Thesis (M.E.S.)--The Evergreen State College, 2007. / Title from title screen viewed (4/8/2008). Includes bibliographical references (leaves 33-39).

Thesis (M.S.)--Western Washington University, 2010. / Includes bibliographical references (leaves 59-61). Also issued online.

The recruitment trends of whitebark pine (Pinus albicaulis Engel.) were investigated in 18 recently burned stands in the Canadian Rockies and the North Cascades. Whitebark pine recruitment in recently burned stands (fires < 60 years prior) was compared to that on paired control stands (no recent fire) to determine if fire was necessary for successful recruitment. Recruitment in recently burned stands was compared with ecological and seed source variables. Along a chronosequence, whitebark pine recruitment was compared with precipitation and with Pacific Decadal Oscillation (PDO). Field sampling consisted of systematic plots established in sampling grids in both burned and control stands. In each plot ecological data was collected as was data regarding whitebark pine age, height, and disease status. Recent fire was not found to be a requirement for recruitment. Both distance to and size of seed source were important predictors of whitebark pine recruitment. Whitebark pine regeneration densities were low on warm steep rocky sites. High whitebark pine recruitment on cooler aspects suggested that whitebark pine could establish on cooler sites when competition was removed by fire. Most stands were composed of mixed conifers, but only lodgepole pine appeared to limit the growth of whitebark pine. Whitebark pine recruitment was episodic on all stands, and recruitment years were correlated among many stands separated by large distances. Episodic recruitment may be due to more than cone masting as recruitment in several stands was also correlated with growing season precipitation and positive PDO values, which may increase the length of growing season. A logistic regression model suggested that infection by white pine blister rust is most likely on older seedlings. The percentage of whitebark pine trees infected by white pine blister rust on a site increased with time since fire. Prescribed fires and wildfires should address retention of whitebark pine seed trees on site. Fires that remove competition from mesic-submesic stands may result in the most rapid recruitment of whitebark pine. With the exception of stands heavily stocked with lodgepole pine, all recently burned stands in this study would benefit from increased stocking of whitebark pine by planting.

The recruitment trends of whitebark pine (Pinus albicaulis Engel.) were investigated in 18 recently burned stands in the Canadian Rockies and the North Cascades. Whitebark pine recruitment in recently burned stands (fires < 60 years prior) was compared to that on paired control stands (no recent fire) to determine if fire was necessary for successful recruitment. Recruitment in recently burned stands was compared with ecological and seed source variables. Along a chronosequence, whitebark pine recruitment was compared with precipitation and with Pacific Decadal Oscillation (PDO). Field sampling consisted of systematic plots established in sampling grids in both burned and control stands. In each plot ecological data was collected as was data regarding whitebark pine age, height, and disease status. Recent fire was not found to be a requirement for recruitment. Both distance to and size of seed source were important predictors of whitebark pine recruitment. Whitebark pine regeneration densities were low on warm steep rocky sites. High whitebark pine recruitment on cooler aspects suggested that whitebark pine could establish on cooler sites when competition was removed by fire. Most stands were composed of mixed conifers, but only lodgepole pine appeared to limit the growth of whitebark pine. Whitebark pine recruitment was episodic on all stands, and recruitment years were correlated among many stands separated by large distances. Episodic recruitment may be due to more than cone masting as recruitment in several stands was also correlated with growing season precipitation and positive PDO values, which may increase the length of growing season. A logistic regression model suggested that infection by white pine blister rust is most likely on older seedlings. The percentage of whitebark pine trees infected by white pine blister rust on a site increased with time since fire. Prescribed fires and wildfires should address retention of whitebark pine seed trees on site. Fires that remove competition from mesic-submesic stands may result in the most rapid recruitment of whitebark pine. With the exception of stands heavily stocked with lodgepole pine, all recently burned stands in this study would benefit from increased stocking of whitebark pine by planting.

Thesis (M.S.)--Montana State University--Bozeman, 2006. / Typescript. Chairperson, Graduate Committee: Lisa J. Graumlich. Includes bibliographical references.

Master of Arts / Department of Geography / Kendra K. McLauchlan / Whitebark pine (Pinus albicaulis) is a critically threatened North American conifer. In modern times, it has experienced a significant decline in population due to pine beetle infestations, blister rust infections, fire suppression, and climate change. While climate, fire, and vegetation are strongly linked on regional and global scales, the relative roles of these three factors are not well-documented during the Holocene in high elevation mountain sites of North America. Recent anthropogenic changes in climate and fire management practices are underway, but the potential responses of subalpine vegetation to these environmental changes remain relatively unknown. Here, I documented the paleoecology of a watershed surrounding an unnamed, high-altitude pond containing a large number of whitebark pine trees located at 2805m elevation in Grand Teton National Park, U.S.A. Using a 1.5 meter lacustrine sediment core collected in 2010, I generated a Holocene-scale fire and vegetation record using fossil pollen, charcoal, and macrofossils preserved within the core. I also conducted a dendrochronological study of the current stand of whitebark pine in the watershed to determine both approximate dates of establishment and responses to past climate change of this modern stand. Sedimentary charcoal data indicate significant variability in both fire frequency and fire intensity during the Holocene. The fire regime observed in the past 1000 years is seemingly unprecedented at this site, with lower fire frequency and higher fire intensity than any other time during the Holocene. Sedimentary pollen data suggest the study site has been primarily dominated by whitebark pine until the last 1000 years, with brief periods of vegetation dominated by non-arboreal taxa that indicate the presence of either successional dynamics or shifts in treeline location. Ages of individual living whitebark pine trees average 365 years, and dendrochronology data suggest that ring widths of the current stand have been declining since 1991. Statistical analyses of PRISM climate data with ring width data suggest that this decrease in annual growth is likely the result of decreased growing season temperature ranges driven by a warming climate. While this stand of whitebark pine is threatened by both warming climate and fire suppression, there is the potential for low-intensity prescribed burns to play a role in conservation and restoration management plans for this threatened conifer.

No description available.

Whitebark pine (Pinus albicaulis) is declining across its range due to disturbances such as mountain pine beetle and white pine blister rust. In this thesis, I assess the response and vulnerability of whitebark pine ecosystems to multiple stressors and disturbances at the northern edge of P.albicaulis range in the Coastal Mountains of British Columbia, Canada. Both the compositional change over time of overstory and understory communities as well as vegetation spatial patterns suggest that different sites or ecosystem types housing whitebark pine may differ in their response to disturbance and stress. Surveys conducted ~ 20 years apart indicate that overstory community change differed between site types following the decline of P. albicaulis over time, while the understory did not change significantly. The spatial pattern of overstory species and understory communities also indicates that site type may be important in determining forest change under ongoing disturbance to whitebark pine. / Forest Biology and Management

Thesis (Ph. D.)--University of Wyoming, 2007. / Title from PDF title page (viewed Feb. 9, 2009). Includes bibliographical references.

Thesis (MS)--Montana State University--Bozeman, 2009. / Typescript. Chairperson, Graduate Committee: Cathy L. Cripps. Includes bibliographical references (leaves 105-121).