Activities: Woodland Inventories

How these activities will help you as a woodland owner:

You typically can rely on a forester to take all the tree measurements needed to help you make woodland management decisions, but engaging in these activities will enable you to:

• Learn the meaning of tree measurement terminology that may appear in your woodland stewardship plan.
• Better understand the accuracy and reliability of tree measurements provided by a forester.
• Monitor your trees and woodland more often.

Part 1 – Tree Measurements

Step 1. Measure tree diameter.

• Step 1A: Read the chapter Introduction and Tree Measurements section on Tree Diameter.
• Step 1B: Buy a diameter tape from a forestry equipment dealer or make your own. You can make your own from a non-stretch ribbon about 6 feet long. Cover each end with heavy piece of tape to prevent fraying. Place marks every 3.14 inches along its length. Number those marks consecutively 1, 2, 3… Each mark represents 1 inch of stem diameter.
• Step 1C: Practice measuring stem diameter on trees of different sizes and shapes. To begin, stand on the uphill side of a tree and measure up 4 ½ feet from the ground. Note where this height hits your body so that you can take all diameter measurements at this height. Then measure the diameter of differently shaped trees, referring to Figure 2-1 as needed.

Part 2 – Stand Measurements

Step 2. Find the number of trees per acre on your woodland.

• Step 2A: Read the section on Stand Measurements.
• Step 2B: Taking stand measurements is generally the role of a forester, but you may be interested in measuring one plot to learn about the process and reliability of measurements and better appreciate the complexities. Identify a stand of interest for measuring its volume, growth rate, and stocking. A stand with only a few tree species and where the main canopy trees are more than 5 inches DBH would be very appropriate for learning.
• Step 2C: Your plot must be located randomly within a stand, so while standing on the edge of the stand, take a compass bearing (azimuth) that will enable you to enter the stand, and walk 100 feet (or any pre-determined distance) into the stand following that azimuth. Put a stake in the ground to indicate your plot center.
• Step 2D: You will measure trees on a 1/10 acre circular plot with a radius of 37.25 feet around the plot center. Be prepared to measure this radius using a tape measure or measured length of string attached to the plot center stake.
• Step 2E: Face toward a distinctive tree or a known direction (e.g., north, east…). Use your tape measure or string to measure to the edge of the plot, a distance of 37.25 feet from the plot center. Count all trees larger than 4 inches diameter within 37.25 feet of the plot center. Continue re-measuring the plot radius as needed to determine which trees are within the plot. Record that tree count on paper. Multiply the number of trees per plot by 10 to determine the number of trees per acre.