Posy Busby

Post-doctoral Associate

I am an NSF Postdoctoral Fellow in Science, Engineering and Education for Sustainability, in the Biology Department (Tewksbury lab) at the University of Washington, and I am also in the Department of Forest, Rangeland and Fire Sciences, at the University of Idaho.  I work on plant and forest disease, insect herbivory, and microbial communities. My current research seeks to characterize the microbial communities that live in trees as well as to test how these microbes influence forest health. For more about what I am up to, check out my website.

Here is a bit about the projects I am working on:

The role of fungal leaf endophytes in plant defense.

Potential, though not well understood, factors influencing forest pests and pathogens are the microbial communities of fungi and bacteria that live within plants (i.e., the plant microbiome). My research takes advantage of state-of-the-art genetic tools to characterize these communities and to test their role in plant defense. My current research focuses on fungal leaf endophyte communities of Populus trichocarpa, the black cottonwood of the Pacific Northwest, and its major foliar disease – Melampsora rust.

Collaborators: George Newcombe

Naupaka Zimmerman

DOE Plant-Microbe Interfaces Group


Geographic variation in plant-endophyte-pathogen interactions.

Skagit River, Washington

The abiotic and biotic factors influencing the outcome of species interactions vary across space. I am currently addressing how geographic variation in tripartite interactions among fungal leaf endophytes, Melampsora rust, and Populus trichocarpa influence range-wide patterns in disease.

Collaborators: George Newcombe

Josh Tewksbury

Kabir Peay


Interdisciplinary research on plant microbes for sustainable bioenergy.

Poplar plantation

Plant microbes could potentially be used to reduce disease in plantation systems. I am conducting an assessment of the environmental, economic and social costs and benefits of using endophytes in feedstock production for bioenergy.

see press

Collaborators: GreenWood Resources

Advanced Hardwood Biofuels Northwest

Luc Hoffman Institute at WWF


Integrating pest and pathogen disturbances into models of tree population dynamics.

Tree infected with beech bark disease

Pest and pathogen disturbances are major drivers of forest structure and function that are expected to intensify with climate change. My research integrates pests and pathogens into a modeling framework that encompasses the full range of factors affecting forest dynamics (e.g., climate change, forest cutting, wind, fire) to better understand their effects on forests at regional and continental scales. I am currently focusing on beech bark disease, an exotic scale-fungus complex, affecting eastern deciduous forests.

Collaborators: Charles Canham