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Variable Probability Sampling Course

About this Event

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Details

The Variable Probability Sampling course is offered as a service to foresters yearly at Oregon State University during their spring break.

Two popular methods of timber cruising will be covered in detail: Variable-plot sampling and 3-P sampling (Probability, Proportional to Prediction).  

2025’s course will be March 24th-28th at Richardson Hall.

The course is currently full. Please contact Nicole@westernforestry.org to get on the waitlist or for more information.

Registration

N/A

Lodging

N/A

Event Agenda

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Monday

1:00 pm Registration at Richardson Hall

1:30 pm

  • Introduction of course
  • History of Variable Plot Cruising
  • Basic principles and theory

3:00 pm Afternoon Break

3:15 pm

  • Determination of Basal Area
  • BAF factors
  • Tree Counts
  • Tree Measurements
Tuesday

7:30 am Coffee and Individual Questions

8:00 am

  • Statistical Analysis
  • Means (Average)
  • Standard Deviation
  • Coefficient of Variation
  • Standard Error

9:30 am Morning Break

9:45 am

  • Sampling Techniques
  • Random
  • Systematic
  • Calculation of BAF
  • Plot Radius Factor
  • Cruise Design
  • Volume Calculations/ grade/defect

11:45 am Box Lunch, Travel to McDonald Forest

1:00-5:00 pm

  • Field Problem – VP
  • Field Problem Calculations
Wednesday

7:30 am Coffee and Individual Questions

8:00 am

  • Volume Calculations
  • Log Grades & defects

9:30 am Morning Break

9:45 am

  • Statistical Issues
  • Stand & Stock Tables
  • Analysis of field problem

12:00 pm Group Lunch

1:00 pm

  • Timber Cruising Guide
  • Balancing TC & VBAR
  • Software for Balancing
  • Advantages of VP sampling
  • Special Session on participant questions.

3:00pm  Afternoon Break

3:15pm

  • 3P Computer Demo
  • 3P Sampling, Crew Chiefs and handhelds

6:00 pm Group Dinner

Thursday

7:30 am Coffee and Individual Questions

8:00 am

  • Intro to 3P Sampling
  • Demo of 3P Process

9:30 am Morning Break

9:45 am

  • Guest Presentations 3P (USFS)
  • Case Studies
  • 3P, Fall and Buck (BLM)

11:45 am Group Lunch, Travel to McDonald Forest

1:00-5:00 pm Field Problem – 3P

Friday

7:30 am Coffee and Individual Questions

8:00 am

  • 3P Volume Calculations
  • Statistical Analysis
  • 3P field problem results
  • Sample Size issues in 3P
  • Check cruising and adjustment
  • Advantages of 3P sampling
  • Wrap Up