Photo Courtesy of Brian J. Harvey
After a single disturbance, these non-pine trees are surviving and doing well.

Two School of Environmental and Forest Sciences professors received grant funding from the National Science Foundation (NSF) for a project with the Washington Department of Natural Resources (DNR).

Assistant professor Brian J. Harvey and associate professor Patrick Tobin, along with two other professors from other institutions and the Washington DNR, will study spatiotemporal interactions among biotic disturbance agents, biological legacies and compensatory responses as it relates to forest resilience. Harvey is the lead principal investigator (PI).

Harvey describes the project this way:

“In brief, we are examining how multiple forest disturbances (e.g., insect outbreaks, pathogens) are interacting and how those interacting disturbances affect forest resilience (or the capacity to recover). Increased rates of disturbances and interactions among multiple disturbances have been documented across western North America in the last few decades, but there are still many unknowns about all the mechanisms that lead to these interactions, and how forests will recover following multiple disturbances.

“Our project will include long-term measurements from permanent plots that date back to the 1940s where there have been multiple episodes of tree mortality, and we will be integrating these field measurements with satellite imagery and other remote sensing data.

“Ultimately, we are interested in tracking what we are calling ‘hotspots’ of disturbance activity (i.e., areas that are experiencing multiple disturbances in short succession) and how forests are recovering from disturbance in those hotspots. You see, forests can sometimes be like the old arcade game of whack-a-mole, in that when one tree dies (i.e., gets whacked) from a bark beetle outbreak, neighboring trees of a different species (that are not susceptible to that bark beetle from the other host tree) typically experience robust growth from the new access to resources left by their dead neighboring trees. Historical evidence shows that there are negative feedbacks among these types of disturbances, at least over short time periods. For example, it is pretty rare historically to have a beetle outbreak where there was already an outbreak in the previous few decades.

“However, we’re seeing in many places that trees within a forest that are of different species are dying from different biotic disturbance agents (e.g., bark beetles, pathogens) at around the same time, leading to a ‘whack-a-mole’ analogy of multiple mallets whacking a bunch of different moles at once. Uncovering the mechanisms behind these patterns, as well as how forests will respond from these multiple disturbances, is critical to our understanding of how these systems work and how we can effectively manage them as the world is changing around them.”