Poster Session II
Project Type
Poster
Faculty Mentor’s Full Name
Scott Ferrenberg
Faculty Mentor’s Department
Ecosystem and Conservation Sciences
Additional Mentor
Gibson Blankenship, Isabella Smith
Abstract / Artist's Statement
Conifers use oleoresin, produced and stored in a network of resin ducts, as a primary source of defense against insects and pathogens. Analyses have shown that trees with a greater number, size, or total area of resin ducts are more likely to resist or survive insect attacks. Fuel reduction treatments, primarily done with the intention of suppressing the likelihood of high-severity fire and restoring fire-adapted landscapes, can increase the availability of limiting resources to residual trees by reducing competition. In ponderosa pine (Pinus ponderosa), increases in resource availability have been associated with an increased production of larger or more abundant resin ducts. How different fuel treatments affect resin duct production is poorly understood, and a better understanding would be useful to influence management decisions to improve resilience to insect attack. To analyze the impacts of fuel treatments on resin production, increment cores with visible resin ducts embedded in annual xylem rings were taken from 36 ponderosa pines involved in the Fire and Fire-Surrogate (FFS) study at Lubrecht Experimental Forest. The FFS study applies three different fuel treatments: thinning, burning, and thinning followed by burning, and compares them to an untreated control. The abundance and area of annually produced resin ducts were measured from 1990-2025, encompassing the treatments which occurred twice, in 2001-2002, and in 2023-2024. Dendrochronological records allow changes in resin duct production to be measured and associated with treatment. Trees in the Thinned and Burned plots showed the greatest post-treatments level of resin duct production.
Category
Life Sciences
Examining Tree Defense Responses to Fuel Reduction Treatments
UC South Ballroom
Conifers use oleoresin, produced and stored in a network of resin ducts, as a primary source of defense against insects and pathogens. Analyses have shown that trees with a greater number, size, or total area of resin ducts are more likely to resist or survive insect attacks. Fuel reduction treatments, primarily done with the intention of suppressing the likelihood of high-severity fire and restoring fire-adapted landscapes, can increase the availability of limiting resources to residual trees by reducing competition. In ponderosa pine (Pinus ponderosa), increases in resource availability have been associated with an increased production of larger or more abundant resin ducts. How different fuel treatments affect resin duct production is poorly understood, and a better understanding would be useful to influence management decisions to improve resilience to insect attack. To analyze the impacts of fuel treatments on resin production, increment cores with visible resin ducts embedded in annual xylem rings were taken from 36 ponderosa pines involved in the Fire and Fire-Surrogate (FFS) study at Lubrecht Experimental Forest. The FFS study applies three different fuel treatments: thinning, burning, and thinning followed by burning, and compares them to an untreated control. The abundance and area of annually produced resin ducts were measured from 1990-2025, encompassing the treatments which occurred twice, in 2001-2002, and in 2023-2024. Dendrochronological records allow changes in resin duct production to be measured and associated with treatment. Trees in the Thinned and Burned plots showed the greatest post-treatments level of resin duct production.