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Results for “Transactions of the American Philosophical Society”

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Geology of the Black Mingo Group (Paleocene) in the Kingstree and St. Stephen areas of South Carolina

Paleocene vertebrate remains from the areas of Kingstree and St. Stephen, South Carolina, come from the Rhems and Williamsburg formations of the Black Mingo Group. Sedimentary textures and fossils indicate that both units accumulated in shallow, nearshore marine, lagoonal, and deltaic depositional environments. Calcareous nannofossils and dinoflagellates indicate that the vertebrate-bearing portions of the Williamsburg Formation near St. Stephen belong within calcareous nannoplankton Zones NP 3-5 (Lower Bridge Member) and within calcareous nannoplankton zones NP 8-9 (Chicora Member). Paleocene vertibrate remains from Kingstree probably all come from near the base of the Rhems Formation.

South Carolina

Extreme rainfall, vulnerability and risk: a continental-scale assessment for South America

Extreme weather continues to preoccupy society as a formidable public safety concern bearing huge economic costs. While attention has focused on global climate change and how it could intensify key elements of the water cycle such as precipitation and river discharge, it is the conjunction of geophysical and socioeconomic forces that shapes human sensitivity and risks to weather extremes. We demonstrate here the use of high-resolution geophysical and population datasets together with documentary reports of rainfall-induced damage across South America over a multi-decadal, retrospective time domain (1960–2000). We define and map extreme precipitation hazard , exposure , affected populations, vulnerability and risk , and use these variables to analyse the impact of floods as a water security issue. Geospatial experiments uncover major sources of risk from natural climate variability and population growth, with change in climate extremes bearing a minor role. While rural populations display greatest relative sensitivity to extreme rainfall, urban settings show the highest rates of increasing risk. In the coming decades, rapid urbanization will make South American cities the focal point of future climate threats but also an opportunity for reducing vulnerability, protecting lives and sustaining economic development through both traditional and ecosystem-based disaster risk management systems.

Philosophical Transactions of the Royal Society A:

Marine disease impacts, diagnosis, forecasting, management and policy

As Australians were spending millions of dollars in 2014 to remove the coral-eating crown of thorns sea star from the Great Barrier Reef, sea stars started washing up dead for free along North America's Pacific Coast. Because North American sea stars are important and iconic predators in marine communities, locals and marine scientists alike were alarmed by what proved to be the world's most widespread marine mass mortality in geographical extent and species affected, especially given its mysterious cause. Investigative research using modern diagnostic techniques implicated a never-before-seen virus [ 1 ]. The virus inspired international attention to marine diseases, including this theme issue.

Philosophical Transactions of the Royal Society B:

The effects of ENSO and the North American monsoon on mast seeding in two Rocky Mountain conifer species

We aimed to disentangle the patterns of synchronous and variable cone production (i.e. masting) and its relationship to climate in two conifer species native to dry forests of western North America. We used cone abscission scars to reconstruct ca 15 years of recent cone production in Pinus edulis and Pinus ponderosa , and used redundancy analysis to relate time series of annual cone production to climate indices describing the North American monsoon and the El Niño Southern Oscillation (ENSO). We show that the sensitivity to climate and resulting synchrony in cone production varies substantially between species. Cone production among populations of P. edulis was much more spatially synchronous and more closely related to large-scale modes of climate variability than among populations of P. ponderosa . Large-scale synchrony in P. edulis cone production was associated with the North American monsoon and we identified a dipole pattern of regional cone production associated with ENSO phase. In P. ponderosa , these climate indices were not strongly associated with cone production, resulting in asynchronous masting patterns among populations. This study helps frame our understanding of mast seeding as a life-history strategy and has implications for our ability to forecast mast years in these species.

Philosophical Transactions of the Royal Society B:

Exploring links between systematics and fisheries management

We argue that the sustainable management of fisheries resources depends on an understanding of the taxonomy and systematics of fish. Toward this end, it is necessary for fisheries managers to understand and apply the various species concepts that have been developed by taxonomists and evolutionary biologists and to decide, based on a philosophical position, what is necessary and sufficient for a taxon to be recognized as a distinct species. If species are viewed as ontological individuals and as such exist in nature, then it makes sense for managers to develop strategies to sustain and manipulate given populations to achieve management goals. In this series of papers, the authors explore species concepts with respect to fish and demonstrate the value of understanding species concepts, systematics, and taxonomy in addressing modern fisheries management problems.

Transactions of the American Fisheries Society