Shovel logging and soil compaction : a case study

Graduation date: 1988Shovel logging is a relatively new ground-based method\ud of yarding tinther. It involves moving logs from stump\ud to landing by successive swinging with a hydraulic\ud excavator modified into a log loader by replacing the\ud shovel bucket with a grapple. Loaders used in shovel\ud yarding can weigh in excess of 100,000 pounds so that\ud the opportunity for soil compaction is great.\ud This study measured the amount of soil compaction\ud that occurs with shovel yarding. The study was done on\ud the Quinault District of the Olympic N.F. in Washington\ud state. The results show that 20.5% of the total area\ud logged consisted of shovel paths. Soil bulk densities\ud in the shovel tracks when compared to undisturbed areas\ud within the unit showed a statistically significant\ud increase of about 7.5%. Soil compaction did not seem to\ud increase after the initial pass up to seven passes.\ud Production rate for the shovel was 7.8 net\ud inbf/hour. Logging with the shovel cost $18.57/inbf less\ud than yarding the same unit with a Washington 208\ud slackline yarder.\ud Three methods of economically analyzing the\ud effects of soil compaction were reviewed and the idea\ud that the value of soil compaction involves more than\ud just the dollar value lost due to future decreased\ud timber production was proposed. Values such as\ud existence value, option value and quasi-option value\ud need to also be considered in any decision allowing soil\ud compaction to occur