| Abstract/Description or Keywords |
British Columbia is currently experiencing a mountain pine beetle epidemic that threatens to kill 80% of the province's commercial lodgepole pine by 2013. To recover the greatest economic value from the dead trees before they burn or decay, the province has accelerated harvest in affected areas. Accelerated harvesting has the potential to influence other forest values such as stream and riparian function, especially when riparian timber is removed. The Forest and Range Practices Act currently allows for harvesting in the riparian zone as an approved activity in a forest stewardship plan (FSP) or under the Forest Planning and Practices Regulation (FPPR) s.51(f) for the purposes of sanitation or s.51(g) to control damage by insects as long as it will not have a material adverse impact on the riparian zone. The riparian zone is a sensitive ecotone that serves many functions, such as erosion and runoff control, protection of water quality, provision of shade and litterfall for aquatic biota, and habitat for wildlife. To gain some understanding of future conditions of riparian zones and streams in MPB salvage areas, the Bowron Watershed was used as a surrogate to identify the current condition of stream and riparian zones 20-30 years after large scale salvage harvesting. In 1975, a spruce bark beetle outbreak occurred in the Bowron River watershed. In response to the infestation, large scale salvage operations were initiated to control the spread of the beetle and recover economic value from infected timber before it burned or decayed. By the time harvesting slowed down in the mid-1980s, approximately 25% of the Bowron watershed was logged, equivalent to 90000 hectares. Harvest activity was most extensive in the upper Bowron, removing 30% of the timber and producing a 50000-ha clearcut. Harvesting was also extensive in the middle and lower Bowron but occurred at a slower rate. During peak harvest, approximately 700 loads of logs were removed from the Bowron every day. Many riparian areas of small and mid-sized streams were completely harvested (Figures 1 and 2). To identify the potential impact of today's mountain pine beetle infestation and large-scale salvage operations on streams and their riparian zones, present levels of ecologic function in the Bowron River watershed more than 25 years after harvesting was determined using the Routine Riparian Effectiveness Evaluation (RREE- FREP). The RREE was used to assess the current condition of streams and riparian areas in 35 basins within the Bowron River watershed. Findings were then used to identify best management practices to protect stream and riparian functions in mountain pine beetle-infested areas. The Bowron Watershed study was initiated to identify the forest management activities that place streams and their riparian areas at risk, as well as identify how they recover following extensive salvage harvesting. The project identifies potential stream and riparian effects due to accelerated harvesting practices that include riparian zones and identifies best management options to maintain stream and riparian function. The principal objectives of this study were: to use the Routine Riparian Management Effectiveness Evaluation (RREE) to evaluate the current condition of streams and riparian areas in the most intensively harvested sub-basins of the Bowron River watershed that were identified during a 1994-1996 interior watershed assessment process (IWAP); to use both evaluations to assess stream and riparian recovery over time in the Bowron River watershed; and to propose best management practices to protect stream and riparian functions in mountain pine beetle-infested areas. |
