Severe Hurricanes Research Articles

Linking soils and streams: Response of soil solution chemistry to simulated hurricane disturbance mirrors stream chemistry following a severe hurricane

Understanding the drivers of forest ecosystem response to major disturbance events is an important topic in forest ecology and ecosystem management. Because of the multiple elements included in most major disturbances such as hurricanes, fires, or landslides, it is often difficult to ascribe a specific driver to the observed response. This is particularly true for the long-term effects of hurricanes on forest ecosystem nutrient cycling. Hurricane disturbance opens the forest canopy by removing leaves and branches or snapping boles, and in so doing turns living biomass into debris that is deposited on the forest floor. At the watershed scale, past work in the Luquillo Mountains of Puerto Rico shows that these changes in forest structure and detrital dynamics result in large increases in stream water nitrate and potassium concentrations in streams draining volcaniclastic terrain. The Canopy Trimming Experiment (CTE) was designed to simulate the major effects of hurricane disturbance, and disentangle the effects of canopy opening and debris addition on forest biology and biogeochemistry following a hurricane. Using the chemistry of soil solution as an integrated indicator of biogeochemical response to hurricane simulation, the experimental manipulations show that the synergistic effects of both canopy opening and debris addition are needed to elicit one of the whole-watershed responses to hurricanes, a large pulse of nitrate (NO3) concentration in stream water that lasted approximately 18months. Manipulation of either canopy openness or debris addition alone had little effect on soil solution chemistry for NO3, or for any other solute measured (dissolved organic matter, phosphate, ammonium, major cations and anions, and silica). None of the treatments resulted in the increased potassium (K) seen in stream water following hurricane disturbance. For NO3, the time course of response and recovery following combined treatments of canopy opening and debris addition was similar to that observed in stream water after actual hurricanes. The CTE provided further evidence that tree regrowth following hurricane disturbance controls the return of NO3 concentrations to pre-hurricane levels in this tropical forest. The lack of response in K to hurricane simulation suggests that leaching of the added debris, which was not captured in the experimental manipulations, is a major driver of K concentrations following disturbance. Hurricane disturbance, which is significant in many humid tropical forests, results in pulsed outputs of nitrogen in stream water that can be clearly ascribed to interactions between damage and recovery of canopy vegetation, and decomposition of detrital inputs on the forest floor.

Coqui frog populations are negatively affected by canopy opening but not detritus deposition following an experimental hurricane in a tropical rainforest

Hurricanes, cyclones, and typhoons are common disturbances in many island and coastal forests. There is a lack of understanding of the importance to forest biota of the two major physical aspects that occur simultaneously during a hurricane: canopy disturbance and detritus (debris) deposition onto the ground. Using a replicated factorial design, our study involved experimentally determining the independent and interactive effects of canopy opening and debris additions to the forest floor on densities of coqui frogs (Eleutherodactylus coqui). Coquies are the dominant amphibian, and second most common vertebrate species, in the Luquillo Experimental Forest (LEF), a montane, tropical rainforest in northeastern Puerto Rico that frequently experiences hurricanes. Frogs were sampled in all twelve 30×30m plots at three periods prior to installing treatments (July 2003, January 2004, July 2004), and at months 1, 3, 6, and 12 post-treatment. The degree of canopy opening and amount of debris deposited onto the forest floor by our experimental treatments closely mimicked conditions resulting from Hurricane Hugo, a severe hurricane that passed over the LEF in 1989. Based on findings from past studies involving natural hurricanes in the LEF, we predicted that coqui densities would increase in response to debris additions, and decrease or remain unchanged in response to canopy disturbance. However, we found that debris deposition had no significant effect on coqui density and that the opening of the canopy was the dominant aspect affecting coqui by significantly reducing their densities. We identified several possible explanations for the decreased coqui densities in open-canopy plots, including decreased litter moisture and insect prey, and temporal and spatial scales associated with disturbance that may have influenced coqui behavior. Following natural hurricanes, and in light of our findings from experimental hurricane impacts, we expect that coquies benefit from patches of intact canopy while suffering reduced densities in open-canopy settings. Furthermore, based on our study and other experimental forest studies involving frogs, future forest practices that remove significant canopy should probably be viewed as having an initially (up to 1year) negative effect on the frog community.

Seven-year responses of trees to experimental hurricane effects in a tropical rainforest, Puerto Rico

We experimentally manipulated key components of severe hurricane disturbance, canopy openness and detritus deposition, to determine the independent and interactive effects of these components on tree recruitment, forest structure, and diversity in a wet tropical forest in the Luquillo Experimental Forest, Puerto Rico. Canopy openness was increased by trimming branches, and we manipulated debris by adding or subtracting the trimmed materials to the trimming treatments, in a 2×2 factorial design replicated in three blocks. Tree (stems ⩾1cm diameter at breast height) responses were measured during the 9-year study, which included at least 1year of pre-manipulation monitoring. When the canopy was trimmed, stem densities increased >2-fold and rates of recruitment increased >25-fold. Deposition of canopy debris did not markedly affect stem densities but did have small yet significant effects on tree basal area. Basal area increased about 10% when debris was added to plots with intact canopies; the other treatments exhibited smaller or no increases in basal area over time. Much of the dynamics of stem densities were due to changes in the smallest size class (1–2.5cm diameter), which responded with a pulse of recruitment in the canopy trimmed treatments, and a steady loss in plots with intact canopies. The decreases in stem densities in the plots with intact canopies is attributed to observed on-going forest thinning from the last natural severe hurricane disturbance in 1998. Given these repeated hurricane effects, our study enabled an experimental test of the Intermediate Disturbance Hypothesis (IDH), for which we predicted an increase in species diversity in canopy trimmed treatments and a loss of species in the treatments with intact canopies. Measured patterns of diversity gave partial support to the predictions of IDH, although raw species richness of sampled plots fit the predictions better than richness adjusted for differences in stem densities among treatments. Ordination of species responses in the community identified a guild of pioneer species responding to the trimmed treatments, but not the debris additions, amongst substantial background variation in species composition unrelated to the experimental treatments. These results are consistent with a growing consensus that, while trade-offs of resilience and resistance govern many species responses to hurricane disturbance, other environmental and historical factors are equally or more important in governing community dynamics in hurricane-disturbed forests.

Understory fern community structure, growth and spore production responses to a large-scale hurricane experiment in a Puerto Rico rainforest

Ferns are abundant in most rainforest understories yet their responses to hurricanes have not been well-studied. Fern community structure, growth and spore production were monitored for two years before and five years after a large-scale experiment that simulated two key components of severe hurricane disturbance: canopy openness and debris deposition. The canopy was opened by cutting branches above 3m and the fallen leaf and woody debris was either added to or removed from the forest floor resulting in four treatments that were replicated three times in a factorial design. Of the 16 fern species observed during the experiment 12 were present before treatments were applied. All but two of the 16 species had densities <250ha−1; Thelypteris deltoidea (2258ha−1) and Cyathea borinquena (1521ha−1) were by far the most common ferns. Under simulated hurricane conditions (open canopy and debris deposition) abundance levels for both T. deltoidea and C. borinquena were highly resilient and returned to pre-disturbance conditions within three years; therefore the resident (non-pioneer) fern species continued to dominate after disturbance. However, several other variables had increasing or decreasing responses that had not returned to pre-treatment levels by the fifth and final year of the experiment. Four pioneer species appeared in low abundance almost immediately after the canopy was opened, including three native species that spread via spore germination and the invasive Nephrolepis brownii that spread by runners. Debris deposition resulted in high mortality for 7 of 12 fern species, with C. borinquena among the species little affected and increases in recruitment following mortality of T. deltoidea under open canopy. Individuals of both T. deltoidea and C. borinquena responded to higher light levels with growth spurts reflected in up to two- to three-fold increases in leaf production and emergence of longer leaves. Spore production rates for both T. deltoidea and C. borinquena had been low in the undisturbed pre-treatment forest, but more than doubled in the years that followed canopy opening. Hurricane impacts to this tropical forest alter the fern community by (1) debris deposition burying individuals and initially reducing some population sizes, and (2) canopy openness overwhelming the negative effects of debris deposition and stimulating growth and reproduction that can last ⩾5years. Changes resulting from hurricane disturbance that affect the fern-dominated herbaceous layer may ultimately influence structure and function of the long-term understory plant community and consequently the habitat of litter- and soil-dwelling organisms.

Retrieving hurricane wind speeds using cross-polarization C-band measurements

Abstract. Hurricane-force wind speeds can have a large societal impact and in this paper microwave C-band cross-polarized (VH) signals are investigated to assess if they can be used to derive extreme wind-speed conditions. European satellite scatterometers have excellent hurricane penetration capability at C-band, but the vertically (VV) polarized signals become insensitive above 25 m s−1. VV and VH polarized backscatter signals from RADARSAT-2 SAR imagery acquired during severe hurricane events were compared to collocated SFMR wind measurements acquired by NOAA's hurricane-hunter aircraft. From this data set a geophysical model function (GMF) at strong-to-extreme/severe wind speeds (i.e., 20 m s−1 &lt; U10 &lt; 45 m s−1) is derived. Within this wind speed regime, cross-polarized data showed no distinguishable loss of sensitivity and as such, cross-polarized data can be considered a good candidate for the retrieval of strong-to-severe wind speeds from satellite instruments. The upper limit of 45 m s−1 is defined by the currently available collocated data. The validity of the derived relationship between wind speed and VH backscatter has been evaluated by comparing the cross-polarized signals to two independent wind-speed data sets (i.e., short-range ECMWF numerical weather prediction (NWP) model forecast winds and the NOAA best estimate 1-minute maximum sustained winds). Analysis of the three comparison data sets confirm that cross-polarized signals from satellites will enable the retrieval of strong-to-severe wind speeds where VV or horizontal (HH) polarization data has saturated. The VH backscatter increases exponentially with respect to wind speed (linear against VH [dB]) and a near-real-time assessment of maximum sustained wind speed is possible using VH measurements. VH measurements thus would be an extremely valuable complement on next-generation scatterometers for hurricane forecast warnings and hurricane model initialization.

Mobility Benefits of Intermediate Crossovers on Contraflow Facilities during Hurricane Evacuation

A contraflow facility, in which the direction of traffic on one or more travel lanes is reversed to increase outbound capacity, is a major component of hurricane evacuation plans in many coastal states. Contraflow facilities typically are implemented when significant evacuation demand is expected (e.g., during a severe hurricane). Typical contraflow plans have one upstream crossover that routes vehicles into the contraflow lanes and one downstream crossover that routes vehicles back into the regular lanes. How can contraflow facilities best be used to optimize evacuation performance? The impact on mobility of additional intermediate crossovers between the beginning and termination points of contraflow is investigated. The proposed heuristic algorithm is the first attempt in the literature to provide a systematic approach–-with iterative elimination–-to determine the critical intermediate crossover locations that provide maximum improvement in evacuation performance. Results of a case study of I-64 in Hampton Roads, Virginia, indicate that adding intermediate crossovers improves network performance for medium-and high-demand evacuation situations. For low-demand situations, the addition of intermediate crossovers does not improve network performance. Therefore, any consideration of intermediate crossovers for low-demand evacuations must be solely to provide access to roadside facilities such as gas, food, and emergency services. For medium- and high-demand situations, the average travel time improved 28% when four intermediate crossovers of the 44 potential crossover locations were deployed in the I-64 corridor.

Performance of Composite Structural Insulated Panels after Exposure to Floodwater

AbstractDegradation of structural material because of floodwater is one of the major damaging effects during flooding events. As a result, thousands of homes in coastal states, especially those that are constructed from wood-based materials, have been destroyed after each severe hurricane. This paper evaluates the performance a new type of composite structural insulated panel (CSIP) after exposure to floodwater. The proposed composite panel is made of low-cost orthotropic thermoplastic glass/polypropylene laminate as the facesheet and expanded polystyrene foam as the core. The proposed CSIP panel is intended to overcome problems of traditional structural insulated panels, especially those resulting from strength degradation. An extensive experimental program was conducted to investigate the flexural strength degradation of CSIPs after exposure to floodwater for various periods of time. The residual flexural strength following full submergence of CSIPs in simulated floodwater was evaluated using a four-poi...

Hurricane-Driven Patterns of Clonality in an Ecosystem Engineer: The Caribbean Coral Montastraea annularis

K-selected species with low rates of sexual recruitment may utilise storage effects where low adult mortality allows a number of individuals to persist through time until a favourable recruitment period occurs. Alternative methods of recruitment may become increasingly important for such species if the availability of favourable conditions for sexual recruitment decline under rising anthropogenic disturbance and climate change. Here, we test the hypotheses that asexual dispersal is an integral life history strategy not only in branching corals, as previously reported, but also in a columnar, ‘K-selected’ coral species, and that its prevalence is driven by the frequency of severe hurricane disturbance. Montastraea annularis is a long-lived major frame-work builder of Caribbean coral reefs but its survival is threatened by the consequences of climate induced disturbance, such as bleaching, ocean acidification and increased prevalence of disease. 700 M. annularis samples from 18 reefs within the Caribbean were genotyped using six polymorphic microsatellite loci. We demonstrate that asexual reproduction occurs at varying frequency across the species-range and significantly contributes to the local abundance of M. annularis, with its contribution increasing in areas with greater hurricane frequency. We tested several competing hypotheses that might explain the observed pattern of genotypic diversity. 64% of the variation in genotypic diversity among the sites was explained by hurricane incidence and reef slope, demonstrating that large-scale disturbances combine with local habitat characteristics to shape the balance between sexual and asexual reproduction in populations of M. annularis.

GCM出力に基づいた日本域における降雨イベントの将来変化に関する研究

There is growing concern on a global scale about the significant increase of extreme meteorological events in recent years, e.g., torrential rains, heavy snows, and severe hurricanes. The current study conducted frequency and scale analysis of torrential rains to examine future variations of rainfall events due to global warming, based on GCM (Global Climate Model) outputs calculated under the present condition (1979-2008), near-future condition (2015-2044), and future condition (2075-2104) by the KAKUSHIN Program of the Ministry of Education, Culture, Sports, Science, and Technology (MEXT). DAD analysis was also attempted to clarify whether and how the statistical relationship will change in the future with global warming between maximum areal rainfall and the area and duration of each rainfall event. Results show that the occurrence frequency of torrential rains could markedly increase in some regions of Japan, and that DAD relationship could significantly change in the future, and there could be a numerical increase in rainfall events which depart from the regression curve of DAD relationship due to a greater rainfall intensity or larger area of rainfall than most other events. Visual inspections of each event suggest that such extreme events could be attributed to Baiu front activated by the sufficient amount of water vapor and typhoons strengthened by the higher sea surface temperature due to global warming in the future.

Population dynamics of threatened elkhorn coral in the northern Florida Keys, USA

Caribbean elkhorn coral Acropora palmata (Lamarck, 1816) was once so widespread and abundant that geologists use its fossils to measure sea levels from the Pleistocene through the Holocene. Now it exists at a small fraction of its former abundance and is listed, along with a con- gener, as 'threatened' under the US Endangered Species Act. We conducted annual demographic surveys on the northern Florida Keys (USA) population from 2004 to 2010. Percent cover of the benthos, number of colonies, and dominance by large individuals declined throughout the study period. We created population matrix models for each annual interval of the study, which included a severe hurricane year (2005-2006). Hurricane recurrence was simulated stochastically along with multiple outplanting scenarios. Population depletion is predicted given a return time for severe hurricanes of 20 yr or less. Elasticity analysis showed that the largest individuals have the greatest contribution to the rate of change in population size. Active management through out- planting can provide a positive population trajectory over the short term, especially if colonies are reared for several years before transplanting. However, the former abundance of this species sug- gests that background life history traits, specifically rates of growth versus shrinkage measured herein, are fundamentally different from what they must have been in the past. Ultimately, recov- ery of this species will depend on enacting local short-term management solutions while improv- ing regional and global environmental conditions.

Climate and catastrophe in Cuba and the Atlantic world in the age of revolution

From 1750 to 1800, a critical period that saw the American Revolution, French Revolution, and Haitian Revolution, the Atlantic world experienced a series of environmental crises, including more frequent and severe hurricanes and extended drought. Drawing on historical climatology, environmental history, and Cuban and American colonial history, Sherry Johnson innovatively integrates the region's experience with extreme weather events and patterns into the history of the Spanish Caribbean and the Atlantic world. By superimposing this history of natural disasters over the conventional timeline of sociopolitical and economic events in Caribbean colonial history, Johnson presents an alternative analysis in which some of the signal events of the Age of Revolution are seen as consequences of ecological crisis and of the resulting measures for disaster relief. For example, Johnson finds that the general adoption in 1778 of free trade in the Americas was catalyzed by recognition of the harsh realities of food scarcity and the needs of local colonists reeling from a series of natural disasters. Weather-induced environmental crises and slow responses from imperial authorities, Johnson argues, played an inextricable and, until now, largely unacknowledged role in the rise of revolutionary sentiments in the eighteenth-century Caribbean. |From 1750 to 1800, a critical period that saw the American Revolution, French Revolution, and Haitian Revolution, the Atlantic world experienced a series of environmental crises, including more frequent and severe hurricanes and extended drought. Drawing on historical climatology, environmental history, and Cuban and American colonial history, Sherry Johnson innovatively integrates the region's experience with extreme weather events and patterns into the history of the Spanish Caribbean and the Atlantic world.

The Lessons of Katrina, Learned and Unlearned

HILL, D., 2012. The lessons of Katrina, learned and unlearned.Originally planned to evaluate storm surge barriers, the New York City Panel on Climate Change (NPCC) instead developed a process for government agencies and private stakeholders to adapt critical infrastructure in New York City to the effects of climate change. In its influential 2010 report, the NPCC ignored the literature documenting the lessons learned from Hurricane Katrina striking New Orleans in 2005. A report by the American Society of Civil Engineers (ASCE) sums up these lessons in 10 calls to action. An examination of the NPCC report suggests that half of these lessons have been learned and half have not. Essentially, the ASCE makes public safety, health, and welfare, not adapting critical infrastructure, its top priorities. The NPCC report fails to quantify the risks, does not address the question of an acceptable level of risk, and does not evaluate the consequences of severe coastal flooding. Although storm surge barriers have been found to be hydrologically and technically feasible, they are dismissed as mere contributions to the discussion that are not needed for at least the next several decades, despite the report's own accounting of the extreme uncertainty and possible effects of severe hurricanes and nor'easters. The NPCC report features Flexible Adaptation Pathways to plan and revise adaptation measures over time, which ignore the possibility of hedging strategies and the well-established precautionary principle. Without an engineering presence, the NPCC also overlooks consideration of lead times in planning major projects. It is concluded that the NPCC report is delaying regional measures against severe coastal flooding, discouraging hedging and the precautionary principle, and deterring adequate measures to protect public safety, health, and welfare.

Recruitment and Growth of Old World Climbing Fern in Hurricane-Caused Canopy Gaps

Abstract Following 2 y of severe hurricanes in 2004 and 2005, we examined the role of canopy gaps in promoting recruitment and growth of the exotic fern, Old World climbing fern Lygodium microphyllum (hereafter Lygodium), on tree islands of the Arthur R. Marshall Loxahatchee National Wildlife Refuge, Florida. We selected 12 sample tree islands, on which we placed three 1-m2 plots in a hurricane-caused canopy gap and three plots in an adjacent closed canopy area. Spore traps were placed in canopy gaps and closed canopy areas to quantify the number of spores reaching the forest floor on each island. In addition, in each plot occurrence and growth of Lygodium was measured across four height classes (recruitment class, understory, midstory, and canopy). We predicted that recruitment and growth of Lygodium would be higher in canopy gaps than in closed canopy areas. After 3 y of biannual monitoring, a significantly greater number of spores were foundin canopy gaps (4,804 spores·m2·d) than in closed canopy areas (4,288 spores·m2·d). Furthermore, we observed significantly greater recruitment and growth in canopy gaps compared with closed canopy areas in the recruitment class only. Presence of recruitment-class Lygodium in canopy gaps increased from four to five treatment areas and decreased from 1 to 0 treatment areas in closed canopy areas. These results suggest differences in recruitment and growth of Lygodium between canopy gaps and closed canopy areas on tree islands after severe hurricanes. However, despite the large number of spores in both canopy gaps and closed canopy areas, recruitment and growth were much lower than expected, with only two treatment areas having an average percent cover greater than 10% in any height class. If conducted within several years after a hurricane, focused monitoring efforts on hurricane-impacted tree islands may allow managers to detect and treat new infestations before they are able to overrun tree islands.

A tool for rapid post-hurricane urban tree debris estimates using high resolution aerial imagery

Coastal communities in the southeast United States have regularly experienced severe hurricane impacts. To better facilitate recovery efforts in these communities following natural disasters, state and federal agencies must respond quickly with information regarding the extent and severity of hurricane damage and the amount of tree debris volume. A tool was developed to detect downed trees and debris volume to better aid disaster response efforts and tree debris removal. The tool estimates downed tree debris volume in hurricane affected urban areas using a Leica Airborne Digital Sensor (ADS40) and very high resolution digital images. The tool employs a Sobel edge detection algorithm combined with spectral information based on color filtering using 15 different statistical combinations of spectral bands. The algorithm identified downed tree edges based on contrasts between tree stems, grass, and asphalt and color filtering was then used to establish threshold values. Colors outside these threshold values were replaced and excluded from the detection processes. Results were overlaid and an “edge line” was placed where lines or edges from longer consecutive segments and color values within the threshold were met. Where two lines were paired within a very short distance in the scene a polygon was drawn automatically and, in doing so, downed tree stems were detected. Tree stem diameter–volume bulking factors were used to estimate post-hurricane tree debris volumes. Images following Hurricane Ivan in 2005 and Hurricane Ike in 2008 were used to assess the error of the tool by comparing downed tree counts and subsequent debris volume estimates with post-hurricane photo-interpreted downed tree counts and actual field measured estimates of downed tree debris volume. The errors associated with the use of the tool and potential applications are also presented.

CHILDREN’S HEALTH: AAP Publishes Oil Protection Guidelines for Children

Sparked by requests from anxious parents throughout the U.S. Gulf Coast region after the Deepwater Horizon oil rig exploded on 20 April 2010, the American Academy of Pediatrics (AAP) worked with the Pediatric Environmental Health Specialty Units (PEHSU)1 to develop fact sheets for clinicians and parents that pulled together the best available information on protecting children against oil exposures.2 The recommendations, which have been endorsed by the American College of Medical Toxicology and the American Academy of Clinical Toxicology, cover a wide range of measures addressing air, water, beach, and food issues, and they can be applied in any oil-exposure situation.3 The recommendations are only professional best estimates based on the limited information about health effects of oil spills on adults, acknowledges Katherine Kirkland, executive director of the Association of Occupational and Environmental Clinics, which runs PEHSU. “There really isn’t any research done on children,” she says. The fact sheets will be updated as more information becomes available, says Scott Needle, a Florida pediatrician and member of the AAP Disaster Preparedness Advisory Council. Along with physical health concerns, the fact sheets address psychological problems that may develop in children because of worries about their own health or that of their parents. Needle says it’s essential for parents to try to head off problems by talking with their children and to reassure them that people are working to clean up the oil and keep this from happening again. “We are also concerned about the potential long-term community effects, particularly economic and psychological, and especially affecting areas that have already been battered by severe hurricanes and other stressors in recent years,” Needle says. “The majority of our experience in long-term effects comes from studying the Exxon Valdez spill in Alaska, and affected communities there are still dealing with the mental health effects.” Even if children do not exhibit health symptoms directly, he says, their overall health and sense of well-being may continue to be impacted on a long-term basis. John Lanza, director of the Escambia County Health Department in Pensacola, Florida, had not heard of the PEHSU guidelines,4 but he says his county adopted similar recommendations based on research conducted by a consortium of Florida panhandle counties after the spill began. The county also conducted an extensive community education effort that parents and children seem to have heeded. The number of acute health problems reported so far has been minimal.5 Data on longer-term effects on children may be hard to come by, however—of the four Gulf states tracking self-reported spill-related health complaints, only Louisiana is breaking out exposure and health effect data by age,5 and no definitive plans for researching health effects on children have surfaced. Moreover, as recently as mid-September new sightings of oil were being reported for several Louisiana beaches, marshes, and offshore areas,6 and there are widespread concerns that oil will continue to resurface in still other areas when storms pass through. It’s extremely difficult to predict how soon after any given storm that it will be safe to visit shoreline areas, says Stephen West, a Coast Guard spokesman working with the Unified Area Command.

Effect of severe hurricanes on biorock coral reef restoration projects in Grand Turk, Turks and Caicos Islands.

Artificial reefs are often discouraged in shallow waters over concerns of storm damage to structures and surrounding habitat. Biorock coral reef restoration projects were initiated in waters around 5 m deep in Grand Turk, at Oasis (October 2006) and at Governor's Beach (November 2007). Hemi-cylindrical steel modules, 6m long were used, four modules at Oasis and six at Governor's Beach. Each project has over 1200 corals transplanted from sites with high sedimentation damage, and are regularly monitored for coral growth, mortality and fish populations. Corals show immediate growth over wires used to attach corals. Growth has been measured from photographs using a software program and is faster at Governor's Beach. After hurricanes Hanna and Ike (September 2008) the Governor's Beach structure was fully standing since the waves passed straight through with little damage, the Oasis structures which were tie-wired rather than welded had one module collapse (since been replaced with a new, welded structure). Hurricane Ike was the strongest hurricane on record to hit Grand Turk. Most cables were replaced following the hurricanes due to damage from debris and high wave action. The projects lost about a third of the corals due to hurricanes. Most of those lost had only been wired a few days before and had not yet attached themselves firmly. These projects have regenerated corals and fish populations in areas of barren sand or bedrock and are now attractive to snorkelers. High coral survival and low structural damage after hurricanes indicate that Biorock reef restoration can be effective in storm-impacted areas.

Loss of Resources and Hurricane Experience as Predictors of Postpartum Depression Among Women in Southern Louisiana

After a natural disaster, mental disorders often become a long-term public health concern. Previous studies under smaller-scale natural disaster conditions suggest loss of psychosocial resources is associated with psychological distress. We examined the occurrence of depression 6 and 12 months postpartum among 208 women residing in New Orleans and Baton Rouge, Louisiana, who were pregnant during or immediately after Hurricane Katrina's landfall. Based on the Conservation of Resources (COR) theory, we explored the contribution of both tangible/financial and nontangible (psychosocial) loss of resources (LOR) on the outcome of depression, measured using the Edinburgh Postnatal Depression Scale (EPDS). We also investigated the influence on depression of individuals' hurricane experience through a Hurricane Experience Score (HES) that includes such factors as witnessing death, contact with flood waters, and injury to self or family members. Both tangible and nontangible LOR were associated with depression cross-sectionally and prospectively. Severe hurricane exposure (high HES) was also associated with depression. Regression analysis showed LOR-associated depression was explained almost entirely by nontangible rather than tangible factors. Consistent with COR theory, however, nontangible LOR explained some of the association between severe hurricane exposure and depression in our models. A similar result was seen prospectively for depression at 12 months, even controlling for depression symptoms at 6 months. These results suggest the need for preventive measures aimed at preserving psychosocial resources to reduce the long-term effects of disasters.

Hurricane Katrina experience and the risk of post-traumatic stress disorder and depression among pregnant women

Objective: Little is known about the effects of disaster exposure and intensity on the development of mental disorders among pregnant women. The aim of this study was to examine the effect of exposure to Hurricane Katrina on mental health in pregnant women.Design: Prospective cohort epidemiological study.Setting: Tertiary hospitals in New Orleans and Baton Rouge, USA.Participants: Women who were pregnant during Hurricane Katrina or became pregnant immediately after the hurricane.Main outcome measures: Post-traumatic stress disorder (PTSD) and depression.Results: The frequency of PTSD was higher in women with high hurricane exposure (13.8 percent) than women without high hurricane exposure (1.3 percent), with an adjusted odds ratio (aOR) of 16.8 (95% confidence interval: 2.6-106.6) after adjustment for maternal race, age, education, smoking and alcohol use, family income, parity, and other confounders. The frequency of depression was higher in women with high hurricane exposure (32.3 percent) than women without high hurricane exposure (12.3 percent), with an aOR of 3.3 (1.6-7.1). Moreover, the risk of PTSD and depression increased with an increasing number of severe experiences of the hurricane.Conclusions: Pregnant women who had severe hurricane experiences were at a significantly increased risk for PTSD and depression. This information should be useful for screening pregnant women who are at higher risk of developing mental disorders after disaster.

Plant responses to simulated hurricane impacts in a subtropical wet forest, Puerto Rico

Summary 1. We simulated two key components of severe hurricane disturbance, canopy openness and detritus deposition, to determine the independent and interactive effects of these components on woody plant recruitment and forest structure. 2. We increased canopy openness by trimming branches and added or subtracted canopy detritus in a factorial design. Plant responses were measured during the 4‐year study, which followed at least 1 year of pre‐manipulation monitoring. 3. The physical conditions of canopy openness and detritus deposition in our experiment resembled the responses to Hurricane Hugo, a severe category 4 hurricane that struck this forest in 1989. 4. Canopy detritus deposition killed existing woody seedlings and provided a mechanical barrier that suppressed seedling recruitment. The increase in understorey light caused by canopy trimming stimulated germination from the seed bank and increased seedling recruitment and density of pioneer species several hundred‐fold when hurricane debris was absent. Many significant interactions between trimming and detritus deposition were evident from the manner in which seedling density, recruitment and mortality changed over time, and subsequently influenced the composition of woody stems (individuals ≥ 1 cm d.b.h.). 5. When the canopy was trimmed, stem densities increased &gt; 2‐fold and rates of recruitment into the stem size class increased &gt; 25‐fold. Trimming had no significant effect on stem mortality. The two dominant species that flourished following canopy trimming were the pioneer species Cecropia schreberiana and Psychotria berteriana. Deposition of canopy detritus had little effect on stems, although basal area increased slightly when detritus was added. There were no evident effects of the interactions between canopy trimming and detritus deposition on stems. 6. Synthesis. The separate and interactive effects of canopy openness and detritus deposition result in variable short‐term trajectories of forest recovery. However, the short interval of increased canopy openness due to hurricane impacts and its influence on the recruitment of pioneer trees is the dominant factor that drives short‐term recovery and may alter long‐term structure and composition of the forest.

Potential of MODIS EVI in Identifying Hurricane Disturbance to Coastal Vegetation in the Northern Gulf of Mexico

Frequent hurricane landfalls along the northern Gulf of Mexico, in addition to causing immediate damage to vegetation, also have long term effects on coastal ecosystem structure and function. This study investigated the utility of using time series enhanced vegetation index (EVI) imagery composited in MODIS product MOD13Q1 for assessing hurricane damage to vegetation and its recovery. Vegetation in four US coastal states disturbed by five hurricanes between 2002 and 2008 were explored by change imagery derived from pre- and post-hurricane EVI data. Interpretation of the EVI changes within months and between years distinguished a clear disturbance pattern caused by Hurricanes Katrina and Rita in 2005, and a recovering trend of the vegetation between 2005 and 2008, particularly within the 100 km coastal zone. However, for Hurricanes Gustav, Ike, and Lili, the disturbance pattern which varied by the change imagery were not noticeable in some images due to lighter vegetation damage. The EVI pre- and post-hurricane differences between two adjacent years and around one month after hurricane disturbance provided the most likely damage area and patterns. The study also revealed that as hurricanes damaged vegetation in some coastal areas, strong precipitation associated with these storms may benefit growth of vegetation in other areas. Overall, the study illustrated that the MODIS product could be employed to detect severe hurricane damage to vegetation, monitor vegetation recovery dynamics, and assess benefits of hurricanes to vegetation.