Pacific Northwest Research Station

Title: Log sampling methods and software for stand and landscape analyses.

Author: Bate, Lisa J.; Torgersen, Torolf R.; Wisdom, Michael J.; Garton, Edward O.; Clabough, Shawn C.

Date: 2008

Source: Gen. Tech. Rep. PNW-GTR-746. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 93 p.

Station ID: GTR-PNW-746

Description: We describe methods for efficient, accurate sampling of logs at landscape and stand scales to estimate density, total length, cover, volume, and weight. Our methods focus on optimizing the sampling effort by choosing an appropriate sampling method and transect length for specific forest conditions and objectives. Sampling methods include the line-intersect method and the strip-plot method. Which method is better depends on the variable of interest, log quantities, desired precision, and forest conditions. Two statistical options are available. The first requires sampling until a desired precision level is obtained. The second is used to evaluate or monitor areas that have low log abundance compared to values in a land management plan. A minimum of 60 samples usually are sufficient to test for a significant difference between the estimated and targeted parameters. Both sampling methods are compatible with existing snag and large tree sampling methods, thereby improving efficiency by enabling the simultaneous collection of all three components—snags, large trees, and logs—to evaluate wildlife or other resource conditions of interest. Analysis of log data requires SnagPRO, a user-friendly software application designed for use with our sampling protocols. Default transect lengths are suggested for both English and metric measurement systems, but users may override default values for transect lengths that better meet their specific sampling designs. SnagPRO also analyzes wildlife snag and large tree data.

Keywords: Coarse woody debris, density, down woody material, line intersect, logs, monitoring, percent cover, sampling technique, snag, large tree, SnagPRO, strip plot, total length, volume, weight, wildlife management, wildlife use.

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Citation

Bate, Lisa J.; Torgersen, Torolf R.; Wisdom, Michael J.; Garton, Edward O.; Clabough, Shawn C.  2008.  Log sampling methods and software for stand and landscape analyses..   Gen. Tech. Rep. PNW-GTR-746. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 93 p.