Social and Behavioral Sciences Commons^™

Spectral Response And Spatial Pattern Of Fraser Fir Mortality And Regeneration, Great Smoky Mountains, Usa, Thomas R. Allen

Political Science & Geography Faculty Publications

High elevation Fraser fir (Abies fraseri) forests of the Southern Appalachians have undergone widespread mortality since the introduction of the balsam woolly adelgid in the 1950s. Resulting changes in ecosystem pattern and process (e.g., stand dynamic processes) have greatly affected floral and faunal communities. In this project, we integrated field observations, geographic information system topographic models, and 1988–1998 satellite imagery to analyze spatial and temporal conditions of Fraser fir and spruce-fir ecosystems in Great Smoky Mountains National Park. Tasseled cap indices (brightness, greenness, and wetness) and associated spectral changes for Landsat TM digital data were statistically modeled by …

Trichodesmium Spp.: Numerical Studies Of Resource Competition, Carbohydrate Ballasting, And Remote-Sensing Reflectance, Tonya Denise Clayton

OES Theses and Dissertations

In recent years, a new appreciation for the role of diazotrophy in the oceans has emerged. This dissertation reports on three modeling studies designed to investigate ecological processes associated with Trichodesmium spp., the most conspicuous marine diazotroph: (1) characterization of a generalized model Trichodesmium and issues of macronutrient resource competition; (2) carbohydrate ballasting by Trchodesmium and implications for the formation of surface accumulations; and (3) the vertical distribution of Trichodesmium and implications for detection from space.

The first study focuses on issues of nitrogen and phosphorus competition and ecosystem structure. It utilizes a simple ecosystem model that includes dissolved nitrogen …