Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 106-116).

Thesis (M.S.)--Ohio University, August, 2004. / Includes bibliographical references (p. 35-40).

Thesis (M.S.)--Ohio University, August, 2004. / Title from PDF t.p. Includes bibliographical references (p. 35-40)

No description available.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 108-115).

Stem respiration is an important part of respiration coming from different dead and living stem tissues of trees, which makes an important contribution to the overall forest carbon balance. This report investigated spatial differences regarding radial diffusion of CO2 through the bark on trees across different old growth forests in Sweden. Some key environmental factors such as precipitation, wetness classes, temperature, stem diameter, distance from the coast, and latitude have been analysed to find relationships with stem respiration. Measurements were carried out on the most common tree species in Sweden, Pinus sylvestris, Picea abies and Betula pubescens. This was done by using a portable gas analyser strapped to the trees. The results show statistical differences in stem respiration for each tree species between some of the forests, while no statistical differences were found between wetness classes within or between forests. The only environmental factor that was found to have a significant relationship with stem respiration was stem diameter for P. sylvestris. Overall, these results indicate that stem respiration rate is relatively insensitive to environmental variation, which potentially simplifies the process of extrapolating this flux over space and time. Knowledge about stem respiration is important for understanding of the carbon cycle and prediction of future global change. Therefore, it is crucial to gain extensive information and understanding about the external relationships that could influence stem respiration.

No description available.

No description available.

This study describes the composition of forest landscapes surrounding northern spotted owl (Strix occidentalis caurina) nests in the central Cascade Mountains of Oregon. I compared forest composition around 126 owl nests in 70 pair territories with forest composition around 119 points drawn randomly from all terrestrial cover-types, and around 104 points drawn randomly from the old-forest (closed canopy, > 80 yrs) cover type. All nest sites and random points were drawn from U.S. Forest Service lands and were not drawn from privately owned lands or Wilderness Areas. Forest cover was classified on a Landsat Thematic Mapper image. I quantified the percentage of old-forest within 200 concentric circular plots (0.04-5.0-km radii), centered on each analyzed point, using a geographic information system. I used logistic regression to make spatially-explicit inferences. Owl nests were surrounded by more old-forest when compared to points drawn randomly from all terrestrial cover types: there was significantly (P<0.05) more old-forest around the owl nests in plots as large as 1.79 km in radius. When compared to points drawn randomly from the old-forest cover type, owl nests were surrounded by significantly (P<0.05) more old-forest in plots with 0.17-0.80-km radii. Exploratory analyses suggest that the landscape scales most pertinent to northern spotted owl nest site positioning in this study area appear to be (in descending order): the surrounding 10-15 ha (~200-m radius), the surrounding 25-30 ha (~300-m radius), the surrounding 200 ha (800-m radius), and possibly the surrounding 700 ha (1,500-m radius). This study supports the assertion that northern spotted owls are strongly associated with older forests. The results also indicate that owl nests are most associated with higher proportions of old-forest near the nest implying that the arrangement of habitat is important for nest-site selection/positioning Since spotted owls in the central Cascade Mountains of Oregon are known to have home-ranges that average 1,769 ha, it is important to recognize that these results apply to nest-site selection/positioning on the landscape and not to the amount of habitat necessary for pair persistence or successful reproduction. / Graduation date: 1998

Thesis (Ph.D.)--Murdoch University, 2004. / Thesis submitted to the Division of Science and Engineering. Bibliography: leaves 360-392.