Loggers' Perception and Cut-Block Design Peter Schiess and Dean Berg Forest Engineering University of Washington

Problem Setting Design is the fundamental basis for timber harvest and efficiency of operation Logging production/costs depend on cut-block layout & site characteristics Interaction of design attributes is difficult to measure

The Problem: How Do You Compare the Relative Efficiency of Different Settings ? It’s Not just a Clearcut Anymore!!

The Past: Time-motion studies are site specific The Past: Time-motion studies are site specific. Extrapolation to other conditions are questionable.

Logging operations are under severe environmental constraints No clear understanding of interaction among design variables Engineers still learning about Structural Retention (STR) Harvest systems with STR involve two principal costs -foregone timber revenue -increased harvesting costs

Structural Retention Aggregated Retention Dispersed Retention Structural Retention is being broadly implemented with little experience on cost and cut-block layout

Interaction of Setting Design Parameters and Human Factors (Perceptions) Borrow from Market Research Technology Evaluate perceptual mapping of loggers through market research Use the above information to develop utility values for setting design

Methodes Pilot study - survey of logging engineers, identified initial 108 cost variables Construct initial survey with 20 variables Use of focus groups to establish critical factors of setting design and to develop questionnaire - 14 variables Use of interviews and questionnaires, 480 loggers polled, with 120 returns Factor analysis and conjoint study Follow-up with interviews

Harvest Cost Variables as Identified by Loggers for Three Silvicultural Systems and two Harvest Systems Harvest Cost Variables Cable System Ground-based System Silvicultural systems Clearcut Aggregated STR Dispersed STR

The 14 harvest cost variables as identified by loggers for three silvicultural systems and two harvest systems Size of Timber (average scaling diameter Payload (pieces/turn Total Harvest Volume Topography (from even to broken) Slope Yarding Distance (500-1000 ft) Yarding Distance (>1000 ft) Stand Density (Trees/acre) Uphill Yarding Downhill Yarding Equipment (types & amount) Labor (Demand) Skill (Experience and Education Haul Distance (from Landing to Mill)

Utility Values for Yarding Distance and Direction

Utility Values for Three Silvicultural Systems

Application of the Study to a Cut-Block Design Utility values can be transformed into design criteria Cut-Blocks can be compared on a quantitative basis The relative merit of one design over another can be evaluated

Applying the Utility Values to Three Cable Settings

The Setting Utility for Three Cable Settings for a Clearcut Scenario

Applying the Utility Values to Three Cable Settings

Comparing Three Clearcut Units

Comparing Three Cable Units with Different Silvicultural Systems

Conclusions Market Research Technology is an Important Tool to Bring Psychometric Data into the Forest Engineering Field Through Market Research, Human Factors can be Brought into the Cut-Block Design - Loggers’ Perceptions about Cut-Block Layout

Conclusions Loggers’ Perception about Cut-Block Layout is an important Step in Understanding the Implications of Alternative Silvicultural Systems on Harvest Costs and Productivity