Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Life Sciences
Rareness Starts Early For Disturbance-Dependent Grassland Plant Species, Matthew Candeias
Rareness Starts Early For Disturbance-Dependent Grassland Plant Species, Matthew Candeias
Biology Theses
Ecological communities always contain a few common species and an abundance of rare species. Mechanisms determining commonness and rarity require experimental investigation. Given that most plant mortality occurs in seeds and seedlings, recruitment best predicts plant community assemblage and distributions. In northeastern North America, grassland plant species constitute a sizable portion of the native flora. Approximately 30% of western New York’s threatened and endangered flora are associated with grasslands, apparent leftovers from a post-glacial landscape. I investigated the mechanisms behind grassland species commonness and rarity by examining how habitat type, disturbance and biotic interactions limit seed recruitment for three rare …
Coarse Woody Debris And The Carbon Balance Of A Moderately Disturbed Forest, Amy V. Schmid
Coarse Woody Debris And The Carbon Balance Of A Moderately Disturbed Forest, Amy V. Schmid
Theses and Dissertations
Landscapes are comprised of multiple ecosystems shaped by disturbances varying in severity and source. Moderate disturbance from weather, pathogens, insects, and age-related senescence, in contrast to severe disturbances that fell trees, may increase standing woody debris and alter the contribution of coarse woody debris (CWD) to total ecosystem respiration (RE). However, woody debris dynamics are rarely examined following moderate disturbances that substantially increase standing dead wood stocks. We used an experimental manipulation of moderate disturbance in an upper Great Lakes forest to: 1) examine decadal changes in CWD stocks through a moderate disturbance; 2) quantify in situ CWD …
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 …