December 16, 2017


Potential Research Questions Using Permanent Forest Plots:
There are a large number of research questions that could be addressed using fixed-area permanent forest plots. The following list provides just a sampling of the questions for which faculty and students could formulate testable hypotheses.  As the online database grows, students will be able to search for and utilize date from plots in other regions for comparison to their own results. PFPP participants are encouraged to share the hypotheses they are testing so that over time groups of faculty and students in different regions can work simultaneously on the same questions and hypotheses.  (Sample Questions)

How many plots to establish?
The number of plots you establish will depend upon your research/teaching goals.  A single 400 m2 plot (20 x 20 m) could be used to demonstrate biomass and carbon monitoring techniques, to follow local plot biomass changes over time, and to provide a local vegetation comparison plot for inclusion in the PFPP database.  New plots could be added in subsequent years and previously established plots re-measured. (It will take significantly less time to re-measure the plot than to establish it.)

Faculty are encouraged to replicate plots whenever feasible. Plot replication can provide a more robust site characterization and allow statistical analyses among and within sites.  Establishing 3 to 5 plots within each forest type, or site condition being studied could be sufficient for this purpose.  For example, to compare biomass in two different local forest types, 3-5 plots could be established in each forest type. (If there is insufficient time in a single year, a pair of plots could be established each year, accumulating plots over time.)

Note: There should be a minimum of 20 m between replicate plots, or between plots representing different forest conditions.

Deciding where to locate your plots:
For the purpose of this project, a Forest Plot is one in which the dominant plant community consists of trees. While the trees may be in any stage of development, these protocols are most appropriate for plots containing tree stems that are ≥ 2.5 cm in diameter at a height of 1.37 m above the ground. While complementary protocols that will assess other plant groups are planned for the future, the focus of the current PFPP inventory procedure is on woody species.

Where you choose to locate your plots will depend upon the types of questions you interested in addressing, and the types of forested locations you have available. We welcome plots in any forested site. We are specifically encouraging the installation of paired plots in the following locations:  urban and non-urban forests; forests with invasive plant species and forests without invasive plants; edge and interior forests;  naturally regenerated and planted forests of similar species; forests with exotic insect/disease pests and those without; and wetland and upland forests. If you are in an area currently or soon to be impacted by an exotic insect or disease (e.g. emerald ash borer; hemlock wooly adelgid; thousand canker disease; oak wilt) and have forests not yet impacted, it would be helpful to install plots before the forest is attacked. For example, as of 2012, the emerald ash borer is moving southward into Kentucky and Tennessee, and it would be helpful to have plots in ash forests to track the arrival and impact of the insect on forest structure and productivity. Current special interests: Edge vs. Interior and Plots with ash species to study impacts of emerald ash borer.


Data Entry Forms

Teacher Resources

Online Database (Now available for you to upload and query data! You will need to be a registered user to access the database. For further information on registering, and to learn how to upload and query data, refer to the PFPP Protocols or go to the EREN – DATA – Permanent Forest Plot Project link.)

Frequently Asked Questions – Link to Google Doc with common questions related to data collection and data entry.


Coming in the future:
Other Data Modules Using Permanent Plots
Site Images
Project Discussion List
Sample Data Analyses
Student Project Papers

Updated Aug. 4, 2012 by KKuers