Rate of Post-Hurricane Barrier Island Recovery

Barrier island foredunes are key indicators of the rate of island transgression, in which small dunes exhibit rapid transgression through washover and breaching, and large dunes exhibit controlled transgression in response to sea level rise. Recent evidence suggests that the largest foredunes at Santa Rosa Island, Florida and Galveston Island, Texas exhibit sigmoidal recovery patterns over an approximately 10 year time period, and that high and low islands vary alongshore in a pattern that is reinforced if there is a sufficient recovery period. This study examines the resiliency of Assateague Island National Seashore, MD through its ability to return to its pre-storm condition following a hurricane. The primary hypothesis of this study is that the rate of recovery of each examined parameter at ASIS will exhibit a sigmoidal pattern as seen at Santa Rosa Island, and that recovery rates will vary alongshore due to high and low island areas. Foredune elevation data from 2000 and 2005 was compared and categorized into recovery periods based on the temporal difference between impactful storm surges and the 2005 elevation data. Morphometric parameters including dune crest, height, volume, and toe were extracted and used to characterize recovery. Logistic curves were modified to represent the growth patterns of each parameter and recovery was examined with respect to high and low island sections. The rates of recovery from this study were compared with the results of a previous at Santa Rosa Island, FL. Results from this study support recovery patterns identified in previous studies. Evidence also suggests that low dunes at Assateague Island cease to recover and that there is a limit to the growth of the smallest dunes. Land managers can use this knowledge as a resource in the preparation for and response to hurricanes, specifically as it relates to varying levels of vulnerability alongshore

Furthering Anti-Racist Practice: Reconciliation in Action (RéconciliACTION) (Discussion Paper)

Nursing scholarship and practice has been historically complicit in the (re)production of racial inequities by not acknowledging and countering their part in the legacy of colonization . This paper will discuss the implementation of an experiential transformative learning project, RéconciliACTION, grounded in critical social justice theory. Four elements – testimonial authority, experiential learning, reciprocity, and relationality - can be implemented in nursing education that value lived experience to create change toward address anti-Indigenous racism in educational settings and health institutions. Lessons from the RéconciliACTION Project reinforce the need to increase nursing educators' knowledge of such methods and practices. Essential to this process is the recognition of lived experience as knowledge via Testimonial Authority. The process of transformation begins with the integration of anti-racist practices and Indigenous content. This project seeks to create leaders and allies in the journey towards reconciliation, reducing anti-racist attitudes and practices in educational and medical facilitie

The Critical Zone of Coastal Barrier Systems

Barrier Islands represent some of the most dynamic and complex systems within the Critical Zone worldwide. Although coastal systems tend not to be recognized as Critical Zone environments, the evolution of Barrier Islands and the ecological functions they provide can be characterized in terms of a complex feedback among sediment supply (lithosphere), hydrology, the atmosphere, and ecology (biosphere). This represents an interesting departure from the traditional view of Barrier Island evolution (either regression or transgression) as a result of variations in sea level, sediment supply, and accommodation space. This chapter takes a Critical Zone approach to the response of Barrier Island evolution to sea-level rise and storm activity, explicitly recognizing the feedback among sediment supply, aeolian transport, disturbance regimes, vegetation development, and hydrology. © 2015 Elsevier B.V

Post-storm beach and dune recovery: Implications for barrier island resilience

The ability of beaches and dunes to recover following an extreme storm is a primary control of barrier island response to sea-level rise and changes in the frequency and/or magnitude of storm surges. Whereas erosion of the beach and dune occurs over hours and days, it can be years to decades before the beach and dune are able to recover to their pre-storm state. As a consequence, there are numerous descriptions of near-instantaneous beach and dune erosion due to storms, the immediate onshore transport of sand, and the initial phases of beach and dune recovery following a storm, but a paucity of data on long-term beach and dune recovery. A combination of previously published data from Galveston Island, Texas and new remotely sensed data from Santa Rosa Island, Florida is used in the present study to quantify the rate of dune recovery for dissipative and intermediate beach types, respectively. Recovery of the dune height and volume on Galveston Island was observed within two years following Hurricane Alicia (1983) and was largely complete within six years of the storm, despite extensive washover. In contrast, the dunes on Santa Rosa Island in Northwest Florida began to recover four years after Hurricane Ivan (2004), and only after the profile approached its pre-storm level and the rate of vegetation recovery (regrowth) was at a maximum. Results show that complete recovery of the largest dunes (in height and volume) will take approximately 10. years on Santa Rosa Island, which suggests that these sections of the island are particularly vulnerable to significant change in island morphology if there is also a change in the frequency and magnitude of storm events. In contrast, the areas of the island with the smallest dunes before Hurricane Ivan exhibited a rapid recovery, but no further growth in profile volume and dune height beyond the pre-storm volume and height, despite continued recovery of the largest dunes to their pre-storm height. A change in storm magnitude and/or frequency is a potential threat to barrier island resilience, particularly for those sections of the island where dune recovery has historically taken the longest time. Further study is required to determine how and why dune recovery varies for the dissipative and intermediate beaches of Galveston Island and Santa Rosa Island, respectively. © 2015 Elsevier B.V

Role of the Foredune in Controlling Barrier Island Response to Sea Level Rise

The height, volume, and alongshore extent of the foredune are primary controls on the response of barrier islands to the elevated storm surge that accompanies hurricanes and extra-tropical storms. In this respect, the ability of the foredune to recover following a storm determines whether a barrier island can maintain elevation as sea level rises and the island migrates landward through the redistribution of sediment to the back of the island through washover and breaching. This chapter provides a review of a body of recent fieldwork on the role of the foredune in controlling island transgression. It is argued that the role of the foredune to control washover and island transgression is analogous to that of a variable resistor in an electrical circuit, with the strength of the resistor dependent on the ability of the dune to recover in height and extent following each storm. Recovery of the foredune requires that sediment removed to the nearshore during a storm be returned to the beachface through the landward migration and welding of the innermost bars where it is eventually transported to the backshore and trapped by vegetation. Field observations from Padre Island in Texas, Santa Rosa Island in Florida, and Assateague Island in Virginia suggest that the recovery of dune height can be modeled using a sigmoidal growth curve, and that recovery can take up to a decade. The slow rate of dune recovery suggests that the resiliency of barrier islands to sea level rise is dependent on whether there is a change in the frequency and magnitude of storm events or an interruption to the exchange of sediment among the nearshore, beach, and dune. Ultimately, the height and volume of the foredune can be controlled by the framework geology (to varying degrees), which determines beach and nearshore state through the availability and texture of sediment and structural controls. In this respect, the response of barrier islands to sea level rise can be expected to vary regionally and alongshore as a reflection of diverse framework geology. The local response to sea level rise depends on the ability of the dune to recover following storms. Assuming no new sediment from alongshore or offshore sources, an increase in the frequency of washover will limit the ability of the dune to recover, and recent field evidence suggests that a change in dune height and volume is self-reinforcing, which suggests a lack of island resiliency. Further testing is required to determine how the field observations and modeling described in this chapter from a select group of barrier islands around the United States are applicable to other islands and consistent throughout the evolution of a barrier island

A Meiotic Drive Element in the Maize Pathogen Fusarium verticillioides Is Located Within a 102 kb Region of Chromosome V

Fusarium verticillioides is an agriculturally important fungus because of its association with maize and its propensity to contaminate grain with toxic compounds. Some isolates of the fungus harbor a meiotic drive element known as Spore killer (SkK) that causes nearly all surviving meiotic progeny from an SkK × Spore killer-susceptible (SkS) cross to inherit the SkK allele. SkK has been mapped to chromosome V but the genetic element responsible for meiotic drive has yet to be identified. In this study, we used cleaved amplified polymorphic sequence markers to genotype individual progeny from an SkK × SkS mapping population. We also sequenced the genomes of three progeny from the mapping population to determine their single nucleotide polymorphisms. These techniques allowed us to refine the location of SkK to a contiguous 102 kb interval of chromosome V, herein referred to as the Sk region. Relative to SkS genotypes, SkK genotypes have one extra gene within this region for a total of 42 genes. The additional gene in SkK genotypes, herein named SKC1 for Spore Killer Candidate 1, is the most highly expressed gene from the Sk region during early stages of sexual development. The Sk region also has three hyper-variable regions, the longest of which includes SKC1. The possibility that SKC1, or another gene from the Sk region, is an essential component of meiotic drive and spore killing is discussed