Forest Growth and Yield Models: What Makes Them Work and What Makes Them Fail?

Thanks to all of our Sponsors
Start Date: April 13, 2015
Location: The workshop will be held at the DoubleTree Hotel Lloyd Center at 1000 NE Multnomah St., Portland, OR. The hotel can be reached at: 503-281-6111. The DoubleTree is at the Lloyd Center/NE 11th Avenue stop on the Portland light rail MAX system.


April 13, 2015

1:00 PM

Understanding the types of forest growth and yield models with an emphasis on FVS, ORGANON and FPS.

5:00 PM



April 14, 2015

8:00 AM

Model Evaluation: Why are you using one particular model and does it give you the answers that you need? Where models succeed and where they are suspect.




12:00 PM


1:00 PM

How do I localize a model for my area? When is it necessary to do a calibration?

  • What is the difference between evaluation and calibration? Basic adjustments will be covered for FVS, FPS and ORGANON.

2:30 PM

Working through the process: Selecting the best model for
unfamiliar areas and little data.




Final Take-Home Message

4:30 PM


About the Conference
How to be a competent user . . . Models of forest growth and yield are complex collections of mathematical functions and computer code designed to simulate the biological growth of forest trees and/or stands. While models may differ in the details, most such models rely on a very similar collection of tree, stand, and forest input data. These data may derive from field measurements, external models and equations, and imputation procedures. An understanding of the model framework is useful to understand the interaction of input data and model components in making predictions. Through this understanding, model users can gain a greater appreciation of models, model results, and conclusions to be drawn from inventory systems. Attendees will also gain insights into approaches for evaluating and comparing the most commonly used models. The agenda is not specific to any particular software. Growth and yield model software experience is not required for workshop attendance.

Terry Droessler, PhD, CF
Terry has over 25 years of experience in quantitative natural resource analyses. His emphasis is in growth and yield model setup, projection of silvicultural scenarios, inventory design and processing, harvest scheduling, timberland appraisal and statistical analysis. Terry is president of Forest Analytics LLC in Monmouth, OR. Examples of past projects include:
• Net present value calculations of future harvest streams for multiple private and tribal entities in the PNW
• Independent analysis of growth, yield and harvesting scheduling for 600,000 acres private timberland in southern Oregon.
• Calibration of FPS growth and yield components for industry entity in California
• Tested and verified net present value calculations, silvicultural prescriptions and revenue flow over 640,000 acres for REIT formation.

Erin Smith-Mateja
Erin has over 15 years of experience in growth and yield modeling, specifically providing user support, training, and model development for the Forest Vegetation Simulator (FVS). She has collaborated on numerous projects with the US Forest Service and cooperators in the Pacific Northwest and throughout the country. Erin has a Masters in Forestry (Biometrics) from Michigan State University.

Dave Walters, PhD
David is the Director, Western Region Manager, and Biometrician for LandVest, an institutional timberlands group where he advices and assists institutional timberland owners in the acquisition, management and disposition of timberland properties in the western United States. He develops company consulting projects involving inventory, growth and yield, forestry research, harvest scheduling, and strategic planning and expands such projects into the western United States. Prior to joining LandVest, David was the Manager and Biometrician, Forest Planning Group with Roseburg Forest Products. He has a PhD In Forest Biometrics from the University of Minnesota.