1. Cruise Summaries

2. Fixed plot vs. Variable point Cruises
Comparing
Fixed plot vs. Variable point Cruises

3. Basal Area by tree size

4. Volume per acre by diameter

5. Summary of Major Points
Fixed Plot
Variable Point
Sampling based on
Frequency of occurrence
Tree size
Expansion Factor
Same for all trees
Varies by tree
Best for
Total stems and number of small trees
Number of large trees
Long term and repeated measuring
Temporary plots
Distribution of DBHs
Basal area and volume estimation
Tally determined
Distance from plot center
Angle device over point
Misc
Slope correction harder than angling prism
Missing large distant trees, Missing hidden trees in dense stands

6. Expanding Measurements
Number of tallied stems for the tract by species
Average DBH, DBH range, QMD
Merchantable Height (average number of logs)
Basal Area Estimates
Board Foot Volume Estimates
Cull Deductions
Tree Grades

7. Trees per Acre
Number of trees measured can be expanded to express number of stems per acre for each species. There is no index of tree size. Generally more stems = smaller stems. Are they too crowded to grow well?

8. Trees per acre
A young natural stand of hardwood trees starts with 4000 to 6000 stems per acre. At maturity, when they measure about 20 inches in diameter, less than 100 trees per acre will survive. This is a natural selection process and it is slow, requiring 150 to 200 years or more to complete.
Mechanical thinning allows ‘crop’ trees room to grow at a faster rate, obtaining mature size in fewer years.

9. Crop tree release Accelerated growth provided by removing competitors
Cost vs. benefit?

10. DBH
Could summarize and report average DBH of stems. If population isn’t normally distributed, this could lead to false conclusions. Adding an indicator of variance sheds more light.
Could use other measures of central tendency like median or mode.
Merchantability depends on that local mills are buying. (species, size, grade)

11. Average logs per tree
Merchantable height indicator of stand age and quality
When dominant trees harvested, most will have similar heights (total and merchantable)
Bucked into manageable sizes for hauling (16’ or less)
Each log graded for lumber yield estimate
(more specific than standing tree grading)

12. Basal Area per Acre
DBH is used to calculate BA, cruise summaries should include this
BA can be used to calculate QMD
Area per area index.

13. 60 ft2 of BA per acre by tree size

14. Volume per Acre Takes your measurements to the 3rd dimension
Along with grade and species, used to assign value to stand
Stand Valuation = another lecture