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Type: Journal Article
Author(s): James D. McIver; Paul W. Adams; J. A. Doyal; Erik S. Drews; Bruce R. Hartsough; L. D. Kellogg; Christine G. Niwa; Roger D. Ottmar; R. W. Peck; M. Taratoot; Torolf Torgersen; Andrew P. Youngblood
Publication Date: 2003

ANNOTATION: Fuel reduction by mechanical thinning and removal was studied in mixed-conifer stands in northeastern Oregon. A single-grip harvester was coupled with either a forwarder or a skyline yarding system, and operational economics, fuel reduction, stand damage, soil disturbance, effects on soil biota and down-woody material were measured. ABSTRACT: Fuel reduction by mechanical thinning and removal was studied in mixed-conifer stands in northeastern Oregon between 1995 and 1997. A single-grip harvester was coupled with either a forwarder or a skyline yarding system, and operational economics, fuel reduction, stand damage, soil disturbance, effects on soil biota and down-woody material were measured in three replicates of paired stands. After logging with the harvester, the two log-extraction systems achieved nearly equivalent fuel reduction with 45.7 and 46.8% mass reduction by the forwarder and skyline system, respectively. Fine-woody fuel increased slightly in all units, but mass of heavy fuels decreased. Most mass reduction in the forest floor occurred in the duff layer with 56 and 49% reduction in forwarder and skyline units, respectively. Reduction in stem density and basal area were similar for the two extraction systems; in forwarder units stem density was reduced by 61.6% and basal area by 55.4%, while in skyline units stem density was reduced by 66.5% and basal area by 51.1%. Of seedlings and trees examined, 32% had noticeable damage after harvest. Damage included bole wounding (38.9% of damaged stems), bark scraping (35.0%), wrenched stems (28.9%), broken branches (26.5%), broken terminal leaders (15.4%), and crushed foliage (4.1%). More damage occurred to residual large trees than to seedlings. Both log-extraction systems met the silvicultural prescription of reducing fuel and protecting residual large-diameter western larch, Engelmann spruce, Douglas-fir, and lodgepole pine. While fuel, stem, and basal area reduction lowered fire risk from a model 10 to a model 8 in all stands, large-woody material for wildlife also changed. Mean log length was lower in harvested units relative to unharvested controls, but this did not decrease occupation of logs by ants or the activities of woodpeckers feeding on them. Of 37 logged hectares, 1.4% (0.5 ha) of the soil area was compacted, mostly in forwarder units, within landings, and within trails close to landings. The percent area with displaced soil varied from 5 to 43% among units and was located within trails or in intertrail areas between the trails. Light displacement of soil resulted in a short-term increase in the abundance of soil microarthropods. The effects of compaction on litter microarthropods was more persistent, with lower numbers in compacted litter a year after harvest. While revenue was similar for forwarder and skyline units ($68 vs. $70/metric ton, respectively), total operational costs were $81/metric ton in the skyline units, compared to $46/metric ton in the forwarder units. These results are discussed in the context of options available to managers for balancing fuel reduction needs with both environmental and economic constraints.

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Citation: McIver, James D.; Adams, Paul W.; Doyal, J.A.; Drews, Erik S.; Hartsough, Bruce R.; Kellogg, L.D.; Niwa, Christine G.; Ottmar, Roger D.; Peck, R.W.; Taratoot, M.; Torgersen, Torolf; Youngblood, Andrew P. 2003. Environmental effects and economics of mechanized logging for fuel reduction in northeastern Oregon mixed-conifer stands. Western Journal of Applied Forestry 18(4):238-249.

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Keywords:
  • Abies grandis
  • Abies lasiocarpa
  • bark
  • Camponotus spp.
  • coniferous forests
  • conifers
  • diameter classes
  • disturbance
  • Douglas-fir
  • Dryocopus pileatus
  • duff
  • fine fuels
  • fire frequency
  • fire hazard reduction
  • fire intensity
  • fire management
  • fire risk reduction
  • foliage
  • forage
  • forest management
  • Formicidae
  • fuel accumulation
  • fuel management
  • fuel treatments
  • fungi
  • habits and behavior
  • heavy fuels
  • insects
  • Larix occidentalis
  • light
  • litter
  • logging
  • nongame birds
  • Oregon
  • Picea engelmannii
  • Pinus contorta
  • population density
  • Pseudotsuga menziesii
  • seedlings
  • site treatments
  • skyline yarding
  • snags
  • soil compaction
  • soils
  • stand characteristics
  • surface fires
  • thinning
  • trees
  • understory vegetation
  • Vaccinium scoparium
  • wildfires
  • wildlife
  • wildlife habitat management
  • woody fuels
  • woody plants
  • xeric soils
Tall Timbers Record Number: 16673Location Status: In-fileCall Number: Fire FileAbstract Status: Okay, Fair use, Reproduced by permission
Record Last Modified:
Record Maintained By: FRAMES Staff (https://www.frames.gov/contact)
FRAMES Record Number: 4654

This bibliographic record was either created or modified by Tall Timbers and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of Tall Timbers.