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Full-Text Articles in Physical Sciences and Mathematics
Estimating Evolutionary Volatility In A Maximum-Likelihood Framework, Samuel Warren Tybout
Estimating Evolutionary Volatility In A Maximum-Likelihood Framework, Samuel Warren Tybout
Graduate Theses, Dissertations, and Problem Reports
Evolutionary volatility is a trait that encompasses a clade’s combined capacity for origination and extinction. High volatility increases extinction risk, and declining global extinction rates are thought to be linked to declining volatility. Despite volatility’s scientific importance, there is no standardized way of measuring it. This study provides a new method, derived from a stochastic birth-death model, of estimating evolutionary volatility from fossil data. Simulations indicate that the method produces accurate and precise estimates for large fossil datasets. Analysis of fossil data for five bivalve families (Lucinidae, Mytilidae, Pectinidae, Pholadomyidae, and Veneridae) indicates that diversity projections made from the estimates …
Habitat Stability In Appalachian Headwater Systems And Potential Impacts On Brook Trout Populations, Zac F.W Zacavish
Habitat Stability In Appalachian Headwater Systems And Potential Impacts On Brook Trout Populations, Zac F.W Zacavish
Graduate Theses, Dissertations, and Problem Reports
The impact climate change will have on the habitat for Brook Trout (Salvelinus fontinalis) could directly impact key demographic characteristics. Traditionally, broad-scale studies of climate change effects on the family Salmonidae focus on the thermal shifts predicted over the next century. While some studies shed light onto other variables such as biotic interactions, flow regime, and disturbance, the significance of the climate-trout interaction is not always observed. With the high degree of influence climate cycles can have on habitat and channel morphology, this study aimed to highlight temporal habitat shifts to begin addressing climate-habitat interaction. By studying habitat distribution …
Leaf Angle And Leaf Stomata Responses To Experimental Drought In Quercus Velutina And Acer Saccharum, Brittany Nichole Casey
Leaf Angle And Leaf Stomata Responses To Experimental Drought In Quercus Velutina And Acer Saccharum, Brittany Nichole Casey
Graduate Theses, Dissertations, and Problem Reports
The possibility of increased severity and frequency of drought conditions, as a result of global climate variability, greatly complicates our ability to forecast future forest functions such as productivity and carbon sequestration. Assessing how tree species vary in their response to drought can aid in predicting the impact on forest ecosystems as a whole. Throughfall exclusion (TfE) experiments are potentially useful tools to simulate realistic drought conditions within intact forest ecosystems. We employed a TfE experiment during the 2018 growing season within the WV Land Trust’s Elizabeth’s Woods Nature Preserve, near Morgantown, WV, to assess the leaf angle and leaf …