Willamette Valley Ponderosa Pine Growth and Yield Tables

The Willamette Valley Ponderosa Pine Conservation Association is soliciting for ponderosa pine plantations in the Willamette Valley for data measurements to provide information for the construction of plantation growth and yield tables.  If you have plantations that may fit the following matrix and want to particitpate contact pineguy@att.net.



The Willamette Valley Ponderosa Pine Conservation Association is in the process of taking data measurements in young ponderosa pine plantations for use in construction of growth and yield tables.  This work will be a cornerstone as we development our commercialization program.  There is very little information on the plantation growth of the Willamette Valley Ponderosa pine seed source in the Willamette Valley which is key to making long term forecasts. 

 Attached are the criteria for a plantation to qualify for consideration.  The sampling matrix below indicates the age / site distribution of plantations necessary to develop the tables.

If you have a plantation that qualifies and you want to participate in this project then determine where in the age /site matrix your plantation fits.  Send us your address, phone number, the plantation location and its age / site matrix box description.  You can also indicate the best time and method of contact for your convenience.

Using your information we will analyze the responses to find which plantations best represent the matrix boxes.  The measurements will be made by Master Woodland Managers early in 2011.

If you do not have a candidate plantation, but know of someone who does feel free to pass this information on to them.  We have 15 boxes to fill with 5 plots each.  It is anticipated that some boxes will be hard to fill so we need all the help we can get.  There is no destructive sampling in this project.

Thank you for your interest in Willamette Valley ponderosa pine.



 Field Measurements for ponderosa pine plantation yield tables

 Candidate plantations should meet the following criteria:

·         Trees with average breast height age of at least 5 years (≥4 whorls above breast height)

·         Total area a minimum of 3 acres

·         Average tree spacing between 8 and 15 feet

·         At least 90% ponderosa pine by basal area 

 Sampling matrix is defined by five breast height age classes and three site quality classes to give 15 age-site combinations to fill.  The target sample includes 5 plots within each of the age-site combinations, giving a total of 75 plots.




Breast height age (years)

Site quality (dominant height at 50 years)

Low (65 ft)

Medium (65-95 ft)

High (>95 ft)