Cruise Design

Question 1

Why would scale based sales be preferred?

Answer 1

-Cruise based sales are based on an estimate and there are a number of cruiser and inherent errors that could cause misestimations.

Question 2

What are the minimum requirements to meet sampling error objectives?

Answer 2

• if less than 250 ha: a 200m grid or 4 ha per plot
• if more than 250 ha: A 250 m grid or 6.25 ha per plot
• Max of 3 count to one measure for coastal cruises

Question 3

What are sampling error objectives for scale based cruises?

Answer 3

-sampling error 15% at 2 S.E.

requirements waived if:
100m x 100m grid has been established and 1 count to 1 measure has not been exceeded (and avg of 4 trees per plot)

70m x 70m grid has been established and full measure plots established with at least 2 trees per plot.

50m x 50m grid and max of 1 count to 1 measure has not been exceeded with at least 1 tree per plot.

Question 4

What are the sampling error requirements for cruise based appraisals?

Answer 4

8% at 2 S.E on all plots
-If count plots used 2 S.E of 12% full measure plots must be used.

All other scale based standards apply except that sampling error cannot be waived.

Question 5

What are the 3 types of appraisal?

Answer 5

• Scale based sale (based on volume at scaling yard)
• Cruise based sale (Based on cruise of standing live timber)
• Special Cases (salvage or right of way sales)

Question 6

What is the objective of timber cruising?

Answer 6

To obtain an unbiased estimate of timber volume and quality to a specified confidence interval and sampling intensity.

Question 7

What does standard error % mean ?

Answer 7

How close the sample mean and the true mean are likely to be on a % basis. Controlled by sample size***

Question 8

explain coefficient of variation.

Answer 8

Compares dispersion of individuals about the true mean (SD) on a % basis.

Question 9

Why is 2 St.E. the minimum requirement for cruising?

Answer 9

Also called the 95% sampling error because there is approximately 95% chance that this interval contains the final answer. 1 S.E would only give about 68% chance of containing the final answer.

Question 10

what is sampling error?

Answer 10

more or less than 1 standard error

standard error = how close your sample mean is to the true mean in units

Question 11

what is sampling error based on?

Answer 11

ratio of count to full measure plots

Question 12

What is the formula for GSD?

Answer 12

SQRT. 10,000 x ha/plots