Writing a Forest Management Plan: Using Stand Inventory Data to Determine Density.

By Norma Kline, Oregon State University Extension Forester for Coos and Curry Counties

This is the 6th article in the Writing a Forest Management Plan series. The objective of this series is to break the process of writing a forest management plan into simple steps intended to make the process accessible and straight forward regardless of your previous skills and knowledge. If you already have a management plan, use these steps to help review and update your plan.

The first articles cover how to generate the basic property information and maps for your forest management plan from web-based mapping resources, map forest cover (stands) based on stand age and species, describe stand characteristics and take simple plot measurements and make simple calculations of stand averages from your plot data. The links to the first five topics are at the end of this article.

In this article, we will describe how to use the basic fixed plot data calculations from the fourth article to describe stand density. Assessing stand density can help determine whether a stand is overcrowded. Depending on a landowner’s management objectives, overcrowded stands can be thinned to maintain stand health, tree growth and wildlife habitat characteristics.

Figure 1. Brush growing in the understory of a stand.

In areas of your forest that are crowded or dense, your first observation might be the lack of sunlight reaching the forest floor and the presence of little to no understory vegetation. Looking up at the canopy in these areas, you will find that overcrowded trees have small live crowns compared to their total height (we described how to measure live crown ratio in the third article in this series). Trees growing in these crowded conditions are competing with each other for resources and some trees will start to die from this competition. Conversely in areas with less crowding, tree crowns will be fuller (have longer live crowns) and there will be the presence of a shrub understory. In fact, if you are in Oregon’s coast range, it might be difficult to walk through these stands because of the thick brush present in the understory (Figure 1). While casual field observations are useful, calculating relative density (RD) using your stand data and referencing an appropriate stand density table will take the guesswork out of knowing whether a stand is overly dense. Stand density tables will also help you determine the best time to thin a stand for stand health.

We will use stand density tables in the Competition and Density in Woodland Stands Extension Publication, link below, to determine if our example stand is becoming overcrowded. Since our stand consists of primarily Douglas-fir, we will use the Douglas-fir density table. Our first step will be to use our basic fixed plot calculations (from the fourth article) to locate the position in the table indicating how the relative density of the stand is ranked in regard to competition. The relative density scale has descriptive names for the different zones of competition. The lowest density is Crown Closure, then the Enthusiastic Growth Zone, Lower Goldilocks Zone, Upper Goldilocks Zone, Danger Zone, Zone of No Return and finally the Maximum density. As you would expect, a stand in the Danger Zone is very dense and will likely have tree mortality.

From our previous basic fixed plot data calculations, we calculated an average of 160 Trees per Acre (TPA), and an average 11.18 inches (arithmetic mean) Diameter at Breast Height (DBH). Now we will use these two values to determine the stand’s location in the density table. This will require some approximation. You will notice that the table uses a diameter referred to as quadratic mean diameter (QMD). The QMD will always be somewhat higher than the arithmetic mean because it is weighted towards larger trees. It is typically used in forestry calculations instead of the arithmetic mean. The calculated QMD for our stand is 11.43 inches. Just keep this in mind if you use the average DBH for your stand to determine the relative density. Otherwise, you can calculate the QMD using the formulas at the end of this article.

Figure 2. Charting a thinning using the Douglas-fir stand density table.

In our example, after locating the position of our stand on the Douglas-fir density table, we see that it is in the Lower Goldilocks Zone. In other words, the stand is still growing without severe competition. Our landowner wants to plan a thinning before the stand reaches the Danger Zone, which is when trees become crowded and start dying. The green arrow depicted in Figure 2 shows the future trajectory of the stand as it increases in diameter (and density). We see that when the stand reaches the Upper Goldilocks Zone it has a diameter of about 13 inches with an average spacing of about 16 feet between trees. The stand will then be thinned so that the density is reduced back to the Lower Goldilocks Zone. The red arrow represents the thinning, which will reduce the number of trees per acre to about 120, the spacing between the remaining trees will be about 20 feet on average between trees. For more information on charting a stand using the density tables refer to the detailed descriptions in the Competition and Density in Woodland Stands publication.

The landowner has determined that the thinning should likely occur within the next 5 years (this will be when the stand reaches the Upper Goldilocks zone). Additional factors to consider in the planning process include determining the number of acres in the thinning project, estimating cost and any potential revenue, and steps required for regulatory compliance (e.g., Power Driven Machinery Permit, Forest Practices Notification). For information on Oregon’s Forest Practice Act and to find your ODF Stewardship Forester, see links in the Resources section below.

The Schedule of Planned Management Actions (starting on page 31 of the Forest Management Template) is a helpful tool to consider all of the necessary steps needed to plan a successful thinning project. Once the landowner has a rough timeline for the project, they can start searching for the right contractors to accomplish the work. For example, scheduling a logger that has expertise and the right equipment for thinning (or a consulting forester that can arrange the work) should all be done well in advance of the planned activity.

Thinning is just one type of management action that the Schedule of Planned Management Actions is used for. Other management actions might include clearcut harvests, road construction, salvage logging, invasive weed eradication, among others.

In the next article of the series we will discuss how to find the information to complete the other parts of the plan including  soils, water resources and fish and wildlife. These are allimportant factors that can help inform management actions on your woodland.

Calculations (for those that are interested)

To calculate the Quadratic Mean Density (QMD) we will need to make a few preliminary calculations. Insert the following formulas into a spreadsheet to make quick calculations.

Our first calculation will be to determine the basal area (BA) of each tree. The BA is the cross-sectional area at breast height (4.5 ft above ground).  Tree Basal Area (BA) = 0.005454 * (DBH)2 (using inches as the unit for DBH)

In the plot data form below, the BA has been entered for each tree. For the first tree in Plot 1, the Tree Basal Area = 0.005454 * (11) 2 = 0.005454 *121 = 0.66 square feet.

The next step is to calculate the Basal Area per acre that the tree represents by multiplying the Tree Basal Area by the expansion factor. (the expansion factor is the denominator of the plot size). For our example we selected a 1/20th acre fixed plot size which gives us an expansion factor of 20.

BA/acre = Tree BA X Expansion Factor

BA/acre = 0.659 square feet X 20 = 13.20 square feet per acre (represented by the first tree in the first plot).

Sum the plot TPA and the plot BA/ac

From the previous article, the sum of the plot TPA is 480.

Plot 1. 7 trees. 7 x 20= 140 trees per acre (TPA).

Plot 2. 9 trees. 9 x 20 =180 TPA

Plot 3. 8 trees. 8 x 20 =160 TPA

The sum of plot TPA =  480

The sum of the plot BA/ac, from the table is 99.37 + 127.30 + 115.41 = 342.07. Use these sums to calculate the average basal area per tree:

Average basal area per tree= sum of plot TPA ÷ sum of plot BA/ac

Average basal area per tree= sum of plot TPA (480) ÷ sum of plot BA/ac (342.07) = .713

This is used to calculate the quadratic mean diameter of a stand:

QMD = √(Average basal area per tree/0.005454)

In our example, the QMD is square root (.713/0.005454)= 11.43

Plot Data

Plot #Tree #SpeciesDBH (Inches)Height (Feet)Live Crown RatioTree Basal Area (sq ft)Basal Area per acre (sq ft)Sum of Basal Area per acre (Sq fit)
11DF1190300.6613.20 
 2DF1495601.0721.38 
 3DF1395500.9218.43 
 4DF1085300.5510.91 
 5DF 980250.448.84 
 6DF1090350.5510.91 
 7DF1290450.7915.71 
        99.37
21DF985250.448.84 
 2DF885250.356.98 
 3DF1495501.0721.38 
 4DF16100601.4027.92 
 5DF15100551.2324.54 
 6DF890250.356.98 
 7DF990300.448.84 
 8DF1095300.5510.91 
 9DF1095300.5510.91 
        127.30
31DF16100501.4027.92 
 2DF1390450.9218.43 
 3DF1390450.9218.43 
 4DF1085300.5510.91 
 5DF985250.448.84 
 6DF985250.448.84 
 7DF1190350.6613.20 
 8DF980300.448.84 
        115.41

Resources

Basic Forest Inventory Techniques for Family Forest Owners. https://pubs.extension.wsu.edu/basic-forest-inventory-techniques-for-family-forest-owners

Competition and Density in Woodland Stands https://extension.oregonstate.edu/catalog/pub/em-9206-competition-density-woodland-stand

Measuring Your Trees. https://extension.oregonstate.edu/catalog/pub/em-9058-measuring-your-trees

Oregon Forest Management Plan Template and Guidance. https://blogs.oregonstate.edu/forestplanning/templates/

Oregon Forest Practice Act Resources https://www.oregon.gov/odf/working/pages/fpa.aspx

Find an ODF Forester https://www.oregon.gov/odf/working/Pages/findaforester.aspx

Articles in the Writing a Forest Management Plan Series:

1 – Start with the Easy Sections. https://blogs.oregonstate.edu/southcoastfieldforest/2024/02/15/writing-a-forest-management-plan-start-with-the-easy-sections/

2 –  Mapping Stands.

3 – Measuring Plots to Describe Your Woodland.

4 – Summarizing Plot Measurements to Describe Your Woodland.

5 – Describing Stand Characteristics.

Writing a Forest Management Plan: Describing Stand Characteristics

By Norma Kline, Oregon State University Extension Forester for Coos and Curry Counties

This is the fifth article in the Writing a Forest Management Plan series. The objective of this series is to simplify the process of writing a forest management plan, making it accessible and straightforward regardless of your prior skills and knowledge. If you already have a management plan, use these steps to review and update it.

Figure 1. Example of a stand with snags, down wood and understory vegetation. Photo by Norma Kline@OSU

The earlier articles cover generating basic property information and maps for your forest management plan using web-based mapping resources. They also discuss mapping forest cover (stands) by stand age and species and taking simple plot measurements. This information can be used to provide key summary information for the “Current Stand & Forest Health Conditions” section of your plan. The links to the first four topics can be found at the end of this article.

In this article, we will describe additional information needed to complete the “Stand Characteristics Table”, including details on a stand’s growth stage, spacing, vertical structure (layers), and forest health observations. We will use the forest stand referenced in the previous articles as an example. Previously, we discussed

Stand Characteristics Table

The Stand Characteristics Table includes fields to describe Growth Stage, Spacing, and Canopy:

  1. Growth Stage: This indicates the developmental stage of trees, ranging from seedlings (less than 4.5 feet in height) to saplings (1–5 inches DBH), small trees (6–11 inches DBH), large trees (12–29 inches DBH), and very large trees (30 inches or more DBH). Based on our plot data (referenced in articles 3 and 4), the growth stage of our example stand ranges from small to large trees.
  2. Spacing: Spacing describes the horizontal structure of a stand. Are the trees evenly spaced (planted in systematic rows), or are they clustered in dense patches with wide spacing or openings? If you measured the distance between trees during your fixed plot inventory, summarize that data here. In our example, the trees are evenly spaced (16–17 feet apart).
  3. Canopy: Canopy refers to the horizontal structure based on whether the tree crowns are “Open” (not touching), “Closed” (touching), or “Variable” (a combination). An open canopy might characterize a young stand in early growth stages or a mature stand with few trees per acre. In our example, the stand has evenly spaced trees with a closed canopy.

The table includes fields for Primary, Second, and Third Layers. Not all stands have multiple layers. In our example, the stand—planted after a clearcut—has one main layer. If multiple layers are present, record data in your inventory notes. For example, a stand may have a primary layer of large conifers (24–40 inches in diameter) and a secondary layer of shade-tolerant species such as western hemlock (around 10 inches in diameter). You can calculate the trees per acre for additional layers based on fixed plot data or provide a general estimate with a description of their distribution (e.g., uniform, variable, or filling openings).

Age may be challenging to determine for additional layers, as small, suppressed trees can be the same age as dominant trees. However, you may know the age if you planted the stand or have records of disturbance events that facilitated seedling germination.

Figure 2. Invasive plants. Photo by Lynn Ketchum@OSU

Additional Observations

  • Snags, Down Wood, and Understory Vegetation: Note observations of standing dead trees (snags), downed wood (logs), and understory vegetation. These elements are crucial for wildlife habitat, providing cover for amphibians and food for various species. If a stand lacks these structures, landowners can implement management actions to enhance habitat diversity (if desired). Figure 1 is an example of a stand with snags, down wood and understory vegetation.
  • Forest Health Conditions: Record observations of insect and disease issues, invasive plants (Figure 2), wildlife damage, storm damage, or excessive fuels. Examples include bear or rodent damage, storm damage, or invasive species. Landowners may use this information to develop management actions, such as eradicating invasive plants, salvaging dead trees, replanting areas with reforestation failures, and reducing fuels.
  • Tree volume? You may have noticed that the general information documented in the Stand Characteristics Table does not include tree volume. If you would like to collect general volume information for a stand, consider using the Tarif System to take your stand data. The Tarif system is described in more detail in Measuring Your Trees and the Basic Forest Inventory Techniques for Family Forest Owners, below.

Management Objectives and Desired Future Conditions

The next step is to establish Management Objectives and Desired Future Conditions. Objectives for a specific stand will align with the overall goals for the property. This information will guide future management actions. Here it might be a commercial harvest or habitat for a desired wildlife species. Examples of desired future conditions you want to see in 5-10 years might include a certain desired harvest volume or a diversity of species and layers.

If your management objective is to keep the stand on the landscape for a long period of time, then keeping track of density (crowding) to make sure that the forest continues to grow vigorously is recommended.

In the next article, we will discuss a few additional calculations that you can take using basic fixed plot data including basal area and the stand quadratic mean diameter which can be used to determine the relative density of a stand, a useful measure for planning future planned actions.

References

Basic Forest Inventory Techniques for Family Forest Owners. https://pubs.extension.wsu.edu/basic-forest-inventory-techniques-for-family-forest-owners

Measuring Your Trees. https://extension.oregonstate.edu/catalog/pub/em-9058-measuring-your-trees

Oregon Forest Management Plan Template and Guidance. https://blogs.oregonstate.edu/forestplanning/templates/

Writing a Forest Management Plan: Start with the Easy Sections. https://blogs.oregonstate.edu/southcoastfieldforest/2024/02/15/writing-a-forest-management-plan-start-with-the-easy-sections/

Writing a Forest Management Plan: Mapping Stands.

Writing a Forest Management Plan: Measuring Plots to Describe Your Woodland.

Writing a Forest Management Plan: Summarizing Plot Measurements to Describe Your Woodland. https://blogs.oregonstate.edu/southcoastfieldforest/2025/02/20/writing-a-forest-management-plan-summarizing-stand-inventory-data-to-describe-stands/

Writing a Forest Management Plan: Summarizing Plot Measurements to Describe Your Woodland.

By Norma Kline, OSU Extension Forester for Coos and Curry Counties

This is the fourth article in the Writing a Forest Management Plan series. The objective is to simplify the process of creating a forest management plan, making it accessible and straightforward regardless of your prior skills and knowledge. If you already have a management plan, use these steps to review and update it.

The first articles cover generating basic property information and maps from web-based resources, mapping forest cover (stands) based on stand age and species, and taking simple plot measurements. Links to the first three topics are at the end of this article.

Figure 2. A stand with brush filled openings.

In this article, we will explain how to use plot measurements to calculate average diameter, height, and trees per acre. This information can be included in the “Stand characteristics” table located in the “Current stand & forest health conditions” section of the Forest Management Plan Template. While the planning process does not require landowners to include a forest inventory or timber cruise unless they are seeking funding for NRCS Cost Share Programs, inventory information can help describe the stand more clearly and assist landowners in considering possible management actions to achieve their goals and objectives.

Figure 2. A stand with extremely dense trees.

The “Stand characteristics” table includes areas to enter information on stocking, diameter, and height class. Stocking describes how well the site is utilized by the trees. Under-stocked stands will typically have openings filled with brush species, Figure 1. Over-stocked stands will be extremely dense with little to no vegetation growing on the forest floor, Figure 2. In over-stocked stands, trees may die from competition.

Trees per acre (TPA) is a useful measure of stocking when considered alongside the stand’s age and growth stage. For example, a healthy mature stand will have substantially fewer trees than a newly planted reforestation unit.

To calculate the average TPA for a stand, multiply the number of trees in each plot by the expansion factor (the plot size denominator). For example, using a 1/20th acre fixed plot size gives an expansion factor of 20. Then, sum the TPA for all plots in the stand and divide by the total number of plots. For stocking surveys of newly planted stands, it is recommended to take more frequent, smaller plots. A typical reforestation stocking survey consists of 1/50th acre (16.7 ft. radius) plots, with at least one plot for every two acres.

Here is an example of the trees per acre calculation, using the plot data located at the end of this article:

Step 1. Multiply the number of trees in each plot by the expansion factor.

Plot 1. 7 trees. 7 x 20= 140 trees per acre (TPA).

Plot 2. 9 trees. 9 x 20 =180 TPA

Plot 3. 8 trees. 8 x 20 =160 TPA

Step 2. Add the TPA for all the plots in the stand and divide by the total number of plots.

The average TPA for this stand is 480 divided by 3 = 160 TPA.

The next steps are to calculate the average DBH and average height for your stand. First calculate the average DBH for each plot, then divide by the total number of plots. In our three plot example, this would be (11.3 in. + 11 in. +11.25 in. )/3 =11.18 in.  Use the same process to calculate the average height. The average height for our example is 90.06 ft.

The process of taking plots and summarizing information provides woodland owners insights into stand development and forest health conditions. This information can be used to assess whether a stand is on a desired trajectory and to determine if management actions are needed. Additionally, including stand averages in addition to written descriptions of each stand in your management plan will help document the stand for future reference. It’s recommended to update your forest management plan every 10 years, in which time you may consider taking additional plots to continue assessing and monitoring your woodland. Including photos of each stand in this section will be helpful for future reference as well.

In the next article, we will discuss additional information required to complete the “Stand characteristics” table, including a description of the stand’s growth stage, spacing, vertical structure (layers) and forest health observations.

Example Plot Data

Plot #Tree #SpeciesDBH (Inches)Height (Feet)Live Crown Ratio
11DF119030
 2DF149560
 3DF139550
 4DF108530
 5DF 98025
 6DF109035
 7DF129045
      
21DF98525
 2DF88525
 3DF149550
 4DF1610060
 5DF1510055
 6DF89025
 7DF99030
 8DF109530
 9DF109530
      
31DF1610050
 2DF139045
 3DF139045
 4DF108530
 5DF98525
 6DF98525
 7DF119035
 8DF98030

References

Oregon Forest Management Plan Template and Guidance. https://blogs.oregonstate.edu/forestplanning/templates/

Writing a Forest Management Plan: Start with the Easy Sections. https://blogs.oregonstate.edu/southcoastfieldforest/2024/02/15/writing-a-forest-management-plan-start-with-the-easy-sections/

Writing a Forest Management Plan: Mapping Stands.

Writing a Forest Management Plan: Measuring Plots to Describe Your Woodland.

Emerald Ash Borer Found in Three New Counties

Emerald ash borer (EAB) has been detected in three new counties. Affected counties include Washington, Yamhill, Marion and Clackamas. Tree materials of ash, olive, and white fringe tree must remain within the quarantine area. While this infestation is still distant from Coos and Curry Counties, it’s important to observe and report any symptoms that you see on Oregon Ash. These include crown dieback, D-shaped emergence holes, sucker shoots emerging from the trunk, S-shaped galleries under the bark, bark splitting on trunk or branches, woodpecker activity, tree dying from top down. Read more about the quarantine area and see photos of symptoms here.

D-shaped emergence hole(0.118 inch (3mm in size)

Testing Composite Panels Made out of Gorse at the Oregon State University Oregon Wood Innovation Center

Scott Leavengood collecting gorse near Bandon, Oregon.

Scott Leavengood, a professor, extension specialist, and director of the Wood Innovation Center (OWIC), has a history of exploring innovative wood products. His previous research includes working with species such as western juniper and hybrid poplar. As the director of OWIC, Scott links research and education with the needs of Oregon wood product firms. He also assists entrepreneurs with market assessments and product testing.

With this background, it is no surprise that Scott’s latest exploration involves a prickly problem on the south coast: gorse. Scott, along with two summer interns, visited the south coast this summer to collect gorse material, which was then processed and formed into test panels. So far, a number of tests are being conducted to determine hardness, durability, water absorption, and internal bond strength. While gorse composite panels are not likely appropriate for structural purposes, they might be useful as decorative panels.

If you are interested in reading more about gorse composite panel processing and testing, check out the website here.

Writing a Forest Management Plan: Measuring Plots to Describe Your Woodland  

By Norma Kline, OSU Extension Forester for Coos and Curry Counties

This is the third article in the Writing a Forest Management Plan series. The objective of this series is to break the process of writing a forest management plan into simple steps intended to make it accessible and straightforward, regardless of your previous skills and knowledge. If you already have a management plan, use these steps to help review and update it.

Figure 1. A simple inventory design.

The first article covers how to get a quick start on your management plan by using the online Landmapper tool to generate basic property information and maps. The second article details how to map forest cover (stands) based on stand age and species. Delineating forest stands will help landowners efficiently monitor their woodlands and plan for future actions. Links to the first two articles are provided at the end of this article.

In this article, we will describe how to take simple plot measurements to estimate diameter, height, and trees per acre. The Current Stand & Forest Health Conditions section in the Forest Management Plan template includes a Stand Characteristics table with space to enter age, diameter class, height, spacing, and tree species. It’s important to note that the forest management planning process does not require landowners to include a forest inventory or timber cruise for their property, although these might be desirable for other reasons based on your management objectives.

If you are interested in getting out on your property and learning a few basic measurement techniques, taking basic inventory plots is an activity that you and your family can accomplish with relatively inexpensive forestry tools. During this process, you may gain increased familiarity with your woodland, discovering interesting new features such as old roads, wildlife, or forest health issues. Alternatively, you may decide that hiring a forestry professional to conduct a forest inventory is the right choice for you.

The most common method used to gather forest inventory information is by measuring plots across each area of interest (a timber unit or stand). For the purposes of developing a management plan, we will focus on the process of taking simple fixed plots for a general forest inventory. You may have heard the terms “inventory” and “cruising” in the context of collecting tree measurement information. Forest inventory typically refers to taking forest measurements to gain a general understanding of the tree cover on a property. The number of plots per stand and the measurements included in an inventory will depend on the landowner’s objectives and how they intend to use the information.

On the other hand, a timber cruise is typically used to determine the volume of merchantable timber in a specific area, such as for a planned timber sale, or across an entire property to assess the value of an estate. The desired accuracy of a timber cruise is generally higher than that of an inventory and would typically involve more plots.

The objective of our forest inventory described here will be to obtain general information for each mapped stand. The number of plots you measure will depend on how you intend to use the information as well as how much energy and time you have. A common inventory design for landowners interested in getting an idea of stand density and general stand volume would be to measure between 15 to 30 plots per stand: 15 plots in a fairly uniform stand and 30 plots in a stand with a fair amount of variability. If this seems like more plots than you have time to measure and your main intent is to obtain a more general description of the stand, then measure at least one plot for every 10 acres with a minimum of 3 plots.

The next step is to determine the location of your plots and the measurement information you will collect. A systematic approach to taking plots is recommended to help prevent bias in sampling. Take your map of delineated stands and draw a grid on each stand. Figure 1 is an example of a simple inventory design created in CalTopo, which is a free online mapping platform. A grid of evenly spaced inventory lines was established to help position plots systematically. The inventory lines cross topographic features to ensure that plots are located on a variety of slope positions. Trees growing near rocky ridges tend to be smaller than those growing near a stream or bench area. Thus, for an unbiased sample, do not orient inventory lines along creeks or ridges.

Figure 1 was generated as a geospatial PDF in CalTopo for use on a handheld mapping app such as Avenza, which can be used to navigate to the plot center. Alternatively, the map can be printed and used along with a compass to navigate along the inventory lines. Another approach is to use a ruler to draw an inventory grid on a printed map. In the field, distances on the ground can be measured with a tape, paced (counting your steps), or by using an electronic rangefinder. Just remember that the distances between plots on the map are horizontal. Use a compass to take the bearings of the inventory lines. Even if you are using a smartphone for plot location, it’s always a good idea to carry a printed map and compass in the field.

Plot Size (acres)Radius (feet)
1/552’8”
1/1037’2”
1/2026’4”
1/3021’6”
1/4018’7”
Table 1. Fixed plot sizes.

Plot size will depend on how widely the trees are spaced. Choose a plot size that allows you to count an average of 5 to 10 trees per plot. Use the same plot size throughout an entire stand. Typical plot sizes are listed in Table 1. A good place to start is a 1/20-acre plot, which has a plot radius of 26 feet and 4 inches (see Table 1). You can test this out in a typical area of your stand by setting up a few preliminary plots to determine the number of trees per plot. If your average tree count exceeds 10 trees per plot, you might consider reducing the plot size.

Figure 2. A fixed radius plot.

It’s a good idea to establish a routine for collecting and measuring plot information. Once you locate the center of each plot, tie a piece of flagging to a stick placed in the ground. Measurements will be easier if you have a helper to hold the end of the tape over the plot center. Measure to the edge of the plot, making sure to keep the tape horizontal. Record the species, diameter, and height of each tree that falls within the plot. For trees that lie on the edge, estimate the center of the tree; if the center is outside the plot radius, it should not be measured (see Figure 2). Start recording trees from the same cardinal direction for each plot and work clockwise until you return to the starting point. You can also tie a piece of flagging at the starting point.

Figure 3. Measuring tree height with a woodland stick.

While there are several tools that can be used to measure the diameter and height of trees in your plot, an inexpensive woodland stick (also called a Biltmore stick) is a relatively simple way to get started. A cloth tape or a logger’s tape can be used to measure 100 feet from your reference tree, as well as the plot radius and the distance between plots.

To measure tree heights, stand 100 feet from the tree and hold the stick straight at 25 inches from your eye (see Figure 3). Height measurements will be more accurate on flat ground. For tree diameters, hold the stick 4.5 feet from the ground; this is known as diameter at breast height (DBH) (see Figure 4).

Figure 4. Measuring tree diameter (DBH) with a woodland stick.

The live crown ratio of each tree is also important to note. This can be estimated (see Figure 5). Another piece of data to consider is the age of the trees. Most small woodland owners estimate the age of a stand using historical records or by counting rings on recently cut stumps, if present. Tree spacing, the average distance between trees, may also be of interest to you. Take some quick distance measurements between trees and record that information as well.

Figure 5. Estimating live crown ratio.

Other stand characteristics of interest include whether the stand has distinct layers of trees. For example, is there a primary layer of overstory trees with an understory (often composed of more shade-tolerant species)? This will be important if your objective is to develop or maintain wildlife habitat. Additionally, take note of any down logs and snags (dead trees). Your inventory data does not have to focus solely on living trees; knowing if you have other elements valuable for wildlife may also be useful.

Record your plot information in a weather-resistant field notebook. There are many options for field notebooks available from forestry supply companies. Write in the stand number, plot number, and column headings for the data you intend to measure (see Figure 6). It’s a good idea to attach your notebook to a field vest or jacket with a cord—you don’t want to lose your data!

Figure 6. Fixed Plot Inventory Form.

As you navigate from plot to plot, take note of any forest health concerns, invasive plants, or unusual features that you find. These can be recorded in your field notebook, marked on your map, or noted using a mapping app on a smartphone to drop a pin, take notes, and even attach a photo.

The Basic Forest Inventory Techniques for Family Forest Owners (link below) is a useful resource if you would like to read more about designing an inventory.

In the next article, we will cover how to use the data you have collected to make some simple calculations.

References

Writing a Forest Management Plan: Start with the Easy Sections. https://blogs.oregonstate.edu/southcoastfieldforest/2024/02/15/writing-a-forest-management-plan-start-with-the-easy-sections/

Writing a Forest Management Plan: Mapping Stands.

Oregon Forest Management Plan Template and Guidance. https://blogs.oregonstate.edu/forestplanning/templates/

Land Mapper. Automated and easy, produces many of the plan maps. https://landmapper.ecotrust.org/

Basic Forest Inventory Techniques for Family Forest Owners. https://pubs.extension.wsu.edu/basic-forest-inventory-techniques-for-family-forest-owners

Avenza. https://store.avenza.com/

CalTopo. https://caltopo.com

Oregon-Myrtle Defoliation

Myrtle with defoliation. Photo by Norma Kline @OSU

Myrtle defoliation caused by a plant pathogen, Calonectria californiensis, has been observed in Coos and Curry Counties. Defoliation starts at the bottom of the tree and proceeds upward. Defoliation can be significant, affecting 80% of the tree.

Leaf symptoms include tan colored spots and blotches surrounded by dark brown margins. Once infested, the leaves can drop off the tree quickly.

Leaf symptoms of Calonectria californiensis, Photo by Norma Kline@OSU

Many Oregon-myrtle trees affected by the pathogen appear to have new foliage growth which is very promising. We are in the process of developing a data sheet where interested landowners can help us monitor the health and environmental settings of their myrtles. At this point, unless a tree poses a particular hazard, we suggest that landowners take a wait-and-see approach to tree health recovery. Once we gather sufficient information, we plan to develop a fact sheet. Calonectria californiensis may also affect other native trees and shrubs such as salal, mock orange, Oregon grape, native rhododendrons and tanoak.  Calonectria IS NOT the same pathogen that causes Sudden Oak Death in Curry County.

Small greenish fruit of Oregon-myrtle. Photo:Patrick Breen@OSU

Oregon-myrtle identification. Oregon-myrtle (Umbellularia californica) goes by several common names: Oregon-myrtle, bay laurel, California-laurel, California bay, pepperwood. They are all the same tree! Oregon-myrtle is a broadleaf evergreen tree with highly aromatic thick and leathery leaves. The small, greenish fruit are less than 1 inch long.

Healthy leaves of Oregon-myrtle. Photo: Patrick Breen @OSU

Are you interested in participating in the Oregon-myrtle monitoring project? Contact Norma Kline, OSU Extension Forester for Coos and Curry Counties. Norma.Kline@Oregonstate.edu

Writing a Forest Management Plan: Mapping Stands

By Norma Kline, Extension Forester for Coos and Curry Counties

In the first article of the Writing a Forest Management Plan series (see link to article below), we discussed how to get started on your management plan. An easy way to gain momentum on a big project is to break it into segments. Fortunately, Oregon’s Forest Management Planning Template is organized into sections that facilitate this approach. The first section, Woodland Discovery, can be quickly addressed by using the online Landmapper tool to generate the basic property information and maps required for that section of the plan. In this article, we will discuss approaches for the next management plan section, Current Stand & Forest Health Conditions. This section will require decisions on how to delineate (map) the various vegetation types or stands on your property. How a woodland owner designates stands on their property is up to them. Woodland owners with small properties might decide to map the forest cover as one stand. Other properties might have a diverse array of age classes and species. Mapping out forest cover based on stand age and species will help landowners efficiently monitor their woodlands and plan for future needed actions. For example, we recommend monitoring recently reforested areas to help catch seedling survival problems early. Young stands should be assessed for pre-commercial thinning needs and older stands will be monitored for forest health concerns.

Some landowners might assess the forest cover across their property and see that it is fairly uniform in terms of age and species. In these instances, where there are no clear differences in forest types, consider if differences in topography and road access will require unique management approaches. For example, gently sloped areas can typically be logged with ground-based machinery while steep slopes would likely require a cable logging system. Other areas may have limited road access that constrains management. Topographic features can be identified using various online mapping platforms such as Google Earth and CalTopo or with paper USGS topographic maps.

Figure 1. Differences in forest cover.

Several approaches can be used to assess the forest cover on your property. The first step is to examine the available aerial imagery for your property. Figure 1 shows aerial imagery for a small woodland parcel near the coast. Let’s examine the imagery and determine if there are any obvious differences in forest cover. The first arrow points to a light green area of forest cover. This is a hardwood species, in this case red alder. The second and third arrows point to darker green areas of forest cover; these are conifer species. If you look closely at the differences between the conifer forest types in the second and third areas you may see that they have different textures. The second area has more shadows than the third area. In this case these shadows suggest a difference in tree sizes; the trees in area 2 have larger crowns than area 3. Using aerial imagery to assess forest types takes practice. The best approach is to take a map with imagery for your area out in the field and compare it to what you see on the ground. You can print out a map in color or use imagery available on a mapping app, such as the map program that comes with your phone or a mapping app such as Avenza that allows the user to view downloaded maps without cell service. 

Figure 2. One approach to delineating stands.

Once you get a sense of how to interpret the different textures and colors on the aerial imagery you can practice delineating stands. Figure 2 is an example of one approach to drawing stands. In this example the landowner has decided to classify their stands based on the average size and dominant species of trees in the stand. Here, the tree size is coded as S, M, L (S- seedlings to small trees up to 11” diameter, M- trees 12-29” diameter, L –  trees 30” diameter and greater). Dominate species or species mixture are coded as: Douglas-fir (DF), mixed conifer (MC), red alder (RA), mixed hardwood (MH), and mixed conifer/ hardwood (MCH). This is just an example of an approach used by this landowner. You might want to classify your stands using more growth stages such as seedling, sapling, small tree, large trees.

Once the stands are mapped out, assign stand numbers or names to each stand. Whichever way you proceed, it’s a good idea to develop a table with an associated map to help you keep track of your stands.

Stand NumberStand Description Code: tree size ( S,M, L), species
1S – RA
2S – DF
3M – MCH
4M – DF
5M – RA
6M – MCH
Table of Numbered Stands

Don’t be nervous about starting to draw your stands on a map. You can draw as many different scenarios as you want on paper printed maps or online. If you have access to a laminator, you can laminate a paper map and use dry erase pens to test out different scenarios. Google Earth Pro and Caltopo are free online mapping tools that can be used to draw and save stand polygons. There are several advantages of working digitally including the ease of editing polygons and the ability to download them to apps like Avenza for field verification. Another free mapping tool is Forest Planner; an easy-to-use drawing tool that allows users to quickly draw stand polygons that snap neatly to property boundaries and adjoining stands (Figure 3). One advantage of using Forest Planner is that the stand data is generated for each stand that you draw, including acres, aspect slope and elevation. This information can then be used to fill in the Current Stand & Forest Health Conditions form. A current disadvantage of Forest Planner is the inability to download the stand polygons to other programs.

Figure 3. Delineating stands and generating stand details with Forest Planner.

You will notice that the Current Stand & Forest Health Conditions section has a table to fill in stand information including age, diameter class, height, spacing, and tree species. This can be a general estimation for each stand. The forest management planning process does not require landowners to include a forest inventory or timber cruise for their property. Although these might be desirable to obtain for other reasons based on your management objectives. Some landowners might decide to hire a forestry consultant to conduct a basic forest inventory. But if you are able and interested in getting out on your property and learning a few basic measurement approaches, this is something you and your family can consider doing on your own with relatively inexpensive forestry tools. By collecting your own information, you will become more familiar with your woodland. You may also observe forest health issues, old roads, other interesting features of your woodland. The next article in this series will discuss taking some simple plot measurements to estimate stand diameter, height and trees per acre.

References

Writing a Forest Management Plan: Start with the Easy Sections. https://blogs.oregonstate.edu/southcoastfieldforest/2024/02/15/writing-a-forest-management-plan-start-with-the-easy-sections/

Oregon Forest Management Plan Template and Guidance. https://blogs.oregonstate.edu/forestplanning/templates/

Land Mapper. Automated and easy, produces many of the plan maps. https://landmapper.ecotrust.org/

Forest Planner. http://forestplanner.ecotrust.org/

Google Earth Pro. https://www.google.com/earth/about/versions/

Avenza. https://store.avenza.com/

CalTopo. https://caltopo.com

Writing a Forest Management Plan: Start with the Easy Sections

As a small woodland owner, you likely already know about the benefits of developing a management plan. These include:

  • Helping you and your heirs guide activities for your woodland.
  • Increasing your knowledge and connection to your property.
  • Helping you strategically develop actions to address your goals and objectives and avoid costly errors.
  • A management plant is also required to receive some grants and funding for management activities.

There are several approaches to starting your management planning journey. Some woodland owners might choose to hire a consulting forester to do all or parts of their plan for them. There may be cost share funding available if you choose that route (see below for funding resources). Or you may want to start developing a plan on your own. Like any big project, it will seem more approachable if you break it up into segments.  Start with the easy sections first; you might be surprised with how easy it is to find property information using online tools. This method will help you build momentum and feel a sense of accomplishment. Here are some tips for getting started (links to the plan template and resources are at the end of this article):

  • Download the management plan template and guidance document.
  • Familiarize yourself with the parts of the plan.
  • Read through the guidance document. This might seem like a lot of information to absorb. Use your skimming skills and get a general idea of what’s in the guidance document. You will be returning to these sections often.
Figure 1. My Forest Stewardship Values

There is a color-coded checklist at the beginning of the management plan template. This checklist breaks down the information that you need to gather for your plan into general categories starting with sections on Woodland Discovery, Current Stand & Forest Health Conditions, and Resources & Management Tools. The Woodland Discovery section asks for basic information describing your property along with maps and photos, followed by a list of your Goals & Actions. It’s a good idea to start the planning process by considering your goals.  Why do you own your property? What are your values and ownership goals? This can be a great way to get your family involved with the process. The My Stewardship Values questions (Figure 1) have been used in extension workshops for many years to help folks get started on this question of values. Your values provide the foundation for your goals and objectives. It’s not surprising that each landowner will have their own unique values, goals and objectives. Many landowners in Oregon have multiple reasons why they own their property. These might include the need for economic return as well as the enjoyment of amenity-based aspects of their property, like aesthetics and recreation or an interest in wildlife and conservation.

Let’s get started on the plan itself. After scanning the Woodland Discovery section you will notice that a number of maps are needed in the plan. Fortunately, recent developments in online mapping programs designed specifically for landowners have made map making surprisingly easy. Landmapper, a free mapping tool (link below), is an online tool that creates a number of maps automatically based on your selected tax lots. First zoom into the general area of your property, you can enter an address or manually zoom in. Select the taxlots that you would like to include in your management plan. Then press Next and a series of maps will be automatically generated. The first is a general map showing the property boundaries and aerial imagery. Basic property data is generated with this map, including acres, elevation range, and other details that will help you fill out the first section of your management plan. You will find additional maps including a vicinity map showing nearby roads, a topographic map, a hydrologic map showing streams along with their classifications, a soil type map, a forest community map, a tree diameter class map, a forest canopy cover map, and a forest density map.

All of these maps can help you describe your property. If you have explored this site in the past, you will find that the canopy cover map, the forest community map, the tree diameter class map and the forest canopy cover map are all recent additions which are based on classifications through remote sensing via satellite or aircraft. Go ahead and take these maps out with you on the property and see how they line up with what you see on the ground. I will cover how to tackle additional sections of the forest management template in upcoming articles.

Links to Management Planning Resources

Download Forest Management Plan Template and Guidelines here:

Land Mapper. Automated and easy, produces many of the plan maps. https://landmapper.ecotrust.org/

Funding Resources:

Oregon Department of Forestry: https://www.oregon.gov/odf/aboutodf/pages/grantsincentives.aspx

Natural Resource Conservation Service: https://www.nrcs.usda.gov/conservation-basics/natural-resource-concerns/land/forests

Planning your year on the forest: tips for creating an annual management plan

By Lauren Grand, OSU Extension Forestry, Lane County

Adapted from the workshop Planning your year on the Forest presented by Matt Fehrenbacher, Trout Mountain Forestry, and Steve and Wylda Cafferata, Master Woodland Managers.

Workshop recording can be found here: https://media.oregonstate.edu/media/t/1_xu7wq2g5

If you manage a woodland or forest, management planning is an essential tool. For small woodland owners we tend to focus on long-term management plans. However, these plans don’t usually reach the level of detail that a forest manager might need to determine the exact activities they would plan on a yearly basis. That usually requires an annual plan. Let’s look a little deeper into why you’d want both a management plan and an annual plan, and what each of those entail.

The term “management planning” usually refers to a longer-term management plan, usually on the horizon of 10 years or so. These are like a corporate strategic plan. They establish a framework for your property that establishes your long-term goals and objectives and usually include ideas and buy-in from family, partners, consultants, etc. These plans are incredibly important because they help you to:

  • Focus your thinking about management and identify opportunities
  • Increase your engagement with your land
  • Clarify your values and approach to ownership and management
  • Document the baseline conditions of your forest
  • Save time and money by avoiding costly mistakes
  • Communicate with others who use the property or who may be caring for it in the future – like family
  • Opens the doors to financial assistance and sustainability certification opportunities.

Figure 1. Sample small landowner annual plan written in the narrative form. Developed by Matt Fehrenbacher, Trout Mountain Forestry

Annual plans, however, are more similar to tactical plans. They use the strategy or goals and objectives that are identified in the long-term plan to guide the more specific activities that will be accomplished in the calendar year. Annual plans should include more detailed timelines, specific activities, budgets, and maps of treatment areas. These plans are usually developed by the focused decision makers and the day-to-day managers of the property. 

Developing these plans is all about timing! You’ll need to consider the activities you want to do in relation to markets, weather, operator availability, plant biology, personal activities, and your finances. For example, if you are considering a thinning operation you’ll want to think about

  • Market – are trees in demand and fetching higher prices, or is there too much inventory pushing prices down
  • Weather – are your roads accessible in rain or snow; are you concerned about the potential of working in the depths of fire season.
  • Operator availability – most loggers are busy in the summer and small jobs are less attractive to them
  • Biology – sap is running in the spring and thinning can cause bark slippage on your remaining trees if there is logging damage. Are you thinning pine? Ips beetles fly in the spring and could be attracted to your property during the logging.
  • Personal activities – maybe you are hosting a family reunion on the property and don’t want an operation to affect the festivities.
  • Finances – do you need to build a road to access the trees to be thinned? Can you afford to build the road before the harvest income is received? 

Annual plans can also help you stay on task with your activities and avoid costly mistakes by linking operations that can save you money and time. For example, linking a harvest with road building. Road building is expensive, but if you are planning a harvest that can be done before, then you might have more liquid finances to pay for the road build. Or, if the contractor that is doing the road is also assisting with the logging, then you only have to pay the set-up costs once instead of twice. 

While annual plans only last a year, you’ll not only consider how they fit into your management strategy, but also how they mesh with last year’s activities and what you are planning for the next year. Remember to be realistic because these activities can sometimes take a while, and weather or fire seasons can be unpredictable. Use a priority rating to help you decide what really must happen and what can fall off the table and be considered for next year. Usually, lower priority activities are stand alone and higher priorities would lead to cascading changes or upsets if they do not happen.

Figure 2. Sample annual plan in the matrix format. Developed by Matt Fehrenbacher, Trout Mountain Forestry.

Annual plans can be organized as a matrix by month or as a narrative. With either style, a map of your proposed activities is always recommended. You’ll also want to include a budget that reflects the relative cost/income expectations. While you won’t be able to predict these exact numbers, estimates can help keep you on track and avoid making large financial risks.

The Goal of your annual plan is to optimize efficiency and effectiveness and get things done. It is all about timing!

For more details about timing and how seasonality affects various management activities watch our webinar! https://media.oregonstate.edu/media/t/1_xu7wq2g5