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Full-Text Articles in Forest Sciences
Assessing The Impact Of Parallel Burnout Fires On Flank Rate Of Spread, Erik Borke
Assessing The Impact Of Parallel Burnout Fires On Flank Rate Of Spread, Erik Borke
Graduate Student Theses, Dissertations, & Professional Papers
The effects of flank-parallel suppression fires on the local rate of spread (ROS) of freely burning headfires through fully cured homogeneous grass fuels are assessed. Data sets include: one thermal image stack of a prescribed burn recorded by drone, and a suite of simulation experiments carried out in Wildland Urban Interface Fire Dynamics Simulator (WFDS). A new approach to computing ROS, curvature proxy driven normals to convex polylines, was developed to carry out this analysis. ROS time series depicting flank acceleration of the prescribed burn and simulation experiments, observable under coarse and fine directional classification schemes respectively, are the primary …
Impacts Of Climate And Wildfire On Western Larch Regeneration, Spencer T. Vieira
Impacts Of Climate And Wildfire On Western Larch Regeneration, Spencer T. Vieira
Graduate Student Theses, Dissertations, & Professional Papers
Fire plays a critical role in forests of the western United States (US), but as wildfire and climate deviate from historical patterns, increasing fire activity may significantly alter forest ecosystems. To understand the impacts of changing climate and wildfire activity on conifer forests, we studied the impact of wildfire and annual post-fire climate on western larch (Larix occidentalis) regeneration. We destructively sampled 1651 seedlings from 57 sites within 32 fires that burned at moderate or high severity from 2000-2015 in the northwestern US. Using dendrochronological methods, we estimated germination years of seedlings to calculate annual recruitment rates. We …
The Birds And The Trees: Quantifying The Drivers Of Whitebark Pine Decline And Clark's Nutcracker Habitat Use In Glacier National Park, Vladimir Kovalenko
The Birds And The Trees: Quantifying The Drivers Of Whitebark Pine Decline And Clark's Nutcracker Habitat Use In Glacier National Park, Vladimir Kovalenko
Graduate Student Theses, Dissertations, & Professional Papers
Whitebark pine (Pinus albicaulis), recently listed as threatened under the Endangered Species Act, is in steep decline in Glacier National Park, Montana, USA due to the non-native pathogen Cronartium ribicola, causal agent of the fatal disease white pine blister rust. A sample of the park’s population suggests that approximately 70 percent of whitebark pines have died, while 65 percent of the remaining trees are infected. Using landscape and climate variables, we show how geographic location, elevation, aspect, solar radiation, relative humidity, and snowpack interact with tree diameter to affect mortality, disease incidence, cone production, and regeneration. We also examine how …
The Effects Of Weather On Facilitating The Intensification And Collapse Of Bark Beetle Outbreaks In Ponderosa Pine Forests Of The Northern Rocky Mountains And The Black Hills, Jordan T. Lestina
Graduate Student Theses, Dissertations, & Professional Papers
Bark beetles are a diverse family of insect herbivores, of which the most aggressive species can cause significant tree mortality, and are integral components of disturbance regimes in conifer dominated forests of North America. Recent drought events across the western U.S. have been broadly associated with the initiation of multiple bark beetle outbreaks in ponderosa pine forests during the last two decades. Changing weather conditions, such as those observed during the onset of drought, affect outbreak progression through their influence on bark beetle physiology and life history traits and the overall vigor and defensiveness of host trees. This study used …