appendix_c_final.pdf

APPENDIX C

MEASUREMENTS

1. Forest Product Net Volume Measurements (Used For Timber Removal Price Schedule)

Methods:

All estimates of volume used for payment of sawtimber and non-sawtimber products will be done to a required sampling error of 30 percent or less.

Area based cruise methods: These cruise methods include fixed area radius plots such as 1/20th acre and also Variable Plots using a factor such as 20 basal area. The total acreage of the cutting units is determined by a traditional traverse or GPS to expand the total volume for a specific task order.

Tree based cruise methods: These cruise methods require a tally of every tree that will be cut and include cruise methods such as Sample Tree where a frequency such as 1in 20 is used to select measure trees.

Another acceptable cruise method is 100 percent tally and cruise, which sometimes is used on very small populations or minor species.

A Fixed/Count Plot cruise method will be the preferred cruise method when determining volumes on most task orders. The first year task orders most likely will include some cruises that were done utilizing a point or sample tree cruise method.

Procedures:

When a specific task order is laid out on the ground, the cutting and/or treatment units will be traversed with a global position system (GPS) to determine acreage and also provide accurate working maps. A grid will be overlaid across all units to select approximately 30 measure plots of a given fixed plot radius.

Timber cruisers will monument these plots on the ground and collect the cruise data for all trees which meet the criteria for cutting. The cruise designer will use the measure plot data to do a analysis of how many count plots are needed to meet the required sampling error of 30 percent based on total net volume for Sawtimber and Non-sawtimber (if removal is required) . A new grid is then overlaid across the cutting units and the desired number of count plots are located and cruised to arrive at the required 30% sampling error for products requiring removal and payment.

2. Non-sawtimber and Biomass Trees per Acre Estimates (Used for Services and Prices Sections B.1 & B.1A - Level of Difficulty)

Methods:

The number of non-sawtimber and biomass trees per acre used to determine the level of difficulty for cost categories Sections B.1 and B.1A (Services and Prices) will be estimated by the Forest Service from fixed area plots. A minimum of 1 plot per 5 acres will be selected from a grid equally spaced across all units.

Plot size will be a minimum of 1/50th of an acre. Larger plots may be used if, in the opinion of the Forest Service, larger plots are needed to achieve an accurate tree count sample. All Non-sawtimber and Biomass trees within the given fixed plot radius will be counted. That data will be expanded and used to estimate the number of non-sawtimber and biomass trees per acre for each unit within a task order. In the event that the Contractor disagrees with the government estimate of trees per acre within a given treatment unit, additional count plots will be established by the Forest Service in an unbiased manor by overlaying an equal grid over the unit to establish additional plot centers to insure that one count plot for every 2.5 acres of treatment unit area is sampled. Additional plots will be equal in size to the original plots. The additional data will be combined with the original data to establish a revised estimate of the average number of non-sawtimber and biomass trees within the unit. If the additional sampling shows that the original estimate of the number of trees per acre fell within the proper level of difficulty in Section B.1 and B.1A, the contractor will pay the government $13.50 per additional count plot. If the additional plots show that the original estimate of the number of trees per acre was not within the correct level of difficulty in Section B.1 and B.1A, the Forest Service will be responsible for the cost of the additional sampling.

The volumes and number of trees per acre are estimates and therefore are not guarantees

Forest Service reserves the right to explore and consider other statistically valid methods of estimating net volumes and trees per acre such as 3-P photo interpretation. Current tests have shown that other methods could be more cost effective and provide for accurate and statistically valid estimates. Changes in the methods used for the determination of net volume, trees per acre, or tons per acre will require mutual agreement between the FS and the Contractor.

3. Treatment or Cutting Unit Average Slope Determination (Used For Services and Prices Sections B.1 & B.1A - Level of Difficulty)

In Sections B.1 and B.1A – Services and Prices, Schedule of Items, to determine the level of difficulty based on the average slope of the treatment unit. The average slope of the cutting units will be derived from the digital elevation model (DEM) within the current Forest Service Geographical Information System (GIS).

The DEM is a digital representation of ground surface topography or terrain. It is a digital data file containing an array of elevation information over a portion of the earth’s surface. DEM’s are used often in GIS systems, and are the most common basis for digitally-produced relief maps. Scanned contour information is interpolated to provide elevation raster values at a 30-meter spacing. This elevation coverage is derived from the DEM by the “contour” command in the GIS. The DEM used by the Forest Service was built by US Geological Survey using remote sensing techniques. DEM’s are created at a scale and accuracy that is appropriated for project scale analysis. For this project, the appropriate scale is 1:24,000, which is the same as a 7.5 minute quadrangle map.

4. Weight Factors For Establishing Tons of Product Removed.

A weighted average estimated weight for Forest Products to be removed will be developed for each specific task order based on the estimated volume, product, and specie mix for that task order from the cruise. All loads from each task order will be weighed on state certified scales (see G.8.1.4). Total tons removed will be added at the end of each month. All forest products removed will be paid for based on the average weight calculated and weighted by estimated species and product volume estimates.

The following weights by product and species will be used to convert to Tons.

Weight Factor Specie Product Pounds per Cubic foot Ponderosa Pine Sawtimber 73.03 Lodgepole Pine Sawtimber 56.97 Douglas Fir Sawtimber 65.78 Spruce Sawtimber 60.50 Ponderosa Pine Non-sawtimber 79.27 Lodgepole Pine Non-sawtimber 72.02 Douglas Fir Non-sawtimber 69.15 Spruce Non-sawtimber 73.89

An example is shown:

Example Task Order

Species CF Volume

% Net Volume

LBS. Per

CF *

WT.

Fraction

Sawtimber PP 976 25.5230 73.03 18.6394 Sawtimber LP 2573 67.2856 56.97 38.3326 Non-Sawtimber PP 200 5.2301 79.27 4.1459 Non-Sawtimber LP 75 1.9613 72.02 1.4125

Total: 3824 100.00

Weighted Pounds per

CF: 62.5304

* Weight factor incorporates 5% scale defect for sawtimber.

5. Area Determination

Treatment and/or cutting unit acreage will be determined by global position system (GPS) traverse according to the standards used for area dependent timber sale cruises detailed in the Forest Service Timber Cruising Handbook, FSH 2409.12, 52.21.