the silvicultural prescription generated by SILVAH.

3 The contribution (stocking) of oak stump sprouts is calculated using the basal area of oak species in the overstory.
User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription 59

The impacts of treatments are compounded throughout a simulation cycle. Projection will occur on

the residual stand after each cut has been removed.

If you choose Silvah expert-recommended prescription, SILVAH will reevaluate stand conditions

prior to recommending a prescription. This is the only way to get different prescriptions along a

simulation period during a run. For instance, if you project growth and yield for 30 years, SILVAH

might not recommend any treatments for the first 10 years, then at year 15 you might see a

commercial thinning, and at year 25 you might see a final harvest prescription.

If you choose to modify a standard prescription or design one of your own, SILVAH will apply that

same prescription consistently, at the end of each 5-year interval throughout the simulation cycle. If

you want to experiment with different treatment designs, you will have to accomplish this through

multiple runs, where you specify different treatments in each run.

To implement a silvicultural prescription on a simulated stand (during the projection of stand growth

and yield):

1. Click the Analysis and Prescription button.

2. Prior to establishing a future stand prescription, you must specify that you want to project

stand growth and yield. Otherwise the future prescription options will be disabled.

3. Click the Simulated Future Rx tab.

4. Choose how to implement a prescription.

5. If you choose No treatment or Silvah expert-recommended prescription, no further

treatment specifications are necessary.

6. If you choose Modify a standard treatment (semi-custom) or Develop a prescription of 

user’s own design (custom), review and modify the treatment parameters as necessary.

Modifying Standard Treatments

Standard SILVAH treatments can be adjusted to suit your needs. Note that this does not alter the

kinds of treatments that SILVAH would prescribe if you were to ask for an expert-recommended

prescription. Instead, by modifying a standard treatment, you can experiment with treatment

parameters to adjust the attributes and the amount of timber cut and the indirect effects on timber

quality, relative density, stand diameter, and species composition in the residual stand.

1. Click the Analysis and Prescription button.

2. Click the Current Rx tab to modify a treatment for the current stand, or the click the

Simulated Future Rx tab to modify a treatment for a stand during simulation of stand

growth and yield.

3. Click Modify a standard prescription (semi-custom).

4. Select a standard treatment that you wish to modify. Treatments are briefly described below.

5. Enter the treatment parameters, explained below.
60 User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription

Even-aged Treatments

Even-aged management prescriptions all share the same parameters. The meaning of these variables

and the implications of the choices made here are described in Roach and Gingrich (1968), Stout

and Nyland (1986), Marquis and Ernst (1991), Nowak (1995), Nowak (1996), and Nowak and

Marquis (1997).

Minimum residual density desired

This is the target relative density desired after the cut is complete.

Maximum percent density to be removed in this cut

This is the maximum percent of the original stand density to be removed at one time. The maximum

amount removed will prevent excessively heavy cuts in stands that are at or above full stocking.

Percent of the cut relative density to come from below mean stand diameter

This controls the structure of the residual stand. Unless you understand the principle here, it is best to

use the 75 percent value that the program suggests, or the 80 percent value supplied for first removal

cuts in oak stands. Using a lower value will result in cutting of more large trees, potentially reducing

average diameter and delaying maturity.

The following even-aged treatments are available:

Precommercial thinning

This treatment is appropriate when relative stand density is 80 percent or more, and when sapling

basal area is at least 20 square feet per acre or more. It is designed to provide more growing space

for the better-quality stems and eliminate excess small saplings. We recommend this treatment only

when used to ensure survival of desirable species in dominant and codominant positions that would

otherwise drop out of the stand.

Pulpwood thinning plus timber stand improvement in saplings

If stand relative density is at least 80 percent or more, this treatment may be appropriate if there is

sufficient volume to make a pulpwood sale, and the landowner is willing to make some investment in

timber stand improvement (precommercial thinning).

Pulp and sawlog thinning plus timber stand improvement in saplings

If stand relative density is at least 80 percent or more, this treatment may be appropriate if there is

sufficient sawlog and pulpwood volume to make an integrated sale, and the landowner is willing to

make some investment in timber stand improvement (precommercial thinning).

Commercial pulpwood only thinning

This prescription is appropriate when relative stand density is 80 percent or more, and there is

sufficient volume in (and market for) pulpwood size trees to justify a thinning. The thinning should

remove smaller and poorer quality trees to concentrate growth on the largest and best quality trees.

The effect should be to raise the average stand diameter and reduce the time required for trees to

reach sawtimber size. Cutting only occurs in the pulpwood sizes.
User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription 61

Commercial pulp and sawlog thinning

This prescription is appropriate when relative stand density is 80 percent or more, and there is

sufficient sawlog and pulpwood volume to make an integrated sale. The thinning should remove

smaller and poorer quality trees to concentrate growth on the largest and best quality trees. The

effect should be to raise the average stand diameter and reduce the time required for trees to reach

sawtimber size. Most of the cutting occurs in pulpwood sizes, but some also occurs in sawtimber sizes.

Thin-harvest

This treatment is appropriate toward the end of the stand rotation. As the stand matures, species will

reach maturity at different ages. Some species may be ready for harvest while other require one or two

more thinnings. This treatment should remove trees from the smaller size classes as well as the largest

size classes. The effect should be to concentrate growth on trees in the small sawtimber size class since

these are the ones that increase most rapidly in value.

Seed cut

This treatment is appropriate in mature Allegheny or northern hardwood stands with high relative

stand density (e.g., 75 percent or higher), and where competitive seedlings are inadequate, but seed

sources are adequate and there are minimal site limitations. This treatment is designed to provide for

the establishment of desirable seedlings and to begin harvesting the stand. It is also prescribed when

seedling establishment is needed in immature stands due to management objectives. This is the first

cut in a shelterwood sequence for these forest types.

First removal cut (mixed oak stands)

This treatment is appropriate in mixed oak stands after oak regeneration has been established. The

treatment should reduce overstory stocking to 40 to 60 percent relative density, and retain sufficient

trees in sawtimber sizes so that a seed source is maintained on the site in case of a regeneration failure.

This is the first harvest in a shelterwood sequence in mixed oak forest types.

Uneven-aged Treatments

Uneven-aged management prescriptions share the same parameters. The meaning of these variables

and the implications of the choices made here are described in Stout (1994) and Miller et al. (1995).

The following two parameters of uneven-aged treatments are shared with even-aged treatments:

minimum residual density desired and maximum percent density to be removed in this cut.

Maximum diameter to be retained

This is the maximum diameter of trees to be retained in the stand.

Q-ratio (also called Q-factor)

This represents a geometric progression of increasing numbers of trees with decreasing diameters

(Smith 1986). For example, using 2-inch diameter classes, if the q-ratio is 1.2, the number of trees

in the 6-inch diameter class will be 1.2 times the number of trees in the 8-inch diameter class. This

controls the residual stand structure, and you need to understand the silvicultural implications of this

parameter to use this option wisely.
62 User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription

The following uneven-aged treatments are available:

Group selection cut (all age)

This treatment is appropriate in stands where the use of moderate canopy openings may permit the

regeneration of some intolerant species, while maintaining a forest canopy at all times. A maximum

tree size of 22 inches is recommended for timber production, along with a higher Q-ratio.

Single-tree selection cut (all age)

This treatment is appropriate in stands where large canopy openings are not permitted and a forest

with the appearance of many large trees is desired. A maximum tree size of 28 to 30 inches is

recommended, along with a low Q-ratio.

Defining Custom Treatments

With this option, it is possible to define almost any kind of treatment desired. Trees can be selected

for removal based on diameter, species, and timber quality. Furthermore, trees can be assigned a

removal priority which provides more control in meeting the objectives of the treatment.

1. Click the Analysis and Prescription button.

2. Click the Current Rx tab to design a treatment for the current stand, or the click the

Simulated Future Rx tab to design a treatment for a stand during simulation of stand growth

and yield.

3. Click Design a prescription of user’s own design (custom).

4. Enter the minimum residual density desired.

5. Enter the maximum percent density to be removed in this cut. This is the maximum

percent of the original stand density to be removed at one time. The maximum amount

removed will prevent excessively heavy cuts in stands that are at or above full stocking.

6. Click one or more of the priority buttons above the grid table to establish rows (records)

by priority in which to enter cutting specifications. A maximum of 24 rows may be used

for establishing cutting specifications. For example, if you established 12 specifications for

priority 1, that would leave 12 rows available for priorities 2 and 3. If you then established 7

specifications for priority 2, 5 rows would be available for priority 3.

7. Enter the cutting specifications for each row.

Add first priority—This button will add a row to the grid table, to be used for cutting priority 1.

Priority 1 specifications are implemented regardless of the effect on timber quality, stand structure, or

relative density. New rows are added at the bottom of existing rows for cutting priority 1, and above

any rows for cutting priorities 2 or 3.

Add second priority—This button will add a row to the grid table, to be used for cutting priority 2.

Priority 2 specifications are implemented on the stand after priority 1 cuts have been implemented,
User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription 63

and within stand density goals entered above. New rows are added at the bottom of existing rows for

cutting priority 2, below any rows for cutting priority 1 and above any rows for cutting priority 3.

Add third priority—This button will add a row to the grid table, to be used for cutting priority 3.

Priority 3 specifications are implemented on the stand after priority 1 and 2 cuts have been

implemented, and within stand density goals entered above. New rows are added at the bottom of

existing rows for cutting priority 3, below any rows for cutting priorities 1 and 2.

Delete record—This button will immediately remove the current row (where a cell has been

highlighted or entered).

Stand Growth Projection

About Stand Growth Projection

The growth and mortality equations in SILVAH have been fairly well tested on 30- to 90-year-old,

even-aged cherry-maple stands in northwestern Pennsylvania (Marquis 1982). There are equations

for other northern hardwoods species and for oaks (Hilt 1985) in the program and the simulator was

tested in stands where these other species dominate the species composition. Schuler et al. (1993)

report those results.

We know that results are erratic in some oak-hickory stands, and in some northern hardwood

stands dominated by sugar maple or beech. There is also no ingrowth function in the program,

so projections using uneven-age procedures should not be attempted for more than a 20- to 40-

year period.

The equations estimate growth and mortality using the following individual tree and

stand parameters:

• Relative diameter (dbh/medial stand diameter)

• Stand density (relative stand density)

• Species

• Site index (oaks only)

• Age

Projecting Stand Growth

The stand growth option is turned off by default. To project stand growth:

1. Click the Analysis and Prescription button.

2. Click the Growth and Yield tab.

3. Uncheck Do not project stand growth.

4. Enter the number of years to grow. The default is 5 years but may be any whole number > 0.
64 User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription

Database Output

About Database Output

SILVAH can output a stand summary into a text file that can be used in building a forest-wide

database. A stand is summarized on a single row comprised of 231 columns separated by commas. If

the stand is cut, two additional rows are output for the cut and residual stand. Even if a stand does

not receive any treatment, it can be output multiple times during a run if database output is requested

at every cycle during the projection of stand growth and yield.

Since each stand is output on a single row, you can aggregate output from separate stands into a single

file if desired. This is accomplished by asking SILVAH to append database output into the same text

file repeatedly during successive runs.

The output can be viewed in any word processor, but it is recommended that you view the data in a

spreadsheet program such as Microsoft Excel.

Each row begins with columns that identify the stand, the output date, source data file (*.sil), tally

date, and whether the row contains the original, cut, or residual stand, and the treatment type. The

next series of 97 columns contain key management factors for the stand, such as deer impact, site

index, total relative density, percent stocking of understory desirable and interfering species, timber

volume, and so on. The final columns contain the basal area per acre of 126 overstory species, in

alphabetical order. Species that do not occur in a stand will be shown with zero (0) basal area.

Generating Database Output

All stands displayed on the Pick Stands tab will be summarized and output to the file of your choice.

If you wish to maintain separate output for one or more stands, you must process them separately.

1. Click the Analysis and Prescription button.

2. Click the Run tab.

3. Under the Database output caption, select when you want database output to be generated.

Click Initial stand if you want to summarize the initial stand conditions prior to any

treatment or growth simulation. Click Every cycle if you want to summarize the stand at each

5-year cycle during simulation of stand growth and yield. Click Final results if you want to

summarize the stand at the end of the growth and yield period. Note: Every cycle and Final

results are disabled unless and until you turn on stand growth projection on the Growth and

Yield tab.

4. Click the Output file button, which will open a Save As dialog. Note: This button will

remain disabled until you select when you want output to be generated (e.g., Initial stand).

5. Browse to and select an existing database output file, or type in a new one.

6. Click Save when you have specified a database output file name.

7. Click Append to file if you selected an existing file in Step 5 and you wish to accumulate

multiple stand summaries in the same file, or click Overwrite current file if you want to

replace the contents of an existing file with new output.
User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription 65

Opening Database Output In Excel

The database output of SILVAH can be opened in Notepad or any word processor. However, the

output is arranged in a tabular format. Because of the extensive number of columns, it is strongly

recommended that you use Microsoft Excel or a similar spreadsheet program to open and view the

database output of SILVAH.

The following instructions pertain to Microsoft Excel.

1. Launch Microsoft Excel.

2. Begin the steps for opening an existing file.

3. From the Files of type list at the bottom of the Open dialog, select text files (*.txt).

4. Browse to the folder that contains the database output from SILVAH. The default file name is

“databaseoutput_silvah.txt.”

5. Click Open.

6. On the first page of the Text Import Wizard, be sure to select Delimited as the file type that

best describes the data. Then, click Next.

7. On the second page of the Text Import Wizard, be sure to check Comma in the choice of

Delimiters. The columns in the database output from SILVAH are separated by commas.

Then, click Next.

8. On the third page of the Text Import Wizard, click Finish.

Running Stands

Running Your Stands

After you have selected stands and chosen options for reports, prescriptions, growth and yield, and

database output, you are ready to run your stands.

Consider using script files if plan to use the same run options repeatedly.

Consider storing your selected stands in a file.

1. Click the Analysis and Prescription button.

2. Click the Run tab.

3. Click the large Run button.

Error handling during a run

SILVAH will process stands one at a time and report errors as they occur. When SILVAH reports an

error in the processing of a stand, a Run Errors dialog will pop up. In most cases you will be provided

with a brief explanation. You will be given the following choices for handling errors in the current run:
66 User’s Guide to SILVAH: Chapter 5 - Analysis and Prescription

STOP - do not continue

Select this option if you want to halt processing for all stands in this run. No further processing will

occur for any stand. Prior to the error, if any stands have already been processed in the run, you will

be able to view the output from those stands.

Continue processing

If you want to continue processing, despite errors, you have two choices. Select Continue displaying 

messages as they occur if you want to be prompted the next time an error occurs. Select Stop 

showing error messages if you want SILVAH to work through all stands in the run, without showing

you error messages during processing. If a stand has minor issues in the data, one or more reports

may include information about the problem. However, SILVAH will not produce any pop-up errors

during the remainder of the run.

Keep a log file

Check this box if you want to keep a history of the errors generated during this run. As soon as you

make this selection, SILVAH will prompt you for a file name. Browse to and select a folder, then

specify a log file name. Click Save when you are finished. SILVAH will display the folder and file

name on the Run Errors dialog.

Viewing the Output

When the run is completed, SILVAH will display the output of the first stand on the Run tab. Other

stands can be selected from the pick list with the caption Display report for stand. To view another

stand, click the pick list arrow. Stands will be listed with the full path and file name in the pick list.

Click once on the name of the stand to display it on the Run tab.

If desired, any stand already displayed on the Run tab can be opened in Notepad by clicking the

Open button. This will allow you to print the output or copy the contents into another word

processor if necessary. Each stand opened in Notepad will be displayed in a separate window, allowing

you to have several stands open at once.

Skipping Options during a Run

Occasionally you may want to skip certain options between runs. You can temporarily disable reports,

prescriptions, and growth and yield as desired, without switching tabs and redoing options each time.

To temporarily skip options during a run:

1. Click the Analysis and Prescription button.

2. Click the Run tab.

3. At the top of the Run tab, check the appropriate boxes to skip treatments or to skip 

stand growth.

4. Check the appropriate boxes to temporarily disable reports at various times during the run.

5. To re-enable any option, uncheck the box and reprocess the stands.
About TreeCalc

How many times have you asked yourself what was the volume of an 18-inch black cherry tree? Or,

what is the basal area or relative density of a tree? TreeCalc helps to answer these questions. It also can

be used to sum all of those values for a number of trees. Thus, TreeCalc is a general purpose volume

table and forestry calculator.

The values that are displayed in TreeCalc are identical to those that are used elsewhere in SILVAH.

In addition, TreeCalc can read the same defaults (.def ) files that are used during Analysis

and Prescription.

To start using TreeCalc, follow these steps:

1. At the top of the SILVAH6 screen, click the TreeCalc button.

2. If you wish to load a defaults (.def ) file, click the DEF file button.

3. Click inside the species cell, enter a species, then click in other cells and enter

appropriate values.

4. When you are ready to calculate, click the Calculate tree button.

How to Use TreeCalc

Some of the boxes (cells) on TreeCalc are white and some are gray. White values are ones that can be

changed, except the row of cells for trees that have been added to the grid at the bottom of the screen.

Gray cells represent calculated values. An example calculation for an 18-inch black cherry is shown in

Figure 4.

Most of the values that can be changed (white cells) are self explanatory, and are described elsewhere

in this documentation. See Chapter 4 for information about the species codes accepted, as well as

how to adjust the calculated volume using pulp and sawlog correction factors (CF).

TreeCalc will use the default species codes and volume correction factors loaded into memory. If you

wish to load your own defaults into TreeCalc, click the DEF file button.

Chapter 6 - TreeCalc, A Volume and Value Calculator
68 User’s Guide to SILVAH: Chapter 6 - TreeCalc, A Volume and Value Calculator

Figure 4.—An example calculation of an 18-inch black cherry in TreeCalc.

Entering Tree Characteristics

To change any of the white cells, click inside the cell with the mouse or use the Tab key to move to

the cell. Type in a new value and press the Enter key, or use the pick list provided for some cells.

When you change species, the pricing and form class information immediately changes. However,

many species are supplied with similar pricing and form class, and the screen may not appear to

change. None of the other values on the screen will change, so be sure that all values are set the way

you want them before you calculate.

Calculating Tree Values

When you have entered all of the characteristics on the tree for which you want volumes and values

calculated, click the Calculate tree button to calculate.
User’s Guide to SILVAH: Chapter 6 - TreeCalc, A Volume and Value Calculator 69

You can calculate volumes and values for several different diameters of any species quickly. Just

click in the diameter field, enter the diameter and press the Enter key, then click the Calculate tree

button. Likewise, you can change any of the other values, such as grades, heights, and so on, and

calculate a series of answers quickly.

The answers displayed in gray cells include Saw ht and Pulp ht, which are based on local height

equations, unless the height was entered. The Lumber price relative field is described in the Stand

Evaluation Tools (SETS) equation system in the topic “Volume and Value Calculations” in Chapter

7 on definitions and references. The percentage breakdowns represent the proportion of trees that are

grade 3 or better, and for those trees, the proportion that are grade 1, grade 2, grade 3, and veneer

grade. The cubic volumes (cuft) are calculated from U.S. Forest Service Region 9 equations. The

board-foot volumes (BF) are calculated by the rule specified, using a generalized formulation of the

Girard-Messavage form class tables. The Basal area is the standard calculation based on the diameter.

And the Rel Dens is the density accounted for by this tree.

Accumulating totals for multiple trees

You can also accumulate volumes and values for a number of trees. This makes it easy to calculate the

volume, value, basal area, and relative density of any tree, and to sum these values for several trees.

TreeCalc can accumulate totals only for trees that have been calculated and added to the grid at the

bottom of the TreeCalc screen.

1. After a tree is calculated, click the Add tree to grid button. The tree will appear as a row in

the grid at the bottom of the TreeCalc screen. As you repeat this process, several trees will

appear in the grid.

2. Check Display totals from tree list below when you are ready to display a total for all of the

trees displayed in the grid. The total values will appear in the middle of the TreeCalc screen in

the gray cells that are also used for displaying values for single trees.

3. When you are ready to resume calculating other trees, uncheck Display totals from tree 

list below.

Managing the Tree List in the TreeCalc Grid

Removing Trees

A tree can be removed from the grid at any time.

1. Click anywhere in the row of the tree you wish to delete.

2. Click the Delete tree button. If TreeCalc is currently displaying an accumulated total for all

trees in the grid, the total will be recalculated based on the remaining trees in the grid.

3. To remove all trees from the grid at once, click the Clear grid button.

Reviewing Tree Values

The values for any tree in the grid can be retrieved and displayed in the TreeCalc screen. Double-click

a row in the TreeCalc grid to retrieve and review the values for that tree.
About SILVAH Calculations

This chapter describes some of the calculations performed in SILVAH. Some literature references are

provided in connection with these calculations. There are many kinds of calculations in the SILVAH

software, and a discussion of all them is beyond the scope of this manual. There are many other

publications from which general information was used in developing the SILVAH approach. These

are cited in Marquis et al. (1992) and Brose et al. (2008).

Cover Types

At present, SILVAH does not use cover type for any calculations or determinations. If users enter

cover type, the information is stored with the stand in any databases that the user may create using

SILVAH data.

SILVAH accepts the following cover types: Forest, Seedlings, Opening, Pasture, Cropland, Wetland,

Water, Urban, and Other.

Forest Types

SILVAH assigns a forest type using the proportion of total stand basal area represented by a particular

species or species group. SILVAH includes all trees 1.0 inch dbh and larger in this determination.

The types recognized are as follows:

Northern hardwood - Stands that have at least 65 percent of the basal area in sugar maple, red maple,

American beech, yellow birch, sweet birch, eastern hemlock, American basswood, cucumber tree, black

cherry, white ash, or yellow-poplar.

Northern hardwood-hemlock - Stands meeting the requirements for the northern hardwood type that

also have at least 50 percent of their basal area in eastern hemlock.

Allegheny hardwood - Stands meeting the requirements for the northern hardwood type that also have

at least 25 percent of their basal area in black cherry, white ash, and yellow-poplar, and less than 50

percent of their basal area in eastern hemlock.

Mixed oak - Stands that have at least 65 percent of their basal area in northern red oak, black oak,

scarlet oak, white oak, or chestnut oak, or any hickory species.

Transition - Stands that have at least 65 percent of their basal area in species of either the northern

hardwood or oak-hickory types, but do not qualify for any of the other types alone.

Unknown - Any stand that does not qualify for one of the types above.

Chapter 7 - SILVAH Calculations
User’s Guide to SILVAH: Chapter 7 - SILVAH Calculations 71

Stand Size Classes

Stand size classes used in SILVAH are based on the “average” stand diameter, which is calculated as the

medial diameter (MD) of all trees 1.0 inch dbh and larger.

Note that the diameter breaking points for stand size classes do not correspond to the diameter breaking

points for individual tree size classes. For example, individual trees grow from the sapling class to the

pole class when they exceed 5.5 inches dbh, but stands with a medial diameter of more than 4.5 inches

are pole stands. This is because the stand diameter usually lags behind the average diameter of the crop

trees in the stand.

The stand size classes are as follows:

1. Sapling stands = MD less than 4.5 inches

2. Small pole stands = MD between 4.5 and 7.5 inches. Such stands will rarely support

commercial cutting.

3. Large pole stands = MD between 7.5 and 10.5 inches. These stands may support a combined

commercial thin—timber stand improvement (TSI)—if there is a good pulpwood market.

4. Small sawtimber stands = MD between 10.5 and 13.5 inches. In most areas, small sawtimber

stands will support commercial thinning.

5. Medium sawtimber stands = MD between 13.5 and 16.5 inches. Medium sawtimber stands

will support commercial thinning or thin-harvests.

6. Large sawtimber stands = MD larger than 16.5 inches. Such stands usually have a MD in

merchantable-size trees of 18 inches or more, and are economically mature.

Tree Size Classes

SILVAH defines several diameter break points for trees, also called tree size classes. These help to

distinguish broad diameter classes of trees. Note that tree size classes do not correspond to diameter

breaking points for stand size classes.

The tree size classes are as follows:

1. Sapling = 1.0 to 5.5 inches

2. Pole = 5.5 to 11.5 inches

3. Small Sawtimber = 11.5 to 17.5 inches

4. Medium Sawtimber = 17.5 to 23.5 inches

5. Large Sawtimber = 23.5 inches or more
72 User’s Guide to SILVAH: Chapter 7 - SILVAH Calculations

Stand Density Classes

SILVAH typically characterizes stand density (Gingrich 1967, Roach 1977, Stout et al. 1987, Stout

1991) as follows:

Relative density over 95 percent - Stands are at or near the maximum density possible. If SILVAH

recommends a partial cutting, SILVAH will constrain the density to be removed.

Relative density between 80 and 95 percent - Stands are above the optimum density for best growth

and the volumes available will usually permit a commercial sale.

Relative density between 50 and 80 percent - Stands are in the optimum density range for growth of

high-quality sawtimber and veneer.

Relative density below 50 percent, but density of AGS above 35 percent - Stands are understocked,

but still contain enough good trees to make further management worthwhile. They simply need time to

accumulate additional growing stock.

Relative density of AGS below 35 percent - Stands do not contain enough good trees to warrant

further management of the existing overstory cohort. They are economically mature, and should

be regenerated.

Volume and Value Calculations

Merchantable Heights

SILVAH will accept field measurements of sawlog merchantable height in 8-foot logs, and use that

information in calculating volumes. If no heights are entered, SILVAH will calculate sawlog height

from an equation developed from data provided by the Hammermill Paper Company (Marquis et al.

1992), where sawlog height is a function of dbh and species.

Before SILVAH calculates board-foot volume, estimated sawlog merchantable height may be

increased or decreased according to the user-entered merchantable height adjustment factor for

the stand.

Measurements of pulpwood height are not accepted. SILVAH always estimates the number of

8-foot bolts in the total merchantable height, which includes the sawtimber and pulpwood portion

of each tree. Instead of calculating pulpwood merchantable height as a means for estimating pulp

volume, SILVAH calculates pulp volume by obtaining the difference between total cubic volume and

sawtimber cubic volume of a tree. We developed the equation (Marquis 1977) for total merchantable

height from Allegheny National Forest data—no Hammermill data were available. Total

merchantable height is a function of dbh, species, and effective age of the stand. If age is unknown,

SILVAH uses 65 years.

Before SILVAH calculates cubic foot and pulp volume, estimated total merchantable height is

increased or decreased according to the user-entered merchantable height adjustment factor for

the stand.
User’s Guide to SILVAH: Chapter 7 - SILVAH Calculations 73

The sawlog heights determined from the Hammermill data average about 25 percent lower than

those from the Allegheny National Forest data. Since the Hammermill data correspond better with

the volumes actually utilized for sawlogs, we use the Hammermill data exclusively for sawlog heights.

To make the total merchantable heights correspond to the utilization standards of sawlogs, total

merchantable heights calculated from the Allegheny National Forest data are reduced by 25 percent.

Height equations return values only if the height is at least half of a full 8-foot bolt (0.5 0.9 bolts is

rounded up to one full bolt). However, fractional bolts are retained for trees with more than 1.0 bolt.

For species on which height equations are unavailable, SILVAH uses equations for sugar maple, red

maple, and northern red oak.

Cubic Volumes

SILVAH calculates gross cubic volumes using a U.S. Forest Service Region 9 composite volume

equation. The equation (Marquis 1977) uses dbh, total merchantable height in 8-foot bolts, and

various transformations and interactions.

Users may enter a cubic-foot correction factor for each species in the SILVAH defaults file. Refer to

the topic “Editing Species Parameters” in Chapter 4 for instructions on entering correction factors.

Cubic-foot correction factors are applied to gross cubic-foot volume—before net cubic-foot volume

is calculated.

SILVAH calculates gross sawlog and gross total cubic volume for any tree with at least one half of an

8-foot bolt.

Board Volumes

SILVAH calculates gross board-foot volume for the International 1/4 inch, Doyle, and Scribner log

rules, as defined in the widely used Mesavage and Girard form-class volume tables (Mesavage and

Girard 1956). These volumes are approximated using a simplified series of equations developed by

Wiant and Castenada (1977).

Users may enter a board-foot correction factor for each species in the SILVAH defaults file. Refer to

the topic “Editing Species Parameters” in Chapter 4 for instructions on entering correction factors.

Sawlog correction factors are applied to gross board-foot volume—before net board-foot volume

is calculated.

SILVAH calculates board-foot volume for any tree with at least one half of an 8-foot log. Board-foot

volume is a function of dbh, sawlog height in 8-foot logs, and form class.

Net Volumes

SILVAH reduces gross volumes of a tree as follows:

Board-foot volume

If tree product grade is unknown, SILVAH may reduce gross board-foot volume by the estimated

proportion of all sawtimber-size trees of similar species and diameter that do not have at least one

log of grade 3 or better, based on examinations of tree grade distributions (Ernst and Marquis 1979,

Myers et al. 1986).
74 User’s Guide to SILVAH: Chapter 7 - SILVAH Calculations

SILVAH also reduces gross board-foot volume by defect percent (if observed). There is no utilization

loss for net board-foot volume.

Pulpwood volume

SILVAH determines gross pulpwood volume by subtracting gross cubic-foot sawtimber volume from

total gross cubic-foot volume of the tree.

SILVAH reduces gross pulpwood volume by defect percent (if observed). After accounting for defect,

SILVAH reduces gross pulpwood volume by 20 percent to reflect typical utilization standards.

About Report Volumes

SILVAH reports five different stand volumes on the Stand Summary Report.

GTOT CDS, or Gross Total Cords, represents the gross amount of cordwood in the stand, including

the cordwood volume equivalence for sawtimber in the stand.

NTOT CDS, or Net Total Cords, represents the net amount of cordwood in the stand, including the

cordwood volume equivalence for sawtimber in the stand. SILVAH computes net cubic pulpwood

volume and converts to cord volume assuming 80 cubic feet per cord.

PULP CDS, or Net Pulpwood Cords, represents the net amount of cordwood in the stand excluding

the volume that will be marketed as sawtimber.

GRS BDFT represents the gross board foot volume in the stand.

NET BDFT represents the net board foot volume in the stand.

See specific volume topics for ways in which volumes are calculated.

Grade

SILVAH will accept field measurements of grade, and use that information in calculating value. If

no grade observations are entered, SILVAH will estimate grade based upon dbh and species. Grade

equations are based on data from Allegheny hardwood (Ernst and Marquis 1979) and oak-hickory

forests (Myers et al. 1986).

Equations are not available for every species. Species with similar form are grouped together. For

example, white ash, cucumber, and basswood use the equation developed for yellow-poplar. For species

of unknown form, the beech-birch equations are used.

Veneer is estimated at 15 percent of the grade 1 butt logs.

In all situations, the proportions calculated above are used for trees entered into SILVAH on which

grade was not recorded. When grade is recorded, SILVAH considers 100 percent of the butt log to

be the grade recorded, while grade distribution for the upper logs (above the first two 8-foot bolts) is

calculated as described.
User’s Guide to SILVAH: Chapter 7 - SILVAH Calculations 75

Value

SILVAH assigns values on the basis of the volume within each product and grade, as determined either

by actual measurements or by the SILVAH equations.

SILVAH calculates pulpwood, firewood, local bulk product, local sawlog product, and veneer values

simply as the volume in that product times the stumpage value for that product entered by the user.

SILVAH evaluates factory grade sawlogs from extensive sawmill recovery data. These data show the

average proportion of the various grades of lumber that can be sawn from trees of a given species,

dbh, height, and butt-log grade. From these data (equations), SILVAH calculates a tree quality index

representing the relative value of the lumber that can be sawn from that tree. That relative value is also

a function of the stumpage value entered by the user. To get total lumber value in the tree, the value

relative is multiplied by the sawlog volume.

SILVAH then subtracts conversion costs from the lumber value. These costs reflect the average cost of

harvesting and transporting the log. They are a function of diameter (it is more economical to harvest

and transport larger diameter logs). All these procedures are documented in the SETS equations

(Debald and Mendel 1976a, Debald and Mendel 1976b, Mendel et al. 1976).

Since the tree quality index and relative value of a tree (under this procedure) are functions of diameter

and merchantable height, the value per MBF is not constant. Instead, it varies from one stand to the

next. So, stumpage value for factory logs rarely will be equal to the volume times the stumpage value

entered by the user. This is an important advantage to the SILVAH program, as the value calculated

reflects the size, height, and quality of the trees in the individual stand.

When entering stumpage values for sawlogs, use a woods run average over many sales. This will be

approximately the value for a 16-inch dbh tree.
Chapter 8 - Data File Format

Data File Format

SILVAH data files (.sil) are written in plain ASCII text and can be edited with any text editor or word

processor with text mode. However, you must exercise caution if you do edit these files since they

require a strict format. It is recommended that you use SILVAH to edit data files since it assures that

the format of the file conforms to this standard.

The .sil files are sequentially accessed files with a record length of 16 characters. They contain several

different kinds of data, including stand identification information, standard (checkmark) regeneration

data, possibly extended regeneration data, overstory data, and possibly nonnative invasive

species data.

Tables 1 through 5 summarize the data blocks, records, and fields that occur in .sil files. Each table

provides a brief description of each data block, each record within a data block, and each field

within a record. Valid field types are either alphanumeric or numeric. Table 1 contains the stand

identification and related data.

Table 1.—Stand identification, management information, and inventory settings cont.

Line Columns Type Description

1 1-4 A SILVAH version number

5-9 N Overstory data flag. If this value is 0, no overstory data is in the file. If this 

value is 999, overstory data is present in the file.

10-14 N

Extended understory data flag. If this value is 0, no extended understory 

data is in the file. If this value is 999, extended understory data is present 

in the file.

2 1-16 - Blank Line, not currently used

3 1-16 A Owner/Agency

4 1-16 A Forest/Property

5 1-16 A County/District

6 1-6 A Compartment/Unit

7-12 A Stand Number (ID)

7 1-16 A Remarks, first 16 characters

8 1-16 A Remarks, characters 17 to 32

9 1-16 A Remarks, characters 33 to 48

10 1-16 A Remarks, characters 49 to 64

11 1-4 A Remarks, characters 65 to 80

continued
User’s Guide to SILVAH: Chapter 8 - Data File Format 77

Table 1.—Stand identification, management information, and inventory settings cont.

Line Columns Type Description

12 1 N Species code type (1=mnemonic, 2=user-defined/local, 3=forest survey/

FIA)

2 N DBH size classes used (1=one inch, 2=two inch)

3-4 N Tally month

5-8 N Tally year

9 N Overstory cruise type (see Appendix A)

10-12 N Number of overstory plots

13 1-6 N Overstory plot size or Prism BAF

7 N Understory cruise type (0=none, 1=checkmark, 2=extended)

8-10 N Number of understory plots

11 N Understory plot size (1=6-ft radius, 2=3.7-foot radius milacre plot)

14 1-6 N Stand area (acres)

7-9 N Actual stand age (calculated; tally year - year of origin)

15 1 N Cover type (see Appendix A)

2-3 N Currently unused

4-7 N Currently unused

8-9 N Site class (1=high quality, 2=average, 3=low quality)

10-12 A Site index species (species code recorded will correspond to species code 

type, see above)

13-15 N Site index

16 1-4 N Height adjustment (user-entered value between 0.5 and 1.5 inclusive)

5-8 N Currently unused

9-12 N Elevation

13-15 N Aspect (azimuth between 0-360 degrees)

17 1-3 N Slope (percent)

4 N Topographic position (see Appendix A)

5 N Operability (1=no limitations, 2=limited)

6 N Accessibility (1=road within stand, 2=road at edge of stand, 3=road within 

1 mile, 4=no road within 1 mile)

7 N Aquatic feature in stand (see Appendix A)

18 1-3 N Clearcut acreage within 1 mile (acreage between 0-1000 acres)

4-6 N Cultivated acreage within 1 mile (acreage between 0-1000 acres)

7-9 N Open acreage within 1 mile (acreage between 0-1000 acres)

10 N Aquatic feature within 1 mile (see Appendix A)

continued
78 User’s Guide to SILVAH: Chapter 8 - Data File Format

Table 1.—Stand identification, management information, and inventory settings cont.

Line Columns Type Description

19 1 N Restrictions on silvicultural system (see Appendix A)

2 N Management value (0=not observed, 1=high value, 2=medium value, 

3=low value)

3 N Deer impact index (see Appendix A)

4 N Manager wants to regenerate stand now (0=no, 1=yes only if stand 

mature, 2=yes regardless of conditions)

5 N Manager wants to increase oak in the stand (0=no, 1=yes)

6 N Prescription charts to follow (1=northern or Allegheny hardwoods, 2=mixed 

oak) 

7 N Manager wants to retain residuals (0=no, 1=yes)

The next block (Table 2) follows the stand identification block and contains regeneration data in

standard (checkmark) format. The standard regeneration block is always present in .sil files, even

when extended regeneration data is also present in the file. However, when extended regeneration

data is present in the file, the fields in the following records will have a value of zero (0).

Table 2.—Standard regeneration data block

Line Columns Type Description (Recorded as number of plots stocked)

20 1-4 N Black cherry

5-8 N Yellow-poplar

9-12 N Conifers

13-16 N New oak

21 1-4 N Established oak

5-8 N Competitive oak

9-12 N Other desirables

13-16 N Established desirables

22 1-4 N Competitive desirables

5-8 N Total oak

9-12 N Residuals

13-16 N Saplings

23 1-4 N Tall woody interference

5-8 N Low woody interference

9-12 N Fern

13-16 N Grass

24 1-4 N Any interference

5-8 N Grapevines

9-12 N Site limits

25 1-16 - Blank line, not currently used
User’s Guide to SILVAH: Chapter 8 - Data File Format 79

The extended regeneration data block (Table 3) follows the standard regeneration block in the .sil

file when extended regeneration data is input by the user. It consists of a series of repeating records—

one record for each non-zero cell in the extended regeneration section of the field tally sheet. The

regeneration class codes displayed in the file are derived from the classes displayed on the extended

regeneration data input screen and are coded in the following manner:

Understory regeneration codes

BCR - Black cherry

CNF - Conifers

COK - Competitive oak

DUF - Thick duff

EOK - Established oak

FRN - Fern

GRP - Grapevine

GRS - Grass

LWI - Low woody interference (species)

LWC - Low woody interference (percent cover)

NOK - New oak

NNS - Nonnative species

ODR - Other desirables

ROC - Rocky soil

RSD - Residuals

SAP - Saplings

TOH - Total height of oak seedlings

TWI - Tall woody interference (species)

WET - Wet soil

YPR - Yellow-poplar

Table 3.—Extended regeneration block

Line Columns Type Description

26+ 1-3 A Understory regeneration code (see above for description 

of codes)

4-7 N Understory plot number

8-11 N Seedling count, species code, yes/no, or other code

A trailer record with a “-1” in the regeneration code column after all of the regeneration data indicates

the end of the extended regeneration data block. This trailer record will appear in the file, even if

there is no extended regeneration data.

The overstory data block (Table 4) follows the standard and/or extended regeneration data. It consists

of a series of repeating records—one record for each overstory observation. A zero in the species

column indicates the end of an overstory plot, and the value that follows in the diameter column is

the plot number.
80 User’s Guide to SILVAH: Chapter 8 - Data File Format

Table 4.—Overstory data block

Line Columns Type Description

26+ 1-3 A Species code (species code recorded will correspond to species code 

type: 1=mnemonic, 2=user-defined/local, 3=forest survey/ FIA)

4-5 N Diameter (any value from 1-40 inches, decimals not used)

6 N Quality (see Appendix A)

7-12 N Height in 8-foot bolts, or count of observations of same species 

and diameter

13 N Grade (see Appendix A)

14 N Percent defect (whole number from 0-9 representing nearest 10 percent, 

i.e., 9=90 percent, and so on)

15 N Crown condition (see Appendix A)

16 N Wildlife code (see Appendix A)

A “-1” in the species column indicates the end of the overstory data. This trailer record will appear in 

the file, even if there is no overstory data.

Following the overstory data is the off-plot nonnative invasive species data (Table 5; plot-based 

observations are recorded in the extended regeneration data described above). It consists of a series 

of repeating records, with each record corresponding to one of the species identified as exotic in the 

plant species module. 

Table 5.—Off-plot nonnative species block

Line Columns Type Description

27+ 1-3 A Species code (species code recorded will correspond to species code 

type, see above)

4-5 N Species present within stand (0=no, 1=yes)

6-7 N Species present near or adjacent to stand (0=no, 1=yes)

A “-1” in the species column indicates the end of the off-plot nonnative species data. This trailer 

record will appear in the file, even if there is no data on invasive species.
Aquatic Features

These are the features that may occur within the stand or within 1 mile of the stand.

Code Description

1 spring or seep

2 stream <15 feet across

3 stream >15 feet across

4 marsh

5 swamp

6 pond

7 lake

Deer Impact Index

An estimate of the impact of browsing pressure from white-tail deer on regeneration is essential for

proper prescription. Deer impact is a function of deer population and the amount of available food in

the one square mile area surrounding the stand in question (Marquis et al. 1992).

Code Description

0 Unknown

1 Very low - Stand is inside a well-maintained woven-wire deer fence.

2 Low - Desirable regeneration abundant and of varying heights. Herbaceous plants such as 

Trillium spp., Indian cucumber, and Canada mayflower present and able to flower and fruit. 

Stump sprouts persist.

3 Moderate - Regeneration present, though height variation may be limited and stump 

sprouts obviously browsed or absent. Non-preferred browse species such as hay-scented 

fern, witch-hazel, striped maple, and beech root suckers common.

4 High - Desirable regeneration rare to absent. Non-preferred and browse-resilient vegetation 

limited in height due to deer browsing. No stump sprouts.

5 Very high - Desirable regeneration absent. Non-preferred species also limited in 

abundance. Browse line evident.

Appendix A - Codes and Input Definitions
82 User’s Guide to SILVAH: Appendix A - Codes and Input Definitions

Land Cover Type

Code Description

1 forest

2 seedlings

3 open (failed clearcuts, savannahs, other 

forest lands lacking tree cover)

4 pasture

5 crops

6 wetland

7 water

8 urban

9 other

Overstory Cruise Type

This is a coded value that reflects how the overstory data was collected, including whether you used

a prism or fixed area plots, whether you recorded stem counts or merchantable heights, and the tree

grading procedure you followed. SILVAH converts your answers into a single code, which is stored in

the data (.sil) file as follows:

Code Description

1 Prism cruise, individual trees, merchantable heights recorded, plots recorded separately. Either 

record grades for all trees or record grades for none of the trees. See also code 7.

2 Prism cruise, individual trees, stem counts recorded, plots recorded separately.

3 Prism cruise, dot tally, all plots tallied together.

4 Fixed-area cruise, individual trees, merchantable height recorded, plots recorded separately. 

Either record grades for all trees or record grades for none of the trees. See also code 8.

5 Fixed-area cruise, individual trees, stem counts recorded, plots recorded separately.

6 Fixed-area cruise, dot tally, all plots tallied together (stand table).

7 Prism cruise, individual trees, merchantable heights recorded, plots recorded separately. Record 

only major products, that is, cull (grade 8) and sawtimber with only pulp volume (grade 6). Similar 

to type 1, but used where you want accurate volumes and values without grading all trees.

8 Fixed-area cruise, individual trees, merchantable heights recorded, plots recorded separately. 

Record only major products, that is, cull and sawtimber with only pulp volume. Similar to type 4, 

but used where you want accurate volumes and values without grading all trees.

0 No overstory data
User’s Guide to SILVAH: Appendix A - Codes and Input Definitions 83

Restrictions on Silviculture System

It is assumed that timber production is an important goal of management for any stands being

prescribed under the SILVAH system. Visual goals are also considered. These codes to indicate

restrictions that visual goals may impose on timber cutting activities. Selection of goals 1 or 2 will

usually lead to an even-age silvicultural system, and will tend to maximize timber production by

maintaining a high proportion of shade intolerant species. Although wildlife goals are not specifically

stated, these goals will tend to favor wildlife species that depend on early successional vegetation,

and will generally maximize wildlife diversity. Selection of goals 3 or 4 will lead to an uneven-age

silvicultural system, and will tend to produce moderate timber yields by favoring a high proportion

of shade tolerant species. These goals will also tend to favor wildlife species that depend on late

successional vegetation.

Code Description

1 No restrictions on cutting methods for visual reasons.

2 Either even- or uneven-age silvicultural systems may be used, but clearcutting is not acceptable 

as a final harvest cutting method for visual reasons.

3 Uneven-age silvicultural systems are desired to maintain mature forest canopy at all times, but 

maximum timber production feasible under this system is desired.

4 Uneven-age silvicultural systems are desired to maintain a mature forest cover at all times. 

Timber production is less important than above, and visual goals call for the maintenance of 

very large trees on the area at all times, and the avoidance of canopy openings.

Topographic Position

Code Description

1 ridge

2 upper slope

3 mid slope

4 lower slope

5 bench

6 upper flat (plateau)

7 bottom
84 User’s Guide to SILVAH: Appendix A - Codes and Input Definitions

Tree Timber Quality

Code Description

1 Acceptable Growing Stock (AGS). These trees are suitable for retention in the stand for at 

least the next 15-year period. They are trees of commercial species and of such form and 

quality as to be salable for sawtimber products at some future date. Saplings are especially 

difficult to judge. Most knots, bumps, and stoppers will be confined to a small core if the 

sapling actually grows to a larger size, so consider most saplings acceptable. If in doubt 

about the correct quality class for any tree, consider it acceptable. Many acceptable trees 

will be removed if a partial cutting is prescribed for the stand, so do not consider the quality 

determination as a cut-leave tally.

2 Unacceptable Growing Stock (UGS). These trees do not have the potential to make salable 

sawtimber products in the future. They may be high risk trees —trees with disease, damage, 

or dieback that threatens their survival—or trees of such poor form that they just have to 

be removed regardless of the effect that removal will have on stand structure and species 

composition.

3 Dead. These are standing dead trees.

Tree Product Grade

Factory logs grades are described in Hanks et al. (1980) and Rast et al. (1973).

Code Description

1 Factory - lumber log grade 1

2 Factory - lumber log grade 2

3 Factory - lumber log grade 3

4 Locally defined log product (such as pallet log, local use log, etc.). Construction log grade.

5 Locally defined bulk product (such as boltwood).

6 Pulpwood (contains a minimum of two contiguous 4-foot bolts with minimum top inside diameter 

of 4 inches and at least 50% sound.

7 Fuelwood (same as pulpwood, but minimum top inside diameter of 1 inch).

8 Cull. Tree less than 50% sound, or does not qualify for any of the grades or products listed.

9 Veneer log

Tree Crown Condition

Code Description

1 Healthy. At least 90% of the crown is living.

2 Good. At least 75% but less than 90% of the crown is living.

3 Fair. At least 50% but less than 75% of the crown is living.

4 Poor. Less than 50% of the crown is living.
User’s Guide to SILVAH: Appendix A - Codes and Input Definitions 85

Tree Wildlife Value

Code Description

1 Potential den tree - live tree with large dead branch or broken top that represents a potential 

den cavity, but tree does not now contain a cavity.

2 Existing den trees - live trees with natural or artificially created hole for den (do not include 

shallow food excavations made by pileated woodpeckers).

3 Snag with potential den - dead or nearly dead trees, but no visible cavities.

4 Snag with existing den - dead or nearly dead trees, but containing an existing den cavity.

Species Codes

Name FIA Mnemonic Local

Other softwoods 1 OSW 2

Other hardwoods 4 OHW 88

Balsam fir 12 BF 2

E. red cedar 68 ERC 2

Larch 70 L 2

Tamarack 71 TAM 2

Spruce 90 S 2

Norway spruce 91 NS 2

White spruce 94 WS 2

Black spruce 95 BS 2

Red spruce 97 RS 2

Pine 100 P 2

Jack pine 105 JP 2

Shortleaf pine 110 SLP 2

Table Mountain pine 123 TMP 2

Red pine 125 RP 2

Pitch pine 126 PP 2

White pine 129 WP 1

Scotch pine 130 SCP 2

Loblolly pine 131 LOB 2

Virginia pine 132 VP 2

Austrian pine 136 AUP 2

Southern pine 170 SP 2

N. White cedar 241 NWC 2

Eastern hemlock 261 EH 6

Maple 310 M 88

Boxelder maple 313 BEM 88

Striped maple 315 STM 99

continued
86 User’s Guide to SILVAH: Appendix A - Codes and Input Definitions

Name FIA Mnemonic Local

Red maple 316 RM 21

Silver maple 317 SVM 88

Sugar maple 318 SM 20

Mountain maple 319 MTM 0

Norway maple 320 NWM 0

Buckeye 330 BUC 88

Devils walking stick 353 DWS 89

Serviceberry 355 SVB 91

Pawpaw 367 PAW 0

Japanese barberry 368 BAR 0

Birch 370 B 50

Yellow birch 371 YB 50

Sweet birch 372 SB 51

Paper birch 375 PB 50

Gray birch 379 GRB 0

Garlic mustard 382 GLM 0

Japanese stiltgrass 383 JST 0

Oriental bittersweet 384 ORB 0

Japanese knotweed 385 JAK 0

Blue beech 391 BB 90

Hickories 400 H 60

Butternut hickory 402 BH 88

Pignut hickory 403 PH 88

Pecan 404 PCN 88

Shellbark hickory 405 SLH 88

Shagbark hickory 407 SGH 88

Mockernut hickory 409 MH 88

American chestnut 421 AMC 0

Allegheny chinkapin 422 ALC 0

Hackberry 460 HAC 88

Yellowwood 481 YW 88

Dogwood 491 DOG 81

Hawthorn 500 HAW 94

Hazelnut 501 HAZ 0

Persimmon 521 PER 88

American beech 531 AB 54

Elaeagnus 534 ELA 0

Autumn olive 535 AUO 0

continued

Species Codes continued
User’s Guide to SILVAH: Appendix A - Codes and Input Definitions 87

Name FIA Mnemonic Local

Ash 540 A 88

White ash 541 WA 55

Northern catalpa 542 CAT 0

Black ash 543 BA 88

Green ash 544 GA 88

Huckleberry 549 HUK 0

Honey locust 552 HL 88

Kentucky coffeetree 571 KC 88

Witch hazel 585 WHL 0

American holly 591 AH 88

Mountain holly 592 MTH 88

Winterberry 593 ILV 0

Butternut 601 BUT 71

Black walnut 602 BW 88

Sweetgum 611 SG 88

Yellow-poplar 621 YP 59

Bush honeysuckle 635 LON 0

Japanese honeysuckle 636 JHN 0

Tartarian honeysuckle 637 THN 0

Prickly-ash 638 PRA 0

Amur honeysuckle 639 AHN 0

Osage-orange 641 OSO 0

Cucumbertree 651 CUC 84

Mountain magnolia 654 MM 88

Crabapple 660 CRB 0

Tupelo 690 T 88

Water tupelo 691 WT 88

Black gum 693 BG 66

Ironwood 701 OST 92

Paulownia 712 PAU 0

Virginia creeper 715 VCR 0

American sycamore 731 AS 88

Mountain laurel 733 MTL 0

Rhododendron 737 RHO 0

Other woody shrub 738 OWS 0

Aspen 740 ASP 63

Balsam poplar 741 BP 88

E. cottonwood 742 EC 88

continued

Species Codes continued
88 User’s Guide to SILVAH: Appendix A - Codes and Input Definitions

Name FIA Mnemonic Local

Bigtooth aspen 743 BTA 88

Quaking aspen 746 QA 88

Pin cherry 761 PC 95

Black cherry 762 BC 76

Choke cherry 763 CC 88

Wild plum 766 PLM 0

Sourwood 771 SW 0

Lowbush blueberry 785 LBL 0

Blueberry 786 BLU 0

Oak 800 O 88

White oak 802 WO 40

Swamp white oak 804 SWO 88

Scarlet oak 806 SO 32

N. pin oak 809 NPO 88

S. red oak 812 SRO 88

Cherrybark oak 813 CBO 88

Overcup oak 822 OO 88

Bur oak 823 BRO 88

Blackjack oak 824 BJO 88

Swamp chestnut oak 825 SCO 88

Chinkapin oak 826 CKO 88

Pin oak 830 PNO 88

Chestnut oak 832 CO 48

N. red oak 833 NRO 30

Shumard oak 834 SHO 88

Post oak 835 PO 88

Black oak 837 BO 31

Buckthorn 845 BTH 0

Common buckthorn 846 COB 0

Glossy buckthorn 847 GLB 0

Poison-ivy 867 PI 0

Currant 870 CUR 0

Black locust 901 BL 88

Multiflora rose 905 ROS 0

Rubus 915 RUB 0

Willow 920 W 88

Sassafras 931 SAS 96

Mountain ash 935 MTA 97

continued

Species Codes continued
User’s Guide to SILVAH: Appendix A - Codes and Input Definitions 89

Name FIA Mnemonic Local

American basswood 951 BAS 58

Elm 970 E 61

American elm 972 AE 88

Slippery elm 975 SE 88

Rock elm 977 RE 88

Nonnative shrub 995 NNS 0

Native shrub 996 NAS 0

Ailanthus 998 AIL 88

Other non-comm. 999 ONC 98

Species Codes continued
Appendix B - Sample Output

Cruise Information (type, Date, File, Sampling Error)

SILVAH V6.02 - SILVICULTURE OF ALLEGHENY HARDWOODS AND OAK 

 FILE: newdemo.sil 

 DEFAULTS FILE: C:\USFS-NRS\SILVAH6\silvah.def 

 OWNER/AGENCY -- USFS DATE TALLIED: Jul/2002

 FOREST/PROPERTY -- Exp For 

 COUNTY/DISTRICT -- Warren 

 COMPT - STAND -- Test Sample TYPE: TRANSITION HARDWOOD

 ACRES -- 10.00 SIZE: MEDIUM SAW 

 STAND AGE -- 63 DENSITY: 80 TO 95 % 

 SITE -- 70 FOR O

 SILVAH DEMO AREA - Uncut Stand 

 OVERSTORY CRUISE INFORMATION

 ----------------------------

 (Feb 26 2014 - newdemo.sil) 

 Overstory data is from an individual tree tally prism cruise, 

 using a 10 factor prism, and with trees tallied by

 1 inch dbh classes, heights, and pulp & cull grades only. 

 Overstory data based on 20 plots.

 Mean basal area is 115.5 plus or minus 8.6 square feet per acre

 at 90 % confidence ( 7.4 % of mean).

 0 additional plots needed to reach 15 % of mean basal area;

 0 additional plots needed to reach 10 % of the mean.

 Mean net bd-ft volume is 9145.6 plus or minus 908.5 bd-ft per acre

 at 90 % confidence ( 9.9 % of mean).

 0 additional plots needed to reach 15 % of mean of net bd-ft volume;

 0 additional plots needed to reach 10 % of the mean.

 Mean net pulpwood volume is 14.8 plus or minus 1.0 cords per acre

 at 90 % confidence ( 6.4 % of mean).

 0 additional plots needed to reach 15 % of mean of net pulpwood volume;

 0 additional plots needed to reach 10 % of the mean.

 UNDERSTORY CRUISE INFORMATION

 -----------------------------

 (Feb 26 2014 - newdemo.sil) 

 Data on competitive regeneration, site limitations and understory

 is from an extended regeneration tally

 using 6-ft radius plots. 

 Understory data is based on 22. plots.
User’s Guide to SILVAH: Appendix B - Sample Output 91

Information on Regeneration, Site, and Exotic Species/ Site 

Characteristics and Regeneration Summary

INFORMATION ON REGENERATION AND SITE - ORIGINAL STAND

 -----------------------------------------------------

 (Feb 26 2014 - newdemo.sil) 

 SPECIES OR % OF PLOTS VALUE

 CATEGORY STOCKED

 ---------- ---------- -----

 DESIRABLE TREE REGENERATION

 ---------------------------

 -- FIELD INVENTORY:

 BLACK CHERRY 0 0 Seedlings/acre

 YELLOW POPLAR 0 0 Seedlings/acre

 CONIFERS 0 123 Seedlings/acre

 NEW OAK 14 15564 Seedlings/acre

 ESTABLISHED OAK 0 700 Seedlings/acre

 COMPETITIVE OAK 0 0 Seedlings/acre

 OTHER DESIRABLES 5 8789 Seedlings/acre

 ESTABLISHED DESIRABLES 5 9612 Seedlings/acre

 COMPETITIVE DESIRABLES 5 8911 Seedlings/acre

 TOTAL OAK 14 16264 Seedlings/acre

 RESIDUALS 23 

 SAPLINGS 0 

 -- SUMMARY VALUES - AMBIENT DEER PRESSURE:

 OAK STUMP SPROUTS 0 33 Sprts/ac expected

 ANY ESTABLISHED REGEN 5 

 ANY COMPETITIVE REGEN 5 

 ANY CMP. REGEN OR RESIDS 23 

 ALL ESTABLISHED OAK 0 

 ALL OAK 14 

 -- SELECT SUMMARY VALUES - WITH FENCING/NO DEER PRESSURE:

 OAK STUMP SPROUTS 5

 ANY ESTABLISHED REGEN 55 

 ANY CMP. REGEN OR RESIDS 69 

 ANY COMPETITIVE REGEN 55 

 ALL ESTABLISHED OAK 14 

 ALL OAK 60 

 ** Under fencing/no deer pressure, summary regeneration stocking values

 reflect the contribution of oak stump sprouts, which contribute

 no more than 20% of total stocking.
92 User’s Guide to SILVAH: Appendix B - Sample Output

FACTORS AFFECTING REGENERATION DIFFICULTY

 -----------------------------------------

 DEER IMPACT 4 HIGH 

 SEED SUPPLY 2 Moderate seed supply 

 Nonnative invasive species were found in this stand, and have

 the potential to displace native vegetation, including desirable

 timber species. There are 0 invasives in the overstory, 1 in

 the understory, and 1 that were found outside the plots.

 INTERFERING UNDERSTORY

 ---------------------

 TALL WOODY INTERFERENCE 70**

 LOW WOODY INTERFERENCE 55 37 Plot average

 FERNS 5 2 Plot average

 GRASSES 0 1 Plot average

 ANY INTERFERENCE 70 

 GRAPEVINES 5 1 Vines/acre

 WOODY INTERFERENCE FOR REGENERATION

 -----------------------------------

 TALL WOODY INTERFERENCE 70**

 DETAILS # PLOTS (%) SPECIES

 2 9.09 AB

 2 9.09 TOTAL; All species

 LOW WOODY INTERFERENCE 54.5 

 DETAILS # PLOTS (%) SPECIES

 12 54.55 MTL

 12 54.55 TOTAL; All species

 UNDESIRABLE SAPLINGS AND POLES 23 sq.ft/ac basal area

 ** SILVAH assigns 70% stocking for tall woody interference

 if there is at least 10 sq.ft./acre of undesirable saplings

 and poles (tallied separately in the overstory) and there

 is less than 70% stocking of tall woody interfering species.
User’s Guide to SILVAH: Appendix B - Sample Output 93

 SITE LIMITATIONS FOR REGENERATION

 ---------------------------------

 SITE LIMITATIONS 0

 SITE INFORMATION - ORIGINAL STAND

 ---------------------------------

 COVER TYPE 1 Forest 

 SITE CLASS 2 Med. productivity 

 SITE SPECIES O

 SITE INDEX 70

 REL MERCH HT 0.00

 ELEVATION 1800

 ASPECT 90

 SLOPE % 5

 TOPO POSITION 6 Upper flat 

 OPERABILITY 1 No limitations 

 ACCESSABILITY 2 4-wh road at stand 

 STRESS FACTORS

 --------------

 DEER IMPACT 4 HIGH 
94 User’s Guide to SILVAH: Appendix B - Sample Output

Information on Regeneration, Site, and Exotic Species/ Exotic 

Species Present

 INFORMATION ON NONNATIVE INVASIVE SPECIES - ORIGINAL STAND

 -----------------------------------------------------------

 (Feb 26 2014 - newdemo.sil) 

 Nonnative invasive (NNIS) species may interfere with management goals and

 thus require careful assessment of their current extent within the stand

 and in neighboring stands if possible. It is of critical importance

 to understand the current/potential impacts of nonnative species prior to

 any operations in the stand. Specific treatment options should consider

 the difficulty of control of each species as well as the economic, aesthetic,

 and ecological value of the areas currently or likely to be infested

 by nonnative invasive species.

 OVERSTORY

 ---------

 No observations found in the data.

 UNDERSTORY - REGEN PLOTS

 ------------------------

 SPECIES # PLOTS % PLOTS CODE

 GARLIC MUSTARD 1 4.55 GLM

 #PLOTS W/NONNATIVE SPECIES % PLOTS

 1 4.55 TOTAL; All NNIS species

 INTERERENCE IN THE UNDERSTORY

 -----------------------------

 TALL INTERFERENCE # PLOTS % PLOTS CODE

 0 0.00 TOTAL; All NNIS species

 LOW INTERFERENCE # PLOTS % PLOTS CODE

 0 0.00 TOTAL; All NNIS species

 OFF-PLOT OBSERVATIONS IN THE STAND

 ----------------------------------

 SPECIES CODE

 GARLIC MUSTARD GLM

 OBSERVATIONS WITHIN ONE MILE OF STAND

 -------------------------------------

 No observations found in the data.
User’s Guide to SILVAH: Appendix B - Sample Output 95

Information on Silvicultural Systems and Wildlife Habitat

 INFORMATION ON SILVICULTURAL SYSTEMS AND WILDLIFE HABITAT - ORIGINAL STAND

 --------------------------------------------------------------------------

 (Feb 26 2014 - newdemo.sil) 

 SILVICULTURAL SYSTEMS

 ---------------------

 NO RESTRICTIONS(EVEN-AGE W/CLEARCUTTING) 

 Timber production for maximum yield, with high 

 proportion of shade-intolerant species. 

 For this system, the stand value is: Medium 

 WILDLIFE TREES NO./ACRE

 -------------- --------

 POTENTIAL DEN TREES 0.000

 EXISTING DEN TREES 0.000

 SNAGS WITH POTENTIAL CAVITIES 0.000

 SNAGS WITH EXISTING CAVITIES 0.000

 OTHER STANDING DEAD TREES (Not Snags) 0.000

 WATER HABITATS WITHIN THIS STAND INCLUDE:

 -----------------------------------------

 Unknown 

 HABITAT CONDITIONS SURROUNDING THIS STAND

 -----------------------------------------

 CLEARCUT ACRES W/I 1 MILE 0.00

 CULTIVATED ACRES W/I 1 MILE 0.00

 OPEN ACRES W/I 1 MILE 0.00

 WATER HABITATS W/I 1 MILE INCLUDE: Unknown 
96 User’s Guide to SILVAH: Appendix B - Sample Output

Product Table / Timber Volume and Value x Species

 VOLUME AND VALUE OF PRODUCTS IN THE ORIGINAL STAND (per acre)

 ----------------------------------------------------------------

 (Feb 26 2014 - newdemo.sil) 

SPECIES > ALL SP |RM NRO CO WO BO CUC SO AB SVB SAS

 NET LOG VOLUME (INT 1/4” LOG RULE) - MBF PER ACRE

 VENEER 0.4 | 0.0 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 GRADE 1 2.1 | 0.1 1.2 0.3 0.1 0.2 0.1 0.1 0.0 0.0 0.0

 GRADE 2 5.3 | 0.6 1.7 1.5 0.9 0.4 0.1 0.1 0.0 0.0 0.0

 GRADE 3 1.4 | 0.8 0.1 0.3 0.0 0.0 0.1 0.0 0.0 0.0 0.0

 PALLET 0.0 | 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 TOTAL 9.1 | 1.5 3.2 2.2 1.1 0.7 0.3 0.2 0.0 0.0 0.0

 NET BULK VOLUME - CORDS PER ACRE

 BOLTWOOD 0.0 | 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 PULPWOOD 14.8 | 4.8 3.5 3.5 1.8 0.7 0.2 0.2 0.1 0.0 0.0

 FIREWOOD 0.0 | 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 TOTAL 14.8 | 4.8 3.5 3.5 1.8 0.7 0.2 0.2 0.1 0.0 0.0

 VALUE - DOLLARS PER ACRE

 VENEER 102.7 | 1.4 89.3 1.6 6.9 1.8 1.4 0.3 0.0 0.0 0.0

 GRADE 1 582.0 | 8.0 506.1 9.3 38.9 10.2 7.8 1.7 0.0 0.0 0.0

 GRADE 2 1019.1 | 33.5 636.9 41.8 285.7 13.9 4.3 2.5 0.5 0.0 0.0

 GRADE 3 49.4 | 21.1 19.9 1.6 6.1 0.0 0.6 0.0 0.1 0.0 0.0

 PALLET 0.0 | 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 TOTAL 1753.3 | 64.1 1252.2 54.3 337.5 26.0 14.1 4.5 0.6 0.0 0.0

 $/MBF 0.0 | 42.8 389.5 25.3 308.5 39.0 54.4 20.3 14.5 0.0 0.0

 BOLTWOOD 0.0 | 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 PULPWOOD 29.5 | 9.7 7.0 7.0 3.5 1.4 0.3 0.5 0.1 0.0 0.0

 FIREWOOD 0.0 | 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 TOTAL 29.5 | 9.7 7.0 7.0 3.5 1.4 0.3 0.5 0.1 0.0 0.0

 $/CORD 0.0 | 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 0.0 0.0

 GR.TOTAL 1782.9 | 73.7 1259.2 61.4 341.0 27.3 14.4 5.0 0.7 0.0 0.0
User’s Guide to SILVAH: Appendix B - Sample Output 97

Overstory Summary (qual, d, age, structure, dens, vol, val)

 OVERSTORY SUMMARY ORIGINAL STAND (2002) - LIVE TREES ONLY 

 ------------------------------------------------------

 (Feb 26 2014 - newdemo.sil) 

 SPECIES > ALL SP | RM NRO CO WO BO CUC SO AB SVB SAS

 COMPOSITION -- BA, % OF BA, TREES

 TOT BA 115.5 | 35.8 28.2 25.8 12.8 5.8 2.0 2.0 1.5 1.2 0.5

 SPECIES% 100. | 31. 24. 22. 11. 5. 2. 2. 1. 1. 0.

 # TREES 185. | 100. 16. 30. 12. 3. 2. 1. 8. 11. 2.

 QUALITY -- % IN AGS

 SAPS 36. | 50. 0. 0. 0. 0. 0. 0. 0. 0. 0.

 POLES 78. | 84. 33. 85. 71. 0. 100. 0. 0. 0. 0.

 SM SAW 92. | 97. 91. 94. 88. 100. 100. 75. 0. 0. 0.

 MED SAW 98. | 100. 96. 100. 100. 100. 100. 100. 0. 0. 0.

 LG SAW 89. | 0. 100. 0. 100. 100. 100. 0. 0. 0. 0.

 ALL SIZE 87. | 85. 93. 89. 88. 100. 100. 88. 0. 0. 0.

 DIAMETERS AND AGES -- INCHES, YEARS

 DIAM 14.9 | 10.2 20.2 15.0 15.1 19.6 17.0 18.6 8.0 4.8 7.0

 DIAM MER 15.6 | 11.1 20.2 15.0 15.1 19.6 17.0 18.6 14.0 6.0 7.0

 QUAD DIA 10.7 | 8.1 18.1 12.6 13.7 19.0 14.4 17.9 5.9 4.6 7.0

 YRS MAT 14. | 34. 0. 20. 19. 0. 5. 0. 27. 80. 73.

 EFCT AGE 87. | 56. 101. 100. 101. 131. 85. 124. 93. 40. 47.

 STRUCTURE

 Q FACTOR 1.33 | 1.41 0.98 1.10 1.03 0.00 0.00 0.00 0.00 0.00 0.00

 RELATIVE DENSITY -- %

 REL DEN 87. | 25. 14. 24. 12. 5. 1. 2. 2. 1. 0.

 AGS RDEN 74. | 20. 13. 22. 11. 5. 1. 2. 0. 0. 0.

 VOLUMES AND VALUES - INT 1/4” LOG RULE

 GTOT CDS 34.7 | 8.8 9.9 8.2 4.2 2.0 0.7 0.7 0.1 0.0 0.1

 NTOT CDS 27.6 | 7.0 7.9 6.6 3.3 1.6 0.5 0.6 0.1 0.0 0.0

 PULP CDS 14.8 | 4.8 3.5 3.5 1.8 0.7 0.2 0.2 0.1 0.0 0.0

 GRS BDFT 11033. | 2542. 3425. 2465. 1256. 713. 294. 241. 96. 0. 0.

 NET BDFT 9146. | 1497. 3215. 2151. 1094. 666. 260. 223. 40. 0. 0.

 DOLLARS 1783. | 74. 1259. 61. 341. 27. 14. 5. 1. 0. 0.
98 User’s Guide to SILVAH: Appendix B - Sample Output

Overstory Species x Diameter Tables / Basal Area

 SPECIES X DIAMETER ORIGINAL STAND (2002) - LIVE TREES ONLY 

 ------------------------------------------------------

 (Feb 26 2014 - newdemo.sil) 

 BASAL AREA - SQ. FT. PER ACRE

 SPECIES > ALL SP | RM NRO CO WO BO CUC SO AB SVB SAS

 DIA.

 1 0.0 | 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 2 0.0 | 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 3 0.0 | 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 4 2.0 | 1.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.5 0.0

 5 5.0 | 3.5 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.5 0.0

 6 2.8 | 2.0 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.2 0.0

 7 3.0 | 2.0 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.5

 8 4.5 | 2.0 0.0 2.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0

 9 4.8 | 3.2 0.5 0.5 0.5 0.0 0.0 0.0 0.0 0.0 0.0

 10 5.8 | 4.0 0.5 0.5 0.8 0.0 0.0 0.0 0.0 0.0 0.0

 11 5.8 | 2.2 0.5 2.5 0.0 0.0 0.5 0.0 0.0 0.0 0.0

 12 10.5 | 6.5 1.0 2.0 0.5 0.0 0.5 0.0 0.0 0.0 0.0

 13 5.2 | 2.2 0.0 1.0 2.0 0.0 0.0 0.0 0.0 0.0 0.0

 14 7.5 | 2.5 1.2 1.8 1.5 0.0 0.0 0.0 0.5 0.0 0.0

 15 5.8 | 2.2 0.8 1.2 0.8 0.5 0.0 0.2 0.0 0.0 0.0

 16 9.8 | 0.8 1.5 4.2 1.5 1.0 0.0 0.8 0.0 0.0 0.0

 17 5.8 | 0.5 1.0 2.5 1.8 0.0 0.0 0.0 0.0 0.0 0.0

 18 5.0 | 0.0 2.0 1.5 1.0 0.5 0.0 0.0 0.0 0.0 0.0

 19 5.5 | 0.0 2.5 1.5 1.5 0.0 0.0 0.0 0.0 0.0 0.0

 20 5.8 | 0.5 2.5 0.8 0.0 1.5 0.5 0.0 0.0 0.0 0.0

 21 5.5 | 0.0 3.5 0.2 0.0 1.2 0.0 0.5 0.0 0.0 0.0

 22 3.5 | 0.0 2.0 1.0 0.0 0.0 0.0 0.5 0.0 0.0 0.0

 23 2.8 | 0.0 1.8 0.5 0.0 0.5 0.0 0.0 0.0 0.0 0.0

 24 2.5 | 0.0 2.0 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0

 25 3.5 | 0.0 2.0 0.5 0.0 0.5 0.5 0.0 0.0 0.0 0.0

 26 0.0 | 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 27 1.5 | 0.0 1.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 28 0.5 | 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 29 0.5 | 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 30 0.5 | 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 31 0.5 | 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 SAPS 7.0 | 5.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 1.0 0.0

 POLES 26.5 | 15.5 1.5 6.5 1.8 0.0 0.5 0.0 0.0 0.2 0.5

 SM SAW 44.5 | 14.8 5.5 12.8 8.0 1.5 0.5 1.0 0.5 0.0 0.0

 MED SAW 28.0 | 0.5 14.2 5.5 2.5 3.8 0.5 1.0 0.0 0.0 0.0

 LG SAW 9.5 | 0.0 7.0 1.0 0.5 0.5 0.5 0.0 0.0 0.0 0.0

 TOTAL 115.5 | 35.8 28.2 25.8 12.8 5.8 2.0 2.0 1.5 1.2 0.5

 SPECIES% 100.0 | 31.0 24.5 22.3 11.0 5.0 1.7 1.7 1.3 1.1 0.4

 ACCEPTABLE GROWING STOCK ONLY

 SAPS 2.5 | 2.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 POLES 20.8 | 13.0 0.5 5.5 1.2 0.0 0.5 0.0 0.0 0.0 0.0

 SM SAW 41.0 | 14.2 5.0 12.0 7.0 1.5 0.5 0.8 0.0 0.0 0.0

 MED SAW 27.5 | 0.5 13.8 5.5 2.5 3.8 0.5 1.0 0.0 0.0 0.0

 LG SAW 8.5 | 0.0 7.0 0.0 0.5 0.5 0.5 0.0 0.0 0.0 0.0

 TOTAL 100.2 | 30.2 26.2 23.0 11.2 5.8 2.0 1.8 0.0 0.0 0.0
User’s Guide to SILVAH: Appendix B - Sample Output 99

Narrative Summary and Analysis of Stand

 NARRATIVE SUMMARY AND ANALYSIS OF STAND

 ---------------------------------------

 (Feb 26 2014 - newdemo.sil) 

 Nonnative invasive species were found in this stand, and have

 the potential to displace native vegetation, including desirable

 timber species. There are 0 invasives in the overstory, 1 in

 the understory, and 1 that were found outside the plots.

 This transition stand is dominated by

 Red Maple, Red Oak, Chestnut Oak, White Oak, Black Oak, and Cucumber, 

 which together comprise 84 % of the basal area.

 This is a medium sawtimber stand, with average diameter of 14.9 inches.

 If this stand is managed under an even-age silvicultural system,

 The several species groups will mature at markedly different times.

 The average time to maturity (MDM = 18 inches) is 13 years.

 The manager wishes to regenerate the stand now.

 Effective stand age is about 87 years.

 If this stand is managed under an all-age silvicultural system,

 the distribution of diameters, proportion of sawtimber, and

 density of shade-tolerant species

 would make it difficult to apply selection cutting.

 Relative stand density is 87 % of the average maximum stocking

 expected in undisturbed stands of similar size and species composition.

 This density is higher than optimum for best individual tree growth.

 At this relative density, growth rate of the biggest trees is probably 

 moderate, while growth rate of the medium and smaller-sized trees

 is probably fair and mortality due to crowding moderate.

 Thinning to provide more growing space for the better stems is

 desirable if it will at least pay the cost of harvesting.

 Total growing stock amounts to 115 sq. ft. of basal area per acre.

 Gross total volume in all trees, to a 4-inch top, is 27.6 cords per 

acre;

 if divided into pulpwood and sawtimber, the net merchantable volume 

 is 14.8 cords of pulp wood and 9145.6 board feet of

 sawtimber Int 1/4”log rule.

 The total stand value is estimated to be about 1782 dollars per acre.

 Trees of acceptable quality for future growing stock 

 provide a fully stocked stand by themselves.

 Non-commercial saplings and poles represent 20 sq. ft. of basal area

 and may need to be treated prior to final harvest cutting.

 Competitive regeneration of all types is insufficient; harvest cuttings

 at this time will not likely result in a satisfactory new stand.

 Undesirable understory plants may interfere with development

 of regeneration. Undesirable plants in this stand include

 tall woody interference, and low woody interference. 
100 User’s Guide to SILVAH: Appendix B - Sample Output

Central Appalachian Oak Guide

 CENTRAL APPALACHIAN OAK GUIDE - ORIGINAL STAND

 PROJECTED STOCKING OF OAK SPECIES IN THE THIRD DECADE AFTER HARVEST

 -------------------------------------------------------------------

 (Feb 26 2014 - newdemo.sil) 

 -- SPROUT-ORIGIN STOCKING: (%)

 CHESTNUT OAK 20

 RED OAK/SCARLET OAK 16

 BLACK OAK 1

 WHITE OAK 2

 TOTAL SPROUT-ORIGIN STOCKING 40

 -- SEED-ORIGIN STOCKING: (%)

 ALL OAK SPECIES 16

 -- EXPECTED TOTAL OAK STOCKING: 55

 ****** CAUTION *******

 This estimate of oak stocking is based on data collected in the ridge 

 and valley region of Central Pennsylvania. Please exercise caution when

 estimating future oak stocking in other regions.
User’s Guide to SILVAH: Appendix B - Sample Output 101

Prescribed Treatment Information / Treatment description with 

marking instructions

RECOMMENDED TREATMENT

 ---------------------

 (Feb 26 2014 - newdemo.sil) 

 FENCE, PREPARATORY CUT, HERBICIDE, RE-INVENTORY 

 The stand is less than 15 years to maturity.

 The manager wishes to begin regenerating this stand now.

 Make a PREPARATORY CUT of a shelterwood system to develop the

 new oak seedlings. Reduce relative density to approximately 70%,

 by removing suppressed, intermediate, and weak codominant trees

 of all species. Then, re-inventory in 5-10 years to determine the

 next course of action.

 Current deer levels will likely prevent regeneration

 developing into a new stand.

 FENCING is recommended. A fence can be constructed either before

 or after treatment. If fencing is constructed after treatment,

 fencing should be done as soon as possible.

 Treat the undesirable understory plants with an application of

 HERBICIDE during the appropriate part of the growing season. Please refer to

 the silvicultural guide for details about implementing this prescription.

 The volumes to be removed are:

 650 bd ft (Int 1/4” log rule) and 2.9 cords.

 ****** CAUTION *******

 This prescription generally produces the desired results, requires

 an investment, and usually will yield an economic return at the

 same time. If such investment meets your organization’s economic

 criteria, we recommend it. If not, we recommend NO treatment.

 In the case of regeneration prescriptions, stands generally will NOT

 reproduce without the recommended treatment.
102 User’s Guide to SILVAH: Appendix B - Sample Output

MARKING INSTRUCTIONS

 --------------------

 LEAVE GUIDES:

 Leave 85 well distributed trees per acre that are 6 inches dbh

 or larger. These trees should be AGS growing in codominant and dom 

 inant crown positions. Within the size and quality constraints be 

 low, favor the best trees wherever possible. Try to preserve seed

 sources of scarce species if they are desired in the regeneration,

 and strive for uniform spacing among residuals whenever possible.

 Spacing among these leave trees should average 23 feet.

 Leave 100 sq. ft. of basal area per acre

 using the approximate basal area distribution below.

 size class Basal Area (sq. ft.)

 SAPLING = 6

 POLES = 12

 SMALL SAW = 41

 MEDIUM SAW = 28

 LARGE SAW = 9

 CUT GUIDES:

 Reduce relative stand density to 71 %.

 Remove trees in the size classes shown below.

 Cut 1 out of 6 trees from the saps size class.

 Cut 1 out of 2 trees from the pole size class.

 Cut 1 out of 8 trees from the ssaw size class.

 Cut 1 out of 8 trees from the msaw size class.

 Cut 1 out of 8 trees from the lsaw size class.

 About 59 % of the trees cut will be UGS.

 This will result in removal of about 77 % of the UGS in this stand,

 and about 100 % of the merchantable-size UGS.
User’s Guide to SILVAH: Appendix B - Sample Output 103

Prescribed Treatment Information / Comparison of original, cut and residual 

stand data

COMPARISON OF ORIGINAL, CUT, AND RESIDUAL STAND

 -----------------------------------------------

 (Feb 26 2014 - newdemo.sil) 

 ORIGINAL CUT RESIDUAL | ORIGINAL CUT RESIDUAL

 BASAL AREA - SQ FT/A | SPECIES COMPOSITION - %

 SAPS 7.0 1.0 6.0 | % CUC 2. 2.

 POLES 26.5 14.0 12.5 | % RM 31. 29.

 SM SAW 44.5 3.5 41.0 | % AB 1. 1.

 MED SAW 28.0 0.5 27.5 | % NRO 24. 27.

 LG SAW 9.5 1.0 8.5 | % WO 11. 11.

 TOTAL 115.5 20.1 95.4 | % CO 22. 22.

 | % OTHO 7. 8.

 NUMBER OF TREES - #/A | QUALITY -- % IN AGS

 # TREES 185. 52. 132. | % AGS 87. 96.

 DIAMETERS - IN. | AGES - YRS.

 DIAM 14.9 15.8 | YRS MAT 14. 8.

 DIAM MER 15.6 16.5 | EFCT AGE 87. 92.

 QUAD DIA 10.7 11.5 | 

 RELATIVE DENSITY - % | STRUCTURE

 REL DEN 87. 71. | Q FACTOR 1.3 1.1

 AGS RDEN 74. 67. | WEIB C 0.0 0.0

 BD FT INT 1/4”, VALUE/A | CORD VOLUME/A

 GR. BDFT 11033. 878. 10155. | TOT CDS 34.7 5.1 29.5

 NET BDFT 9146. 654. 8492. | NET CDS 27.6 4.0 23.6

 DOLLARS 1783. 87. 1696. | PULP CDS 14.8 2.9 11.9

 ------------------------------- TOTAL STAND -------------------------------

 M BD FT INT 1/4”, VALUE | CORD VOLUME

 GR. MBF 110.3 8.8 101.5 | TOT CDS 347. 51. 295.

 NET MBF 91.5 6.5 84.9 | NET CDS 276. 40. 236.

 M DOLLAR 17.8 0.9 17.0 | PULP CDS 148. 29. 119.
104 User’s Guide to SILVAH: Appendix B - Sample Output

Newdemo.prx

SILVAH V6.02 - SILVICULTURE OF ALLEGHENY HARDWOODS AND OAK 

 DECISION FACTORS FOR THE PRESCRIPTION RECOMMENDED IN THE FILE “C:\

USFS-NRS\SILVAH6\newdemo.prn”.

 ******RECOMMENDED TREATMENT:******

 FENCE, PREPARATORY CUT, HERBICIDE, RE-INVENTORY 

 (silvah treatment code: 1663)

------------------------Beginning Chart A------------------------

Management goals permit even-age management.

Site Limits do not appear to limit regeneration.

Stand is NOT mature (MDM < 18 in.). At least 35% of relative density is comprised of AGS.

User intends to regenerate the stand now.

Regen data was collected.

User wants to follow the prescriptions for oak/mixed oak ecosystems.

------------------------Beginning Chart F------------------------

Competitive oak is NOT adequate on at least 50% of plots.

User wants to increase oak.

------------------------Beginning Chart G------------------------

All established oak is not adequate on at least 50% of plots, with 

or without a deer problem.

------------------------Beginning Chart I------------------------

All oak regeneration is adequate inside a fence.

Sunlight is limiting (relative density is greater than 75%).

Interfering plants are a problem. At least 30% of plots have some 

kind of interfering vegetation.

Deer impact is high (index >= 4).
User’s Guide to SILVAH: Appendix B - Sample Output 105

Newdemo.NNS

 SILVAH V6.02 - SILVICULTURE OF ALLEGHENY HARDWOODS AND OAK 

 DESCRIPTIONS FOR NONNATIVE INVASIVE SPECIES IN THE FILE “newdemo.prn”.

 -----------------------------------------------------------------------------------

 GARLIC MUSTARD

 Alliaria petiolata (Bieb.) Cavara & Grande

 Plant Description:

 Upright forb with a shallow, slender taproot. The stem is slightly ridged, light

 green, with one to several stems from the same rootstock; approximately 2- to 4-foot

 tall. All parts of the plant emit a garlic odor when crushed. Leaves: At

 germination, forms a circular cluster of nearly round or kidney-shaped leaves just

 above the ground, remaining green during first winter. In the second year it 

 produces stems with alternate, heart-shaped or triangular leaves, approximately 2

 inches wide with coarsely-toothed margins, sometimes shallow to irregularly toothed.

 Reproduction: biennial.Flowers in April to May of second year. At tip of stem,

 tight clusters of small, white, four-petaled flowers; single flower is approximately

 1⁄4 inch wide. Flowering progresses up the stem as older flowers bear seeds below.

 Seeds form in late spring of second year. Four-sided, slender capsule (pod), 1 to 5

 inches long, resembling a branch of the main stem. Green, then ripening to tan and 

 becoming papery, exploding to expel tiny black seeds. Plant dies after producing

 seed.

 Plant Ecology:

 Shade tolerant. Found under forest canopies, and at forest margins and openings;

 also in floodplains. Reported to be associated with calcareous soils and intolerant

 of acidic substrates. Seed pods burst and can expel seeds up to 10 feet. Rodents,

 birds, and deer may disperse seeds. People distribute seeds on boots, pant cuffs,

 and by roadside mowing and on cars. May lie dormant for 2 to 6 years before

 germinating in spring. Experiences year to year variations in population densities.

 Allelopathic, emitting chemicals that kill surrounding plants and microbes. May

 occur as isolated plants, expanding to form extensive colonies.

 Response to Management:

 Large densities of garlic mustard will outcompete and displace native wildflowers

 and tree seedlings. Disturbed forest and riparian communities are most susceptible

 to garlic mustard invasion and may dominate the herb strata within ten years. Once

 established, this plant can be hard to control. It is important to spot small

 infestations early, when it is relatively easy to manage. Spreads easily by foot

 traffic, horses, and ATVs.

 -----------------------------------------------------------------------------------

 Additional information is available from the following sources:

 http://www.nps.gov/plants/alien/index.htm

 http://www.dcnr.state.pa.us/forestry/invasivetutorial/index.htm

 http://dnr.wi.gov - invasive species information

 “Michigan Trees”. Barnes and Wagner. 1981. University of Michigan Press, Ann Arbor
Solutions to Common Problems

Some fields in the reports contain *****

The value to be printed is too large for the space available. This usually means there is an error in the

data somewhere. Look especially at the cruise type, basal area factor, plot size, or number of plots.

Data values are unreasonable

This could be several things. Your acreage value or number of plots or prism factor or plot size may

be in error. Or you may have specified the wrong overstory cruise type. Check these values. Watch for

tree heights that have been misinterpreted as counts and vice versa.

All species in reports list as “Other Hardwoods”

You have used the wrong species code type under inventory settings.

Volumes do not agree with those I usually use

You probably use a different log rule, different minimum diameters, and so on. See the topic

“SILVAH Calculations” in Chapter 7 for a description of how SILVAH calculates volume. Call us if

you want to discuss.

Sawlog stumpage prices shown in the Product Listing do not agree with those I entered in the 

defaults (.def) file

They are not supposed to. The sawlog stumpage prices reflect species, size, and grade in each stand,

and will rarely equal the volume times the stumpage price. See the topic “SILVAH Calculations” in

Chapter 7 for a description of how SILVAH calculates sawlog value.

SILVAH calculates pulpwood volumes, but I have no pulpwood market

Change the minimum diameter for pulpwood to 41 inches in the defaults (.def ) file.

SILVAH prescribes partial cutting in stands where the volumes to be cut are too small to be 

economically feasible

Change the minimum volumes required for various types of cuts in your defaults (.def ) file.

Appendix C - Troubleshooting
About Tally Sheets

The tally sheets included in this appendix contain all of the inventory variables currently available in

SILVAH. Stand characteristics and management criteria are recorded on the understory tally sheet.

Two versions of the understory tally sheet are provided to accommodate the mixed oak and Allegheny

hardwood forest types. The information on these understory tally sheets is the same, but the order of

the variables listed on the 6-foot plot is different.

The overstory tally sheet can be used in any forest type.

If you prefer to use fewer variables, or follow a different arrangement when you are collecting data,

you can create your own tally sheets by configuring the data entry screens in SILVAH to match

your preferred order. The data entry screens (grids) can be copied into a spreadsheet program, such

as Microsoft Excel, where you can perform additional modifications as necessary. See the topic

“Configuring data fields on the Grid” in Chapter 3 for further information on arranging the order of

inventory variables.

Appendix D - Tally Sheets
Required Optional

Plot Species dbh

Quality

Height or

Count

Grade

Defect

Crown

Wildlife

Required Optional

Plot Species dbh

Quality

Height or

Count

Grade

Defect

Crown

Wildlife

Required Optional

Plot Species dbh

Quality

Height or

Count

Grade

Defect

Crown

Wildlife

Overstory Inventory

USDA Forest Service, Northern Research Station, Warren, PA June 2010
Regeneration & Interference

Plot Number

6 ft. plot

Black cherry (#) Yellow-poplar (#)Other desirable (#) Competitive Oak (#)Established oak (#)New oak (#) Conifers (#)Saplings (spp. code)Residuals (spp. code)Tall Woody Interf. (spp. code)

26 ft. plot

Low Woody Cover (%)Low Woody Interference (spp. code)Fern Cover (%)Grass/Sedge Cover (%)Grapevine (#)Site Limitations (1-3)Deer Impact (1-5)NNIS (spp. code)

Identifi cation Data

OwnerForest NameCountyCompartmentStand AreaYear of OriginDeer Impact unknown very high high mod. low very low

Site IndexSite Index SpeciesSite ClassRestrictions on Silvicultural System?

None No clearcut No even-aged No multi-tree gaps

Prescription Chart? No./Allegheny Hdwd. Mixed OakStart Regenerating? Yes Yes, if stand is mature No

Increase Oak? Yes No Residuals Desired? Yes No

Comments:

Allegheny Hardwood — Understory Inventory

USDA Forest Service, NRS, Warren, PA
Regeneration & Interference

Plot Number

6 ft. plot

Competitive Oak (#)Established oak (#)New oak (#) Black cherry (#)Conifers (#)Yellow-poplar (#)Other desirable (#)Saplings (spp. code)Residuals (spp. code)Tall Woody Interf. (spp. code)

26 ft. plot

Low Woody Cover (%)Low Woody Interference (spp. code)Fern Cover (%)Grass/Sedge Cover (%)Grapevine (#)Site Limitations (1-3)Deer Impact (1-5)NNIS (spp. code)Aggregate Oak Height (milacre plot)

Identifi cation Data

OwnerForest NameCountyCompartmentStand AreaYear of OriginDeer Impact unknown very high high mod. low very low

Site IndexSite Index SpeciesSite ClassRestrictions on Silvicultural System?

None No clearcut No even-aged No multi-tree gaps

Prescription Chart? No./Allegheny Hdwd. Mixed OakStart Regenerating? Yes Yes, if stand is mature NoIncrease Oak? Yes No Residuals Desired? Yes No

Comments:

Mixed Oak — Understory Inventory

USDA Forest Service, NRS, Warren, PA
accessibility—A subjective estimate of the ease of access to a stand as it may affect timber and

wildlife management. See Appendix A.

acre—A unit of measure describing surface area. One acre contains 43,560 square feet. A football

field (without the end zones) is 45,000 square feet—slightly larger than an acre. The inside of a

professional baseball diamond is about 1/4 of an acre.

advance regeneration—Seedlings or saplings that develop or are present in the understory.

aquatic features—In SILVAH, the indication of a water course within the stand and/or within one

mile of the stand, that may be of value to wildlife. See Appendix A.

basal area—The area of the cross section of a tree’s stem at 4 1⁄2feet above ground, or breast height,

in square feet. Basal area of a forest stand is the sum of the basal areas of the individual trees in the

stand. It is usually reported in square feet of basal area per acre and is used as a measure of stand

stocking, stand density, and stand volume.

black cherry (seedling count)—In SILVAH, the count of all black cherry seedlings that are at least 2

inches tall, with two normal-size leaves. Stems greater than 1 foot tall are counted as two stems.

board-foot volume—The amount of wood products expressed as the number of boards 1 foot wide

by 1 foot long and 1 inch thick that are sawn from logs.

bulk wood product—A product made of wood chips or wood fiber, as opposed to boards or lumber.

Bulk wood products are most often measured in cubic feet or tons.

clearcut acreage—In SILVAH, the acreage in clearcut areas (stands cut within the past 10 years and

still in the process of regenerating to trees) within one mile of a stand.

clearcutting—A method of regenerating an even-aged stand in which a new age class develops in a

fully-exposed microclimate after removal, in a single cutting, of all trees in the previous stand.

commercial treatment—Any activity producing forest products that have at least enough value to

cover the direct costs of the activity.

competitive oak (seedling count)—In SILVAH, the count of oak stems more than 3 foot tall or

with a root collar diameter greater than 0.75 inches. Stump sprouts are tallied as competitive oak

regardless of height—up to three stems per stump may be counted.

conifer—Trees, mostly evergreens, bearing cones and needle-shaped or scale-like leaves.

conifers (seedling count)—In SILVAH, the combined count of any eastern hemlock, pine, or spruce

seedling with two whorls or at least 6 inches tall. Stems with three or more whorls or that are more

than 1 foot tall are counted as two stems.

count (stem count)—In SILVAH, used when merchantable height is not being recorded in the

overstory. Count can be used to reduce data entry time. For a given record or row in the grid, count

represents the number of stems of the same species, diameter, quality, and other attributes.

Glossary
112 User’s Guide to SILVAH: Glossary

county—The county or district in which the property is located, if desired, or other information

needed to identify the property in SILVAH.

crop tree—Any tree selected to provide a specific benefit such as mast, dens, veneer, or sawtimber.

crown—The part of a tree or woody plant bearing living branches and foliage.

crown condition—In SILVAH, an estimate of the health of the tree represented as the percentage of

the crown that appears healthy. See Appendix A.

cubic-foot volume—The amount of wood products expressed as the number of cubes 1 foot wide by

1 foot long and 1 foot high that are in a log or stem.

cultivated acreage—In SILVAH, the acreage in cultivated farm crops within 1 mile of a stand.

dbh—Diameter at breast height; the diameter of the trunk of a tree measured at 4 1⁄2 feet above

ground level. It is measured on the uphill side of the tree. If estimated, it is recommended to record

diameter in 2-inch diameter classes.

dbh class—In the SILVAH inventory settings, this specifies how tree diameters were recorded

in SILVAH.

deer impact index—An estimate of the impact of browsing pressure from white-tail deer on

regeneration in a stand. A function of deer density and available food for deer. See Appendix A.

defect—In SILVAH, the percentage to the nearest 10 percent of the merchantable volume in the tree

that is unmerchantable due to decay, sweep, crook, or other deformity.

den tree—A living tree that has holes in the trunk, or stem, from broken branches and decay, or

hollow trunks; a cavity tree.

diameter class—An interval of sizes of trees or logs; or the trees and logs themselves that fall into

such an interval.

dieback—The death of branch tips and loss of foliage in the upper and outer areas of tree crowns.

Trees usually recover in several years by producing new branches. Various damaging agents can cause

tree crowns to die back.

elevation—The approximate height of a stand, in feet, above sea level.

established oak (seedling count)—In SILVAH, the count of oak stems and seedling-sprouts that are

at least 6 inches tall but less than 3 feet tall, or with a root collar diameter of 0.25 to 0.75 inch.

even-aged stand—A stand of trees containing a single age class in which the range of tree ages is

usually less than 20 percent of rotation.

even-aged system—A planned sequence of treatments designed to maintain and regenerate a stand

with one age class.

fern—In SILVAH, the estimate of the percent cover of fern on the 26-foot interference plot. The

cover of non-rhizomatous species such as wood fern may be divided by two. Sum the total of all

fern and record the estimate in 5-percent increments if total cover is less than 50 percent, and in

10-percent increments if total cover is more than 50 percent.

forest name—The name or identification of the property entered in SILVAH. For example:

Allegheny National Forest; Elk State Forest; South Woodlot.
User’s Guide to SILVAH: Glossary 113

grade—Indicates the relative value and merchantability of trees for timber products. See Appendix A.

grapevine—In SILVAH, the number of grapevines rooted in the 26-foot interference plot reaching

into the forest canopy.

grass and sedge—In SILVAH, the total combined cover of all grass and sedge species on the 26-foot

interference plot. Record 1 percent even if only a trace of grass or sedge is present.

group selection—An uneven-aged silvicultural technique involving the removal of trees in groups

usually 1/10 to 2/3 acre in size, but sometimes up to 3 to 5 acres. Group selection can be applied in

combination with single-tree selection between groups.

herbicide—Any chemical preparation used to kill or inhibit the growth of certain plants, particularly

herbs, or their spores or seeds. This term generally includes arboricides which are specific for trees and

other woody plants.

intermediate treatment—Any treatment or “tending” designed to enhance growth, quality, vigor,

and composition of the stand after seedlings are established and before mature trees are regenerated.

For example, thinning is an intermediate treatment.

land cover type—The general cover type of the property, entered in SILVAH. See Appendix A.

low woody interference—In SILVAH, these are woody shrubs and undesirable trees less than 6-feettall that will interfere with the regeneration of species desirable for management objectives. Also

included is foliage that occurs in this stratum from taller trees. Record the dominant species of low

woody interference on the 26-foot interference plot. Also record an estimate of the combined total

coverage of all low woody interfering species in 5-percent increments if total cover is less than 50

percent, and in 10-percent increments if total cover is more than 50 percent.

management value—In SILVAH, the relative value of a stand for the management goal listed.

Originally was intended for prescriptions that involved gypsy moth damage. It is not currently used.

merchantable height—In SILVAH, the number of 8-foot bolts in a sawlog-size tree, up to a point

where the diameter drops below 10.5 inches inside bark, or the height at which the bole breaks up.

Only the sawlog height is recorded. SILVAH does not accept pulpwood heights.

merchantable height adjustment—In SILVAH, a value between 0.5 and 1.5, inclusive, which allows

for the adjustment of estimated sawtimber heights when they are not representative of the site. To be

used only when merchantable heights are not recorded in the field.

medial diameter—The average of the diameter or size-class midpoints of a stand, weighted by the

proportion of basal area in each size class or diameter. This is approximately the same as the diameter

at the midpoint of the basal area distribution. Medial diameter is favored by some (over both simple

average and quadratic mean diameters) because it better reflects the size of the crop trees and is less

influenced by small understory trees.

native plant—A species that naturally occurs in a given location where its requirement for light,

warmth, moisture, shelter, and nutrients are met.

new oak (seedling count)—In SILVAH, the count of oak stems that are too small to be in the

established oak category; less than 6 inches tall.

noncommercial treatment—Any activity that does not produce at least enough value to cover the

direct costs of that treatments.
114 User’s Guide to SILVAH: Glossary

open acreage—In SILVAH, the acreage in pastures, failed clearcuts, and similar openings within 1

mile of a stand.

operability—A subjective estimate of the operability of a stand for timber harvest and other

mechanized activities. See Appendix A.

other desirables (seedling count)—In SILVAH, the combined count of all seedlings that are at

least 2 inches tall with two normal-sized leaves, that are desirable species not specifically provided for

elsewhere in SILVAH (i.e., other than black cherry, yellow-poplar, oak, and conifers).

owner—The person, agency, or corporation entered as the owner of a stand in SILVAH.; limited to

16 characters.

pole—A tree, that is larger than 5 inches dbh and smaller than 11 inches dbh.

poor drainage—In SILVAH, one of three recognized site limitations that can impede stand renewal.

The water table persists close to the soil surface during all or part of the growing season.

prescribed burn—The application of fire in forested or other areas, usually under specific conditions

of weather and fuel moisture, to control vegetation for silvicultural purposes or to reduce hazards.

prescription—The specific instructions for controlled applications of silvicultural treatments based

on information about the stands to which they apply.

rock or thin soil—In SILVAH, one of three recognized site limitations that can impede stand

renewal. Occurs when little soil overlays large rocks or bedrock, making shallow-rooted regeneration

vulnerable to desiccation.

q-factor—Also called q-ratio. Represents a geometric progression of increasing numbers of trees with

decreasing diameters (Smith 1986). For example, using 2-inch diameter classes, if the q-ratio is 1.2,

the number of trees in the 6-inch diameter class will be 1.2 times the number of trees in the 8-inch

diameter class.

regeneration—The seedlings and/or saplings in a new forest stand or age class. Natural regeneration

originated from seeds, sprouts, or root suckers. Also, the act of establishing young trees naturally

or artificially.

regeneration method—A cutting method by which a new age class is created. These methods

include clearcutting, seed tree, shelterwood, single-tree selection, and group selection; also called

reproduction method.

regeneration cuttings—Silvicultural cuttings designed to naturally regenerate the stand by providing

for seedling (or vegetative stems) establishment or development, or both. SILVAH includes two

even-aged techniques (clearcutting and shelterwood), and two uneven-aged techniques (single-tree

selection and group selection).

relative density—An index of crowding for forest stands, also called the tree-area ratio; a measure

of the absolute stand density expressed as a ratio to the density of some reference level. The reference

level is usually the density of a fully stocked stand for a particular species composition, average tree

size, and site.

remarks—Description or identification of the stand entered in SILVAH. Limited to 80 characters.
User’s Guide to SILVAH: Glossary 115

residuals—In SILVAH, residuals are pole-size (6 to 10 inch dbh) trees that may be retained after a

final harvest to meet policy guidelines or for other values. Record the species code in the regeneration

plot only if the residual is of a desirable species of good form and vigor. In mixed oak stands, residuals

do not count toward regeneration stocking, and in both Allegheny hardwood and mixed oak stands,

undesirable tree species of this size may be counted as tall woody interference.

rotation—In even-age systems, the period between regeneration establishment and final harvest.

sapling—A tree, usually young, that is larger than a seedling but smaller than a pole-sized tree,

between 1 and 5 inches in dbh. In SILVAH, saplings of desirable species and a distinctly younger age

class than the rest of the overstory are recorded on the regeneration plot. Record the species code of

the dominant sapling species when the regeneration sample plot meets stocking criteria for saplings.

Occasionally, saplings sampled on the regeneration plot will be sampled again during the overstory

tally, depending on sapling dbh and basal area factor.

sawlog—A log suitable in size and quality to be milled in to lumber of any size. Usually sawlogs are

at least 8 inches in diameter after the bark is removed.

sawtimber—Trees large enough to be cut into sawlogs.

seedling—A tree grown from a seed. Usually the term is restricted to trees smaller than saplings, or

less than 6 feet tall or smaller than 1 inch dbh.

shelterwood—A method of regenerating an even-aged stand in which a new age class develops

beneath the moderated micro-environment provided by the residual trees, at least some of which are

later removed.

silvicultural system—A planned process whereby a stand is tended, and re-established. The system

name is based on the number of age classes (for example even-aged or two-aged), and/or the

regeneration method used (for example, shelterwood, crop-tree, or selection).

silvicultural treatment—A process or action that can be applied in a controlled manner according to

the requirements of a prescription or plan to a forest community to achieve management objectives

within a planned silvicultural system.

silviculture—The art and science of controlling the establishment, growth, composition, health, and

quality of forests and woodlands to meet the diverse needs and values of landowners and society on a

sustainable basis.

single-tree selection—A regeneration method of creating new age classes in uneven-aged stands in

which individual trees are removed more or less uniformly throughout the stand to achieve desired

stand structural characteristics.

site—The combination of biotic, climatic, topographic, and soil conditions of an area; the

environment at a location.

site class—In SILVAH, a subjective approximation of site quality for tree growth. Site class can be

used as an alternative to site index and species.

site conditions—The site conditions representative of a stand that are sometimes designated by soil

factors (parent material, texture, drainage, or soil series), or by direct measurements such as site index.
116 User’s Guide to SILVAH: Glossary

site index—A measure of actual or potential forest productivity expressed in terms of the average

height of a certain number of dominants and codominants in the stand at an index age (50 in

SILVAH). In SILVAH, site class can be used as an alternative to site index.

site index species—The species used in determining site index.

slope percent—The slope angle of a stand to the nearest 1 percent.

snag—A standing dead tree without branches, or the standing portion of a broken-off tree. Snags

may provide feeding and/or nesting sites for wildlife.

stand - A contiguous group of trees sufficiently uniform in age class distribution, composition, and

structure, and growing on a site of sufficiently uniform quality, to be a distinguishable unit.

stand ID—The stand number or other means of identification of a stand entered into SILVAH;

limited to six characters.

stand structure—The arrangement of trees of different sizes and ages in a stand.

stocking—An indication of growing-space occupancy relative to a pre-established

standard. Common indices of stocking are based on percent occupancy, basal area, relative density,

and crown competition factor. In SILVAH, stocking includes the adequacy of existing advance

regeneration on individual plots to ensure desirable trees in future stands.

tall woody interference—In SILVAH, this includes any undesirable species more than 6 feet tall that

will interfere with the regeneration of species desirable for management objectives. Record the species

code of the dominant woody interfering species in the regeneration plot.

thick duff—In SILVAH, one of three recognized site limitations that can impede stand renewal.

Usually indicated by soil that feels spongy underneath, marked by more than 2 inches of accumulated

organic matter in various stages of decay. Often found under conifer-dominated areas or under

ericaceous shrubs.

thinning—A silvicultural treatment made to reduce stand density of trees primarily to improve

growth, enhance forest health, or to recover potential mortality. In SILVAH, may also be used to

enhance acorn production.

timber stand improvement—A silvicultural treatment applied to age classes of trees when they reach

crown closure in group openings (group selection) or stands (even-aged systems) prior to achieving

merchantable sizes. SILVAH recommends that these prescriptions only be applied when they are

required to ensure persistence of desired species.

topographic position—An indication of the relative position of a stand within the terrain; position

on slope. See Appendix A.

tree grading procedure—In the SILVAH inventory settings, this specifies how trees were graded in

the stand. If you prefer to get accurate volumes without grading all of the trees, select culls and large 

pulp and record grades only trees that are cull (grade 8) or large, sawtimber-size trees that only have

pulpwood volume (grade 6).

uneven-aged stand—A stand with trees in three or more distinct age classes, either intermixed or in

small groups, growing on a uniform site. These stands generally contain trees of many sizes (seedling

through sawtimber) due to the range in age as well as differences in growth rate among species.
User’s Guide to SILVAH: Glossary 117

uneven-aged system—A planned sequence of treatments designed to maintain and regenerate a

stand with three or more age classes.

veneer—A thin sheet of wood of uniform thickness, produced by rotary cutting, slicing, or sawing.

wildlife habitat potential—In SILVAH, the potential of a tree to provide habitat to wildlife in the

form of dens and cavities. See Appendix A.

year of origin—The year when a stand originated, entered in SILVAH.

yellow-poplar (seedling count)—In SILVAH, the count of all yellow-poplar seedlings that are at

least 2 inches tall with two normal-size leaves. Stems more than one foot tall are counted as two

stems. Do not count yellow-poplar on dry sites where there are no dominant yellow-poplar trees in

the canopy, as this species is not long-lived on such sites.
Brose, P.H.; Gottschalk, K.W.; Horsley, S.B.; Knopp, P.D.; Kochenderfer, J.N.; McGuinness,

B.J.; Miller, G.W.; Ristau, T.E.; Stoleson, S.H.; Stout, S.L. 2008. Prescribing regeneration 

treatments for mixed-oak forests in the Mid-Atlantic region. Gen. Tech. Rep. NRS-33.

Newtown Sqare, PA. U.S. Department of Agriculture, Forest Service, Northern Research Station.

90 p.

Debald, P.S.; Mendel, J.J. 1976. An individual-tree approach to making stand evaluations. 

SETS: Stand Evaluation Tools 1. Res. Paper NE-336. Upper Darby, PA: U.S. Department of

Agriculture, Forest Service, Northeastern Forest Experiment Station. 13 p.

Debald, P.S.; Mendel, J.J. 1976. Composite volume and value tables for hardwood pulpwood. 

SETS: Stand Evaluation Tools 3. Res. Paper NE-338. Upper Darby, PA: U.S. Department of

Agriculture, Forest Service, Northeastern Forest Experiment Station. 43 p.

Ernst, R.L.; Marquis, D.A. 1979. Tree grade distribution in Allegheny hardwoods. Res. Note

NE-275. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest

Experiment Station. 5 p.

Gingrich, S.F. 1967. Measuring and evaluating stand density in upland hardwood forests in the 

Central States. Forest Science. 13:38-53.

Hanks, L.F.; Gammon, G.L.; Brisbin, R.L.; Rast,E . 1980. Hardwood log grades and lumber 

grade yields for factory lumber logs. Res. Pap. NE-468. Broomall, PA: U.S. Department of

Agriculture, Forest Service, Northeastern Forest Experiment Station. 92 p.

Hilt, D.E. 1985. OAKSIM: An individual-tree growth and yield simulator for managed evenaged upland oak stands. Res. Pap. NE-562. Broomall, PA: U.S. Department of Agriculture,

Forest Service, Northeastern Forest Experiment Station. 21 p.

Marquis, D.A. 1977. Volume table for Allegheny hardwoods. Unpublished progress report,

4110-FS-NE-1108-93, on file at the Forestry Sciences Laboratory, Northern Research Station,

PO Box 267, Irvine, PA 16329.

Marquis, D.A. 1982. SIMAH: a stand growth simulator for Allegheny Hardwoods. Unpublished

office report on file at the Forestry Sciences Laboratory, Northern Research Station, PO Box 267,

Irvine, PA 16329.

Marquis, D.A.; Ernst, R.L. 1991. The effects of stand structure after thinning on the growth of an 

Allegheny hardwood stand. Forest Science. 37(4): 1182-1200.

Marquis, D.A.; Ernst, R.L.; Stout, S.L. 1992. Prescribing silvicultural treatments in hardwood 

stands of the Alleghenies (revised). Gen. Tech. Rep. NE-96. Radnor, PA: U.S. Department of

Agriculture, Forest Service, Northeast Forest Experiment Station. 101 p.

References
User’s Guide to SILVAH: References 119

Mendel, J.; Debald, P.S.; Dale, M.E. 1976. Tree value conversion standards for hardwood 

sawtimber. SETS: Stand Evaluation Tools 2. Res. Paper NE-337. Upper Darby, PA: U.S.

Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 74 p.

Mesavage, C.; Girard, J.W. 1946. Tables for estimating board foot volume of timber. Washington,

DC: U.S. Department of Agriculture, Forest Service. 94 p.

Miller, G.W.; Schuler,T.M.; Smith, H.C. 1995. Method for applying group selection in central 

Appalachian hardwoods. Res. Pap. NE-696. Radnor, PA: U.S. Department of Agriculture,

Forest Service, Northeastern Forest Experiment Station. 11 p.

Myers, J.R.; Miller, G.W.; Wiant, H.V.; Barnard, J.E. 1986. Butt-log grade distributions for five 

Appalachian hardwood species. Res. Pap. NE-590. Upper Darby, PA: U.S. Department of

Agriculture, Forest Service, Northeastern Forest Experiment Station. 4 p.

Nowak, C.A. 1995. Individual tree- versus stand-level approaches to thinning: is it a choice 

of one or the other, or a combination of both?. In: Gottschalk, K.W.; Fosbroke, S. L. C.,

eds. Proceedings, 10th Central Hardwood Forest Conference; 1995 March 5-8; Morgantown,

WV. Gen. Tech. Rep. NE-197. Radnor, PA: U.S. Department of Agriculture, Forest Service,

Northeastern Forest Experiment Station: 399. (Abstract).

Nowak, C.A. 1996. Wood volume increment in thinned, 50- to 55-year-old, mixed-species 

Allegheny hardwoods. Canadian Journal of Forest Research. 26: 819-835.

Nowak, C.A.; Marquis, D.A. 1997. Distribution-of-cut guides for thinning in Allegheny 

hardwoods: a review. Res. Note NE-362. Radnor, PA: U.S. Department of Agriculture, Forest

Service, Northeastern Forest Experiment Station. 7 p.

Rast, E.D.; Sonderman,D.L.; Gamon, G. 1973. A guide to hardwood log grading. Gen. Tech. Rep.

NE-1. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest

Experiment Station. 32 p.

Roach, B.A. 1977. A stocking guide for Allegheny hardwoods and its use in controlling 

intermediate cuttings. Res. Pap. NE-373. Upper Darby, PA: U.S. Department of Agriculture,

Forest Service, Northeastern Forest Experiment Station. 30 p.

Roach, B.A.; Gingrich, S.F. 1968. Even-aged silviculture for upland central hardwoods. Agric.

Handb. 355. Washington, D.C.: U.S. Department of Agriculture, Forest Service. 39 p.

Schuler, Thomas M.; Marquis, David A.; Ernst, Richard L.; Simpson, Brian T. 1993. Test of four 

stand growth simulators for the northeastern United States. Res. Pap. NE-676. Radnor, PA:

U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 14 p.

Steiner, K.C.; Finley, J.C.; Gould, P.J.; Fei, S; McDill, M. 2008. Oak regeneration guidelines for 

the Central Appalachians. Northern Journal of Applied Forestry. 25 (1): 5-16.

Stout, S.L. 1991. Stand density, stand structure, and species composition in transition oak stands 

of northwestern Pennsylvania. In: McCormick, L.H.; Gottschalk, K.W., eds. Proceedings of

the 8th Central Hardwood Forest Conference; 1991 March 4-6; University Park, PA. Gen. Tech.

Rep. NE-148. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest

Experiment Station: 194-206.
120 User’s Guide to SILVAH: References

Stout, S. L. 1994. Principles and practices of uneven-age management. In: Marquis, D. A., ed.

Quantitative silviculture for hardwood stands of the Alleghenies. Gen. Tech. Rep. NE-183.

Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment

Station: 329-362.

Stout, S.L.; Nyland, R.D. 1986. Role of species composition in relative density measurement in 

Allegheny hardwoods. Canadian Journal of Forestry Research. 16(3): 574579.

Stout, S.L.; Marquis, D.A.; Ernst, R.L. 1987. A relative density measure for mixed-species stands.

Journal of Forestry. 85: 45-47.

Wiant, H.V., Jr.; Castenada, F. 1977. Mesavage and Girard’s volume tables formulated. Resource

Inventory Note BLM 4. Denver, CO: U.S. Department of the Interior, Bureau of Land

Management. 4 p.
Index

A

Accessibility................................................. 111

AGS............................................................ 84

Aquatic features in stand............................. 81

B

Black cherry regeneration tally..................... 111

Board volumes............................................. 73

C

Checkmark data.......................................... 28

Checkmark regen tally................................. 26

Competitive oak regeneration tally.............. 111

Configuring data fields on the grid.............. 18

Conifers regeneration tally........................... 111

Converting older formats........................ 14, 40

Count (stem count)..................................... 111

Cruise information...................................... 15

Cubic volumes............................................ 73

Cultivated acreage....................................... 112

Custom treatments...................................... 62

Cutting priority........................................... 62

D

Database output.......................................... 64

Data entry shortcuts.................................... 17

Data files................................................. 14, 76

Deer impact index....................................... 81

Default commercial sale breakpoints........... 41

Default diameters for volume calculations... 41

Default inventory settings........................... 43

Default log rule........................................... 42

Default management values......................... 43

Defaults file................................................. 38

Default species parameters........................... 46

Defect......................................................... 112

E

Editing data................................................ 12

Entering regen data..................................... 26

Entering tree data........................................ 21

Established oak regeneration tally................ 112

Exporting data from grid............................. 19

F

Fern............................................................ 112

File format.................................................. 76

Forest types................................................. 70

G

Grade................................................ 22, 74, 84

Grapevines.................................................. 113

Grass........................................................... 113

Growth and mortality................................. 63

Growth projection....................................... 63

I

Importing data........................................ 32–37

Installation................................................ 7, 10

Interfering vegetation.......................... 113, 116

Inventory settings........................................ 15

L

Low woody interference.............................. 113

M

Management value...................................... 113

Merchantable heights.................................. 72

Modifying a standard treatment.................. 59

N

Navigation keys in TREECALC.................. 67

Net volumes................................................ 73

Nonnative invasive species....................... 29–31
122 User’s Guide to SILVAH: Index

O

Opening files........................................... 14, 39

Operability.................................................. 114

Other desirables regeneration tally............... 114

Output.................................. 14, 52–53, 55, 64

Overstory cruise type..................................... 82

Overstory data............................................... 20

P

Prescription....................................... 48, 56–57

Proofreading data........................................ 14

Q

Quality........................................................ 22

R

Relative density........................................... 72

Reports.................................................... 52–53

Residuals..................................................... 115

Rocky soils.................................................. 114

Running SILVAH......................................... 49

S

Sapling regeneration tally............................ 115

Saving files.............................................. 13, 39

Script mode................................................. 51

Sedge........................................................... 113

Shortcuts..................................................... 17

Silvicultural restrictions............................... 83

Site class...................................................... 16

Species codes........................................... 44, 85

Species type code......................................... 44

Species X diameter table.............................. 54

Stand physiography and site........................ 16

Stand relative density thresholds.................. 72

Stand size classes.......................................... 71

T

Table, Species X Diameter........................... 54

Tall woody interference............................... 116

Thick duff................................................... 116

Timber stand improvement......................... 116

Topographic position.......................... 83, 116

TREECALC............................................... 67

Tree grade.................................................... 84

Tree quality................................................. 84

U

UGS............................................................ 84

Understory data collection.......................... 26

V

Value........................................................... 75

Viewing output........................................... 66

W

Wildlife codes............................................. 85

Y

Year of origin............................................... 117

Yellow-poplar regeneration tally................... 117
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Knopp, Peter D.; Stout, Susan L. 2014. User’s guide to SILVAH. Gen. Tech. Rep. NRS-128.

Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research

Station. 122 p.

This user’s guide for the SILVAH computer program, version 6.2, supersedes the 1992 user’s

guide (Gen. Tech. Rep. NE-162). Designed for stand-alone Windows-based personal computers,

SILVAH recommends a silvicultural prescription for a forest stand based on a summary and

analysis of field inventory data. The program also includes a simulator that can be used to

project stand growth and development, estimating yields from either prescribed or user-defined

treatments. The software is distributed with an online help system and this printed user’s

manual. The computer program described in this publication is available on the Internet at

http://nrs.fs.fed.us/tools/silvah

KEY WORDS: silvicultural prescriptions, management guides, regeneration, Allegheny

hardwoods, northern hardwoods, mixed oak forest type, decision support system, software.
Northern Research Station

www.nrs.fs.fed.us