Good Forestry in the Granite State: Recommended Voluntary Forest Management Practices for New Hampshire
Good Forestry in the Granite State:
Recommended Voluntary Forest Management Practices for New Hampshire

5.4 LOGGING DAMAGE

BACKGROUND

Excessive damage to residual trees during a timber harvest can negate the intended benefits of forest improvement operations.

Activities associated with felling, winching, and skidding can damage 20 to 40 percent of the residual trees (trees left behind).

Young trees may be bent or broken during felling or crushed by harvesting equipment. Branches and tops of residual trees may be broken during felling, reducing crown area and eventually tree vigor. Valuable lower trunks of larger trees may be wounded, allowing entry of fungi or insects that cause wood discoloration and decay. Injuries resulting in exposed sapwood wounds of 100 square inches or greater are likely to develop decay. Approximately 80 percent of skidding injuries are from bark scraped from the butt log of residual trees.

Skidding can cause root damage, allowing entry of rot-causing microorganisms. Repeated passes of heavy equipment over certain types of soils, especially during wet conditions, can compact soil air spaces, impeding root growth. Most healthy forest soils maintain about 50 percent solids, 25 percent air space and 25 percent water by volume. When these ratios change through compaction, roots are damaged and their growth restricted, erosion and run-off increase due to decreased permeability, and changes in soil temperature and microbial action disrupt soil nutrient cycling.

Logging may also combine with other stress factors to make individual trees (and eventually entire stands) more susceptible to dieback. Poor vigor invites attacks by insect pests and diseases. Also, though a stand may not be physically damaged, removing trees may reduce the stand's ability to withstand wind.

OBJECTIVE

Control and minimize logging damage to residual trees, and reduce the total area of soil compacted during harvest operations.

CONSIDERATIONS

RECOMMENDED PRACTICES

CROSS REFERENCES

2.3 Regeneration Methods; 3.1 Timber Harvesting Systems; 3.2 Logging Aesthetics; 3.3 Aesthetics of Skid Trails, Truck Roads and Landings; 3.5 Soil Productivity; 5.1 Insects, Diseases.

ADDITIONAL INFORMATION

Bennett, K. P. (tech. coordinator). 2001. Proceedings of Residual Stand Damage Workshop. UNH Cooperative Extension. http://extension.unh.edu/resources/files/Resource000410_Rep432.pdf Accessed March 11, 2010.