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Full-Text Articles in Life Sciences
Evidence Of Late Quaternary Fires From Charcoal And Siliceous Aggregates In Lake Sediments In The Eastern U.S.A., Joanne P. Ballard
Evidence Of Late Quaternary Fires From Charcoal And Siliceous Aggregates In Lake Sediments In The Eastern U.S.A., Joanne P. Ballard
Doctoral Dissertations
The late-glacial transition to the Holocene, 15,000–11,600 cal yr BP, is an enigmatic period of dynamic global changes and a major extinction event in North America. Fire is an agent of disturbance that transforms the environment physically and chemically, and affects plant community composition. To improve understanding of the linkages between fire, vegetation, and climate over the late glacial and Holocene in the eastern U.S., I analyzed lake-sediment cores for charcoal and indicators of wood ash, and compared results to existing pollen records. A new microscopic charcoal record from Anderson Pond, Tennessee revealed high fire activity from 23,000–15,000 cal yr …
The Influence Of Current Year Fire On Leaf Litter Decomposition Rates And Microbial Enzyme Activity In Forests Undergoing Ecological Restoration, Megan E. Overlander
The Influence Of Current Year Fire On Leaf Litter Decomposition Rates And Microbial Enzyme Activity In Forests Undergoing Ecological Restoration, Megan E. Overlander
Electronic Theses and Dissertations
As a result of fire suppression, open oak woodlands, once characteristic of the interior of the southern USA, are being lost to mesophication. This process leads to changes in the plant community and has the potential to change rates of decomposition and nutrient cycling through changes in environmental conditions or leaf litter composition. Restoration projects to reduce the effects of mesophication include thinning the canopy to remove mesophytic species and prescribed burn regimens to return the plant community to a fire tolerant and dependent one. However it is unclear what effects restoration (or mesophication) has on the decomposition of leaf …
Nonstructural Carbohydrate Concentrations Of Pine Trees As A Function Of Evolutionary History, Joshua T. Mims
Nonstructural Carbohydrate Concentrations Of Pine Trees As A Function Of Evolutionary History, Joshua T. Mims
Electronic Theses and Dissertations
Nonstructural carbohydrates (NSC) can supply substrate during periods when current photosynthate is unavailable or inadequate to meet metabolic demands. I hypothesized that natural selection has favored higher nonstructural carbohydrate concentrations ([NSC]) in species that have an evolutionary history of frequent disturbance and tested this using three southern pine species that have evolved under a continuum of disturbance frequencies (evolutionary history of fire ~ longleaf > slash > loblolly). Stem and root samples were collected from 12 similar-sized individual trees of each species during time periods that reflect the annual minimum and maximum [NSC]. A modified colorimetric method was performed on the samples …