Poster Session II
Project Type
Poster
Project Funding and Affiliations
W.A. Franke College of Forestry and Conservation
Faculty Mentor’s Full Name
Scott Ferrenberg
Faculty Mentor’s Department
Department of Ecosystem and Conservation Science
Additional Mentor
Isabella Smith: isabella1.smith@umconnect.umt.edu (graduate student), Gibson Blankenship: gibson.blankenship@umconnect.umt.edu (graduate student)
Abstract / Artist's Statement
Increasing global temperatures and drought severity place trees at a higher risk of wildfires and water stress. While fuel management treatments were initially designed for wildfire mitigation, they may also promote drought resistance by altering growth strategies. I evaluated the impact of mechanical thinning, prescribed burning, and a combined treatment on the hydraulic growth characteristics of ponderosa pines (Pinus ponderosa) at the University of Montana’s Lubrecht Experimental Forest. Increment cores display a tree's rings, which are composed of annual earlywood and latewood layers that reflect their growth strategy in response to seasonal resource availability. Earlywood cell structure favors rapid growth, but allows for greater risk of cavitation. In contrast, latewood cell structure prioritizes smaller vessel sizes as a strategy to continue growth, but reduce drought-induced cavitation. I used earlywood and latewood radial growth measurements and their response to Basal Area Increment (BAI) to analyze water allocation. Thinned treatments significantly increased total growth relative to the Burn-Only and Control groups. Most notably, BAI was the overwhelming driver of earlywood and latewood variations, rather than the direct effect of treatment alone. The Thin and Burn treatments increased overall tree growth and the proportion of latewood. This suggests that ponderosa pines are reducing cavitation risk, buffering against negative drought effects and lowering mortality potential. This study informs forest managers of effective strategies to create forest stands better suited to withstand water stress.
Category
Life Sciences
Ponderosa pines reduce cavitation risk by altering growth strategies in response to fuel reduction treatments
UC South Ballroom
Increasing global temperatures and drought severity place trees at a higher risk of wildfires and water stress. While fuel management treatments were initially designed for wildfire mitigation, they may also promote drought resistance by altering growth strategies. I evaluated the impact of mechanical thinning, prescribed burning, and a combined treatment on the hydraulic growth characteristics of ponderosa pines (Pinus ponderosa) at the University of Montana’s Lubrecht Experimental Forest. Increment cores display a tree's rings, which are composed of annual earlywood and latewood layers that reflect their growth strategy in response to seasonal resource availability. Earlywood cell structure favors rapid growth, but allows for greater risk of cavitation. In contrast, latewood cell structure prioritizes smaller vessel sizes as a strategy to continue growth, but reduce drought-induced cavitation. I used earlywood and latewood radial growth measurements and their response to Basal Area Increment (BAI) to analyze water allocation. Thinned treatments significantly increased total growth relative to the Burn-Only and Control groups. Most notably, BAI was the overwhelming driver of earlywood and latewood variations, rather than the direct effect of treatment alone. The Thin and Burn treatments increased overall tree growth and the proportion of latewood. This suggests that ponderosa pines are reducing cavitation risk, buffering against negative drought effects and lowering mortality potential. This study informs forest managers of effective strategies to create forest stands better suited to withstand water stress.