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Percentage of annual harvest area with soil loss due to establishment of permanent access roads

Geographic Scale: 

“Permanent access structures include on-block roads, landings, gravel pits, borrow pits, quarries and permanent logging trails that are reasonably required for timber harvesting and other forest management activities. To be considered permanent they must satisfy either of the following two conditions:
• they will be required for a long enough time (either continuously or periodically) such that a commercial crop of trees could not be produced on the area they occupy by the time a commercial crop is established in the adjacent cutblock area; or
• they will be constructed through soil or rock that is not suitable (or will be composed of ballast or other material that is not suitable) for necessary soil rehabilitation treatments to grow a commercial crop of trees.
Permanent logging trails include any logging trail (including an excavated or bladed trail) that is specifically identified in an approved silviculture prescription as a permanent logging trail. These trails are required for repeated stand entries to carry out periodic harvesting of areas where partial cutting silvicultural systems or commercial thinning operations are prescribed. They will not be reforested or rehabilitated. However, they must be constructed and used in a manner that minimizes soil erosion and sediment delivery to streams” British Columbia Ministry of Forests (2001a)

“The proportion recorded in the prescription should be based on the maximum estimated amount of permanent access structures proposed for the cutblock. In most circumstances, permanent access structures should not occupy more than 7% of the total area under the prescription. Examples of circumstances that may warrant occupancy that exceeds 7% include small cutblocks containing main haul roads, cutblocks with a switchbacking haul road, and other cases where topography and engineering constraints limit the options for road location and development. Where the proportion specified is more than 7% of the area a rationale for the higher level of occupancy should be provided with the prescription” British Columbia Ministry of Forests (2001a)


“To facilitate forest management, part of the forest land base is permanently occupied by roads and other structures that provide access to the forest. Minimizing the amount of productive forest land occupied by these structures is an important objective of forest management” British Columbia Ministry of Forests (200a1)

“In areas with existing road networks, the determination of how much additional access may be required should reflect a commitment to minimizing the loss of growing site, and the conversion of productive forest land to no more than 7% of a watershed or forest development planning area” British Columbia Ministry of Forests (2001a)


Remote Sensing (aerial photography or satellite)

“Engineering and design specifications can be used to estimate and rationalize the area that will be occupied by the permanent access structures. When estimating the area that will be occupied by permanent access structures the width of the structures to be used will depend on what portion of the fill slope will be available for growing a future crop of commercial trees. Widths are measured as horizontal distances taken from the top of the cutslope… “(See page 4 of the Soil Conservation Guidebook for further details) British Columbia Ministry of Forests (2001a)


British Columbia's Forest and Range Evaluation Program (FREP) Soil Resource Stewardship Monitoring Indicator: "Percent of the cutblock area occupied by unproductive soil as a result of access construction"
The British Columbia Forest and Range Practices Act uses “The proportion of the total area under the prescription (gross cutblock area) to be occupied by permanent access structures should be determined on a site-specific basis.” British Columbia Ministry of Forests (2001a)
Government of British Columbia (2004) indicators and measures

Uncertainties/Research Needs: 

“Although the indicator represents a key element of healthy ecosystems (soil sustainability), it is only meaningful at the ecosystem level, needs to be considered over time, and cannot be taken by itself as a sufficient indicator of sustainability. The Ministry will present more comprehensive information in a "State of the Forests" report published periodically.” British Columbia Ministry of Forests (2004)

There is no defined threshold for the amount of harvested land that can be lost to permanent access structures, as this will vary with terrain. Most losses are associated with road building, and the minimization of roads, and the rehabilitation of roads after harvesting, will reduce losses. However, road access may be an important social value to forested areas, facilitating recreation, hunting and other activities.

Further Reading: 

Adams, M. B. , Ramakrishna, K. , Davidson, E. A. 1998. The contribution of soil science to the development of and implementation of criteria and indicators of sustainable forest management. Proceedings of a symposium sponsored by the S-7 and S-11 divisions of the Soil Science Society of America, the United States Department of Agriculture Forest Service Northeastern Forest Experiment Station, and the Woods Hole Research Center; October 31 1995, St. Louis, MO, pp. xvii-156.

O’Neill, K.P., Amacher, M.C., and Palmer, C.J. 2004. Developing a national indicator of soil quality on U.S. forestlands: methods and initial results. Environmental Monitoring and Assessment. 107: 59-80.

Rab, M.A. 1999. Measures and operating standards for assessing Montreal process soil sustainability indicators with reference to Victorian Central Highlands forest, southeastern Australia. Forest Ecology and Management 117(1-3):53-73.

Raison, R.J., and Khanna, P.K. (1995). Sustainability of forest soil fertility: Some proposed indicators and monitoring considerations [abstract]. In: Richardson B., Skinner, M.F., West, G. (eds.).1999. Forest Ecology and Management 122: 125-137.

Ruf, A., Beck, L., Dreher, P., Hund-Rinke, K., Rombke, J., and Splenda, J. 2003. A biological classification concept for the assessment of soil quality: “biological soil classification scheme” (BBSK). Agriculture Ecosystems & Environment 98: 263-271.


This will be addressed in the Ministry of Forests and Range “State of the Forests Report” in the future. Government of British Columbia (2004a)