Bioclimatic modeling of Armillaria altimontana in western North America

Abstract

Relatively little is known about the ecology and distribution of Armillaria altimontana compared with some other Armillaria species in North America. After first being recognized as an unnamed North American Biological Species X based on mating tests (Anderson and Ullrich 1979), A. altimontana was subsequently formally described by Brazee et al. (2012). While A. altimontana is occasionally found as a pathogen causing Armillaria root disease, it is often only found in a saprophytic state as rhizomorphs on diverse coniferous and broad-leaved trees and shrubs. A previous study suggests that A. altimontana found in this saprophytic state may also function as an in situ biological control agent for Armillaria root disease caused by A. solidipes (Warwell et al. 2019). Subsequent studies have compared the A. solidipes and A. altimontana genomes and their associated soil microbiomes (microbial communities) to gain insights into their ecological functions (Ibarra Caballero et al. 2023). Armillaria altimontana occurs widely across the northwestern USA to southern British Columbia, Canada (Figure 1A). Efforts are underway to better understand the ecology and distribution of A. altimontana. Recently, bioclimatic modeling using MaxEnt (Maximum Entropy) have been used to model suitable climate for forest pathogens and their hosts (e.g., Klopfenstein et al. 2009, Stewart et al. 2017, Hanna et al. 2020, Kim et al. 2021, Kim et al. 2023). These models can be projected for different future time periods, using a combination of emissions scenarios and global circulation models, to predict suitable habitat (potential distribution) for a species under future-climate scenarios. Such information provides valuable insights into geographic regions where A. altimontana is predicted to potentially occur under various climate scenarios, which can guide forest management in decisions to promote desirable outcomes for forest ecosystems in the future.

Citation

Hanna, John W.; Kim, Mee-Sook; Bennett, Patrick I.; McDonald, Geral I.; Klopfenstein, Ned B. 2024. Bioclimatic modeling of Armillaria altimontana in western North America. In: Brooks, Rachel K., compiler. Proceedings of the 68th Western International Forest Disease Work Conference; 5-9 June 2023; Rohnert Park, CA. Online: https://www.wifdwc.org. p. 161-167.