Forest areas and growing stock

specification for the MERLYN harvesting model


{Areas} Excel sheet, giving block area details

The MYRLIN Harvest Model has two worksheets which describe the initial condition of the growing stock. These are the {Areas} and {StandTables} sheets. The {Areas} sheet (right) lists the forest blocks, and gives their areas in ha. The sequence number can be used for sorting the block list in Excel. Fellings are actually scheduled according to the list order. The areas input must be net forested areas. This table can be copied from the {Areas} sheet in the MYRLIN#1 module .

The {StandTables} sheet is identical in general format to the stand tables produced by the MYRLIN#1 module. There must be one table for each block in the areas list, with the lines of the table representing species groups consistent with the growth model data supplied.

However, the diameter class requirements are more rigid. They must be in ascending sequence without gaps or overlaps, and only the last class may be a cumulative class. 10-cm classes are suggested. Larger classes may degrade model performance. The example below shows appropriate settings.

Part of Excel {StandTables} sheet showing recommended diameter class settings

It will also be noted that whereas MYRLIN#1 can compile stand tables of N/ha, m2/ha or N/km2, the stand table in MERLIN#3 must be based on N/km2 or results will be incorrect.