Oral Presentations
Presentation Type
Presentation
Faculty Mentor’s Full Name
Philip Higuera
Faculty Mentor’s Department
Ecosystem and Conservation Science
Abstract / Artist's Statement
Montane and mixed-mesic conifer forests in the northwestern United States are burning at rates greater than any time in recent decades, due to the combined impacts of global warming and historical and contemporary land use and land management. Western larch (Larix occidentalis) is a tree of high regional significance, exhibiting a variety of traits that make it resistant and resilient to fire. Because seedlings are generally more sensitive to environmental stressors than adults, the impacts of climate change are expected to be detectable first in juvenile trees. Recent research shows that the natural regeneration of western larch after wildfires has not been significantly impacted by recent climate change (Vieira, 2023), although the prolonged vitality of these seedlings is of question.
To understand how seedlings naturally regenerating after wildfire respond to interannual variations in climate, I studied the influence of seasonal measures of moisture and energy inputs on the annual radial growth of western larch juveniles. The study calls on > 1600 destructively sampled western larch seedlings that were regenerating in post-fire ecosystems across the geographic range the species in the US (i.e., Montana, Idaho, Washington, Oregon). From 53 sites sampled within 30 wildfires that burned between 2000 and 2015, dendrochronological techniques were used to determine the establishment year of each seedling. Image analysis was used to then measure annual growth rings for each seedling.
I analyzed the data with a variety of statistical techniques. Using a simple correlation analysis, I assess the correlation between multiple measures of seasonal climate and radial growth of seedlings at both the plot and individual tree level. Findings reveal complex relationships between climate and radial growth, with variability in both magnitude and direction of correlations within and among sites. I then modeled climate-growth relationships using a continuous mixed effects linear regression model to infer how annual growth varies based on different climatic factors, as well as site-specific and fire-related factors (e.g., fire severity). Understanding how climate influences the annual growth of western larch seedlings is crucial for understanding, predicting, and effectively managing the future composition and structure of montane and mixed-mesic conifer forests.
References
Vieira, Spencer T., "IMPACTS OF CLIMATE AND WILDFIRE ON WESTERN LARCH REGENERATION" (2023). Graduate Student Theses, Dissertations, & Professional Papers. 12238. https://scholarworks.umt.edu/etd/12238
Category
Life Sciences
Interannual growth-climate relationships of western larch after wildfire in the northwest United States
UC 326
Montane and mixed-mesic conifer forests in the northwestern United States are burning at rates greater than any time in recent decades, due to the combined impacts of global warming and historical and contemporary land use and land management. Western larch (Larix occidentalis) is a tree of high regional significance, exhibiting a variety of traits that make it resistant and resilient to fire. Because seedlings are generally more sensitive to environmental stressors than adults, the impacts of climate change are expected to be detectable first in juvenile trees. Recent research shows that the natural regeneration of western larch after wildfires has not been significantly impacted by recent climate change (Vieira, 2023), although the prolonged vitality of these seedlings is of question.
To understand how seedlings naturally regenerating after wildfire respond to interannual variations in climate, I studied the influence of seasonal measures of moisture and energy inputs on the annual radial growth of western larch juveniles. The study calls on > 1600 destructively sampled western larch seedlings that were regenerating in post-fire ecosystems across the geographic range the species in the US (i.e., Montana, Idaho, Washington, Oregon). From 53 sites sampled within 30 wildfires that burned between 2000 and 2015, dendrochronological techniques were used to determine the establishment year of each seedling. Image analysis was used to then measure annual growth rings for each seedling.
I analyzed the data with a variety of statistical techniques. Using a simple correlation analysis, I assess the correlation between multiple measures of seasonal climate and radial growth of seedlings at both the plot and individual tree level. Findings reveal complex relationships between climate and radial growth, with variability in both magnitude and direction of correlations within and among sites. I then modeled climate-growth relationships using a continuous mixed effects linear regression model to infer how annual growth varies based on different climatic factors, as well as site-specific and fire-related factors (e.g., fire severity). Understanding how climate influences the annual growth of western larch seedlings is crucial for understanding, predicting, and effectively managing the future composition and structure of montane and mixed-mesic conifer forests.
References
Vieira, Spencer T., "IMPACTS OF CLIMATE AND WILDFIRE ON WESTERN LARCH REGENERATION" (2023). Graduate Student Theses, Dissertations, & Professional Papers. 12238. https://scholarworks.umt.edu/etd/12238