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FORS 8450 • Advanced Forest Planning Lecture 8 Threshold Accepting Example

FORS 8450 • Advanced Forest Planning Lecture 8 Threshold Accepting Example. Objectives. Development of a research plan for testing several silvicultural approaches to develop mid- to late-successional forest structure.

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FORS 8450 • Advanced Forest Planning Lecture 8 Threshold Accepting Example

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  1. FORS 8450 • Advanced Forest Planning Lecture 8 Threshold Accepting Example

  2. Objectives Development of a research plan for testing several silvicultural approaches to develop mid- to late-successional forest structure The development of a long-term, replicated study to test hypotheses and evaluate the success of various silvicultural approaches The major ecological and silvicultural focus of the replicated study is to test the effect of gap size on the success of Douglas-fir regeneration

  3. Objectives Development of a plan for comparing long-rotation even-aged management with uneven-aged management approaches Leave open the opportunity to examine the relative successes of even-aged and uneven-aged approaches at developing mid- to late-successional forest structure

  4. Objectives Development of a strategy to provide adequate habitat for northern spotted owls The development of a foundation for an adaptive management strategy should the College decide to pursue a Habitat Conservation Plan for a pair of spotted owls that are nesting in the South Zone of the forest The development and maintenance of high levels of nesting, roosting, and foraging habitat for the owls

  5. Objectives Generation of revenue to support the College of Forestry A portion of the operating expenses of the College of Forestry comes from revenue generated by the Research Forest The implementation of the research experiment will result in a positive net revenue The overall forest plan for the South Zone should produce a minimum net present value

  6. Spatial Elements of the Landscape McDonald-Dunn forest, South Zone

  7. Spatial Elements of the Landscape Parts Patches Blocks Owl Circle Forest Zone

  8. Spatial Elements of the Landscape Owl Circle Forest Zone

  9. Spatial Elements of the Landscape Blocks

  10. Spatial Elements of the Landscape Parts Patches

  11. Objectives of the Harvest Scheduling Approach Given the complicated spatial requirements of the experiment, schedule management activities so that we maintain or increase nesting, roosting, and foraging habitat and maximize net present value • Develop a managed forest with many of the structural elements found in a mid- to late-successional forests • Maintain a Douglas-fir dominated forest • Install a replicated experiment • Maintain at least 40% of the forest in nesting, roosting, and foraging habitat • Maximize net present value of the plan • Provide databases and tools to support implementation of the plan

  12. Problem Formulation Objective function(s): 1) maximize net present value OR 2) maximize nesting, roosting, and foraging habitat for spotted owls

  13. Problem Formulation Constraint #1: Minimum volume per time period Constraint #2: Maximum volume per time period

  14. Problem Formulation Constraint #3: Minimum net present value Constraint #4: Minimum harvest age

  15. Problem Formulation Constraint #5: Minimum amount of nesting, roosting, foraging habitat Constraint #6: Minimum net revenue per experimental block, per entry

  16. Problem Formulation Constraint #7: Clearcut re-entry period within a block is 30 years Constraint #8: Thinning re-entry period within a block is 15 years *

  17. Problem Formulation Constraint #9: Timing of treatments within a block must be synchronized

  18. Problem Formulation Constraint #10: Green-up (adjacency) constraints

  19. Problem Formulation Constraint #11: Only 20% of patches in a block can be clearcut in a time period

  20. Solution Method Threshold Accepting Initially described by Dueck and Scheuer (1990) [ Journal of Computational Physics 90:161-175 ] Monte Carlo neighborhood search Similar to Simulated Annealing, Yet accepts every new proposed solution that is not much worse than the previous solution Solutions are as good as SA solutions

  21. Randomly choose unit and period to harvest, and check constraints Calculate ΔE (value of proposed new solution - current solution) ΔE> ( - current threshold) ? No Threshold Accepting Yes Current solution = Proposed new solution “Long time” no increase in best solution? No Yes Change Threshold Reached stopping criteria? Stop and report best solution No Yes

  22. Software Interface to define the problem objectives and goals

  23. Software User-defined prices and costs User-defined timing of treatments, harvest ages, green-up, etc.

  24. Results Clearcut harvest patterns Maintain 40% NRF Maintain 45% NRF

  25. Results Clearcut volume (thousand board feet) 40% 45%

  26. Results Thinning volume (thousand board feet)

  27. Results Nesting, roosting, foraging habitat Maintain 40% NRF Maintain 45% NRF 20 yrs 100 yrs

  28. Results Net present value Maintain 40% NRF Maintain 45% NRF $12,900,000 $11,385,000 Difference: $ 1,515,000

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