Northwest Timber Supply Dynamics

Timber supply has traditionally been thought of as the quantity of available forest acres under active management.  Wood flow capacity was then simply a matter of the number of acres times the annual production capacity per acre.  Factor one is the number of harvestable acres.  Factor two is the growth capacity of these acres.

Alternative silvicultural regimes have emerged as a third factor affecting timber supply.  This silviculture factor may be more significant than either of the first two factors.

Northwest Timber Dynamics Report This paper describes the results of a two-level analysis of Northwest Forests.  The first level defines the forest capacity in total acres and site growth capacity (Factors 1 and 2).  The second level presents the impact of alternative silvicultural approaches when applied to these acres (Factor 3).  The objective is to understand of the relative impacts of varying methods and goals of forest management on human, wildlife and ecosystem dynamics.

2014: IUFRO- CIF – SAF

The FBRI is actively participating in the 2014 IUFRO- CIF – SAF International Convention in Salt Lake City on October 6 – 11, 2014. Come to visit us in the Exhibit Hall, Booth #1007. Three of our FBRI Directors will be on site.

The FBRI will be presenting three papers at the convention.

Session Title: Implementation of silvicultural treatments and their effects into forest growth models.  Tuesday October 7, 2014 8:00am – 10:30am Room 150E

  • The Forest Projection and Planning System (FPS) fully integrated forest management system.

Session Title: Making and interpreting long-term forecasts. Friday October 10, 2014 1:30pm – 3:00pm Room 255D

  • The Mathematics of Trees – static and dynamic dimensions of trees and stands

Session Title: Learning and success in partnerships.  Saturday October 11, 2014 1:30pm – 3:00pm Room 255E

  • A new paradigm – The Non-profit Research Corporation

2012 SAF Convention: Measuring and Mapping Forest Site Capacity

October 24, 2012 * Spokane Convention Center, Spokane, Washington

Tour Description as printed:

This hands-on field workshop will be about measuring and mapping forest site capacity across an ownership, watershed, or forest. The Forest Biometrics Research Institute has developed an effective methodology for identifying and classifying natural site growth capacity that can be applied in any region and on any tree species. This method provides a means to extrapolate site growth capacity across nonforested and heavily cut-over forest acres, provides a strong and stable productivity basis for long-term forest planning, and has shown great potential as a basis for quantifying possible shifts in growth capacity due to climate change.

Each field location will have felled sample trees for making detailed measurements and effects of differences in soil, topography, and climate between sites will be discussed. All participants will obtain complete written details on computing and using the 10-meter site index methodology on individual trees and methods of building forestwide GIS site



2005 Managing Stand Density Symposium Presentation

March 16, 2005 * Canyonville, Oregon
For diagrams and charts, click here for PowerPoint presentation
SAF: Managing Stand Density

Sample Slides

Slide1: What is Clumpiness?

  1. Clumpiness is a Stand Attribute
  2. Clumpiness is an Index of Spatial Regularity
  3. How to Get There:
    • Phototype the Forest into Stand Polygons
    • Typically by Species, Size & Density
    • Set Minimum Polygon Size (Typically 5-acres)
    • Absorb Small Openings and Thickets (< 5-acres)
    • Clumpiness is the Dispersion within the Polygon
    • Use Cruise Compiler to Compute the Index
    • Load the Index into your Inventory Database

Slide 2: Tree v Plot Attributes

  1. Plot Parameters
    • Site Index
    • Stand Density (SDI, CCF, Rd, Tpa, Basal Area)
    • Clumpiness (spatial pattern)
  2. Species Parameters
    • Genetic growth form, Shade Tolerance
  3. Tree Parameters
    • Species, Dbh, Height, Taper, Age
    • Tree-centered Density (CSI)

Slide 3: Stand Density Indices

  1. Stand Density Index (SDI), Reineke (1933)
    • Assumes Quadratic Mean Dbh
    • Assumes All Trees with Dbh > 0
  2. Relative Density (Rd), Curtis (1982)
    • Assumes Quadratic Mean Dbh
    • Includes Only Trees with Dbh > 0
    • SDI = 5.8 * Rd
  3. Crown Competition Factor, Krajicek etal (1961)
    • Summation of Individual Tree Growing Space
    • Includes All Trees, All Sizes including Dbh = 0
    • CCF = 5.0 * Rd (General Rule of Thumb)

Slide 9: A Tree-Centered Density Index

  1. Competitive Stress Index (CSI), Arney (1973)
    • Uses Same Individual Tree Growing Space Area as CCF
    • Includes All Trees, All Sizes (even Dbh = 0)
    • Competing Trees Overlap into “Subject Tree” Growing Space
    • Primary Sampling Unit is the Individual Tree
    • Provides Distribution of Density across Plot
  2. Plot-Centered Density Index (CCF)
    • Competing Trees Overlap into “Plot” Growing Space
    • Primary Sampling Unit is the Plot
    • Provides only Average Density across Plot

Slide 11: Application of Clumpiness Index

  1. Spatial Variability Index on Research Plot

    • Stem Map Trees on Research Plot
    • Clumpiness = Spatial Variance / Mean Spacing
    • FPS Translates to 0 – 1 Clumpiness Scale
    • Tree Sizes and Spacing determine CSI
  2. Estimate of Density Distribution on Cruise

    • Prism Plots provide Point Estimates of CSI
    • Clumpiness = CSI Variation / Average CSI


The FBRI participated in the 2014 IUFRO- CIF – SAF International Convention in Salt Lake City on October 6 – 11, 2014.

      Posted on: September 19, 2014The FBRI will be presenting three papers at the convention.

2012 SAF Convention: Measuring and Mapping Forest Site Capacity

      Posted on: October 24, 2012October 24, 2012 * Spokane Convention Center, Spokane, Washington

2012 PNW Reforestation Council Presentation

      Posted on: October 11, 2012October 11, 2012 * Heathman Lodge, Vancouver, WA

2010 SAF National Convention

      Posted on: October 28, 2010October 21, 2010 * Albuquerque, New Mexico

2008 FBRI General Meeting

      Posted on: April 7, 2008April 7, 2008 * Corvallis, Oregon

2005 Managing Stand Density Symposium Presentation

      Posted on: March 16, 2005March 16, 2005 * Canyonville, Oregon

2003 GIS & Forest Management: A Practitioner’s Forum Presentation

      Posted on: October 29, 2003October 29 – 30, 2003 * Wilsonville, Oregon