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Poster: Epidemiology: Climate Change


Potential species distributions of Armillaria solidipes and Pseudotsuga menziesii under contemporary and changing climates in the interior western USA
J. HANNA (1), M. Warwell (2), H. Maffei (3), M. Fairweather (4), J. Blodgett (5), P. Zambino (6), J. Worrall (7), K. Burns (8), J. Jacobs (9), S. Ashiglar (2), J. Lundquist (10), M. Kim (11), A. Ross-Davis (2), C. Hoffman (12), R. Mathiasen (12), R. Hofst

Pseudotsuga menziesii and Armillaria solidipes are native forest host/pathogen species of the interior western USA that have co-evolved over millions of years. Armillaria root disease caused by A. solidipes is a major limitation for growth, survival, and economic/environmental benefits of P. menziesii. Historically, A. solidipes played a beneficial ecological role by preferentially attacking maladapted trees. However, under increasing climate change, more forest trees will likely become progressively maladapted, leading to increased damage from Armillaria root disease. We developed species-distribution models using Maximum Entropy (MaxEnt) to predict area suitable for A. solidipes and P. menziesii under changing climatic conditions. We compared contemporary (1950-2000) predicted suitable climate for A. solidipes and P. menziesii versus year 2070 (2061-2080) predictions using the “business as usual” greenhouse gas-emissions pathway 8.5 (RCP8.5) paired with the HadGEM2-ES global circulation model. Our predictions of suitable climate for A. solidipes and P. menziesii are highly correlated, and the predicted suitable climate space moves dramatically northward for year 2070 under the RCP8.5 scenario. In many areas of the inland west, A. solidipes is predicted to persist under climate change, and it will likely cause major damage where maladapted forest trees remain.