Ash Reduction Model (Metric)   2 cm Diameter Class              
Version 2.0, Tara L. Eberhart, Andrew J. Storer, Linda M. Nagel  
Copyright Michigan Technological University   Version 2.0 Input Requirements  
  ASH Trees Only  
    Trees per Hectare  
    This information should be available from stand and stock tables.  
  Note: this model version is in METRIC units  
  2cm Size Class Increments    
  DBH Class cm No. Trees/Hectare % Phloem Basal Area                
  6         Retaining Small Trees  
  8     Target Percentages    
  10           Diameter Limit Cut    
  12           99%    
  14           95%    
  16           90%    
  18           75%    
  20           *Cutting all ash down to this size limit  
  28     Retaining Large Trees    
  30       Target Percentages    
  32     Diameter Limit Cut    
  34     99%      
  36     95%      
  38     90%      
  40     75%      
  42     * Cutting all ash up to this size limit  
This version of the model serves to show what diameter limit cut would be needed in order to reduce the total of ash phloem basal area in a stand.  
Over 500 ash trees were measured to find the average phloem width and calculated phloem basal area by diameter class.  
Phloem is the food source and breeding substrate used by emerald ash borer in ash trees.  
This model only works with the ash component of a stand regardless of total stand size, other tree species presence, or how much ash there is present.  
Depending on management goals, this model can be used to determine a lower diameter limit cut to retain small trees,  
and an upper diameter limit cut to retain large trees.  
Use of this model in management decisions will reduce the ash resource available to emerald ash borer  
by a target percentage and help maintain ash as a component in our forests.  
Note: basal area reduction will reduce the amount of phloem in the stand by a target level,  
thereby reducing the population potential of eab, not ensuring remaining ash to be uninfested.  

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