Climate change can increase the risk of mountain pine beetle outbreaks in western Canada

Transcription

1 Climate change can increase the risk of mountain pine beetle outbreaks in western Canada DPW Huber Kishan R. Sambaraju 1, Allan L. Carroll 2, Jun Zhu 3, and Brian H. Aukema 1, 4 Presentation to UNBC Forest Insect Research Group 1 University of Northern British Columbia, Prince George, BC, Canada; 2 Department of Forest Sciences, University of British Columbia, Vancouver, BC, Canada; 3 Department of Statistics, Colorado State University, Fort Collins, CO, USA; 4 Natural Resources Canada-Canadian Forest Service, Pacific Forestry Centre, Prince George, BC, Canada

2 Mountain pine beetle Major tree-killing bark beetle in North America (Photo credit: Brytten Steed, USDA Forest Service, Bugwood.org) Tree death occurs due to beetle mass attack mediated through an aggregation pheromone ( red( attack ) Under suitable temperature regimes and host availability, landscape-scale scale population eruptions occur (Photo credit: William Ciesla, Forest Health Management International, Bugwood.org)

3 e.g. High-quality host trees and conducive temperatures facilitated the largest recorded beetle outbreak in British Columbia, Canada Annual area (ha x 10 6 ) of mortality Year Kilometers British Columbia Prince George Vancouver Victoria Kelowna Alberta WA ID MT Range expansion into the boreal pine forests of north-western Alberta

4 Temperature and mountain pine beetle ecology Temperature affects: Rate of beetle development Phenology and univoltine life cycle Synchronicity of spatially patchy populations Initiation/collapse/range expansion of outbreaking populations

5 Projected Climate Change Source: IPCC AR4 (2007)

6 Specific Objective Study the potential outbreak patterns of the mountain pine beetle under simulated climate change and climatic variability scenarios using a landscape-level level autologistic model

7 Study area N Yukon Northwest territories British Columbia Alberta Saskatchewan

8 Model Development N British Columbia Alberta Model P (Y=1 X) Temperature Degree days Spatial infestations Past infestations 1. Overlaid mountain pine beetle infestation data: Summer Temperature Winter Temperature Cold Snaps Temperature Drops Extreme min. thresholds 2. Merged temperature data 3. Developed an auto-logistic model through backward elimination

9 Climate Change Simulations Added random numbers (μ( = 0, 1, or 2ºC, 2 σ 2 = 1 or 2ºC2 2 ) to baseline daily temperature data Model run using the climate change data set; calculated predicted probability per grid cell Grouped predicted probabilities into risk categories Summary statistics

10 Conclusions Potential, new outbreak areas were mostly concentrated around infested neighbourhoods New outbreak areas included potential high-elevation regions along the Rocky mountains Cooler, northern latitudes may become climatically favourable due to climate change thus facilitating future mountain pine beetle outbreaks Manuscript in pre-submission review

11 Acknowledgements University of British Columbia, Vancouver, BC Kerstin Stahl and Dan Moore University of Northern British Columbia, Prince George, BC Honey-Marie Giroday and Ping Bai, GIS support Jordie Fraser, Dezene Huber Forest Insect Research Group (FIRG) Pacific Forestry Centre, Canadian Forest Service, Victoria, BC Gurp Thandi (forest cover data)

12 Contact Information Kishan R. Sambaraju University of Northern British Columbia 3333 University Way Prince George, BC V2N 4Z9 Phone: Funding Support: BC FSP Y103277