1. Comparison between intensity based inventory and sampling based inventory Bogdan Strimbu Louisiana Tech University

2. Issue Inventory of the forest resources Practical applications: preset intensity Alternative: sampling design Legal constraints 2

3. Objective Questions to answer: 1.Is preset-intensity inventory legally defendable? 2.Are there significant differences between preset- intensity inventories and sampling based inventories? 3

4. Approach USFS and Florida Assessor guidelines Sampling error standards dependent on the estimated value of the sale alpha=5% 4

5. Sampling error standards USFS Alpha=5% ValueSE <1500020% <3500019% <5500016% <7500014% <9500012% >9500010% Florida merchantable planted pinealpha=5%SE=10% merchantable natural timberalpha=10%SE=10% pre-merchantable pinealpha=32%SE=10% 5

6. Settings Preset - intensity inventories: 5% and 10% Alpha=5% → Approximate t=2 Plot size: 0.1. ac Simple Random Sampling without replacement Homogeneous stand → No stratification The population has a mean 6

7. Formulae 7

8. Sample size vs. CV Area=10 ac 8

9. Sample size vs. CV Area=20 ac 9

10. Sample size vs. CV Area=50 ac 10

11. Sample size vs. CV Area=100 ac 11

12. Sample size vs. Sample error Area= 10 ac 12

13. Sample size vs. Sample error Area= 20 ac 13

14. Sample size vs. Sample error Area= 50 ac 14

15. Sample size vs. Sample error Area= 100 ac 15

16. Intensity – CV for  =10% 16

17. Intensity – CV for  =5% 17

18. Summary USFS guidelines more strict then state guidelines Intensity based inventory – legally defendable using USFS or state guidelines (Florida) most of the cases Stratification recommended for high variable stands Intensity based inventory for stands>20 ac at least double the cruising effort For stands larger than 50 ac the cruising effort is almost comparing with the sampling based inventory 18

19. Cauchy distribution 19