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Full-Text Articles in Life Sciences
Dynamics Of Canopy Cover In A Wet Forest In Costa Rica, Carolina Brinez
Dynamics Of Canopy Cover In A Wet Forest In Costa Rica, Carolina Brinez
FIU Electronic Theses and Dissertations
I examined the effects of soil and slope conditions on canopy dynamics in terms of openness and leaf area index through time as measured by hemispherical photography. Specifically, I compared alluvial versus residual soil and slope versus plateau and flat plots in an old-growth tropical wet forest in Costa Rica. No significant effects of slope were found for any estimator of canopy coverage in any analysis. Soil type approached significance as a single factor and several soil*year interactions were highly significant. In addition, I found highly significant inter-annual variation in all analyses that was concordant on all plot types. This …
Phenology, Sexual Reproduction, And The Factors Affecting Sexual Reproduction Of The Marine Angiosperm, Thalassia Testudinum, In The Florida Keys National Marine Sanctuary (Fknms), Kevin M. Cunniff
FIU Electronic Theses and Dissertations
This study investigated phenology and the factors affecting sexual reproduction of Thalassia testudinum in the FKNMS. Flowering was assessed at 30 permanent monitoring sites via direct observation and age reconstruction techniques of seagrass cores in 2002. The mean flowering frequency was 1.49%, was spatially variable, and exhibited sex-specific timing in floral anthesis. Historical flowering reconstruction demonstrated that flowering frequencies are not temporally variable. Floral sex ratios were female-biased, spatially variable, and likely temporally variable. Relative nitrogen availability was most important in influencing flowering and was negatively correlated with flowering. Higher flowering occurred with low N availability and lower flowering occurred …
Conservation Ecology Of Amphibians And Reptiles In Sarapiqui, Costa Rica : Forest Fragmentation And Long Term Population Change, Kristen E. Bell
Conservation Ecology Of Amphibians And Reptiles In Sarapiqui, Costa Rica : Forest Fragmentation And Long Term Population Change, Kristen E. Bell
FIU Electronic Theses and Dissertations
In order to explore the conservation ecology of frogs and lizards in the Sarapiqui region of Costa Rica, I compared populations and communities among forest fragments and La Selva Biological Station, as well as across 35 years of sampling at La Selva. Species richness in nine fragments combined was 85% of that found in La Selva, and community composition varied among sites and by fragment size class. Although communities in fragments differed fundamentally from those in intact forest, the high diversity observed across all fragments indicates that preserving a network of small forest patches may be of great conservation value …
The Use Of Capillary Electrophoresis (Ce) In Drug Analysis, Agnes D. Garcia
The Use Of Capillary Electrophoresis (Ce) In Drug Analysis, Agnes D. Garcia
FIU Electronic Theses and Dissertations
Capillary electrophoresis is currently a very powerful technique for the analysis of seized drugs. A rapid analytical CE method for the screening and quantification of GHB and GBL was achieved using 300mM CTAC/25mM phosphate buffer pH 6.3. Reversed phase HPLC was achieved using 25mM phosphate buffer pH 6.5 and a Cl8 Aqua column. Chiral separation of 9 amphetamine type stimulants was obtained using a highly sulfated gamma-cyclodextrin as a chiral selector. MECC and CZE were compared for the analysis of psilocybin, while a rapid and robust method is presented for the analysis of major opium alkaloids, using dynamically coated capillary …
Shoot Architecture And Growth In The South Florida Wet Prairie Macrophyte, Eleocharis Cellulosa, Shanaz Baksh
Shoot Architecture And Growth In The South Florida Wet Prairie Macrophyte, Eleocharis Cellulosa, Shanaz Baksh
FIU Electronic Theses and Dissertations
Eleocharis cellulosa is a dominant macrophyte in Everglades wet prairie communities. The development of the shoot system in the genus has been described as sympodial but with an unusual adnation of the horizontal and vertical shoots. The growth pattern of E. cellulosa was studied from field collected plants and plants grown in the greenhouse. Plants were extracted and measurements of horizontal and vertical shoot were taken. Dissections, paraffin sectioning and SEM's were used to examine shoot structure in early developmental stages. E. cellulosa was transplanted from the field to the greenhouse and different levels of Nitrogen and Phosphorus were added …