What is it?
Natural Resources Canada defines sustainable forest management as a way of using and caring for forests so as to maintain their environmental, social and economic values and benefits over time.
In Alberta, timber is a valuable resource and the forestry industry is centred on harvesting trees for timber. But forests and their trees deliver extremely valuable water quality services, including slowing down water flows during rain events. Tree roots also hold soil in place, protecting soil from the crumbling and eroding effects of wind and rain.
Because forests perform valuable water quality functions, logging activities can result in negative water quality impacts. Sustainable forest management is therefore, in part, about minimizing negative impacts on water quality through the appropriate harvesting and planting of trees (forest resources).
How does forest management impact water quality in the Bow River Basin?
During a rain event, areas that have been harvested for timber usually experience higher runoff volumes traveling downstream at a faster rate. The result: higher flows in creeks and rivers and an increased potential for erosion.
Clear-cut logging and using heavy equipment to harvest trees can disturb the topsoil and undergrowth of a forest, resulting in sediment flowing into streams. Exposed soil can also release natural chemicals, nutrients and metals (e.g., mercury), which can contaminate water.
Removing trees, especially from a riparian area or wetland, may impair that area’s ability to hold sediment in place, and can capture and remove some sediment and contaminants already in the water. When these functions are impaired, water quality decreases.
Like the agriculture sector, the forestry sector uses Best Management Practices (BMPs) that are designed to reduce negative water quality impacts.
What can we do about it?
Reducing the damage to the soil, regenerating the forest quickly, and not harvesting on slopes or near water bodies are all good forest management practices.
Some of the most important forest management BMPs include selection of access road locations to reduce potential for erosion and soil disturbance, implementing a well-designed road drainage system that reduces erosion and sediment delivery to streams, installation and maintenance of silt screens or fences, and conducting selective harvesting.
Where can I find more information?
Food and Agriculture Organization of the United Nations. Forests and water quality. Retrieved from: http://www.fao.org/docrep/011/i0410e/i0410e04.pdf
Holaday, S., Wagner, C. (2010). Field manual for loggers, landowners, and land managers. Wisconsin Department of Natural Resources. Retrieved from: http://dnr.wi.gov/topic/forestmanagement/documents/pub/fr-093.pdf
Pike, R., Feller, M., Stednick, J., Rieberger, K., Carver, M. Water quality and forest management. Retrieved from: https://www.for.gov.bc.ca/hfd/pubs/docs/lmh/Lmh66/Lmh66_ch12.pdf
Government of Canada. (2016, July 1). Water pollution: erosion and sedimentation. Retrieved from: https://www.ec.gc.ca/eau-water/default.asp?lang=En&n=32121A74-1#reason4
Regional Aquatics Monitoring Program. Potential effects of forestry on aquatic ecosystems. Retrieved from: http://www.ramp-alberta.org/resources/forestry/potential+effects.aspx
McLellan, B. (2016, Oct. 24). Impact of forest harvest. Alberta Agriculture and Forestry. Retrieved from: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/apa3317