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Maine Bulletin No. ME 450-13-3

 

                                                                                             December 4, 2012

 

Subject: TCH – CAP-106 Forestry Inventory Criteria

Purpose. To clarify the criteria for the CAP-106 Forest Inventory for Maine.

There are several types of Forest Management Plans defined by the State of Maine. Each type of Forest Management Plan has different inventory criteria. The Maine NRCS CAP–106 Forestry Inventory Criteria document is located in Section III – Conservation Activity Plans Technical Criteria – Forest Management Plan Criteria Activity (Code 106) folder of the eFOTG. The NRCS CAP-106 Inventory Criteria within Section III of the eFOTG as defined as follows:

A field inventory based on fixed area plots or variable radius points is required, and the regeneration must be inventoried.

Field plots/points must include, at a minimum, species and diameter (at breast height, <=2” classes) for all live trees > 5.0 dbh inches. Regeneration plot/point must include, at minimum, species, diameter classes, and stem count for all live trees > 1.0 and < 5.0 dbh within sapling stands. The lack of existing access does not exempt stands from this requirement.

Sample Size: The field inventory for the property must meet one of the following sampling standards. Sampling must occur in all stands:

  • Fixed area plots; a minimum 3% sample of the stand area (distributed sample so that it’s proportional to the stand size or systematically);
  • Fixed area regeneration plots: a minimum 1% sample of the stand area (distributed sample so that it’s proportional to the stand size or systematically);
  • Variable radius plots: an average minimum intensity of 1 sample point (10 BAF) per 3 acres, or 1 sample point (15 BAF) per 2.25 acres, or 1 sample point (20 BAF) per 1.5 acres (distributed sample so that it’s proportional to the stand size or systematically;
  • A showing that the estimated mean Basal Area per Acre, for each inventoried stand, is within an allowable error of less than 30% with a probability (confidence level) of 68%. For statistical purposes, an individual stand of 5 acres or less may be grouped with another stand of similar type and structure;
  • A showing that the overall estimated mean Basal Area per Acre, for the entire woodlot, i.e., an unstratified sample of all inventoried stands, is within an allowable error of less than 15% with a probability (confidence level) of 90%.

Contact. If you have any questions or concerns, please contact Gerald Barnes, State Forester at 207-990-9580 or email Gerald.barnes@me.usda.gov
 

/s/ Juan C. Hernandez

JUAN C. HERNANDEZ
State Conservationist