Soil Science Commons^™

Changes Of Soil Biogeochemistry Under Native And Exotic Plants Species, Yujie Hua

FIU Electronic Theses and Dissertations

Invasive plant species are major threats to the biodiversity and ecosystem stability. The purpose of this study is to understand the impacts of invasive plants on soil nutrient cycling and ecological functions. Soil samples were collected from rhizosphere and non-rhizosphere of both native and exotic plants from three genera, Lantana, Ficus and Schinus, at Tree Tops Park in South Florida, USA. Experimental results showed that the cultivable bacterial population in the soil under Brazilian pepper (invasive Schinus) was approximately ten times greater than all other plants. Also, Brazilian pepper lived under conditions of significantly lower available phosphorus …

Soil Building Processes In Reconstructed Tree Islands In The Everglades, Florida, Andres F. Rodriguez

FIU Electronic Theses and Dissertations

Soil building processes were studied in reconstructed tree islands in the Loxahatchee Impoundment Landscape Assessment, Florida. Soil building was evaluated by measuring litter production, litter decomposition, soil accretion, and changes in soil elevation under different hydrologic conditions, and by determining physicochemical characteristics of newly accreted soils. Tree islands showed higher litter production and soil accretion but a larger loss of soil elevation caused by subsidence at higher elevations and shorter inundation periods. Newly accreted soils exhibited higher nutrient concentrations, and organic matter (OM) than older soils. Most of the soil phosphorus was stored in the organic fraction. A positive correlation …

Elemental Analysis And Forensic Comparison Of Soils By Laser-Induced Breakdown Spectroscopy (Libs) And Laser Ablation Inductively Coupled Plasma Mass Spectrometry (La-Icp-Ms), Sarah C. Jantzi

FIU Electronic Theses and Dissertations

The elemental analysis of soil is useful in forensic and environmental sciences. Methods were developed and optimized for two laser-based multi-element analysis techniques: laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and laser-induced breakdown spectroscopy (LIBS). This work represents the first use of a 266 nm laser for forensic soil analysis by LIBS.

Sample preparation methods were developed and optimized for a variety of sample types, including pellets for large bulk soil specimens (470 mg) and sediment-laden filters (47 mg), and tape-mounting for small transfer evidence specimens (10 mg). Analytical performance for sediment filter pellets and tape-mounted soils was similar …