McLaren, P., 2014. Sediment trend analysis (STA^®): kinematic vs. dynamic modeling.

The number of techniques commonly used to determine sediment transport (its erosion, movement, and deposition) is limited. They include geomorphological observations, tracers, in situ measurements, and numerical modeling, each of which has various practical difficulties or a necessity for assumptions that may be inadequate or incorrect. Another approach, using the relative changes in grain-size distributions to derive the net sediment-transport patterns and sediment behavior, has become increasingly common, and a number of methods applying its theory has been developed. This article concerns itself principally with the technique, developed by the author, known as Sediment Trend Analysis (STA). Unlike a dynamic model in which processes resulting in sediment transport must be assumed, STA is a kinematic model, whereby the behavior of sediment particles is described without regard to the process. Kinematic modeling is, in comparison to dynamic modeling, simple to do and, in many practical situations, may supply sufficient information for most sediment management issues. If not, however, it is suggested that a kinematic model is a necessary prerequisite to assess the most-effective methods for obtaining quantitative information, including directing and validating the more-complex techniques of dynamic modeling.

McLaren, P. and Teear, G., 2014. A sediment trend analysis (STA^®) in support of dredged material management in Lyttelton Harbour, Christchurch, New Zealand.

About 300 sediment samples were collected from outer Lyttelton Harbour for the purpose of carrying out a sediment trend analysis (STA). The purpose was to assess the sediment behaviour of dredged material placed along the harbour's north side, where disposal operations have been occurring yearly since 1969 (43 years ago at the time of sampling for the STA). Prior to 1969, material had been placed on the south side of the harbour. STA is a technique that determines net sediment transport pathways and the behaviour of bottom sediments from the relative changes in grain-size distributions. The STA determined 68 sample sequences (lines of samples) showing that the dominant source for the harbour sediments is from the steep surrounding hillsides. Sediments are moved from the shoreline into the harbour and progress seaward into the Pacific Ocean. There is no longer any evidence for dredged material on the south side; however, material on the north side becomes incorporated into the existing transport regime and can result in temporary deposition in its transport out of the harbour. The conceptual understanding of the transport regime and the dispersal of dredged material did not conflict substantively with previous hydrodynamic observations and modelling.

Ren, H.; Guo, Q.; Liu, H.; Li, J.; Zhang, Q.; Xu, H., and Xu, F., 2014. Patterns of alien plant invasion across coastal bay areas in southern China.

An understanding of the ways in which levels of invasions by alien species are correlated with environmental factors is helpful to manage the negative impacts of these invasive species. Two tropical coastal areas in South China, Shenzhen Bay and Leizhou Bay, are national nature reserves, but they are threatened by invasive plants. Here, we investigated the level of invasion by exotic plants at both bays, and its relationship with selected environmental factors. We found a total of 34 invasive plant species, 18 of which were present at both bays; among these, 15 species were in terrestrial areas, three were at the ecotone, and one was in the mangroves. The two bays had a similar degree of invasion but were dominated by different species. Three invasive species (Ipomoea purpurea, Wedelia trilobata, and Panicum repens) were abundant at both bays, and only one species, Sonneratia apetala, was present in the mangroves. The number of alien species increased from mangrove to ecotone to terrestrial areas in both bays, while, in proportion, ecotone supported the most alien species in Shenzhen Bay. The relationships between plant invasion and habitat features depended on the variables that were used to measure the degree of invasions. In general, the occurrence of alien species was positively correlated with soil organic carbon and total N content but negatively correlated with the leaf area index and soil salinity. The biomass of alien plants was, on the other hand, positively correlated with total N and soil water content in the soil, and the density of alien plants was not correlated with habitat characteristics. Most of the alien plants originated from tropical America, but a few were from Africa and south Asia. We recommend restoration efforts that include removal of alien species, soil improvement, and the planting of native species.

Girjatowicz, J.P., 2014. Ice thrusting and hummocking on the shores of the southern Baltic Sea's coastal lagoons.

This study concerns hydrological and meteorological conditions during which ice thrusting and hummocking events were observed on the shores of the Szczecin and Vistula Lagoons. The author documented four events of extensive (over distances longer than 100 m) onshore ice thrust: three thrusting events (1 March 1976, 14 January 1993, and 28 January 2003) in the Szczecin Lagoon and one (8 February 2011) in the Vistula Lagoon. The thrusting sheets of ice were usually 15 to 20 cm thick, and their thrust was associated with a very strong wind. The extensive ice thrusting was facilitated by the flatness of the shore and by a high water level. At low water levels and on steeper shores, the ice becomes hummocked. Ice hummocking close to the shore proceeds in three stages, the second stage being the most important: the sheet of ice coming from the windward side breaks up, under its own weight, on the leeward side to form ice rubble. At this stage, the size of the ensuing ice hummock is being determined. In 1955–2011, a total of 51 hummocking events were catalogued. Correlation and regression analyses applied to explore associations between the ice field thickness and the maximum wind speed, as well as between the maximum ice hummock height and the thickness of the ice field building it, showed the relationships to be highly significant (α = 0.001).

Verville, J.-F.; Filion, L., and Lajeunesse, P., 2014. Evidence for changes in paleoenvironments along the lower Cap–Rouge River, Québec (Canada), in relation to a high water stand during the mid-Holocene Laurentian transgression.

At the outlet of the Cap-Rouge River, upstream of the Québec sound on the St. Lawrence north shore, a 5-m-high stratigraphic section was excavated within an urban area, specifically, in a schoolyard located on the 14 m terrace on the east side of the river. Our stratigraphic and high-resolution macrofossil data show that major paleoenvironmental changes occurred along the lower Cap-Rouge River during the mid-Holocene. Macrofossil assemblages indicate that during a low water stand between 6320 and 6230 cal YBP, eastern hemlock (Tsuga canadensis [L.] Carr.) and white pine (Pinus strobus L.) formed mixed stands on the sandy terraces flanking the river. They also indicate that these mesophytic forests shifted to hydrophytic plant communities (eastern larch and aquatic plants) ca. 6230 cal YBP. These rapid changes in plant communities occurred during a mid-Holocene high water stand. Whether waters flowing at the Cap-Rouge River's outlet were brackish or soft waters during this highstand cannot be determined with certainty in absence of halophytes in the macrofossil records. Similar paleoenvironmental changes in plant cover have been well documented at several locations on the south shore of the St. Lawrence Estuary, where they were attributed to a rise in sea level coinciding with the Laurentian transgression. We also discuss the possibility that ice jams played a role in fluvial inundation and sedimentation over the last centuries at the mouth of several tributaries of the St. Lawrence River.

Sousa, S.H.M.; Amaral, P.G.C.; Martins, V.; Figueira, R.C.L.; Siegle, E.; Ferreira, P.A.L.; Silva, I.S.; Shinagawa, E.; Salaroli, A.; Schettini, C.A.F.; Santa-Cruz, J., and Mahiques, M.M., 2014. Environmental evolution of the Caravelas Estuary (northeastern Brazilian coast, 17° S, 39° W) based on multiple proxies in a sedimentary record of the last century,

A sediment core (∼100 cm long) taken from the upper Caravelas estuary was interpreted based on sedimentological, microfaunal, geochemical, and historical data for the last 70 years. Outcomes are a significant contribution to the understanding of the relationship between anthropogenic impact and natural ecosystem change. The results obtained for the period between the 1930s and the beginning of the 1970s do not reveal any evidence of natural and/or anthropogenic impacts in the estuary. This period is characterized by a higher percentage of sandy sediments, lower pollution load index (PLI) values, and a mixed source of organic matter (C3 land plants and marine dissolved organic carbon [DOC]). During the period from the 1970s to the 1990s, widening of the inlet and the entrance of marine water initiated a rapid natural environmental transformation of the area, increasing the amount of mud and producing an abundance of open marine–dwelling ocean foraminifera species, including Pararotalia cananeiaensis, and a decrease of foraminifera density and diversity values. The slight increase of PLI values and the predominance of C3 land plant organic matter observed in this period might be the result of anthropogenic activities related to the soil occupation in the area, which are also reflected in the abundance of Ammonia tepida. During the last decade, dredging operations close to the inlet channel may have contributed to increased transport and deposition of marine sediments into the estuary.

Liu, X.; Xia, J. (C.); Blenkinsopp, C.; Arnold, L., and Wright, G., 2014. High water mark determination based on the principle of spatial continuity of the swash probability

This study presents a model that determines the position of the high water mark (HWM) based on the spatial continuity of inundation probability due to swash for a range of HWM indicators. These indicators include mean high water (MHW), high water line (HWL), and a number of shoreline features, such as the vegetation line. HWM identifies the landward extent of the ocean and is required for cadastral boundary definition, land-use and infrastructure development along the foreshore ,and for planning associated with climate change adaptation. In this paper, shoreline indicators are extracted using an object-oriented image analysis (OOIA) approach. Ten-year hourly swash heights (shoreline excursion length) are fitted into a cumulative distribution function. The probability that swash will reach the various HWM indicators over a 10 y period is then estimated. The spatial continuity distances of the swash probability of HWM indicators are calculated using semivariogram models that measure similarity of swash probability. The spatial continuity distance is defined as the distance between the lower bound of sampling position (the most seaward HWM indicator) and the position where autocorrelation, or the similarity of swash probability of the various HWM indictors, approaches zero. The latter is considered as the HWM position in this study. This HWM determination method is evaluated at two study sites at different latitudes and with distinct coastal features.

González, S.A.; Stotz, W., and Lancellotti, D., 2014. Effects of the discharge of iron ore tailings on subtidal rocky-bottom communities in northern Chile.

Some of the many mining operations that exist in northern Chile dispose their mine tailings directly into the sea. Little is known about the effects of these tailings on shallow rocky subtidal communities. This study reports these effects for an iron ore pelletization plant that has discharged for ca. 23 years in the intertidal of a cove on the exposed rocky coast of northern Chile, generating high turbidity in the water column and deposit of sediments on the bottom. A nonparametric multidimensional scaling (nMDS) ordination analysis for the species of the rocky subtidal communities, based on the Bray-Curtis dissimilarity index, showed great differences, the affected communities being dominated by incrusting invertebrates, whereas the unaffected areas at the same depth had kelp beds. The effects were observed only close to the discharge and were not observed in the more shallow water communities, which in affected and unaffected areas consisted of barren grounds dominated by calcareous algae and sea urchins. The effect on the vertical zonation pattern of communities did not produce differences in the effective diversity, which turned out to be similar among affected and control sites. This occurred because of the replacement, more than the elimination, of species on affected sites. This type of study, in which information is generally maintained in reports only seen by industry and governments, needs to be published to contribute to a more comprehensive database for the improvement of decision-making processes regarding coastal subtidal rocky communities and the effects of human activities on these environments.

En el norte de Chile se concentran numerosas operaciones mineras, las que en algunos casos depositan las colas de sus procesos directamente al mar, habiéndose reportado mortalidades masivas de peces, algas e invertebrados. Si bien se han realizado diferentes estudios para describir el impacto de estas descargas sobre las comunidades intermareales y de fondos blandos, los efectos sobre las comunidades submareales de fondos rocosos son escasamente conocidos. El presente estudio reporta los efectos sobre las comunidades de fondos rocosos producto de la descarga de sólidos inertes vertidos como colas de un proceso de pelletización de hierro por más de 23 años en Ensenada Chapaco, próxima a la ciudad de Huasco en el norte de Chile. La descarga del proceso minero generó alta turbidez en la columna de agua y un alto grado de sedimentación de material particulado fino sobre el fondo. El estudio incluyó un examen cuantitativo de las comunidades de organismos marinos presentes en los fondos rocosos al interior de Ensenada Chapaco. El análisis de ordenación nMDS, en base a las disimilitudes entre la flora y fauna bentónica de distintos sectores de estudio, usando el indice Bray-Curtis, mostró que las comunidades más profundas de Ensenada Chapaco presentan una estructura única, distinta a las comunidades de similares profundidades, pero ajenas al area de influencia de la descarga. Los resultados del análisis nMDS fueron consistentes para la comunidad completa, organísmos móviles, sesiles y organismos suspensívoros. Las comunidades afectadas estuvieron dominadas por organismos sésiles, como el caso de poliquetos tubícolas, cirripedios, mitílidos y briozoos mayormente de hábitos crípticos, siendo esta condición distinta a áreas no impactadas, donde se desarrollan bosques de algas pardas laminariales dominadas por Lessonia trabeculata. No obstante, estos efectos fueron evidentes sólo en puntos cercanos al area de descarga, no siendo afectadas, aparentemente, las comunidades de aguas someras. Estas comunidades, como también las de áreas ajenas a la decarga, presentan típic

Zheng, J; Zhang, W; Zhang, P, and Zhu, Y., 2014. Understanding space–time patterns of long-term tidal fluctuation over the Pearl River delta, South China.

Principal component analyses (PCA) were used to identify the space–time patterns of long-term tidal fluctuation in the Pearl River delta (PRD) region. The tidal levels of the 35 stations over the entire PRD were divided into four regions by the PCA. The results show that different regions display different trends, indicating spatial variability of long-term tidal fluctuations in PRD region. The regional pattern of the first component loadings is mainly located near the outlets. Time series of the factor scores of the the first principal component (PC) shows a significant increasing trend. The regional pattern of the second component loadings is concentrated in the upper part of the PRD region. The factor scores of the the second PC, however, display a significant deceasing trend. The trend in the factor scores of the the third PC of the middle part of the North River is not significant, but it has to face the highest flood risk. As for the upper part of the East River, the factor scores of the the fourth PC also show a significant downward trend that demonstrates that the tidal level shows an obviously decreasing trend in the upper part of the East River. The impacts of the intensive human activities on these changes in the PRD region in the latest three decades are the dominant factor. In particular, the large-scale and long-term sand excavation in the whole PRD region directly results in the riverbed down-cutting, leading to the tidal level in the upper part of the delta decreasing obviously. More tidal prism can enter the delta much more easily also due to the sand excavation, which can fill out the volume not only to keep the tide level, but also even increase the tide level in the middle part of the North River. What's more, intensive reclamation in the estuary is another main factor for tide increase at the outlets of the PRD region.

Dentale, F.; Donnarumma, G., and Pugliese Carratelli, E., 2014. Simulation of flow within armour blocks in a breakwater.

This paper provides some results of a new procedure to analyze the hydrodynamic aspects of the interactions between maritime emerged breakwaters and waves by integrating computer-aided design and computational fluid dynamicsCFD. The structure is modeled in the numerical domain by overlapping individual three-dimensional elements (Xbloc^®), very much like the real world or physical laboratory testing. A computational grid is fitted fine enough to provide enough computational nodes within the flow paths. Flow of the fluid within the interstices among concrete blocks is evaluated by integrating the Reynolds averaged Navier–Stokes equations inside the voids instead of using the “porous media” approach. The aim is to investigate the reliability of this approach as a design tool. Therefore, for the results' validation, the numerical run-up and reflection effects on virtual breakwater (armour in Xbloc, toe protection, and filter layer in stones) were compared with some empirical formulas and some similar laboratory tests. Obviously, the presented model can be supportive to the physical modeling, comparing multiple preliminary design solutions, and providing guidance on the optimal choice to be subjected to subsequent laboratory tests. Here are presented the results of a first simple validation procedure. The validation shows that, at present, this innovative approach can be used in the breakwater design phase for comparison between several design solutions with a significant minor cost.

Ahmed, M.T.T.; Sato, S., and Tajima, Y., 2014. Quantitative estimation of longshore sediment transport based on thermoluminescence: two case studies around Tenryu and Nile River mouths.

Longshore sediment transport (LST) is one of the key factors determining coastal deformation. Appropriate understanding of LST is thus essential to sustain coastal management and propose efficient countermeasures. However, it is quite difficult to quantify LST where detailed information of waves and bathymetries is not available. This study provides a novel methodology for quantitative estimation of LST by utilizing the residual thermoluminescence (TL) properties of feldspar grains. A newly proposed TL-based system estimates LST as a function of alongshore distributions of TL and dominant wave heights at the study sites. This study first analyzed and developed the TL-based bleaching curves due to sun exposure of the 180–300 μm fraction of feldspar grains from three different regions: Egypt, Japan, and Sri Lanka. On the basis of the obtained bleaching curves, the spatial distribution of TL along the coast was estimated, and the alongshore slope of TL decay was compared with the locally estimated average longshore current velocity, mixing sand layers, and moving sand volume, all of which were subsequently linked to LST. The newly proposed methodology was applied to two coastal areas around the Tenryu River and Nile River mouths, and it was found that the proposed methodology is capable of estimating directions and amount of LST around river mouths where sand with high TL is discharged continuously.

Schmid, K.; Hadley, B., and Waters, K., 2014. Mapping and portraying inundation uncertainty of bathtub-type models.

Data errors are an unavoidable reality in maps of present conditions, but with the prevalence of ease-of-use formats and software these errors are becoming less evident. In earlier maps, the resolution or scale of the information and its presentation on a physical medium (e.g., contours) could inherently convey a level of vagueness that corresponded to the accuracy limitations. Maps of modeled output have additional accuracy considerations, especially if extrapolating future or potential events (e.g., 100-year storm). Sea-level rise (SLR) mapping falls into this category but is also highly dependent on present topographic conditions. SLR and other ecological models use continuous surfaces or digital surface models to generate derived information; however, presentation of the uncertainty information can be difficult or confusing. A technique that conveys uncertainty boundaries for a given confidence level was developed for the National Oceanic and Atmospheric Administration Coastal Services Center's SLR and inundation-visualization tool. The technique and definition of uncertainty levels described herein varies from other common methods, but the use of root-mean-square error (RMSE) to derive the assessment is similar. The technique uses the reported RMSE of both elevation and tidal surface and their relationship to a normal distribution. In this way, user-defined confidence levels can be used to map uncertainty both above and below the deterministic value produced in typical single-surface or bathtub models. The technique is used in this context for SLR and inundation mapping but also has applicability in mapping other phenomena.

Breaker, L.C.; Murty, T.S., and Carroll, D., 2014. A frequency domain approach for predicting the signal strength of tsunamis at coastal tide gauges.

A method for predicting the signal strength of a tsunami at coastal tide gauges once the event is underway is presented. It is based on the calculation of a transfer function for a linear system whose input is obtained from Deep-ocean Assessment and Reporting of Tsunamis (DART) bottom pressure recorders (BPRs) and the output from coastal tide gauges. To perform the calculations, a data window for the input and output signals must initially be chosen that requires a compromise between signal purity and resolution. Limited experience suggests that windows in the range of 6–12 hours duration are a reasonable choice for 1-minute data. The method is illustrated with three examples, the first two taken from the tsunami generated by the Great Tōhoku Earthquake of 2011 and the third from the tsunami generated by the Chilean earthquake of 2010. Magnitude spectra from the transfer functions in each case reflect the influence of oscillations present in the tide gauge data, a requirement that must be met if the transfer functions are to be of predictive value. The magnitude spectra for each of two pairs of DART BPRs employed in two cases were generally similar, suggesting that the results are robust in the sense that they are not strongly location dependent. This approach provides an alternate view of the forecasting process that should be useful in identifying spectral components in the coastal response that may be critical to the forecast. Once implemented, the method will be rapid, easily competing with other precomputed database methods. Finally, with further development the method could be used to augment other tsunami forecast methodologies that are presently in use.

Gontz, A.M.; Moss, P.T., and Wagenknecht, E.K., 2014. Stratigraphic architecture of a regressive strand plain, Flinders Beach, North Stradbroke Island, Queensland, Australia.

Regressive beaches are commonly composed of extensive and complex beach ridge systems. The physical and stratigraphic relationships of the beach ridges can help decipher the interactions between sea-level changes, variation in storm periodicity and intensity, changes in current directions, and alterations in sediment sources. Similar systems have been identified on the SE coast of Queensland and the spatial and temporal relationships between the various depositional environments are poorly understood. A small-strand plain system was identified on the NE coast of North Stradbroke Island, Queensland, Australia, and targeted for study with ground-penetrating radar (GPR). A series of GPR transects were acquired to elucidate the subsurface architecture of the system and to establish a geologic and geomorphic framework for the system through the application of stratigraphic analysis and decipher the spatial relationship. The GPR survey was concentrated in the center of the system and acquired approximately 3 km of 250-MHz data. The survey shows the stratigraphic relationship between modern sand dunes, beach ridge sequences, wetlands, and the much older Pleistocene sand dunes and identifies a potential Holocene storm record. We established a stratigraphic link between environments and propose a model driven by sea-level change, which proposes beach-ridge development during the early/mid-Holocene regression.

Kuang, C.; Chen, W.; Gu, J.; Zhu, D.Z.; He, L., and Huang, H., 2014. Numerical assessment of the impacts of potential future sea‐level rise on hydrodynamics of the Yangtze River Estuary, China.

Recent research suggests that sea levels are rising even faster than projected by the Intergovernmental Panel on Climate Change (IPCC). Under a sea level rise (SLR) scenario, estuarine and coastal areas would be affected first. In this paper, the effects on the Yangtze River Estuary (YRE) by potential future SLR are studied using a hydrodynamic (MIKE21) model. The model is calibrated with field data. Scenarios of 0.5, 1, and 2 m SLR in the flood season are simulated with the calibrated model. The predicted results show that under SLR (1) the tidal level of the YRE increases and its increase rate decreases gradually upstream along the channel; (2) the tidal wave propagates at a faster speed upstream, which leads to the advancement of a tidal limit and tidal current limit to the upstream; (3) the increases in flood and ebb velocities occur around the Nanhui Tidal Flat, the Hengsha Eastern Shoal, the Jiuduansha Shoal, the upper reach of the North Branch, the North Channel, the South Channel, the South Branch, and the “South Branch above”; the ebb velocity decreases in the North Passage and the South Passage; and the flood and ebb velocity in shoals have the highest increasing rate; and (4) the ebb discharge of the North Branch has the highest increasing rate, with the ebb flow split ratio increasing up to almost 5% under the 2 m SLR scenario. Hence, SLR will reduce the protective capacity of embankments and may aggravate erosion in shoals, which is not good for maintenance of the Deepwater Navigation Channel and formation of potential land resources in the YRE.

Kuang, C.; He, L.; Gu, J.; Pan, Y.; Zhang, Y.; Yang, Y.; Qiu, R., and Zhang, J., 2014. Effects of submerged breakwater on hydrodynamics and shoreline change of the East Beach of Beidaihe, Bohai Bay, China.

The beaches in Beidaihe of Bohai Bay of China have been eroded since 1950s, clearly evidenced by sand coarsening, rock outcropping, and slope steepening. Beach nourishment is a common coastal management strategy used to protect beaches from erosion along sandy coastlines, and it has already been applied to recover several beaches of Beidaihe since 2008. In this paper, the effects of a submerged breakwater used as part of a beach nourishment project on hydrodynamics and shoreline changes of the East Beach of Beidaihe are presented. First, the brief descriptions of phase I and phase II of the beach nourishment project of East Beach are given. And then numerical models, including tidal current model, wave model, and one-line model for simulating hydrodynamics (tidal currents and waves) and shoreline changes are established and verified by field measurements. These well-verified numerical models are adopted to compute the tidal current fields, wave fields, and shoreline changes of East Beach with and without the submerged breakwater. The results show that the submerged breakwater plays a very important role in protecting East Beach to a certain degree. The effects of alterations of the freeboard and the width and the length of the submerged breakwater on shoreline changes are also discussed, and the results show that increasing the above three parameters will better protect the beach. Overall, a submerged breakwater can play a certain role in protecting a beach against erosion; additional beach nourishment is needed to stabilize East Beach in long term.

Pan, Y.; Kuang, C.; Gu, J.; He, L.; Zhang, Y.; Yang, Y.; Qiu, R., and Zhang, J., 2014. Assessment of a measure for water exchange strengthening of artificial headland bays based on shoreline change and flushing time.

Artificial headlands are used around the world to form headland bays to contain beach materials. However, the artificial headland would weaken the water exchange in the bay and in some cases would make the water quality deteriorate. In this paper, we propose reserving a tidal channel in the landward end of the artificial headland, thus enabling the tidal current to pass through the channel, as a solution. The effects of the tidal channel on the weakening of beach protection and the strengthening of water exchange were investigated via numerical studies based on a beach nourishment project. A shoreline change model was set up to investigate the weakening of the beach protection. Four project schemes were simulated, and the results indicated that weakening of the beach protection is acceptable and the response of the shoreline to the tidal channel is influenced by the state of the beach. A three-dimensional (3D) flow model and a 3D constituent transport model were applied to evaluate the strengthening of water exchange using flushing time as the indicator. The results indicate that the reservation of the tidal channel induces an approximate 50% reduction in flushing time. The specific reduction amount of the flushing time is influenced by the length of the tidal channel, the tidal condition, and the direction of the artificial headland. The conclusions suggest that the tidal channel is a feasible and effective measure to strengthen the water exchange in an artificial headland bay at the cost of an acceptable loss of beach protection effect.

Curado, G.; Rubio-Casal, A.E.; Figueroa, E., and Castillo, J.M., 2014. Plant zonation in restored, nonrestored, and preserved Spartina maritima salt marshes.

This study analyzes the vegetation zonation and the abiotic environment (sediment elevation, pH, redox potential, and electrical conductivity) 2.5 years after salt marsh restoration using Spartina maritima and Sarcocornia perennis plantations in the Odiel Marshes (SW Iberian Peninsula) in comparison with preserved and degraded marshes. Restored marshes presented higher species richness (10 spp.) than nonrestored (6 spp.) and preserved (3 spp.) marshes, as a result of milder abiotic conditions (more oxygenated sediments than preserved marshes) and higher habitat diversity (sandy patches at higher elevations). Marshes restored using S. maritima (planted at a density of 1 clump m⁻²) achieved a similar relative cover to preserved marshes (ca. 50%) 2.5 years after transplanting. Spartina maritima showed higher tiller height in preserved (40 ± 2 cm) than in restored marshes (34 ± 1 cm). Sarcocornia perennis cover was similar in the three areas, being concentrated at higher elevations in the tidal gradient. Our results show the success from the point of view of vegetation of restoring European low salt marshes using S. maritima and S. perennis plantations, since they are able to reproduce, 2.5 years after restoration, the typical zonation pattern.

Ennis, B.; Peterson, M.S., and Strange, T.P., 2014. Modeling of inundation characteristics of a microtidal saltmarsh, Grand Bay National Estuarine Research Reserve, Mississippi.

Intertidal saltmarsh habitats are unique productive estuarine systems in that their relative productivity is strongly influenced by the morphology of the landscape and the degree of water inundation. Despite the recognized effect that flooding in saltmarsh intertidal zones has on the natural history of resident fauna and the conservation of the habitat itself, limited data are available with regard to hydrological conditions to conduct proper assessment of these habitats. In this paper we describe a geographic information system–based model that was used to quantify the inundation characteristics of intertidal habitats within the microtidal Crooked Bayou, Grand Bay National Estuarine Research Reserves (GNDNERR), Mississippi, system. Using water levels from a nearby National Oceanic and Atmospheric Administration tide station, inundation characteristics were generated by the model for multiple sample sites and for plots within each site along a common marsh elevation gradient. The derived characteristics generated by the model were used in a principal components analysis to create factor scores depicting flooding conditions. These factor scores were then used as the means of comparison of cumulative inundation characteristics between sites and the plots within sites. Overall, inundation characteristics were found to vary significantly between sampling sites (Kruskal-Wallis, χ² = 26.13, p < 0.001) and among the plots (Friedman's, χ² = 19.27, p < 0.001) across the elevation gradient. In general, although the inundation potential of the sampling plots within each site significantly decreased as the marsh elevation gradient increased, there were marked differences among and within sites because of the considerable microtopography patterns we identified that exemplify the microtidal, low-lying intertidal landscape of GNDNERR.