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The Biology And Ecology Of The Yellowmargined Leaf Beetle, Microtheca Ochroloma Stal, (Coleoptera: Chrysomelidae) On Crucifers., Abdullahi Olod Ameen
The Biology And Ecology Of The Yellowmargined Leaf Beetle, Microtheca Ochroloma Stal, (Coleoptera: Chrysomelidae) On Crucifers., Abdullahi Olod Ameen
LSU Historical Dissertations and Theses
The biology and ecology of the yellowmargined leaf beetle, Microtheca ochroloma Stal, were studied on cabbage, Brassica oleracea var capitata L., collard, B. oleracea var acephala L., mustard, B. juncea Cosson, turnip, B. rapa L., and radish, Raphanus sativus L. The life cycle of the beetle consists of an egg stage, four larval instars, prepupal, pupal and adult stages. There were no significant differences in the effect of host plant on duration of development of immature beetles (p = 0.3353). The mean duration of development from oviposition to adult emergence ranged from 26.6 d on turnip to 27.5 d on …
The Role Of Seed Banks, Disturbance, And Sea Level Rise In Determining The Plant Community Structure Of Oligohaline Coastal Marshes., Andrew Hamilton Baldwin
The Role Of Seed Banks, Disturbance, And Sea Level Rise In Determining The Plant Community Structure Of Oligohaline Coastal Marshes., Andrew Hamilton Baldwin
LSU Historical Dissertations and Theses
Coastal wetlands worldwide are threatened by sea level rise, which is expected to affect the growth and survival of wetland vegetation by increasing water level and salinity. While the effects of salinity and inundation on adult vegetation of oligohaline marshes have been widely studied, the species composition of the seed bank and its response to elevated salinity and water level have not been examined. Additionally, the role of disturbances of different intensities in structuring marsh plant communities and possible interactions between disturbance and rising sea level have received little attention. Disturbances in coastal marshes include nonlethal disturbances such as fire …
Impacts Of Fire And Vertebrate Herbivores On Plant Community Characteristics And Soil Processes In A Coastal Marsh Of Eastern Louisiana, United States Of America., Mark Alan Ford
LSU Historical Dissertations and Theses
Both vertebrate herbivores and fire have long been known to have dramatic and important effects on wetlands. In the first part of this study, conducted in the Pearl River Basin coastal marshes of Louisiana, the interaction between the effects of mammalian herbivores, especially nutria and wild boar, and fire was examined in three marsh community types: those dominated by Sagittaria lancifolia, Panicum virgatum, or Spartina patens/Scirpus americanus. Overall, above-ground biomass was reduced by burning but increased by fencing. Richness only increased in plots that were both burned and fenced. In the three communities, only Scirpus americanus cover was enhanced by …
Role Of Hurricane Disturbance In The Dynamics Of The Southern Mixed Hardwood Forest: A Case Study In Northern Florida., William Bennett Batista
Role Of Hurricane Disturbance In The Dynamics Of The Southern Mixed Hardwood Forest: A Case Study In Northern Florida., William Bennett Batista
LSU Historical Dissertations and Theses
The objective of this dissertation was to characterize the role of hurricanes in the dynamics of old-growth Southern Mixed Hardwood Forests from the coastal plain of the northern Gulf of Mexico. First, we used data from five stands to describe the structure, composition, and disturbance regime of these forests. All five stands have Magnolia grandiflora and Fagus grandifolia among the dominant species, and have been affected by frequent but relatively mild hurricanes (4-6 per century, windspeed $<$200 km/h). Second, we examined the changes in tree recruitment, growth, and mortality occurred in Woodyard Hammock, northern Florida, after this forest was affected by Hurricane Kate in 1985. The analysis was based on data from biennial censuses of a 4.5 ha plot conducted between 1978 and 1992. Hurricane Kate produced extensive canopy disruption but limited tree mortality. This disturbance prompted a phase of increased recruitment, growth, and survival of understory trees, and decreased growth and survival of overstory trees. Release of small understory individuals appeared to be critical for the persistence of three short-lived dominant species, Pinus glabra, Ostrya virginiana and Carpinus caroliniana. However, persistence of the longer-lived dominants Magnolia grandiflora, Fagus grandifolia, Liguidambar styraciflua, Nyssa sylvatica, and Ilex opaca, appeared to depend primarily on resistance to hurricane damage. Third, we used matrix population models to test specific hypotheses about mechanisms of persistence of F. grandifolia in Woodyard Hammock. These models showed that, both before and after Hurricane Kate, this population was close to equilibrium. This result supported the hypothesis that persistence of F. grandifolia has resulted from hurricane resistance. Sensitivity analyses of the models suggested that the key for hurricane resistance has been the high survival of medium-size trees. Life-history strategies involving resistance and survival to hurricane disturbance, rather than release and rapid growth, appear to have been prevalent in these forests. However, the hurricane regime would have resulted in coexistence of species with the two types of strategy. Hurricanes would have been frequent enough to secure the persistence of species dependent on release, and mild enough not to compromise that of species dependent on resistance.
Molecular Systematics Of Red Algae., Jeffrey Craig Bailey
Molecular Systematics Of Red Algae., Jeffrey Craig Bailey
LSU Historical Dissertations and Theses
Phylogenetic analyses of nucleotide sequences for the nuclear-encoded small subunit ribosomal RNA (SSU) gene were used to test current hypotheses of relationships within the Corallinales and among the florideophycidaean orders of red algae. Analyses of SSU gene sequences indicate that the order Corallinales includes four major lineages. The Sporolithaceae is resolved as the earliest-diverging lineage within the order and forms the sister group to a monophyletic Corallinaceae. The molecular data also support the monophyly of the subfamilies Melobesioideae and Corallinoideae. The latter subfamily is inferred as sister to a fourth lineage including non-geniculate and geniculate species classified in the subfamilies …
Low Carbon Dioxide-Inducible Genes And Proteins In Chlamydomonas Reinhardtii., Zhi-Yuan Chen
Low Carbon Dioxide-Inducible Genes And Proteins In Chlamydomonas Reinhardtii., Zhi-Yuan Chen
LSU Historical Dissertations and Theses
At low CO$\sb2$ conditions, C. reinhardtii, like many other green algae, induces a CO$\sb2$ Concentrating Mechanism (CCM) to raise the internal Ci concentration. During the induction, at least five new polypeptides and six different genes are upregulated and some of the corresponding mRNAs or proteins are absent in high CO$\sb2$ requiring mutants. However the identities and functions of these genes are unknown. In this dissertation, I partially characterized four low CO$\sb2$ inducible genes and one low CO$\sb2$ inducible protein LIP-36. The complete cDNA sequences of clones 11I3 and 2I5 are 1311 bp and 985 bp, respectively. Neither of these two …
The Effects Of Timber Management Activities On Understory Plant Succession In Young Loblolly Pine (Pinus Taeda) Plantations., Donald Paul Reed
The Effects Of Timber Management Activities On Understory Plant Succession In Young Loblolly Pine (Pinus Taeda) Plantations., Donald Paul Reed
LSU Historical Dissertations and Theses
An understory vegetative succession study was conducted on the LSU Lee Memorial Forest near Bogalusa, Louisiana. Research blocks were established within fifteen-year-old overstocked loblolly pine (Pinus taeda) stands, in specific areas classified as with or without a history of prescribed burning for the current timber rotation. Silvicultural treatments involved precommercially thinning randomly selected blocks to various stand densities, along with the establishment of unthinned control areas. Growth rates of residual trees were determined from tree diameter measurements, on all timbered plots. Burn-history areas received a further treatment, involving the mechanical destruction of all timber on specified areas, followed by site-preparation …
Plant Species Diversity And Community Structure In A Louisiana Coastal Marsh., Laura Gough
Plant Species Diversity And Community Structure In A Louisiana Coastal Marsh., Laura Gough
LSU Historical Dissertations and Theses
The factors that control plant species diversity have been examined by many researchers, but with little consensus as to the causes of diversity patterns. Plant diversity has been correlated with disturbance, competition, soil resources, and other variables. In the research presented here, I investigated the relationship between plant species richness and biomass, competition, nutrient enrichment, flooding, salinity, and herbivory in field studies in Louisiana coastal marshes. Biomass alone was a poor predictor of richness in two Louisiana marshes. When environmental variables (flooding, salinity, and soil fertility) were included with biomass in a multiple regression model, 82% of the variance in …
Floral Development And Systematics Of The Caesalpinieae (Leguminosae: Caesalpinioideae)., Katherine Ellen Kantz
Floral Development And Systematics Of The Caesalpinieae (Leguminosae: Caesalpinioideae)., Katherine Ellen Kantz
LSU Historical Dissertations and Theses
The floral development of representatives from some of the informal taxonomic groups of the Caesalpinieae was examined. The floral developmental data was then used in a phylogenetic analysis in combination with more traditional morphological characters, including floral, vegetative and fruit characters. The analysis of 53 taxa and 84 characters produced 1215 equally parsimonious trees of length 386 (CI =.317, RI =.585, RCI =.186). Based on this analysis Caesalpinia sensu lato is not monophyletic, since at least two of the other genera in the Caesalpinia group are nested within Caesalpinia sensu lato. Of the infrageneric groups within Caesalpinia sensu lato, the …