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Full-Text Articles in Life Sciences
Post-Fire Interactions Between Soil Water Repellency, Islands Of Fertility, And Bromus Tectorum Invasibility, Kaitlynn Jane Fernelius
Post-Fire Interactions Between Soil Water Repellency, Islands Of Fertility, And Bromus Tectorum Invasibility, Kaitlynn Jane Fernelius
Theses and Dissertations
An intrinsic link exists between soil moisture and soil nitrogen. Factors that increase or decrease soil moisture can have a profound effect on soil nitrogen cycling, which may have later repercussions in the plant community. Post-fire soil water repellency is one factor that can limit soil moisture acquisition and may indirectly affect nitrogen cycling and weed invasion in woody islands of fertility. Plots centered on burned Juniperus osteosperma trees were either left untreated or treated with a surfactant to ameliorate water repellency. Two years later, soils were excavated from the untreated and treated field plots. In the greenhouse, half of …
Population Genetic Structure Of Bromus Tectorum In The American Desert Southwest, Desiree Rochelle Eldon
Population Genetic Structure Of Bromus Tectorum In The American Desert Southwest, Desiree Rochelle Eldon
Theses and Dissertations
Following its introduction to North America in the late nineteenth century, Bromus tectorum L., an inbreeding invasive winter annual grass, has become dominant on millions of hectares of sagebrush steppe habitat throughout Intermountain Western North America. It appears that within the last 30-40 years, B. tectorum has expanded its range southward into the Mojave Desert and also into more climatically extreme salt desert environments. Previous research using microsatellite markers and experimental studies has suggested that lineages found in desert habitats are genetically distinct from those found in the sagebrush-steppe habitat and possess suites of traits that pre-adapt them to these …
The Bromus Tectorum-Pyrenophora Semeniperda Pathosystem, Heather Finch
The Bromus Tectorum-Pyrenophora Semeniperda Pathosystem, Heather Finch
Theses and Dissertations
Variable mortality of Pyrenophora semeniperda--infected Bromus tectorum seeds has been referred to as a "race for survival", stating that seeds that germinate quickly are more likely to escape pathogen-caused mortality. Dormancy status is not the only variable determining outcomes within the Bromus-Pyrenophora pathosystem. Varying temperature and exposure to water may strongly influence germination outcomes of B. tectorum when in the presence of P. semeniperda. Low water potentials characteristic of semi-arid soils are often over-looked in the context of seed pathogens, and are ecologically relevant- especially for plant species that inhabit intermittently dry environments. To adequately characterize the Bromus tectorum-Pyrenophora semeniperda …