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Chapter 12 Problem Solutions

DPEM

Listed below are all files for construction and the textbook policy analysis using the Daniel Pickett Ecosystem Management (DPEM) model.

POLMOD (folder) linear equation files for each of the 9 policy models (P1A, P1B, P2A, P2B, P3, P4, P5, P6, P7_08) used for DPEM policy analysis.

DpemRCM.XLS A spreadsheet used to construct the basic DPEM RCM model. (When this spreadsheet is saved in .WK1 format it serves as input to the SARA EQUATION program).

Dpem.PRN 9 solutions files for the 9 policies in a spreadsheet importable file. (This file was produced by the SARA MATRIX program.)

Dpem.RCM This is the linear equation form of the DpemRCM model. (It was produced by the SARA EQUATION program from a DPEM.WK1 file saved from DPEMM.XLS)

DpemGraph.xls This file shows the imported 9 solutions of Dpem.PRN, and the various tables and graphs used in the textbook to display the results of the policy analysis.

DPEM DFC

Listed below are all files used for the textbook sensitivity study of how the DP activities, outcomes, and conditions (especially habitat size structure) vary with (1) different target desired future condition (DFC) structures and (2) the time period in which the structure is to be attained.

DFCPolmod. A listing containing the 9 policy models (three DFC targets for three time periods) that were used in combination with the DPEM.RCM model in a goal programming policy formulation for the sensitivity study.6a04, 6a08, 6a12, 6b04, 6b08, 6b12, 6c04, 6c08, 6c12.

DFCGraph.XLS The spreadsheet showing the solutions from the 9 sensitivity study runs and the graphs used to present these results in the textbook.

DPEM E-E Tradeoff

Below are all the files used to do the ecological-economic tradeoff study in Chapter 12.

EEto2.POL an example policy file. The objective is to minimize the sum of DVSUM -0.01PNV12. The rest of the policy file is the DFC policy Dpmp6b08.pol used in the DFC study. The coefficient . 0.01 is systematically altered between 1.0 and 0.0001 in a series of runs to obtain the tradeoff surface data.

EEtoLIN.lin is the complete linear equation file used for the EETO analysis. (EEtoLIN.lin = EEto2.pol +DPEM.RCM)

EEto.XLS is a spreadsheet that shows the results of the tradeoff study

DPEM.HRV

Listed below are all files used for formulating a weighted goal programming version of the DFC model that defines a target DFC to represent the "average" historical vegetative structure and numerical ranges for deviations from this target over time. This formulation defines two positive ranges and two negative ranges and weights deviations heavier in the ranges further from the target.

**Note. Question 12- 5 in chapter 12 asks the student to reformulate this model so that it encourages some variation in structure over time. One way to approach this is to define three ranges of deviations on each side of the average structure target and then weight the range close to the target and the range most distant with larger weights than the middle range of deviations. This should encourage a management plan that provides a moderate range of structural variation. You will have to try different weights to find out if and to what extent this is possible given the options for management provided by the DPEM.RCM model.

HRVpol.POL A sample policy model used for HRV analysis. It is complex but self documented. (Note the definition of deviation ranges here is the same technique to developing a demand or supply curve for some output in a linear model.) This file is a starting point for doing additional HRV analysis.

HRVlin.LIN A complete linear equation file for solution by mathematical programming.

HRVlin.lin = HRVpol.Pol +DPEM.RCM

HRVout.out is the solution to the problem of HRVlin.lin.

This model can be used as is to study how different weights on deviations within a range or range of deviation specifications would effect the other outcomes of the forest. You could also set it up with an objective similar to that of the EETO study by making the objective to minimize the sum of RWDVSUM . wPNV12 and ranging the value of the coefficient w.

SOLVER DPEM(folder)

This folder contains some example of the EXCEL SOLVER formulations of the DEPEM model prepared by Dr. Tara Barrett of the University of Montana. As shown they were formulated based on an earlier version of DEPM.XLS that only had 7 prescription options instead of the 10 prescription options used the final version of the model presented in this textbook. They will hopefully be updated to the text DPEM model in the future. You could also do the update yourself as a project to expand the decision variables (columns) in a spreadsheet model.

DPEMwhr.XLS this spreadsheet uses the basic policy 2A and was solved by EXCEL SOLVER.

DPEMbeta.XLS is set up to maximize PNV12 with only harvest flow and the land constraints of policy 2A

DPEMgamma.XLS is set up as a goal program to minimize deviations under policy 2A but with additional constraints to achieve a target structure in period 12 of 250 acres in each of the 12 possible habitat structure classes tracked in the model.

Forest Management, 4e
Questions and Answers

"This link takes you to the Forest Management site at the University of Georgia. There you will find the complete end of chapter questions with answers and questions contributed from other instructors from around the world."

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