scholarly journals Influence of hydrodynamic setting on Posidonia oceanica meadow landscape and architecture

2015 ◽  
Author(s):  
Matthew Pace ◽  
Joseph A Borg ◽  
Charles Galdies
Keyword(s):  
Seagrass Meadow ◽  
Posidonia Oceanica ◽  
High Energy ◽  
Wave Exposure ◽  
Exposure Model ◽  
Eastern Coast ◽  
Seagrass Habitat ◽  
Physical Factors ◽  
The North ◽  
Architectural Features

Seagrass meadow characteristics, including distribution, shape, size, and within-meadow architectural features may be influenced by various physical factors, including hydrodynamic forces. However, such influence has hardly been assessed for meadows of the ecologically important and endemic Mediterranean seagrass Posidonia oceanica. Estimates of wind- generated wave energy and the energy attenuated by depth were computed by a hydrodynamic model, WEMo (Wave Exposure Model), for five sites on the north-eastern coast of the Maltese Islands which each supported patchy, reticulate and continuous bed types of Posidonia oceanica. The distribution of P. oceanica meadows at these sites were mapped to a depth of circa 15m using a combination of aerial photography and SCUBA diving surveys. Data on meadow architectural attributes were collected for each of the three P. oceanica bed types at each of the five study sites. Metrics for P. oceanica landscape features were calculated via FRAGSTATS v4 for replicate 2500m2 subsamples that were extracted from the seagrass habitat maps. The results indicate that landscape and architectural features of relatively deep P. oceanica meadows are significantly influenced by the hydrodynamic setting. P. oceanica meadows tend to be patchier with lower overall cover, more complex patch shapes and reduced architectural complexity along a wave exposure gradient from low to high energy. The findings from the present study highlight the importance of understanding the influence of hydrodynamic factors on the natural dynamism of seagrass meadow landscape and architecture for the conservation and management of P. oceanica habitat.

scholarly journals Influence of hydrodynamic setting on Posidonia oceanica meadow landscape and architecture

2015 ◽  
Author(s):  
Matthew Pace ◽  
Joseph A Borg ◽  
Charles Galdies
Keyword(s):  
Seagrass Meadow ◽  
Posidonia Oceanica ◽  
High Energy ◽  
Wave Exposure ◽  
Exposure Model ◽  
Eastern Coast ◽  
Seagrass Habitat ◽  
Physical Factors ◽  
The North ◽  
Architectural Features

Seagrass meadow characteristics, including distribution, shape, size, and within-meadow architectural features may be influenced by various physical factors, including hydrodynamic forces. However, such influence has hardly been assessed for meadows of the ecologically important and endemic Mediterranean seagrass Posidonia oceanica. Estimates of wind- generated wave energy and the energy attenuated by depth were computed by a hydrodynamic model, WEMo (Wave Exposure Model), for five sites on the north-eastern coast of the Maltese Islands which each supported patchy, reticulate and continuous bed types of Posidonia oceanica. The distribution of P. oceanica meadows at these sites were mapped to a depth of circa 15m using a combination of aerial photography and SCUBA diving surveys. Data on meadow architectural attributes were collected for each of the three P. oceanica bed types at each of the five study sites. Metrics for P. oceanica landscape features were calculated via FRAGSTATS v4 for replicate 2500m2 subsamples that were extracted from the seagrass habitat maps. The results indicate that landscape and architectural features of relatively deep P. oceanica meadows are significantly influenced by the hydrodynamic setting. P. oceanica meadows tend to be patchier with lower overall cover, more complex patch shapes and reduced architectural complexity along a wave exposure gradient from low to high energy. The findings from the present study highlight the importance of understanding the influence of hydrodynamic factors on the natural dynamism of seagrass meadow landscape and architecture for the conservation and management of P. oceanica habitat.

scholarly journals Occurrence and distribution of different bed types of seagrass Posidonia oceanica around the Maltese Islands

2009 ◽  
Vol 10 (2) ◽  
pp. 45 ◽  
Author(s):  
J.A. BORG ◽  
A.A. ROWDEN ◽  
M.J. ATTRILL ◽  
P.J. SCHEMBRI ◽  
M.B. JONES
Keyword(s):  
Large Scale ◽  
Posidonia Oceanica ◽  
Eastern Coast ◽  
Small Scale ◽  
Northern Coast ◽  
Maltese Islands ◽  
The North ◽  
Bare Sand ◽  
Sandy Substratum ◽  
Continuous Beds

The small-scale distribution of Posidonia oceanica bed types were mapped at four locations off the northern coast of the Maltese Islands, using aerial photography supplemented by surveys using SCUBA diving. Results showed a similar pattern of occurrence of the seagrass at all locations surveyed. In shallow waters (2 m – 4 m), P. oceanicaoccurred as patches of variable size on a rocky and/or sandy substratum. In deeper waters (5 m – 10 m), the patches of seagrass were often replaced by reticulate beds consisting of P. oceanicainterspersed with areas of bare sand. Deeper still (11 m – 13 m), a transition from reticulate to continuous beds occurred. Continuous beds extended to depths of around 25 - 30 m and eventually became reticulate or patchy in deeper waters (>25 m). Values of total seagrass percentage cover increased, while the ratio of fragmented:continuous bed cover decreased for the four study locations on moving southwards (Ramla Bay to St Thomas Bay), indicating that P. oceanica habitat was more abundant and less fragmented in the south-eastern parts of the Maltese Islands. However, values calculated using an exposure index did not did indicate a relationship between exposure and the observed decease in fragmentation of seagrass beds on moving northwest to southwest along the north-eastern coast. Data from the four sites surveyed, together with data from other surveys, were used to show the large-scale distribution of P. oceanica beds around the Maltese Islands. The implications of the study findings for the conservation and management of P. oceanica habitat around the Maltese Islands are discussed.

scholarly journals Ovaries of Chrysanthemum Irradiated with High-Energy Photons and High-Energy Electrons Can Regenerate Plants with Novel Traits

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1111
Author(s):  
Natalia Miler ◽  
Iwona Jedrzejczyk ◽  
Seweryn Jakubowski ◽  
Janusz Winiecki
Keyword(s):  
Total Dose ◽  
In Vitro Regeneration ◽  
High Energy ◽  
Mutation Breeding ◽  
Chrysanthemum Morifolium ◽  
Physical Factors ◽  
Strong Impact ◽  
Breeding Method ◽  
High Energy Electrons

Classical mutation breeding using physical factors is a common breeding method for ornamental crops. The aim of our study was to examine the utility of ovaries excised from irradiated inflorescences of Chrysanthemum × morifolium (Ramat.) as explants for breeding purposes. We studied the in vitro regeneration capacity of the ovaries of two chrysanthemum cultivars: ‘Profesor Jerzy’ and ‘Karolina’ preceded by irradiation with high-energy photons (total dose 5, 10 and 15 Gy) and high-energy electrons (total dose 10 Gy). Growth and inflorescence parameters of greenhouse acclimatized regenerants were recorded, and ploidy level was estimated with flow cytometry. The strong impact of genotype on regeneration efficiency was recorded—cultivar ‘Karolina’ produced only 7 viable shoots, while ‘Profesor Jerzy’ produced totally 428 shoots. With an increase of irradiation dose, the regeneration decreased, the least responsive were explants irradiated with 15 Gy high-energy photons and 10 Gy high-energy electrons. Regenerants of ‘Profesor Jerzy’ obtained from these explants possessed shorter stem and flowered later. The highest number of stable, color and shape inflorescence variations were obtained from explants treated with 10 Gy high-energy photons. Variations of inflorescences were predominantly changes of shape—from full to semi-full. New color phenotypes were dark yellow, light yellow and pinkish, among them only the dark yellow phenotype remained stable during second year cultivation. None of the regenerants were haploid. The application of ovaries irradiated within the whole inflorescence of chrysanthemum can be successfully applied in the breeding programs, provided the mother cultivar regenerate in vitro efficiently.

scholarly journals On the Relationship between Winter Sea Ice and Summer Atmospheric Circulation over Eurasia

2013 ◽  
Vol 26 (15) ◽  
pp. 5523-5536 ◽  
Author(s):  
Bingyi Wu ◽  
Renhe Zhang ◽  
Rosanne D'Arrigo ◽  
Jingzhi Su
Keyword(s):  
Sea Ice ◽  
Atmospheric Circulation ◽  
Rainfall Variability ◽  
Summer Rainfall ◽  
Eastern Coast ◽  
Northern Eurasia ◽  
Sea Ice Concentration ◽  
The North ◽  
Circulation Anomalies ◽  
Atmospheric Circulation Anomalies

Abstract Using NCEP–NCAR reanalysis and Japanese 25-yr Reanalysis (JRA-25) data, this paper investigates the association between winter sea ice concentration (SIC) in Baffin Bay southward to the eastern coast of Newfoundland, and the ensuing summer atmospheric circulation over the mid- to high latitudes of Eurasia. It is found that winter SIC anomalies are significantly correlated with the ensuing summer 500-hPa height anomalies that dynamically correspond to the Eurasian pattern of 850-hPa wind variability and significantly influence summer rainfall variability over northern Eurasia. Spring atmospheric circulation anomalies south of Newfoundland, associated with persistent winter–spring SIC and a horseshoe-like pattern of sea surface temperature (SST) anomalies in the North Atlantic, act as a bridge linking winter SIC and the ensuing summer atmospheric circulation anomalies over northern Eurasia. Indeed, this study only reveals the association based on observations and simple simulation experiments with SIC forcing. The more precise mechanism for this linkage needs to be addressed in future work using numerical simulations with SIC and SST as the external forcings. The results herein have the following implication: Winter SIC west of Greenland is a possible precursor for summer atmospheric circulation and rainfall anomalies over northern Eurasia.

A Note on the Shipbuilding in Bengal in the Late Eighteenth Century

Itinerario ◽  
1995 ◽  
Vol 19 (3) ◽  
pp. 167-174 ◽  
Author(s):  
Bhaswati Bhattacharya
Keyword(s):  
Eighteenth Century ◽  
Early Modern ◽  
Direct Evidence ◽  
Early Modern Period ◽  
Eastern Coast ◽  
Shipbuilding Industry ◽  
The North ◽  
Indian Ocean Trade ◽  
History Of ◽  
The Indian Ocean

Both overseas trade and shipbuilding in India are of great antiquity. But even for the early modern period, maritime commerce is relatively better documented than the shipbuilding industry. When the Portuguese and later the North Europeans entered the intra-Asian trade, many of the ships they employed in order to supplement their shipping in Asia were obtained from the Indian dockyards. Detailed evidence with regard to shipbuilding, however, is very rare. It has been pointed out that the Portuguese in the sixteenth century were more particular than their North-European counter-parts in the following centuries in providing information on seafaring and shipbuilding. Shipbuilding on the west coast has been discussed more than that on the eastern coast of India, particularly the coast of Bengal. Though Bengal had a long tradition of shipbuilding, direct evidence of shipbuilding in the region is rare. Many changes were brought about in the history of India and the Indian Ocean trade of the eighteenth century, especially after the 1750s. When the English became the largest carriers of Bengal's trade with other parts of Asia, this had an impact on the shipbuilding in Bengal. It was in their interest that the British in Bengal had their ships built in that province.

Detection of a change in the North-South ratio of count rates of particles of high-energy cosmic rays during a change in the polarity of the magnetic field of the Sun

JETP Letters ◽  
2015 ◽  
Vol 101 (4) ◽  
pp. 228-231
Author(s):  
A. V. Karelin ◽  
O. Adriani ◽  
G. C. Barbarino ◽  
G. A. Bazilevskaya ◽  
R. Bellotti ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
High Energy ◽  
The Sun ◽  
High Energy Cosmic Rays ◽  
The North ◽  
The Magnetic Field

scholarly journals Climatology of Heavy Orographic Rainfall Induced by Tropical Cyclones over Madagascar: From Synoptic to Mesoscale Perspectives

2016 ◽  
Vol 5 (2) ◽  
pp. 132 ◽  
Author(s):  
Tatiana A. Arivelo ◽  
Yuh-Lang Lin
Keyword(s):  
Tropical Cyclones ◽  
Southern Oscillation Index ◽  
Southern Oscillation ◽  
Rainfall Variability ◽  
Eastern Coast ◽  
Quasi Biennial Oscillation ◽  
Trade Winds ◽  
Southwest Indian Ocean ◽  
The North ◽  
Orographic Rainfall

Variability of and generation mechanisms for Madagascar rainfall are studied by conducting climatological, synoptic and mesoscale analyses. It is found the rainfall variability is highly sensitive to seasons with high variability in summer (Nov-Apr). The rainfall in summer is controlled by the Intertropical Convergence Zone (ITCZ) and orographic rainfall associated with tropical cyclones (TCs), while the rainfall in winter (May-Oct) is controlled by trade winds and local orographic rainfall along the eastern coast. Synoptic analysis reveals that major climate variations in summer are associated with ITCZ position, which is closely related to TC genesis locations and quasi-biennial oscillation (QBO). Linkages between El-Niño Southern Oscillation Index (ENSO) and Southern Oscillation Index (SOI) are identified as the cause of inconsistent dry or wet summers. Mesoscale analysis depicts the importance of the orographic effects on prevailing wind, which are controlled by the orography in both seasons. In winter, the prevailing trade winds over the Southwest Indian Ocean are from the east and are split to the north and south when it impinges on Malagasy Mountains. On the other hand, in summer the prevailing easterlies are weaker leading to the production of lee vortices, in addition to the flow splitting upstream of the mountain. Thus, the flow is classified into two regimes: (a) flow-over regime with no lee vortices under high Froude number (Fr=1.2-1.8) flow, and (b) flow-around regime with lee vortices under low Fr (=0.88-1.16) flow. A case study of TC Domoina (1984) indicates that the long-lasting heavy rainfall was induced by the strong orographic blocking of Madagascar. The shorter-term (e.g., 2 days) heavy orographic precipitation is characterized by large VH ∙Ñh which is composed by two common ingredients, namely a strong low-level wind normal to the mountain (VH) and a steep mountain slope (∇h).

scholarly journals THE CONFIGURATION OF MASS LAY-OUT AND EXTERNAL SPACE EXPLOITATION OF FISHING VILLAGES Study objects: The Fishing Villages of Cilincing and Marunda in North Jakarta

2017 ◽  
Vol 1 (1) ◽  
pp. 17-36
Author(s):  
Levina Levina
Keyword(s):  
Fishing Community ◽  
Exterior Space ◽  
Fishing Villages ◽  
The North ◽  
Physical Data ◽  
Architectural Features ◽  
Java Sea ◽  
Data Collection Technique ◽  
The One

Abstract- Cilincing and Marunda are two kampongs situated in the north of Jakarta, immediately bordering on the Java Sea. The existence of the fishing villages sketches the lives of these communities. They make their living out of catching fish and other produce, so the lives of the fishing community take place between water and land. This situation has led to their settlement differing from others in the urban kampong. The synergy stimulated by the water-based context has inspired the unique architectural features of these villages, in terms of planning the lay-out of the dwelling-places or residential area.This research study is a descriptive-comparative analysis of the exploitation of exterior space based on the configuration pattern of the mass lay-out of the fishing villages observed. The data collection technique consists of gathering the relevant physical data along with those covering related activities. The physical data have been obtained by way of field mapping and observation, while the data concerning activities have been collected through observation and interviews conducted with the respondents, namely the inhabitants of the Cilincing fishing village (RT 012) and of Marunda (RT 03). The data have been divided based on the major outdoor activities of the community involved (sea-faring and residing). Finally, a comparison has been drawn between the research results of these two villages.The findings indicate that the configuration of the mass lay-out in these two fishing villages has created a quality of exterior space exploitation that is different as well. The one that displays a scattered lay-out pattern has a large volume of exterior space at its disposal that is left unexploited by its inhabitants, both for sea-bound activities and residential land-bound ones. The propinquity of the mass has created exterior space that is more intimate in nature.Keywords: Configuration of mass lay-out, exterior space

scholarly journals Geomorphology of the north-eastern coast of Gozo (Malta, Mediterranean Sea)

2018 ◽  
Vol 14 (2) ◽  
pp. 402-410 ◽  
Author(s):  
Mariacristina Prampolini ◽  
Christopher Gauci ◽  
Anton S. Micallef ◽  
Lidia Selmi ◽  
Vittoria Vandelli ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Eastern Coast ◽  
The North ◽  
North Eastern

The onset of the early Toarcian flooding of the Pliensbachian carbonate platform of Central Tunisia (North-South Axis) as inferred from trace fossils and geochemistry

2021 ◽  
pp. SP514-2021-10
Author(s):  
Matías Reolid ◽  
Mohamed Soussi ◽  
Jesús Reolid ◽  
Wolfgang Ruebsam ◽  
Ilef Belhaj Taher ◽  
...  
Keyword(s):  
Carbonate Platform ◽  
High Energy ◽  
Trace Fossils ◽  
Energy Conditions ◽  
Local Conditions ◽  
Content Type ◽  
The North ◽  
Sea Bottom ◽  
Supplementary Material ◽  
South Axis

AbstractThe flooding of the Lower Jurassic shelf in the North Gondwana Palaeomargin during the early Toarcian occurred on a fragmented and irregular topography affected by differential subsidence—due to the activity of listric faults along the North-South Axis of Tunisia—that favoured lateral changes in facies and thickness at a kilometric scale. The onset of Toarcian sedimentation (Polymorphum ammonite Zone, NJT5c nannofossil Subzone) in two adjacent sections was characterised by the deposition of limestones under high-energy conditions. The Châabet El Attaris section was located in a depressed sub-basin, and recorded restricted environmental conditions owing to water stagnation and an oxygen-depleted sea-bottom. Therefore, dark mudstones developed, with increased TOC contents and enhanced accumulation of redox-sensitive elements. The sedimentation of limestones bearing gutter cast structures is related to gravity flows probably linked to storm activities. These processes favoured the remobilization of sediments at the sea floor, as well as oxygen input to bottom waters, as shown by the record of trace fossils including Zoophycos, Ophiomorpha, and secondarily, Chondrites and Diplocraterion. The thinly interbedded dark mudstones are locally rich in thin-shelled bivalves that re-colonised the sea bottom after the sedimentation of these high-energy deposits, and subsequently underwent mass mortality related to the return of oxygen-depleted conditions. The Kef El Hassine section is located in the upper part of a tilted, less subsident block, as indicated by its reduced thickness compared with the Châabet El Attaris section; the absence of dark mudstones implies oxic conditions. The Polymorphum Zone consists of limestones showing evidence of sedimentation under high-energy conditions, along with hardgrounds. The occurrence of Zoophycos (deep-tiers) in the upper part of some limestone beds of the Polymorphum Zone is linked to minor erosive processes. The top of the high-energy sequence—below the deposits of a marly interval corresponding to the Levisoni Zone—is interpreted as a hardground given the high content of belemnites and Arenicolites, some of them boring on the eroded Zoophycos and Thalassinoides. This study shows that the sedimentary expression of the Jenkyns Event is not uniform across Tunisia, supporting the importance of local conditions in determining the development of anoxic conditions.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5510162

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