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Root Morphology, Distribution Of Mycorrhizae, And Nutrient Status Of The Terrestrial Orchid Spiranthes Cernua., Veronique Simone Pileri
Root Morphology, Distribution Of Mycorrhizae, And Nutrient Status Of The Terrestrial Orchid Spiranthes Cernua., Veronique Simone Pileri
Student Work
The rhizosphere is a complex of biotic and abiotic factors and their interactions. It includes the soil, the micro- and megafauna, and a variety of autotrophic species. The goal of this study is to understand the belowground dynamics of the terrestrial orchid, Sniranthes cemua. through the characterization of soil nutrients, root system morphology, and mycorrhizal infection. Interrelationships among the soil, the mycorrhizae and S. cemua may explain the role of mycorrhizae in adult chlorophyllous orchids as well as the influence of soil nutrients on mycorrhizae. Understanding mycorrhizal relationships, will also contribute to the conservation and reestablishment of threatened and endangered …
Analysis Of Potential Base-Pairs Between 16s And 23s Ribosomel Rna In Escherichia Coli., Bruce Carden
Analysis Of Potential Base-Pairs Between 16s And 23s Ribosomel Rna In Escherichia Coli., Bruce Carden
Student Work
Each ribosome in E. coli is composed of two associated subunits, the 30s small subunit and the 50S large subunit, forming the translationally competent 70S ribosome. Ribosomal subunit association is a critical feature of all stages of translation. One proposal for subunit association involves rRNA-rRNA interactions between the 790 loop in 16S rRNA and the 2750 loop in 23S rRNA. Each of these sequences are highly conserved, and more intriguingly have the potential to form Watson-Crick base-pairs with each other. The objectives of the study were to detail the role of the 2750 loop in subunit association and test the …
The Relationship Between Nectar Sources And Regal Fritillary (Speyeria Idalia Drury) Butterfly Populations., Jeffrey J. Huebschman
The Relationship Between Nectar Sources And Regal Fritillary (Speyeria Idalia Drury) Butterfly Populations., Jeffrey J. Huebschman
Student Work
I investigated the relationship between nectar source diversity and regal fritillary (Speyeria idalia Drury) butterfly populations at ten native tallgrass prairie sites in eastern Nebraska. Walking-transect surveys were used to establish regal fritillary population-density indices in 1996 and 1997. Flowering-plant surveys were also conducted, coincident with the butterfly surveys, and were used to develop blossom-density, and abundance indices. Spearman rank correlation was used to examine relationships between regal fritillary density indices and plant survey variables. Two significant, positive correlations were identified between (1) 1996 population-density indices and 1996 blossom-diversity indices for known nectaring sources of the regal fritillary (n = …
Tallgrass Prairie Remnants Of Western Iowa Cemeteries., Carrie L. Menges-Schaben
Tallgrass Prairie Remnants Of Western Iowa Cemeteries., Carrie L. Menges-Schaben
Student Work
Tallgrass prairie remnants situated in eight western Iowa cemeteries were sampled during 1995 and 1996 to compare both the frequency and season of mowing and burning on plant species composition. Dominant, native tallgrass prairie species, such as big bluestem (Andropha gerardii), Indian grass (Sorghastrum nutans) and leadplant (Amorpha canescens), generally showed a significant increase with burning, whether mowed or not. Mowing, however, adversely affected other species, including flower spurge (Euphorbia corollate) and porcupine grass (Stipa spartea), whether burned or not. Non-native species, in particular smooth brome (Bromus inermis) increased with mowing and the absence of fire. Overall, my study suggests …
Comparison Of Seeding And Sod-Transplant Methods For Restoring Tallgrass Prairie In Southeastern Nebraska., Gary P. Sullivan
Comparison Of Seeding And Sod-Transplant Methods For Restoring Tallgrass Prairie In Southeastern Nebraska., Gary P. Sullivan
Student Work
Data were collected in Fall, 1993 from a 55-year-old re-established grassland to determine the degree of success of seeding and sodding in re-establishing native prairie species. Species Richness of native species was highest in one seeded re-established site (S = 44), but lowest in a second re-established site (S = 23). Species Richness was second highest at the Native site (S = 42). There was a significant difference (P ≤ 0.05) in Species Diversity between the one seeded and the native treatments. The high diversity in re-established treatments is consistent with that expected of the Intermediate-Disturbance-Hypothesis suggesting the seral nature …