Assessing the Risks of a Changing Climate to Forest Management

Monthly and daily climate change time series allow assessing the frequency of occurrence of events that could affect forests. Southern British Columbia, Canada is projected to see increases in temperature of 2 to 4°C in all seasons and precipitation increase winter of 5 to 15% and a decrease in summer of 10 to 20%. Changes in daily extreme precipitation events, snow accumulation and melt and summer fire conditions were evaluated for increase in risk to forest infrastructure. The 80 km long In-SHUCK-ch forest service road runs by the Lillooet River and is surrounded by mountains up to 2000 m in elevation. Risks to road infrastructure and to a 20 km wide forested area either side of the road were evaluated for impacts of a changing climate. The 20-year return extreme maximum temperature for the area is projected to increase to 4±2°C by 2050s and 7±2°C in 2080s under rcp 8.5. The 20-year return 1- and 3-day annual maximum precipitation is projected to increase by 20 to 50% by 2050s. Increases in extreme precipitation will result in a need for larger stream crossings (culverts and bridges), and along with changes in freeze/thaw conditions and snow cover this will affect road surface maintenance. There will also be an increase in the risk of landslides and debris flows. An increase in fall and winter precipitation will not be sufficient to offset the effect of warming on the winter snow regime. A shorter snow season along with warmer summers and reduced precipitation result in an increase in the risk of forest fire. Warmer and dry weather will increase the frequency of drought stress conditions which will affect forest growth and likely increase the risk to insect infestations. By the 2080s, the current forest ecosystems will be exposed to climate conditions well outside of their current range.