Section 1537.20  Stand Description and Analysis

a)         A description is required for each forest stand regardless of size in acres.  The information and data must be described and interpreted in detail and include all items listed in Section 5 of Exhibit A for each forest or reforestation stand.

b)         Systematic Inventory

A systematic inventory of each forest stand must be conducted and must include all forest trees of 2 inch diameter or larger.

1)         For each forest stand under 10 acres, data may be collected through any valid systematic or professional methodology agreed upon by the IDNR Forester.

2)         Each forest stand 10 acres or greater requires that a detailed forest inventory be conducted.  Inventory data must be analyzed by statistically sound software programs or hand calculation based on forest measurement principals.  Inventory-analysis programs must be approved by the IDNR Forester.  Criteria for forest inventory accuracy are ±10% of the basal area/acre and ±10% of the volume/area using a 90% statistical confidence level.   

c)         Copies of inventory plot data and field notes must be delivered to the IDNR Forester for review upon request.  The IDNR Forester will determine if all of the required inventory data meets accuracy requirements.  Forestry inventory data is considered valid for 10 years from the growing season it was recorded.  Use of older data is not allowed unless specifically approved in writing by the IDNR Forester in advance of Plan preparation.

(Source:  Amended at 41 Ill. Reg. 15790, effective December 18, 2017)