FAQs Help Documentation Manual and Tutorials Contacts Workshops/Training Crop Plan Design and Test Multiplan Design and Test Creating and Importing Stand Data Publications and References

FAQs

• Crop Plan, Design and Test
• Multiplan Design and Test
• Creating and Exporting Stand Data

Help

Documentation Manual and Tutorials

MGM comes complete with a comprehensive on-line reference manual , which includes a context sensitive Help system. The Self-study Tutorial Series is only available in printed form for this release. Contact the support centre to request a copy. Note that hardcopy tutorials will not be updated. Watch this website for release of the online version.

Additional information about the Q'Nial language:

Nial Systems Limited, 366 King St. East, Suite 540, Kingston, Ontario, Canada K7K 6Y3 Tel: (800) 465-1798 or (613) 542-6964, Fax: (613) 542-8277

E-mail: info@nial.com, Internet: http://www.nial.com

Contacts

For additional information about the model visit the MGM website from the University of Alberta

For additional information or specific help, please contact:

Dr. S.J. Titus, Ph.D., Professor, Department of Renewable Resources, University of Alberta

For more information about the MGM interface and Help facilities contact W.S.(Bill) Adams.

Workshops/Training

Training for MGM is currently available upon request contacting the following individuals:

Victoria, BC: George Harper
Prince George, BC: Larry Badowski
Edmonton AB: Dr. S.J. Titus

Crop Plan Design and Test

A crop plan is a formalized tabular description of the establishment, growth and environmental factors affecting a stand. The MGM system executes the crop plan, event by event, to simulate the sequence of events in the development of the stand.

The main phases of crop plan design are shown below. A worked example (Ex. 1) is available for reference as you familiarize yourself with the phases of design.

Design the initial stand
Ex.1 (Phase 1)

Deals with setting the disturbance year, selecting environmental factors and establishing the initial stand Initial design of a crop plan normally starts from a "skeleton" or "empty" stand retrieved from the Stands database. One can also start from a previously-designed plan that has similar characteristics. The new crop plan is then adapted to your current needs by editing or deleting existing events and inserting new ones. All plans start off with Initialize, Options and Establish events.

Design the management scenario
Ex.1 (Phase 2)

The key event is setting the growth intervals which determine the ages or years at which yields are calculated. Other management events include thinning, harvesting and regeneration.

Design the collection and recording of results
Ex1. (Phase 3)

The Yields table is automatically updated in executing the growth events and need not specifically planned for. Any worksheet may be recorded for further study or for archiving.

Execute the crop plan
Ex.1 (Phase 4)

Single step execution is used for initial testing of a crop plan to see if the various settings are correct. Stop events are often inserted to allow autonomous execution of parts of a crop plan. After all the debugging is finished, the complete crop plan is executed automatically to do the "production" run.

Analyze the results
Ex.1 (Phase 5)

Yields are automatically graphed in a variety of useful ways in the Graphs worksheet.

Multiplan Design and Test

A "multiplan" is simply a means of grouping any number of crop plans together and giving them a group name for saving as a unit. At execution time, the crop plans are executed in the order in which they appear in the multiplan. The grouping mechanism is a matched pair of events - a "Multi Plan" event at the beginning and an "End" event as the last event in the entire Crop Plan sheet.

Typically, you may want to compare various scenarios, varying one or more parameters in each crop plan within the Multiplan and then comparing the results at the end by means of graphs or other techniques.

Select Individual Crop Plans
Ex. 2: (Phase 1)

Open a new (empty) multiplan and create each crop plan by insertion or editing.

Design Crop Plan Comparisons
Ex. 2: (Phase 2)

Up to four different crop plan yields can be collected for comparison with the Multigraph facility. Main one: Yields event to save in Y1,Y2, etc.

Execute Multiplan
Ex. 2: (Phase 3)

Test each crop plan individually in Crop Plan execution.

Analyze the results
Ex. 2: (Phase 4)

Can record results in record Sheet. Comparison graphs for any column of Yields can be plotted using the Multigraph facility. They may also be recorded for archiving in the MGM Records database. Use of Multigraph and button.

Creating and Importing Stand Data

Creating a stand from external data is fairly easy once you have the data in an Excel worksheet. Excel has powerful facilities for importing data from other programs. You can also enter data manually in a variety of ways using the Auto-filter and Form facility in the Excel Data menu. Where large volumes of stand data have to be handled, automatic methods can usually be developed using Visual Basic techniques. Once the data is in a spreadsheet, all you need do is rearrange the table of trees to conform to the MGM Stand sheet format and enter a few parameters such as the name of the stand, the number of trees and the stand age.

The procedure for creating a stand using your own data begins with the MGM menu item "Create New Stand". The process proceeds as follows:

1. You are prompted for the general information about the stand. This includes stand identification name, site vector, and stand age--time since disturbance or "origin", other items are not currently used. A site value must be included for each species present in the tree list. Species are grouped as:
   
   [Sw, Pl, Aw, Sb] = [Sw Se Fd, Pl Pj Pf Pw, Aw Pb Bw, Sb Fb Lt Lw La Fa]
   
   If a species is not present, the site vector may include and "NA" entry
   
2. A new "stand" worksheet is created in the MGM workbook using the name you provided in step 1. Note that this newly created stand worksheet is NOT the same as the "Stand" worksheet that is reserved for use by MGM as it simulates stand growth. This newly created stand worksheet must be moved into the MGM Stands DB workbook (MGM Stands.xls ) so that it can be retrieved when needed and used for growth simulation in a Crop Plan.
   
3. You are prompted to enter tree data (cohorts--this terminology will be removed later). You may enter data using the form provided; click the Accept button to enter additional trees. Alternatively, you may click "Done" immediately if you don't want to enter data using this form.
   
   Notes for data entry:

• Enter NA for missing data
• Species is a required entry based on Alberta LFS codes:

• Dbh – if dbh is NA, then height may not be NA
• Trees/ha – required, the number of trees/ha represented by the tree
• Height – if height is NA, then Dbh may not be NA
• Total age – if total age is NA, then breast height age may not be NA
• Breast height age – if breast height age is NA, then total age may not be NA

4. Once you click on "Done", you are asked for permission to move the sheet to the Stands DB workbook. If you click Yes, the sheet is moved to the Stands DB workbook, otherwise it remains in the MGM workbook as a separate sheet with the stand id name as provided in step 1. If you didn't provide tree data in step 3, it is recommended that you don't allow the sheet to be moved to the Stands DB workbook. If desired, you can open the "MGM Stands.xls" workbook to verify that the stand has been moved. Close the workbook after verifying that the newly created stand is present.
   
5. If you did not move the worksheet to the Stands DB workbook, you can continue to make additions or corrections and then move the Stand worksheet to the Stands DB workbook manually. Tree data may be imported using any Windows or Excel cut/paste or other import procedures. Place the data into the columns as required by the column headings (Species, Diameter, etc). Count the number of trees and enter this number into cell C5. Finally, move the worksheet as follows:

• Open the MGM Stands.xls workbook.
• Go back to the MGM workbook, making sure the new stand worksheet is the active worksheet.
• Select the Excel menu item Edit|Move or Copy Sheet…
• Uncheck "Create a Copy" box if it is checked.
• Select the "MGM Stands" workbook as the destination for the sheet.
• Click on the sheet following "Index" and press "OK"
• Close the MGM Stands workbook.

6. To use the newly created stand in a Crop Plan, you must edit the "establish" event on a new or existing crop plan. Click on the "New Tree Source" button and then click the "MGM Stands DB" when prompted to select the tree source. A list of stands will appear (stands found in the MGM Stands.xls workbook). Select the name of the stand you have just created and click OK. When the Crop Plan is executed, the stand will be retrieved from the MGM Stands.xls workbook and then the growth simulation will proceed. Note also that editing the Establish event and specifying an external stand replaces the stand located in the Stand worksheet.
   
7. To edit the stand data after it has been created and moved to the Stand.xls workbook:

• Retrieve the stand by executing the Establish event
• Edit the stand data as needed
• Save the stand using the MGM Toolbar Save button
• If the stand age was altered, you must edit the Establish event, select the appropriate stand name, and click OK. This is necessary to update the stand ages in the Crop Plan.
• If desired, the Crop Plan should be saved to reflect the changes.

Publications and References

Arabatzis, A.A. and Burkhart, H.E. 1992. An evaluation of sampling methods and model forms for estimating height-diameter relationships in loblolly pine plantations. For. Sci. 38:192-198.

Burkhart. H.E., Parker, .R.C., Strub, M.R., and Oderwald, R.G. 1972. Yield of old-field loblolly pine plantations. School of Forest and Wildlife Resources, Virginia Polytechnic and State University. Publ. FWS-3-72.

Hostin, P.J. and S.J. Titus. 1996. Indirect site productivity models for white spruce in Alberta's boreal mixedwood forest. Forestry Chronicle 72(1): 73-79.

Huang, S, 1992. Nonlinear simultaneous diameter and height growth models for major Alberta tree species. PhD thesis, University of Alberta, Edmonton. 202pp.

Huang, S, 1994. Ecologically based individual tree volume estimation for major Alberta tree species. Report #1, Individual tree volume estimation procedures for Alberta: methods of formulation and statistical foundations. Alberta Environmental Protection, Land and Forest Service, Forest Management Division, 80 pp. Note that there are 11 other related reports summarizing the results for the different species and regions, including diameter/height functions.

Huang, S., S.J. Titus, and D. Wiens, 1992. Comparison of nonlinear height-diameter functions for major Alberta tree species. Can. J. Forest Research 22:1297-1304.

Huang, S. and S. J. Titus. 1993. An index of site productivity for uneven-aged or mixed-species stands. Can. J. Forest Research. 23: 558-562.

Huang, S. and S.J. Titus, 1994. An age-independent individual tree height prediction model for boreal spruce-aspen stands in Alberta. Can. J. Forest Research 24:1295-1301.

Huang, S. and S.J. Titus, 1995. An individual tree diameter increment model for white spruce in Alberta. Can. J. Forest Research 25:1455-1465.

Titus, Stephen J. 1998. Adaptation of the Mixedwood Growth Model (MGM) to Northeastern British Columbia. BC Ministry of Forests, Resources Inventory Branch, Final Report Contract #JV99-011.

Wang, C.H. and Hann, D.W. 1988. Height-diameter equations for sixteen tree species for the western Willamette valley of Oregon. For. Res. Lab., Oregon State University, Corvallis. Res. Pap. 51.

Wykoff, W.R. Crookston, N.L, and Stage, A.R. 1982. User’s guide to stand prognosis model. USDA For, Serv. Gen. Tech. Rep. INT-133.

Yao, X., 1996. Modeling juvenile growth and mortality mixedwood stands of Alberta. PhD thesis, University of Alberta, Edmonton.