Today on the Mushroom Hour Podcast we are honored to be joined by Geoff Williams PhD, International Sentinel Network Coordinator for the US Forest Service. Geoff studies the social dimensions and microbial ecology of host range expansions and geographic range expansions of forest trees, their fungal pathogens, and their insect herbivores. Geoff just moved to Oregon from West Lafayette, Indiana where he studied the role of the microbiome in Thousand Cankers Disease of Eastern black walnut in the Department of Forestry and Natural Resources at Purdue University. Prior to that he has worked and lived in Idaho, Arizona, Mexico, and Chicago, originally hailing Ann Arbor, Michigan. In his current position he is gathering information on forest insects and pathogens across the world. The ultimate goal is to build networks of cooperation and information exchange with international collaborators to help protect native forest tree species in the US and all over the world from the next highly destructive or devastating insect or fungal pathogen that could be introduced through trade and travel. The opinions expressed by Geoff in our show to do not represent policy stances of the US government.    TOPICS COVERED:    A Winding Path towards Forest Pathology   Fungal Phytopathogens   Community Assembly in Forest Ecosystems   Novel Pathogenic Interactions in the Age of the Anthropocene   Proactive Approach to Managing Forest Pathogens   Complex Social Impacts of Forest Pathogens    Interconnectedness of Forest Ecosystems Across Continents    Global Forest Health Crisis   Interplay of International Trade Agreements & Natural Resource Protections   Sentinel Tree Network   Urban Forest Management   “Invasive Species” & Invasion Biology Framework   Invasive Species vs Invasive Populations   Citizen Scientist Role in Monitoring Forest Pathogens   EPISODE RESOURCES:    Geoffrey Williams Website: https://geoffreymwilliams.weebly.com/   Thousand Cankers Disease: https://www.aphis.usda.gov/aphis/ourfocus/planthealth/plant-pest-and-disease-programs/pests-and-diseases/thousand-cankers-disease/thousand-cankers-disease   Geosmithia morbida (fungal pathogen): https://en.wikipedia.org/wiki/Geosmithia_morbida   Juglans nigra (Eastern Black Walnut): https://en.wikipedia.org/wiki/Juglans_nigra   Laurel Wilt Disease: https://www.fdacs.gov/Agriculture-Industry/Pests-and-Diseases/Plant-Pests-and-Diseases/Laurel-Wilt-Disease   Sentinel Trees: https://link.springer.com/article/10.1007/s10340-018-1041-6   Cortinarius violaceus: https://en.wikipedia.org/wiki/Cortinarius_violaceus