When considering a MARVL (Method of Assessing Recoverable Volume by LogType) inventory for pre-harvest or mid rotation style inventory there are 3 common templates using in New Zealand. These being called commonly as RAD05, RAD05-A and RAD06. So what are these? How do they differ? How are people implementing them?
What are they?
These are for used to assess the stem for stem features and attributes that YTGEN will use to “buck” or “logmake” the stem into end log products. They include features for assessing sweep, branching and features of the stem which drive typical log product grading decisions. An example of the types of features assessed are shown below in a quick reference stem feature assessment
How do they differ?
Common to all is the inventory headers from population down to tree level, with only minor variations at the tree feature cruising level.
For example dealing with changes in the “Br” branch domain:
• in RAD05 “Br” has breaks at 0,1,7,10,12,25,99cm classes
• in RAD05-A “BrA” has breaks at 0,1,4,7,10,12,25,99cm classes
• in RAD06 “BrB” has breaks at 0,1,4,7,10,14,20,99cm classes
Within each PlotSafe template this is displayed as below. If you are not aware of which template are in use this is as well a good place to check
Then the cruising dictionary is defined as using the stem feature domains of:
• RAD05 uses Br, Sw, F, I
• RAD05-A uses BrA,Sw,F,I
• RAD06 uses BrB,Sw,F,I
This way each stem feature domain is consisted independent of the dictionary used. It also reduces the complication of final cutting strategies over time.
Is important to note that the variations called RAD05 or RAD06 are not a domain in the YTGEN sense of the word. It is a “cruising dictionary template”, meaning it is a collection of domains that are, by convention, often used together. But they don’t need to be used together always.
How are people implementing them?
Clients have the option to freely choose between the RAD05, RAD05-A and RAD06, the templates varies little so inventory staff can easily swich between templates. When planning an inventory managers should consider the following from a template perspective, a few examples:
- Has there been done any inventories before, if so check which template or MARVL dictionary has been used.
- An inventory should represent the forest, to be able to do this each tree has to be described as close to reality as possible, if they are small branched consider using RAD05-A or RAD06.
- Generally RAD06 is commonly used for minor sawlogs species in NZ and Australia.
YTGen and branches codes, what to be aware off!
When processing the data in WTGen users should be aware of the difference which has to be applied to the cutting strategy to get an accurate result.
Above is an example of a generic RAD05 cutting strategy, unique to RAD05 is its branch code of “Br” as of above. For RAD05-A this would have to be changed to “BrA” and “BrB” for RAD06. If I were running a RAD06 inventory through, using the displayed RAD05 cutting strategy changing the domain file (within YTGen) would not help, I would physical have to change within cutting strategies ‘Conditions’ e.g. substitute ‘Br’ with “BrB”
How does YTGen handle a mix in branch codes?
If the correct branch code is not used e.g. miss match between template and conditions in cutting strategy, it would affect output since grades will be skipped when processed, hereby falsifying the end-user yield result.
Determination of what Branch code is used can be determinate in either the plotsafe file or in YTGen population file.
For above RAD05 have been used.
So if the output file is not showing any results, one of the first checks to do are to verify which branch code is used.
Get the RAD05,RAD05A or RAD06 Domain file for YTGEN
You can also download from our website for free the cruising domain file (just register for free at our feedback form) for loading into the YTGEN cutting strategy editor. This is useful for creating log specs and checking strategies within YTGEN. It is also formatted to indicate the accepted use of each code with a suffix after the “…” showing you the general application of the code to a logtype; for example “… rough sawlogs, pulp”
If you want more information about using Plotsafe/YTGen, feel free to contact us via our feedback form.