Section 20.02.01.050 - RESIDUAL STOCKING AND REFORESTATION01.Purpose. To provide requirements for residual stocking and reforestation that will maintain a continuous growing and harvesting of forest tree species, and for sites not requiring reforestation, to maintain soil productivity and minimize erosion. The rules specify the minimum number of acceptable trees per acre and the maximum period of time allowed after harvesting for establishment of forest tree species.02.Quality of Residual Stocking. On any operation, trees left for future harvest must be of acceptable species and adequately protected from harvest damage to enhance their survival and growth. Locate roads and landings and conduct felling, bucking, skidding, yarding, and decking operations to minimize damage to residual trees. Acceptable residual trees should have a minimum live crown ratio of thirty percent (30%), minimum basal scarring, and should not have dead or broken tops. When stands have a high percentage of unacceptable trees, consider stand replacement rather than intermediate cuttings.03.Sites Impractical to Reforest. Sites impractical to reforest, generally ponderosa pine and drier Douglas-fir habitat types, must not be harvested below minimum stocking, unless the site is converted to some other use or, in instances of wildfire, insects, disease or other natural causes, where salvage of damaged timber is planned.a. When harvesting timber on these sites, one (1) of the following actions must be taken to ensure minimum stocking:i. Establish a new stand by leaving seed trees on the site and inter-planting at least once within five (5) years of harvest completion.ii. Establish a new stand of timber by planting the site with an acceptable tree species, and inter-planting at least once within five (5) years of the original planting.b. If the efforts listed above in a.i. and a.ii. do not provide the minimum stocking level, the landowner will be encouraged but not required to perform additional reforestation efforts.04.Stocking.a. Stocking is satisfactory immediately following harvest if the following number of acceptable trees per acre, within each specified region, for at least one (1) diameter range are reasonably well distributed over the area affected by harvesting. (NOTE: (1) DBH = Diameter (outside of the bark) of a tree four and one half (4.5) feet above mean ground level): MINIMUM STOCKING - ACCEPTABLE TREES
Idaho Region | Diameter Range DBH (inches) | Average Number of Retained Trees Per Acre | Average Spacing (feet) |
North | 0" - 2.9" | 170 | 16 x 16 |
South | 0" - 2.9" | 125 | 18 x 18 |
North | 3.0" - 10.9" | 110 | 19 x 19 |
South | 3.0" - 10.9" | 75 | 24 x 24 |
North | 11.0" and greater | 20 | 46 x 46 |
South | 11.0" and greater | 15 | 53 x 53 |
b. If the stand consists of retained trees of mixed diameter ranges reasonably well distributed over the harvested area and none of the diameter ranges individually equal or exceed the minimum trees per acre shown above, stocking is satisfactory if the weighted total of all of the diameter ranges of the retained trees exceeds a value of one hundred seventy (170) for a stand in the North Region and one hundred twenty-five (125) in the South Region. Calculate the weighted total by multiplying the number of retained trees per acre in each diameter range by the weight below and then sum the results. Diameter Range | Weight |
0" - 2.9" | 1 |
3.0" - 10.9" | 1.6 |
11.0" and greater | 8.4 |
c. Harvested stands which are not adequately stocked, as defined above, are subject to supplemental reforestation requirements specified in Subsection 050.06.05.Reforestation Exemptions.a. Reforestation is not required for:i. Noncommercial forest land;ii. Land converted to another use. This may include land converted to roads used in a forest practice;iii. A forest practice which will result in ten (10) acres or less below minimum stocking levels.b. On lands where reforestation is not being planned in accordance with Subsection 050.03, establish some form of grass or planted cover within one (1) year in order to maintain soil productivity and minimize erosion.06.Supplemental Reforestation. Seeding and/or planting may be required if after three (3) growing seasons from the date of harvest, stocking levels do not meet the standards in Subsection 050.04. Complete required seeding and/or planting before the end of the fifth growing season following the time of harvest; the Director must grant an extension of time if suitable seeds or seedlings are not available or if weather or other conditions interfere.a. Reforestation practices must ensure seedlings become established. This can be accomplished by adequate site preparation, using acceptable seed or seedlings, following accepted planting or sowing practices, or other suitable means.b. The party responsible for reforestation is the landowner during the harvest which reduced stand stocking below the minimum levels stated in Subsection 050.04.Idaho Admin. Code r. 20.02.01.050