Climate and terrestrial vegetation have had mutual feedbacks for nearly five hundred million years, yet both are now departing from recent historical norms, with uncertain implications for forest ecosystems. This dissertation outlines the current and potential future climate responses of lichen and bryophyte communities in the United States as part...
This dissertation describes patterns in epiphytic macrolichen community composition along a nitrogen deposition gradient in the Yosemite region of the Sierra Nevada in California. This region is part of the largest federal air quality Class 1 designated air-shed in the western United States, covering the entire crest of the Sierra...
The dominant theme in the literature indicates an increase of weight bias as the weight of the average Americans rises (e.g., Andreyeva, Puhl, & Brownell, 2008; Fryar, Kruszon-Moran, Gu, & Ogden, 2018). Both weight and gender biases can lead to acts of social injustice. The majority of the studies show...
I focus on addressing knowledge gaps relating to management of cryptogams in Oregon's public lands in Pseudotsuga menziesii-Tsuga heterophylla forests on the west side of the Cascade Range and dryland steppe in the Cascade Range's rainshadow.
While a great deal of research has illustrated the importance of late-successional forests for...
In recent years, our ecological knowledge of tropical dry forests has increased dramatically. However, whole components of the ecosystem, like lichenized fungi, remain mostly unknown. Crustose lichens in these forests are so abundant, that they are responsible for the characteristic appearance of a “white bark forest” during the dry season....
The unifying purpose of this dissertation was to describe, model, and map
relationships between epiphvtic macrolichen communities and air quality in Ibrests of
northern and central California. First, multivariate analyses were used to subdivide the
large study area into three model areas with similar climate, topography, and lichen
communities: the...
This dissertation describes patterns in epiphytic macrolichen community composition, diversity, and biomass across various stand types in the Blue River watershed of western Oregon. It first examines the relative importance of ecological factors such as stand age, remnant tree retention, and topography to lichen communities in the landscape. It then...
Lichens play many important roles in subarctic terrestrial ecosystems by fixing nitrogen, colonizing rock and gravel, stabilizing otherwise bare soil, adding significantly to vegetation biodiversity and serving as the primary food for caribou in the winter. In these chapters, I analyzed lichen community and ecological trait structure along environmental gradients,...
This thesis includes four separate studies. The first two studies assessed edge effects in a
700-year-old forest. After 20 years of exposure, epiphyte assemblages on the clearcut edge
were similar to those of the forest interior, but there were some differences in vertical
distribution patterns. Several species restricted to the...