Learn about Maine forests and forest ecology by establishing and monitoring a long-term Forest Inventory Growth Plot in your community. Partner with a local forestry professional to collect key data within the plot.

Looking ahead to Level 2, individual plots become part of the statewide Online FERN Network. Long-term datasets from all plots are available online to those contributing to the FERN community. We’ll work together to find patterns, identify trends, and understand forest systems better as we focus on a common research question: How are Maine’s forests changing over time? Investigations extend learning beyond the classroom, expose students to careers in forestry, and ground learning (math, science, social studies, and language arts) in real scientific practice and fieldwork. The plots offer a springboard from which teachers and students may further explore and discuss concepts, issues, and questions that arise from their annual monitoring efforts and from National Project Learning Tree lessons. See Level 2 for these details.


  • Students will work as a collaborative team to establish a Forest Inventory Growth Plot in a local forest.
  • Students will meet with a forestry professional who will guide plot set-up, support students as they learn and apply forestry skills, share his/her career path, and ensure quality monitoring efforts.
  • In the first year, students will establish a baseline dataset for their plot: tree species, status, height, diameter at breast height (DBH), crown damage, and bole damage. In subsequent years, students will monitor these factors annually or biannually, and flag changes.

STEP 1. Connect with a Forester Partner

Your professional forester partner is a critical resource for students as they establish their FERN Plot, and as they learn, practice, and apply forestry skills. Connecting with a professional has the added benefit of exposing students to careers in forestry, and to giving students’ learning real purpose and meaning beyond the classroom. The forestry pro will make sure your plot is set up properly, will review data protocols and tools with students, and will set data quality expectations to maintain consistency and integrity from one year to the next.

FERN Project foresters come from Maine Forest Service, Maine Society of American Foresters Education Outreach, Forest Stewards Guild, and the University of Maine.

STEP 2. Prep for Plot Set Up

1. Find a location for your plot. In collaboration with your forester, decide on a site located near your school or organization for the FERN plot. Get landowner permission as necessary for your long term study. Consider travel time and accessibility when planning plot location.

2. Gather Materials for plot setup. Materials can be borrowed from your forester or Maine Project Learning Tree.

  • 50-foot tape measure
  • Landscaping stake or center post
  • Landscaping flags or flagging tape
  • Forester’s labeling paint (Nelson Tube Marker) or aluminum tags
  • 4.5-foot stick for the standard marking of DBH
  • DBH tapes
  • Compass or app

3. Practice Fieldwork Skills. Before going into the field, make sure everyone understands basic measurement with a tape measure. Students will be measuring 37.24 foot boundary lines, and 4.5 foot heights for future tree diameter measurements.

4. Make a Team Plan: Watch the Plot Setup Video and review the Plot Diagram

Talk through the plot layout and instructions with your team. Decide how you will work together to mark your plot. What role will each person take on? How will you make decisions once you are in the field?

STEP 3. Set Up Your Plot

1. Mark the Center. Establish the center of the 1/10 acre fixed radius plot and mark it with a permanent center post or stake.

2. Mark the Boundary. Mark the outer boundary of the 1/10 acre circular plot by

  • Placing numerous landscaping flags 37.24 feet from the center post
  • OR by tying flagging tape around the next nearest tree beyond the boundary.

Measuring straight lines in the forest is difficult with trees and topography as obstacles. It may not be a perfect circle, similar to a tree’s circumference.

3. Number the Trees. Starting from Magnetic North and moving in a clockwise direction, measure the diameter of each tree:

  • For trees with a diameter at breast height (DBH) of < 5.0 inches, do nothing
  • For trees with a DBH 5.0 inches or greater, give them unique numbers
    Put an aluminum numbered tag at the 4.5 foot DBH height
    If aluminum numbered tags are not available, use flagging Tape and a Sharpie marker, or marking paint to number your trees. Make this decision with your forester partner prior to the field visit. Your DBH measurements will be taken consistently at the metal stake or paint line.
  • On each numbered tree, use your 4.5 foot stick to measure and make a horizontal line at breast height (4.5 feet from the higher ground) with paint (Nelson Marking Paint). Paint is the best marker for longevity.

STEP 4. Prep for Baseline Measurements or Monitoring

1. Plot Orientation and Protocol Review. Students involved in the first year plot set up will already know the plot well, but it will be important to orient students to the plot in subsequent years. Remind or familiarize students with the FERN Plot set up using the diagram, video, or a map students may have made. Review the protocols for establishing permanent plots, making correct identifications, and taking quality measurements.

2. Last Year’s Prediction. If past students did a Level 3 Analysis, they may have made a prediction (based on the data they’ve analyzed and trends they’ve identified) for what the inventory results will be next year. Review their prediction together. Consider inviting former students in to present their predictions.

This is intended to be a quick, fun, pass the baton, motivating, rah-rah thing. It will cement the idea and value of long-term data collection, while letting kids make and reflect on predictions.

3. Gather Materials. Materials can be borrowed from your forester or Maine Project Learning Tree.

4. Teamwork. Talk through the tools, measurements, datasheet and instructions with your team. Decide how you will work together to take measurements and record data. What role will each person take on? Example:

  • 1 data recorder
  • 1 tools manager
  • 2 measurement specialists (DBH, height)
  • 2 tree specialists (ID, damage, tagging)

5. Understand and Practice Fieldwork Skills and Tools. Before officially collecting data, make sure students understand the tools, skills, and data collection components they are responsible for. Practice can happen in the classroom or in the field. Often your forester partner will lead the practice.

Step 5. Measure Trees!

1. Download and print out a datasheet (1/10 acre plot).

2. Measure Trees and Record Data. Record data on your paper datasheet. If your site has phone or wireless connectivity, you may enter data directly online with a tablet or smartphone. However, this is not recommended: (1) You will lose your data if your connection hiccups. (2) There’s great value in the discussions and quality-checking that happen during data transcription from paper to the online data entry form.

For each marked tree ( > 5.0 in DBH) measure and record:


3. With your forester, measure the HEIGHT of the tallest tree in your plot. There are many lessons and tools involved in measuring tree height. The forester may take small groups of students aside for these lessons, or may do a group lesson after all plot data are collected.

4. Photo Journal. Standing at the center point of your plot, take photographs of your plot to the North, South, East, and West. Make sure there are no people in your photographs, and especially no faces.

5. In-field Data Quality Check. Before leaving the field, have a teammate or your forester partner look through your data. Now is the time to double check identifications and measurements you are unsure of. It is important to get the best, most accurate data you can while in the field. You want your own analysis and conclusions – and the analyses that will happen 10 years from now! – to be based on a solid, high quality dataset.

  • TIP: If you are collecting data in pairs or teams of three, have two students measure each tree to make sure your DBH measurements are correct
  • TIP: Before moving to the next tree, have the data recorder read the DBH measurement out loud to make sure he/she recorded it correctly

That’s plenty for us

Stop here. Send a copy of your paper data sheet to us by email

We want to put our data online!

Great. We want you to do that, too. Join the online FERN network and PLT community today to upload you 1/10th Acre Plot data.