Characterizing Heterobasidion Root Disease in 3D

Presenter: Alexander Flores

Presenter Status: Graduate student

Academic Year: 22-23

Semester: Spring

Faculty Mentor: Lisa Bentley

Department: Biology

Abstract:
As climate change increases abiotic stress on forest ecosystems, biotic threats such as root diseases can capitalize on weakened trees. Heterobasidion is a fungus native to California and has changed from a saprotrophic decomposer to a root disease because of drought stress. This study aims to characterize the structural effects of Heterobasidion on Sierra Nevada mixed conifer forests. Using laser point cloud modelling, we will characterize forest structure via measurements of the horizontal and vertical distribution of aboveground biomass and forest heterogeneity. These measurements will occur in 20 circular plots (approximately 4,000 m2) in the Plumas National Forest in northern California during July 2023. Ten plots have been infected by Heterobasidion for the past 50 years, while 10 plots are located outside of these infected areas (control). Since this disease spreads from a central origin, we expect to find a pattern of increasing vertical biomass and decreasing horizontal biomass as radial distance from plot center increases. We also expect heterogeneity to increase farther from the plot center, since the plot perimeters maintain healthy forest structure and composition. Our findings will quantify Heterobasidion associated changes in distribution of aboveground biomass, thus informing their management as areas of long term disturbance.