Short- and Long-Term Vegetative Propagation of Two <Emphasis Type="Italic">Spartina</Emphasis> Species on a Salt Marsh in Southern Brazil

Spartina alterniflora and Spartina densiflora are native salt marsh plants from the Atlantic coast; their habitats in Patos Lagoon estuary (southern Brazil) are characterized by a microtidal regime (<0.5 m) and, during El Niño events, high estuarine water levels and prolonged flooding due to elevated freshwater discharge from a 200,000-km² watershed. During and between El Niño events, the vegetative propagation of these two Spartina species in the largest estuary of southern Brazil (Patos Lagoon) was evaluated by monitoring transplanted plants for 10 years (short-term study) and interpreting aerial photos of natural stands for 56 years (long-term study). During the short-term study, S. alterniflora quickly occupied mud flats (up to 208 cm year^?1) by elongation of rhizomes, whereas S. densiflora showed a modest lateral spread (up to 13 cm year^?1) and generated dense circular-shaped stands. However, moderate and strong El Niño events can promote excessive flooding and positive anomalies in the estuarine water level that reduce the lateral spread and competitive ability of S. densiflora. During the long-term study, natural stands of S. alterniflora and S. densiflora had steady lateral spread rates of 152 and 5.2 cm year^?1, respectively, over mud flats. In the microtidal marshes of the southwest Atlantic, the continuous long-term lateral expansion of both Spartina species embodies periods of intense flooding stress (moderate and strong El Niños), when there is a decrease of vegetative propagation and less stressful low water periods of fast spread over mud flats (non-El Niño periods and weak intensity El Niños).     

Tropicalization of the Northern Gulf of Mexico: Impacts of Salt Marsh Transition to Black Mangrove Dominance on Faunal Communities

The tropically associated black mangrove (Avicennia germinans) is expanding into salt marshes of the northern Gulf of Mexico (nGOM). This species has colonized temperate systems dominated by smooth cordgrass (Spartina alterniflora) in Texas, Louisiana, Florida and, most recently, Mississippi. To date, little is known about the habitat value of black mangroves for juvenile fish and invertebrates. Here we compare benthic epifauna, infauna, and nekton use of Spartina-dominated, Avicennia-dominated, and mixed Spartina and black mangrove habitats in two areas with varying densities and ages of black mangroves. Faunal samples and sediment cores were collected monthly from April to October in 2012 and 2013 from Horn Island, MS, and twice yearly in the Chandeleur Islands, LA. Multivariate analysis suggested benthic epifauna communities differed significantly between study location and among habitat types, with a significant interaction between the two fixed factors. Differences in mangrove and marsh community composition were greater at the Chandeleurs than at Horn Island, perhaps because of the distinct mangrove/marsh ecotone and the high density and age of mangroves there. Infaunal abundances were significantly higher at Horn Island, with tanaids acting as the main driver of differences between study locations. We predict that if black mangroves continue to increase in abundance in the northern GOM, estuarine faunal community composition could shift substantially because black mangroves typically colonize shorelines at higher elevations than smooth cordgrass, resulting in habitats of differing complexity and flooding duration.     

Living on the Edge: Increasing Patch Size Enhances the Resilience and Community Development of a Restored Salt Marsh

Foundation species regulate communities by reducing environmental stress and providing habitat for other species. Successful restoration of biogenic habitats often depends on restoring foundation species at appropriate spatial scales within a suitable range of environmental conditions. An improved understanding of the relationship between restoration scale and environmental conditions has the potential to improve restoration outcomes for many biogenic habitats. Here, we identified and tested whether inundation/exposure stress and spatial scale (patch size) can interactively determine (1) survival and growth of a foundation species, Spartina alterniflora and (2) recruitment of supported fauna. We planted S. alterniflora and artificial mimics in large and small patches at elevations above and below local mean sea level (LMSL) and monitored plant survivorship and production, as well as faunal recruitment. In the first growing season, S. alterniflora plant survivorship and stem densities were greater above LMSL than below LMSL regardless of patch size, while stem height was greatest in small patches below LMSL. By the third growing season, S. alterniflora patch expansion was greater above LMSL than below LMSL, while stem densities were higher in large patches than small patches, regardless of location relative to LMSL. Unlike S. alterniflora, which was more productive above LMSL, sessile marine biota recruitment to mimic plants was higher in patches below LMSL than above LMSL. Our results highlight an ecological tradeoff at ~LMSL between foundation species restoration and faunal recruitment. Increasing patch size as inundation increases may offset this tradeoff and enhance resilience of restored marshes to sea-level rise.     

Vegetation Dynamics in Rhode Island Salt Marshes During a Period of Accelerating Sea Level Rise and Extreme Sea Level Events

Sea level rise is a major stressor on many salt marshes, and its impacts include creek widening, ponding, vegetation dieback, and drowning. Marsh vegetation changes have been associated with sea level rise across southern New England, but most of these studies pre-date the current period of rapidly accelerating sea level rise coupled with episodic events of extreme increases in water levels. Here, we combine data from two salt marsh monitoring and assessment programs in Rhode Island that were designed to assess marsh responses to sea level rise and use these data to document temporal and spatial patterns in marsh vegetation during the current period of extreme water level increases. Vegetation monitoring at two Narragansett Bay salt marshes confirms the ongoing decline of the salt meadow species Spartina patens during this period as it becomes replaced by Spartina alterniflora. Bare ground resulting from vegetation dieback was significantly related to mean high water levels and led to the rapid conversion of mixed Spartina assemblages to S. alterniflora monocultures. A broader spatial assessment of RI marshes shows that S. alterniflora dominance increases at lower elevation marshes toward the mouth of Narraganset Bay. Our data provide additional evidence that S. patens continues to decline in southern New England marshes and show that losses can accelerate during periods of extreme high water levels. Unless adaptive management actions are taken, we predict that marshes throughout RI will continue to lose salt meadow habitat and eventually resemble lower elevation marshes that are already dominated by S. alterniflora monocultures.     

<Emphasis Type="Italic">Spartina alterniflora</Emphasis> Biomass Allocation and Temperature: Implications for Salt Marsh Persistence with Sea-Level Rise

To predict the impacts of climate change, a better understanding is needed of the foundation species that build and maintain biogenic ecosystems. Spartina alterniflora Loisel (smooth cordgrass) is the dominant salt marsh-building plant along the US Atlantic coast. It maintains salt marsh elevation relative to sea level by the accumulation of aboveground biomass, which promotes sediment deposition and belowground biomass, which accretes as peat. Peat accumulation is particularly important in elevation maintenance at high latitudes where sediment supply tends to be limited. Latitudinal variation in S. alterniflora growth was quantified in eight salt marshes from Massachusetts to South Carolina. The hypothesis that allocation to aboveground and belowground biomass is phenotypically plastic was tested with transplant experiments among a subset of salt marshes along this gradient. Reciprocal transplants revealed that northern S. alterniflora decreased allocation to belowground biomass when grown in the south. Some northern plants also died when moved south, suggesting that northern S. alterniflora may be stressed by future warming. Southern plants that were moved north showed phenotypic plasticity in biomass allocation, but no mortality. Belowground biomass also decomposed more quickly in southern marshes. Our results suggest that warming will lead northern S. alterniflora to decrease belowground allocation and that belowground biomass will decompose more quickly, thus decreasing peat accumulation. Gradual temperature increases may allow for adaptation and acclimation, but our results suggest that warming will lower the ability of salt marshes to withstand sea-level rise.     

Impact of Armored Shorelines on Shore-Zone Fish Density in a Mid-Atlantic,USA, Estuary: Modulation by Hypoxia and Temperature

Anthropogenic modifications of estuarine environments, including shoreline hardening and corresponding alteration of water quality, are accelerating worldwide as human population increases in coastal regions. Estuarine fish species inhabiting temperate ecosystems are adapted to extreme variations in environmental conditions including water temperature, salinity, and dissolved oxygen across seasonal, daily, and hourly time scales. The present research utilized quantitative sampling to examine the spatiotemporal distribution of shore-zone estuarine fish species in association with four unique shoreline types across a range of water temperature and dissolved oxygen conditions. Fish were collected from the intertidal and shallow subtidal region of four shoreline types, Spartina alterniflora marsh, Phragmites australis marsh, riprap, and bulkhead, in the summer and fall of 2009 and 2010. Analyses were performed to (1) compare mean fish density among shoreline types across all water conditions and (2) explore relationships of the complete fish assemblage, three functional species groupings, and two fish species (Fundulus heteroclitus and Menidia menidia) to unique shoreline/water conditions. Significantly greater mean fish densities were found along S. alterniflora shorelines than armored shorelines. Several metrics including fish density, species richness, and occurrence rates suggest S. alterniflora shorelines may serve as a form of refuge habitat during periods of low dissolved oxygen and high temperatures for various species, particularly littoral-demersal species including F. heteroclitus. Potential mechanisms that could contribute to a habitat providing refuge during adverse water quality conditions include tempering of the adverse condition (decreased temperatures, increased dissolved oxygen), predation protection, and increased foraging opportunities.     

<Emphasis Type="Italic">Salpingoporella</Emphasis> (dasycladalean algae) species from the Lower Cretaceous carbonate facies of Kopet Dagh basin (NE Iran)

Salpingoporella species from algal bearing of Barremian-Aptian limestones in the Kopet Dagh basin (NE of Iran) are described. Different species (S. cemi, S. hasi, S. heraldica, S. hispanica, S. milovanovici, S. muehlmbergi, S. parapiriniae, S. piriniae, S. cf. biokovensis, S. steinhauseri, S. polygonalis) are investigated from different biometrical aspects such as depositional environments and biogeographical distribution as well as their systematic palaeontology from two formations (the Tirgan and Sarcheshmeh formations) in nine stratigraphic sections.     

Reproductive success of wading birds using<Emphasis Type="Italic">Phragmites</Emphasis> marsh and upland nesting habitats

Colonial nesting of long-legged wading birds (Ciconiiformes) in the coastal northeastern U.S. is limited primarily to islands, which provide isolated habitats that are relatively free of ground predators. Estuarine wetlands in this heavily developed region, including foraging wetlands and fringe marshes surrounding nesting islands, are often dominated byPhragmites australis. On Pea Patch Island in Delaware Bay, site of one of the largest and most enduring mixed-species heron colonies on the East Coast, wading birds nest inPhragmites marsh habitat as well as in adjacent upland shrubs and trees. BecausePhragmites is aggressively managed in Delaware Bay, we investigated the relative habitat value of marsh and upland nesting sites for the purpose of developing recommendations for marsh and wildlife management. Utilization of marsh habitat by nesting birds ranged from 27–82% during 1993–1998. Two species (great blue heronArdea herodias and great egretA. alba) never nested inPhragmites, four species (little blue heronEgretta caerulea, snowy egretE. thula, cattle egretBubulcus ibis, and black-crowned night-heronNycticorax nycticorax) nested in approximately equal proportions in both habitats, and one species (glossy ibisPlegadis falcinellus) was largely confined to marsh nesting. Productivity (egg and nestling production) varied between habitats for some species. Cattle egrets produced larger clutches and had higher hatching rates inPhragmites compared to upland habitat. Little blue herons were more successful in the uplands. Managers should retainPhragmites marsh at colony sites, such as Pea Patch Island, where it provides critical habitat for nesting wading birds both as substrate for nesting and buffer habitat to control human disturbance.     

Systematic paleontology,biostratigraphy, paleobiogeography of <Emphasis Type="Italic">Loftusia</Emphasis> (foraminifera) and <Emphasis Type="Italic">Rudist</Emphasis> assemblages in a regressive sequence in the Hekimhan-Malatya area (Eastern Anatolia) Turkey

The Maastrichtian regressive sequence of the Hekimhan-Malatya area in Eastern Turkey consists of dolomitic limestones, limestones and calcareous mudstones which are dominated by rudists and Loftusia (foraminifera) assemblages. Several Loftusia species indicating middle to late Maastrichtian age such as Loftusia anatolica Meriç, L. baykali Meriç, L. coxi Henson, L. harrisoni Cox, L. minor Cox and L. morgani Douvillé have been recorded. Other benthic foraminifers present include Orbitoides medius d’ Archiac, Omphalocyclus macroporus (Lamarck), Laffitteina conica Drooger, Laffitteina mengaudi (Astre) and Laffitteina oeztuerki Inan. The rudists are abundant in the dolomitic limestones in the study area. The genus Miseia Patrulius is dominant and represented by Miseia bilacunosa Özer and Miseia hekimhanensis Karacabey-Öztemür. The Loftusia species and the Rudists assemblage indicates middle to late Maastrichtian age for the formation. The paleobiogeographic distribution of the assemblage has been discussed taking this find into account.     

<Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> and <Emphasis Type="Italic">Melandrium album</Emphasis> in trace elements biomonitoring and air pollution tolerance index study

The accumulation efficiency of selected trace elements in the leaves of Melandrium album and Robinia pseudoacacia grown on heavy metal contaminated sites in comparison with a non-contaminated one was evaluated. The study was undertaken to calculate air pollution tolerance index and to determine the contents of selected metabolites: glutathione, non-protein thiols, ascorbic acid, chlorophyll and the activity of antioxidant enzymes: guaiacol peroxidase and superoxide dismutase. Such estimations can be useful in better understanding of plants defense strategies and potential to grow in contaminated environments. The results in the most contaminated site revealed higher contents of metals in M. album leaves, especially Zn, Cd and Pb (3.4, 6 and 2.3 times higher, respectively) in comparison with the R. pseudoacacia. Better accumulation capacity found in M. album was shown by metal accumulation index values. The plants could be used as indicators of Zn, Cd (both species) and Pb (M. album) in the soil. Glutathione content (in both species) and peroxidase activity (in M. album), general markers of heavy metals contamination, were increased in contaminated sites. In most cases in contaminated areas R. pseudoacacia had decreased ascorbic acid and chlorophyll levels. Opposite tendency was recorded in M. album leaves, where similar or higher contents of the above-mentioned metabolites were found. In our study, M. album and R. pseudoacacia proved to be sensitive species with the air pollution tolerance index lower than 11 and can be recommended as bioindicators.     

Feeding Behavior of the Native Mussel <Emphasis Type="Italic">Ischadium recurvum</Emphasis> and the Invasive Mussels <Emphasis Type="Italic">Mytella charruana</Emphasis> and <Emphasis Type="Italic">Perna viridis</Emphasis> in FL,USA, Across a Salinity Gradient

The feeding behavior of three species of mussels, the native Ischadium recurvum and the invasives Mytella charruana and Perna viridis, was studied in an invaded ecosystem in Florida (USA). In situ feeding experiments using the biodeposition method were performed along a salinity gradient in four different locations along the St. Johns River. Water characteristics, such as salinity, temperature, dissolved oxygen, and seston loads, were recorded to identify relationships between these variables and the feeding behavior of the mussels. Feeding behavior of the species varied by study site. Clearance, filtration, organic ingestion, and absorption rates of I. recurvum were negatively affected by salinity. For the invasive mussel, M. charruana, rejection was positively related to salinity while total ingestion, organic ingestion, and absorption rates were positively related to the percentage of organic matter in the seston. For P. viridis, total and organic ingestion rates were negatively affected by salinity but positively affected by total particulate matter. Condition indices for P. viridis and M. charruana were 13.16?±?0.64 and 6.63?±?0.43, respectively, compared to 4.82?±?0.41 for the native species I. recurvum, indicating that these mussels are well adapted to the environmental conditions in the area. This study indicates that the three species have different preferred habitats because of their specific responses to water characteristics. Thus, the invasive mussels will not totally occupy the niche of the native mussel in Florida despite overlapping zones. These data may help identify potential invaded areas and understand the extent of the invasion.     

Conodont-based stratigraphy of the Mosolovian Regional Stage (Eifelian,Middle Devonian) of the Voronezh Anteclise

Conodonts from the deposits of the Mosolovian Regional Stage (Middle Devonian) of the Voronezh Anteclise are studied on the basis of the data from six boreholes. Three assemblages are recognized. The index species of the lowermost assemblage is Icriodus formosus Naz. The index species of the middle assemblage are I. formosus Naz. and Pseudobipennatus ziegleri Kon. et Kim, as well as I. arkonensis Stauff. and I. jejunus Naz. This assemblage is the most diverse and is recognized in all boreholes. The deposits containing this assemblage correspond to the maximum of the Nara transgression. The upper assemblage is also recognized in all the studied boreholes. Its index species is Ps. ziegleri Kon. et Kim. The Mosolovian Regional Stage is assigned to the kockelianus Zone. The distribution diagrams of species in the most diverse middle assemblage support the hypothesis that, in the southeastern regions of the Voronezh anteclise, the depth was greater than in its western part. The characteristic conodont species are shown in the plates.     

Ammonite assemblages from basal layers of the Ryazanian Stage (Lower Cretaceous) of Central Russia

Five successive ammonite assemblages are distinguished in the basal part (Riasanites rjasanensis Zone s. l.) of the Ryazanian Stage of the East European platform. These are (from the base upward) (1) Hectoroceras tolijense; (2) Hectoroceras kochi; (3) Riasanites swistowianus; (4) Riasanites rjasanensis; and (5) Transcaspiites transfigurabilis assemblages. Two lower assemblages consist entirely of boreal taxa, which occur in association with diverse ammonites of the Tethyan origin higher in the section. The data obtained show that three upper assemblages are correlative with the Berriasian Dalmasiceras tauricum, Riasanites rjasanensis-Spiticeras cautleyi, and Euthymiceras euthymi subzones of the northern Caucasus. The succession of five–six ammonite assemblages established in the East European platform above the top of the Craspedites nodiger Zone may correspond to the same number of ammonite assemblages characterizing lower subzones of the standard Berriasian. Berriasella rulevae Mitta, sp. nov. from the upper part of the Riasanites rjasanensis Zone (transfigurabilis biohorizon) is described.     

Smaller foraminifers from type sections of the Bolorian stage,the Lower Permian of Darvaz

Smaller foraminifers from Upper Yakhtashian and Bolorian deposits of the stratotype area (Pamir, Darvaz, Tajikistan) are investigated. Four assemblages are defined. The first assemblage is from Chalaroschwagerina vulgaris-Pamirina darvasica Zone. The second assemblage found in the transitional Yakhtashian-Bolorian beds includes Globivalvulina, Palaeotextulariidae, Hemigordiidae, and Glomospira, associated with the first Pachyphloia and Langella forms. Characteristic taxa of third assemblage from the Misellina (Brevaxina) dyhrenfurthi Zone are Geinitzinidae, Globivalvulina, Palaeotextulariidae, Glomospira, and rare Pachyphloia. The forth assemblage of Hemigordiidae, Pachyphloia, Palaeotextulariidae, Geinitzinidae, Pseudoagathammina is identified in the M. (Misellina) parvicostata Zone. The assemblages were compared with concurrent analogs from China, Japan, and Russia. New species and subspecies Glomospira paleograndis sp. nov., G. darvasica sp. nov., Agathammina darvasica sp. nov., Pachyphloia darvasica sp. nov., Nodosinelloides cubanicus elongatus subsp. nov., and Hemigordius saranensis darvasicus subsp. nov. are described.     

Detailed stratigraphy of the Jurassic-Cretaceous boundary beds of the Lena River lower reached based on ammonites and Buchiids

The Jurassic-Cretaceous (Volgian-Lower Valanginian) boundary deposits in the lower reaches of the Lena River (near the village of Chekurovka and on the Cape Chucha, North Yakutia) are described bed-by-bed. The taxonomic composition of ammonites and bivalves (mainly Buchia) is determined. The species assemblages are biostratigraphically analyzed and biostratigraphic units of the bed and zone ranks are recognized based on by Buchia and ammonites. Analogues of the Buchia Zones (buchiazones) Unschensis, Okensis, Tolmatschewi, Inflata and ammonite zones Exoticus, Okensis, Sibiricus, Analogus, Mesezhnikowi and ? Klimovskiensis are established in this region for the first time. A correlation of the distinguished buchiazones with the buchiazones of the Nordvik Peninsula, New Siberian Islands (Stolbovoy Island), the basin of the Anyuy River, and Northern California is proposed. The ammonite assemblages constantly contain phylloceratids; some stratigraphic intervals also contain lytoceratids; this is probably connected with a Paleo-Pacific influence. Unlike the ammonite assemblages of the same age of the Khatanga depression, the subzones cannot be distinguished in the Sibiricus and Kochi Zones of the Lower Lena due to differences in the stratigraphic ranges of some ammonite species. Hectoroceras in the Kochi zone is very rare and Praetollia predominates here.     

Presence of Fish on the Shallow Flooded Margins of a Small Intermittently Open Estuary in South Eastern Australia under Variable Flooding Regimes

Shallow water habitats within estuarine systems are believed to be important areas for small fish. While a wide variety of shallow habitats have been studied, the land that becomes inundated by the damming effect after the closure of intermittently open mouths has previously been overlooked. Fish were sampled monthly from both the main channel and flood zone of an intermittently open estuary between July 2004 and June 2005 using minifyke nets during the day and at night. A total of 7,787 fish were collected during the study representing 13 species and 11 families. Philypnodon grandiceps was the most abundant species and, together with Atherinosoma microstoma, Pseudogobius olorum, and Galaxias maculatus, made up 94% of the total catch. Inundation of the flood zone occurred in two discrete forms associated with mouth condition, which consisted of sporadic flooding while the mouth was open, to long-term flooding for 6 months after its closure. Large numbers of fish were captured on the flood zone, which included nine species; however, A. microstoma dominated the catch. A distinct shift in the flood zone fish assemblage occurred between the two mouth conditions, which is likely associated with changes in hydro-period and food availability of the flood zone and physico-chemical parameters in the main channel. There was no longitudinal variation in the fish assemblage in both the main channel and flood zone; similarly, the diel period was found to have little effect on the fish assemblage. The total catch per unit effort did not vary across seasons and suggests that fish abundance within the estuary is stable throughout the year. Unlike other estuarine systems where shallow water fish assemblages may be structured by variations in tide and elevation within the Surrey, freshwater inflow and, more importantly, mouth condition appear to have the greatest influence in composition of the shallow water flood zone fish assemblage of intermittently open estuaries.     

Representatives of genera <Emphasis Type="Italic">Malbosiceras</Emphasis> and <Emphasis Type="Italic">Pomeliceras</Emphasis> (Neocomitidae,Ammonoidea) from the Berriasian of the Crimean Mountains

The revised representatives of ammonite genera Malbosiceras and Pomeliceras from the Berriasian of the Crimean Mountains are classed with seven species, four of the first genus [M. malbosi (Pictet), M. chaperi (Pictet), M. broussei (Mazenot), M. pictetiforme Tavera] and three of the second one [P. aff. boisseti Nikolov, P. breveti (Pomel), P. (?) funduklense Lysenko et Arkadiev sp. nov.]. The identified species are described. The genus Mazenoticeras is considered as synonym of Malbosiceras. The above species prove that all the Berriasian zones (jacobi, occitanica and boissieri) are characteristic of corresponding deposits in the Crimean Mountains.     

Impacts of Invasive <Emphasis Type="Italic">Phragmites australis</Emphasis> on Diamondback Terrapin Nesting in Chesapeake Bay

The range expansion of exotic plant species, including the invasive reed Phragmites australis, causes widespread structural and functional changes to coastal ecosystems along the Atlantic and Gulf Coasts of North America. Native estuarine species, such as the diamondback terrapin (Malaclemys terrapin), are at risk of adverse effects from rapid habitat changes due to exotic invasions. Diamondback terrapins currently face population threats including by-catch mortality in crab pots, predation, and habitat loss, and populations may continue to suffer if deleterious plant invasions into preferred nesting habitats are left unchecked. We examined the extent to which Phragmites affects nesting of a breeding population of diamondback terrapins at Fisherman Island National Wildlife Refuge on the eastern shore of Virginia, where Phragmites has recently expanded into known areas of terrapin nesting. With data collected from the 2015 nesting season, we quantified the extent to which Phragmites shading could impact nest incubation temperature and determined how Phragmites density impacts the risk of rhizome invasion into nests. We conclude that Phragmites cover greater than 50% would decrease incubation temperatures of terrapin nests sufficiently to produce predominantly male hatchlings. Phragmites cover had no observed effect on root growth into simulated nests, but cover by other dune plant species explained observed trends in root growth. These results suggest that terrapins may be negatively impacted by Phragmites expansion into open nesting sites. Breeding site fidelity exhibited by terrapins and other estuarine species could limit the ability of their populations to adjust to rapid coastal expansion of invasive plant species.     

Middle Pleistocene-Holocene calcareous plankton and benthos biostratigraphy of the Markova Depression,equatorial atlantic

The analysis of nannoplankton, planktonic and benthic foraminifer assemblages provided detailed biostratigraphic characteristics of the upper part of sedimentary cover in the Markova Depression, rift valley of the Mid-Atlantic Ridge. The Gephyrocapsa oceanica and Emiliania huxleyi nannofossil zones, (LO) Helicosphaera inversa biohorizon, Emiliania huxleyi Acme Zone, and planktonic foraminiferal Globigerina calida calida, Globigerina bermudezi and Globorotalia fimbriata subzones were recognized. The compiled paleotemperature curve is correlated with the upper 10 oxygen isotope stages. The recovered deposits were accumulated during 400 ka. Changes in abundance and species composition of benthic foraminifer assemblages are suggested to be correlative with hydrothermal activity outbreaks in the rift zone.     

Determinants of expansion for<Emphasis Type="Italic">Phragmites australis</Emphasis>, common reed,in natural and impacted coastal marshes

The rapid spread ofPhragmites australis in the coastal marshes of the Northeastern United States has been dramatic and noteworthy in that this native species appears to have gained competitive advantage across a broad range of habitats, from tidal salt marshes to freshwater wetlands. Concomitant with the spread has been a variety of human activities associated with coastal development as well as the displacement of nativeP. australis with aggressive European genotypes. This paper reviews the impacts caused by pure stands ofP. australis on the structure and functions of tidal marshes. To assess the determinants ofP. australis expansion, the physiological tolerance and competitive abilities of this species were examined using a field experiment.P. australis was planted in open tubes paired withSpartina alterniflora, Spartina patens, Juncus gerardii, Lythrum salicaria, andTypha angustifolia in low, medium, and high elevations at mesohaline (14‰), intermediate (18‰), and salt (23‰) marsh locations. Assessment of the physiological tolerance ofP. australis to conditions in tidal brackish and salt marshes indicated this plant is well suited to colonize creek banks as well as upper marsh edges. The competitive ability ofP. australis indicated it was a robust competitor relative to typical salt marsh plants. These results were not surprising since they agreed with field observations by other researchers and fit within current competition models throught to structure plant distribution within tidal marshes. Aspects ofP. australis expansion indicate superior competitive abilities based on attributes that fall outside the typical salt marsh or plant competition models. The alignment of some attributes with human impacts to coastal marshes provides a partial explanation of how this plant competes so well. To curb the spread of this invasive genotype, careful attention needs to be paid to human activities that affect certain marsh functions. Current infestations in tidal marshes should serve as a sentinel to indicate where human actions are likely promoting the invasion (e.g., through hydrologic impacts) and improved management is needed to sustain native plant assemblages (e.g., prohibit filling along margins).