Logging

For other uses, see Log.

A gum tree (eucalyptus) being felled. Dated to c. 1884-1917, Australia.

Logging is the process in which certain trees are cut down for forest management and timber.

In forestry the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard. In common usage however the term may be used to indicate a range of forestry or silviculture activities. For example the practice of the removal of valuable trees from the forest has been called selective logging, sometimes confused with selection cut.

Illegal logging refers to what in forestry might be called timber theft.

In common usage what is sometimes called clearcut logging is not is necessarily considered a type of logging but a harvest or silviculture method and is simply called clearcutting or block cutting. In the forest products industry logging companies may be referred as logging contractors.

Logging usually refers to above-ground forestry logging. Submerged forests exist on land that has been flooded by damming to create reservoirs. Such trees are logged using underwater logging or by the lowering of the reservoirs in question. Ootsa Lake and Williston Lake in British Columbia, Canada, are notable examples where timber recovery has been needed to remove inundated forests.

Logging methods

The Washington Iron Works Skidder in Nuniong is the only one of its kind in Australia, with donkey engine, spars and cables still rigged for work.

The above operations can be carried out by different methods, of which the following three are considered industrial methods:

Tree-length logging

Trees are felled and then delimbed and topped at the stump. The log is then transported to the landing, where it is bucked and loaded on a truck. This leaves the slash (and the nutrients it contains) in the cut area where it must be further treated if wildland fires are of concern.

Full-tree logging

Horse logging in Poland

Trees and plants are felled and transported to the roadside with top and limbs intact. The trees are then delimbed, topped, and bucked at the landing. This method requires that slash be treated at the landing. In areas with access to cogeneration facilities, the slash can be chipped and used for the production of clean electricity or heat. Full-tree harvesting also refers to utilization of the entire tree including branches and tops. This technique removes both nutrients and soil cover from the site and so can be harmful to the long term health of the area if no further action is taken, however, depending on the species, many of the limbs are often broken off in handling so the end result may not be as different from tree-length logging as it might seem.

Cut-to-length logging

Modern excavator fit up with forestry attachment

Cut-to-length logging is the process of felling, delimbing, bucking and sorting (pulpwood, sawlog, etc.) at the stump area, leaving limbs and tops in the forest. Harvesters fell the tree, delimb and buck it, and place the resulting logs in bunks to be brought to the landing by a skidder or forwarder. This method is usable for smaller timber on ground flat enough that forwarders can operate, but does not work well on steep slopes.

Transporting logs

Logging operations in Buffalo City, North Carolina

Felled logs are then generally transported to a sawmill to be cut into timber, a paper mill for paper pulp, or for other purposes like fence posts. Log transportation can be challenging and costly since trees are often far from navigable roads. Road building and maintenance may be restricted in National Forests or other wilderness areas since it can cause erosion in riparian zones. When felled logs sit adjacent to a road, heavy machinery may simply lift logs into trucks. Many methods exist to transport felled logs lying away from roads. Cable logging involves a yarder which pulls one or several logs along the ground to platform where a truck is waiting. When the terrain is too uneven to pull logs on the ground, a skyline can lift logs off the ground vertically, similar to a ski lift. Heavy-lift helicopters, such as the CH-47 Chinook or Kaman K-MAX, may be used when cable logging is not allowed due to environmental concerns or when roads are lacking. Helicopters are the most expensive form of log transport. Less mainstream forms of log transport, or methods used previously include horses, oxen, or balloon logging.We can try this..

Safety considerations

Computerized log cutting with heavy machinery increases capital costs, yield and productivity, but improves personnel safety.

Logging is a dangerous occupation. In the United States, it has consistently been one of the most hazardous industries, having a fatality rate over 21 times higher than the rate for all workers. Loggers work with heavy, moving weights and the use of tools such as chainsaws and heavy equipment on uneven and sometimes unstable terrain. Loggers also deal with severe environmental conditions, such as inclement weather and severe heat or cold. An injured logger is often far from professional emergency treatment.

Traditionally, the cry of "Timber!" developed as a warning alerting fellow workers in an area that a tree is being felled, so they should be alert to avoid being struck. The term "widowmaker" for timber that is neither standing nor fallen to the ground demonstrates another emphasis on situational awareness as a safety principle.

The risks experienced in logging operations can be somewhat reduced, where conditions permit, by the use of mechanical tree harvesters, skidders and forwarders.

See also

• Deforestation
• Log scaler
• Logging wheels
• Salvage logging
• Shovel logging
• Sierra Nevada logging
• Skyline logging
• World Forestry Congress (WFC)
• World Logging Championship

References

Sources

• Costa, F., & Magnusson, W. (2002). Selective logging effects on abundance, diversity, and composition of tropical understory herbs. Ecological Applications, 12, 807-819.
• Pinard, M. A., & Putz, F. E. (1996). Retaining forest biomass by reducing logging damage. Biotropica, 28, 278-295.
• Shukla, J., Sellers, P., & Nobre, C. (1990). Amazon deforestation and climate change. Science, 247, 1322-1325.
• Sokal, R. R., Gurevitch, J., & Brown, K. A. (2004). Long-term impacts of logging on forest diversity in Madagascar. Proceedings of the National Academy of Sciences of the United States of America, 101, 6045-6049.
• Putz, F., Sist, P., & Frederickson, T. (2008). Reduced-impact logging: challenges and opportunities [Abstract]. Forest Ecology & Management, 256, 1427-1433.

External links

• National Institute for Occupational Safety and Health — Logging safety