Some “driving forces” structuring communities of the sublittoral Antarctic macrobenthos

2000 ◽  
Vol 12 (3) ◽  
pp. 297-313 ◽  
Author(s):  
Julian Gutt
Keyword(s):  
Driving Forces ◽  
Structural Diversity ◽  
Intermediate Disturbance Hypothesis ◽  
Weddell Sea ◽  
Sediment Type ◽  
Physical Parameters ◽  
Underwater Imaging ◽  
Benthic Assemblages ◽  
Two Factors ◽  
Stability Time

Community analyses of the macrobenthos living on the Weddell Sea shelf revealed a distinct horizontal patchiness. Within some systematic groups a specific faunistic classification could clearly be defined, e.g. for asterozoans and holothurians. Whilst for fish, only a general zoogeographical pattern was discernible, there were some recognisable relationships to different microhabitats. The extreme differences in the distribution of sponges observed seems to reflect their highly variable biological characteristics. Studies using underwater imaging methods for benthic research have provided strong evidence for the ecological significance of two factors. The first, iceberg scouring, leads to a variety of simultaneous stages of recolonization, which result in an increase in beta-diversity. As a consequence, it is unlikely that regionally a stage approaching a theoretical climax will ever be attained. Secondly, the structural diversity of living substrata provides the basis for an additional variety of epibiotic species. Only weak or non-detectable correlations have been found between benthic assemblages and physical parameters, such as water depth, sediment type, bathymetric features and the abundance of deposited phytodetritus. This indicates a benthic system which is relatively uncoupled from processes in the water column. The combination of stable environmental conditions and disturbances taking place over long periods of time, which are partly a special feature of Antarctica's glacial history, shaped the diversity and faunal composition of the macrobenthos. Consequently, neither Houston's “intermediate-disturbance-hypothesis” nor Sander's “stability-time-hypothesis” can be rejected for this part of the Antarctic ecosystem.

Extravagant “fake” morphemes in Dutch. Morphological productivity, semantic profiles and categorical flexibility

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kristel Van Goethem ◽  
Muriel Norde
Keyword(s):  
Driving Forces ◽  
Morphological Properties ◽  
Distributional Semantics ◽  
Corpus Study ◽  
Left Hand ◽  
Semantic Coherence ◽  
Two Factors ◽  
Type Frequency ◽  
Imitation Leather ◽  
Artificial Grass

AbstractDutch features several morphemes with “privative” semantics that occur as left-hand members in compounds (e.g., imitatieleer ‘imitation leather’, kunstgras ‘artificial grass’, nepjuwelen ‘fake jewels’). Some of these “fake” morphemes display great categorical flexibility and innovative adjectival uses. Nep, for instance, is synchronically attested as an inflected adjective (e.g., neppe cupcake ‘fake cupcake’). In this paper, we combine an extensive corpus study of eight Dutch “fake” morphemes with statistical methods in distributional semantics and collexeme analysis in order to compare their semantic and morphological properties and to find out which factors are the driving forces behind their exceptional “extravagant” morphological behavior. Our analyses show that debonding and adjectival reanalysis are triggered by an interplay of two factors, i.e., type frequency and semantic coherence, which allow us to range the eight morphemes on a cline from more schematic to more substantive “fake” constructions.

Future study of textile industry in Iran using the MICMAC and soft operational research methods

foresight ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammad Reza Fathi ◽  
Seyed Mohammad Sobhani ◽  
Mohammad Hasan Maleki ◽  
Gholamreza Jandaghi
Keyword(s):  
Research Methods ◽  
Future Study ◽  
Textile Industry ◽  
Operational Research ◽  
Driving Forces ◽  
Business Environment ◽  
Systems Methodology ◽  
Content Type ◽  
Delphi Approach ◽  
Two Factors

Purpose This study aims to formulate exploratory scenarios of the textile industry in Iran based on MICMAC and soft operational research methods. Design/methodology/approach In this study, to formulate plausible scenarios, literature reviews and external experts’ opinions of this field have been gathered through the Delphi approach and uncertainty questionnaires. After the utilization of the most important uncertainties, the textile industry’s plausible scenarios have been mapped with the help of experts through co-thinking workshops. Results show that two factors, including the business atmosphere and membership in World Trade Organization (WTO), play a more important role than the other factors. These two factors were considered for the formulation of the scenario. To formulate plausible scenarios, soft systems methodology, which is a kind of soft operational research methods, is applied. Findings Based on the results, four scenarios are presented. These scenarios include the Elysium scenario, Hades scenario, Tatarus scenario and Sisyphus scenario. In the Elysium scenario, the business atmosphere has improved and Iran has been granted membership of the WTO. In Hades scenario, Iran has joined the WTO, but due to the government’s weakness and inactivity and key decision-makers, the required preparations have not been made. In the Tatarus scenario, Iran is not a WTO member and the business atmosphere is disastrous. In the Sisyphus scenario, the government takes reasonable actions toward a better business environment. Originality/value Formulating plausible scenarios of the textile industry is an excellent contribution to the key beneficiaries and actors of this industry so they can present flexible preparation-based programs in the face of circumstances. Future study of the textile industry familiarizes the actors and beneficiaries of this industry with the procedures and the driving forces that influence this industry’s future and it will ascertain various scenarios for the actors of this field.

Effects of structural diversity and identity of patches of habitat on diversity of benthic assemblages

2010 ◽  
Vol 35 (7) ◽  
pp. 743-751 ◽  
Author(s):  
M. G. MATIAS ◽  
A. J. UNDERWOOD ◽  
R. A. COLEMAN
Keyword(s):  
Structural Diversity ◽  
Benthic Assemblages

Sampling sediments

2009 ◽  
Author(s):  
John S. Gray ◽  
Michael Elliott
Keyword(s):  
Three Dimensional ◽  
Monitoring Programme ◽  
Sediment Type ◽  
Positioning System ◽  
Benthic Assemblages ◽  
Technological Advances ◽  
Continental Shelves ◽  
Global Positioning ◽  
Sediment Particles

One of the truisms of sampling design is that the design depends on the objectives. Too often objectives are not defined properly, with the result that the data collected cannot be used to answer the questions posed. A good example is that of a monitoring programme that aims to detect changes in an assemblage of benthic organisms caused by eutrophication but where the magnitude of change was not specified in the objectives, with the result that the monitoring programme was so loosely designed that insufficient samples were taken. A posteriori analyses of the results may show that the monitoring would take 10 years to detect a 10% change in the faunal composition. You may think that this is an unrealistic and hypothetical example, but our experience shows that far too often results such as this are the norm. We return to the types of monitoring in Chapter 11, but for now let us start with perhaps the simplest case: we wish to survey an area of coastal soft sediment simply to find out what is there (i.e. to map the habitats and prepare for a more detailed quantitative study of the benthic assemblages). Up to the last couple of decades, sampling subtidally below diveable depths was usually done blind. One had to resort to charts, perhaps prepared in the nineteenth century, which have depths and descriptions of sediments made from soundings done with handlines with candlewax in a hollowed-out part of the lead weight that touched sediment particles, enabling the sediment type to be crudely mapped. Since the 1980s huge technological advances have been made in mapping sediments. Two types of instrumentation have been developed: depth sounders of various types and remote-operated vehicles (ROVs). With sounders, accurate maps of the contours of the seabed can be produced and then indications of the hardness and roughness superimposed on the depth and good three-dimensional images produced with modern software. Sophisticated multibeam echosounders have been used to map the whole continental shelves of many countries. Now that the satellite-based differential global positioning system (DGPS) is generally available with an accuracy to a few metres, mapping of subtidal sediments has become much easier and more accurate.

scholarly journals Eutrophic water or fertile sediment: which is more important for the growth of invasive aquatic macrophyte Myriophyllum aquaticum?

2018 ◽  
pp. 3 ◽  
Author(s):  
Bingchang Tan ◽  
Hu He ◽  
Jiao Gu ◽  
Kuanyi Li
Keyword(s):  
Water Column ◽  
Nutrient Loading ◽  
Aquatic Macrophyte ◽  
Control Group ◽  
Sediment Type ◽  
Myriophyllum Aquaticum ◽  
Treatment Groups ◽  
Two Factors ◽  
Outdoor Experiment ◽  
Lateral Branches

Invasive macrophyte Myriophyllum aquaticum is capable of assimilating nutrients from both the sediments and the water column. However, which is the major source of nutrients supporting M. aquaticum growth under various nutrient regimes has not been well documented. Here we conducted a two-factorial outdoor experiment (three levels of nutrient loading and two types of sediments) from 23 May to 27 June 2016, to assess M. aquaticum responses to different nutrient levels in the water column and the sediment. Results showed that concentrations of total nitrogen, total phosphorus and chlorophyll a in the water column increased in the treatment groups, but decreased slightly in the control group (nutrient-poor sediment and no nutrient addition). Sediment type had a significant effect on the growth M. aquaticum, while there were no significant effects of nutrient loading levels and the interactions between the two factors. Mean relative growth rate, mean plant height, mean stem diameter, the number of lateral branches and roots in the nutrient-rich sediment treatments were 1.6, 1.2, 1.6, 3.2 and 5.9 folds greater than in the nutrient-poor sediment treatments, respectively. These results suggest that nutrient-rich sediment has a positive effect on the growth of M. aquaticum. This study reveals possible expansion mechanism of the exotic M. aquaticum in China, and may provide valuable information on the ecological restoration of eutrophic freshwaters.

scholarly journals Probing the Tides in Interacting Galaxy Pairs

1990 ◽  
Vol 124 ◽  
pp. 537-542
Author(s):  
Kirk D. Borne
Keyword(s):  
Gravitational Field ◽  
Binary System ◽  
Driving Forces ◽  
Elliptical Galaxies ◽  
Physical Parameters ◽  
Tidal Interactions ◽  
The Galaxy ◽  
Merger Rate ◽  
The Masses ◽  
Best Fit

AbstractDetailed spectroscopic and imaging observations of colliding elliptical galaxies have revealed unmistakable diagnostic signatures of the tidal interactions. It is possible to compare both the distorted luminosity distributions and the disturbed internal rotation profiles with numerical simulations in order to model the strength of the tidal gravitational field acting within a given pair of galaxies. Using the best-fit numerical model, one can then measure directly the mass of a specific interacting binary system. This technique applies to individual pairs and therefore complements the classical methods of measuring the masses of galaxy pairs in well-defined statistical samples. The “personalized” modeling of galaxy pairs also permits the derivation of each binary’s orbit, spatial orientation, and interaction timescale. Similarly, one can probe the tides in less-detailed observations of disturbed galaxies in order to estimate some of the physical parameters for larger samples of interacting galaxy pairs. These parameters are useful inputs to the more universal problems of (1) the galaxy merger rate, (2) the strength and duration of the driving forces behind tidally-stimulated phenomena (e.g., starbursts and maybe QSOs), and (3) the identification of long-lived signatures of interaction/merger events.

Proxies, drivers, and impact of macrofaunal transport in sediment of the southern North Sea.

2020 ◽  
Author(s):  
Andreas Neumann ◽  
Justus van Beusekom ◽  
Annika Eisele ◽  
Kay-Christian Emeis ◽  
Jana Friedrich ◽  
...  
Keyword(s):  
Exchange Rates ◽  
Pore Water ◽  
German Bight ◽  
Benthic Communities ◽  
Coastal Sediments ◽  
Ex Situ ◽  
Environmental Drivers ◽  
Sediment Type ◽  
Physical Parameters ◽  
Water Control

<p>Coastal sediments play an important role in the nutrient cycling, and the intensities of exchange processes between bottom water and pore water control the balance between sequestration and recycling of nutrients. Pore water advection as one major exchange mechanism is determined by physical parameters and thus well describable with models. By contrast, biotransport (bioirrigation, bioturbation) as the other major transport mechanism is much more complex and observational data are often scarce to quantify these processes.</p><p>We present ex-situ observations of oxygen and nutrient fluxes, sediment characteristics, and fauna composition over the past six years from all benthic provinces of the German Bight, which enable us to describe the spatial and seasonal variability of the benthic- pelagic coupling. We employ this dataset to detect environmental drivers of the observed variability and to test several proxies of faunal activity.</p><p>Our results show that abiotic parameters (sediment type, local primary production) explain the spatial variability while the dynamics of temperature and faunal activity explain the temporal variability. Effects of the complex benthic communities on benthic exchange rates can be parameterized by surprisingly simple proxies, which may help to improve benthic exchange models. By comparing in-situ measurements of pore water advection with ex situ observations, we conclude that biotransport approximately doubles the benthic- pelagic exchange rates in the German Bight.</p>

scholarly journals The biodiversity of the deep Southern Ocean benthos

2006 ◽  
Vol 362 (1477) ◽  
pp. 39-66 ◽  
Author(s):  
A Brandt ◽  
C De Broyer ◽  
I De Mesel ◽  
K.E Ellingsen ◽  
A.J Gooday ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Deep Water ◽  
Deep Sea ◽  
Large Scale ◽  
Environmental Parameters ◽  
Weddell Sea ◽  
Sediment Type ◽  
Biodiversity Patterns ◽  
Biogeographic Patterns ◽  
Relationship Of

Our knowledge of the biodiversity of the Southern Ocean (SO) deep benthos is scarce. In this review, we describe the general biodiversity patterns of meio-, macro- and megafaunal taxa, based on historical and recent expeditions, and against the background of the geological events and phylogenetic relationships that have influenced the biodiversity and evolution of the investigated taxa. The relationship of the fauna to environmental parameters, such as water depth, sediment type, food availability and carbonate solubility, as well as species interrelationships, probably have shaped present-day biodiversity patterns as much as evolution. However, different taxa exhibit different large-scale biodiversity and biogeographic patterns. Moreover, there is rarely any clear relationship of biodiversity pattern with depth, latitude or environmental parameters, such as sediment composition or grain size. Similarities and differences between the SO biodiversity and biodiversity of global oceans are outlined. The high percentage (often more than 90%) of new species in almost all taxa, as well as the high degree of endemism of many groups, may reflect undersampling of the area, and it is likely to decrease as more information is gathered about SO deep-sea biodiversity by future expeditions. Indeed, among certain taxa such as the Foraminifera, close links at the species level are already apparent between deep Weddell Sea faunas and those from similar depths in the North Atlantic and Arctic. With regard to the vertical zonation from the shelf edge into deep water, biodiversity patterns among some taxa in the SO might differ from those in other deep-sea areas, due to the deep Antarctic shelf and the evolution of eurybathy in many species, as well as to deep-water production that can fuel the SO deep sea with freshly produced organic matter derived not only from phytoplankton, but also from ice algae.

scholarly journals Ocean Convective Available Potential Energy. Part I: Concept and Calculation

2016 ◽  
Vol 46 (4) ◽  
pp. 1081-1096 ◽  
Author(s):  
Zhan Su ◽  
Andrew P. Ingersoll ◽  
Andrew L. Stewart ◽  
Andrew F. Thompson
Keyword(s):  
Energy Source ◽  
Potential Energy ◽  
Convective Available Potential Energy ◽  
Weddell Sea ◽  
Physical Parameters ◽  
Type Ii ◽  
Moist Convection ◽  
Available Potential Energy ◽  
Type Iii ◽  
Polar Oceans

AbstractThermobaric convection (type II convection) and thermobaric cabbeling (type III convection) might substantially contribute to vertical mixing, vertical heat transport, and deep-water formation in the World Ocean. However, the extent of this contribution remains poorly constrained. The concept of ocean convective available potential energy (OCAPE), the thermobaric energy source for type II and type III convection, is introduced to improve the diagnosis and prediction of these convection events. OCAPE is analogous to atmospheric CAPE, which is a key energy source for atmospheric moist convection and has long been used to forecast moist convection. OCAPE is the potential energy (PE) stored in an ocean column arising from thermobaricity, defined as the difference between the PE of the ocean column and its minimum possible PE under adiabatic vertical parcel rearrangements. An ocean column may be stably stratified and still have nonzero OCAPE. The authors present an efficient strategy for computing OCAPE accurately for any given column of seawater. They further derive analytical expressions for OCAPE for approximately two-layer ocean columns that are widely observed in polar oceans. This elucidates the dependence of OCAPE on key physical parameters. Hydrographic profiles from the winter Weddell Sea are shown to contain OCAPE (0.001–0.01 J kg−1), and scaling analysis suggests that OCAPE may be substantially enhanced by wintertime surface buoyancy loss. The release of this OCAPE may substantially contribute to the kinetic energy of deep convection in polar oceans.

Dynamics of Hydrocarbon Expulsion from Shale Source Rocks

2005 ◽  
Vol 23 (5) ◽  
pp. 333-355 ◽  
Author(s):  
Xiongqi Pang ◽  
Zhenxue Jiang ◽  
Shengjie Zuo ◽  
Ian Lerche
Keyword(s):  
Source Rock ◽  
Driving Forces ◽  
Water Solution ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Two Factors ◽  
Hydrocarbon Expulsion

Expulsion of hydrocarbons from a shale source rock can be divided in four stages. In the first stage, only a small amount of hydrocarbons can be expelled in water solution and by diffusion. Compaction and hydrocarbon concentration gradient are the major driving forces, whereas their corresponding hydrocarbon expulsion amounts make up 30% and 70% to the total, respectively. In the second stage, in addition to transport by water solution and by diffusion, source rocks expel a large quantity of gas in free phase. In the third stage, the most important feature is that source rocks expel oil as a separate phase and gas in oil solution. Hydrocarbon expulsion by diffusion through the source rock organic network, dehydration of clay minerals, and thermal expansion of fluids and rocks are the three major driving forces in the second and the third stages, whereas the corresponding hydrocarbon expulsion accounts for 40–60%, 10–20%, and 5–10%, respectively, of the total amount expelled. In the fourth stage, source rocks mainly expel dry gas as a free phase. Volume expansion of kerogen products and capillary force are the two major driving forces for hydrocarbon expulsion. The expulsion accounts for 60% and 30% to the total gas expulsion of this stage, respectively, for each driving force. Hydrocarbon expulsion, including the hydrocarbon expulsion threshold (HET), the relative phases and the dynamics, are controlled by two factors: the hydrocarbon generation amount, and the ability of source rocks to retain hydrocarbons. Source rocks cross the HET and begin to expel a large quantity of hydrocarbons when the generated hydrocarbons have met all of the needs for hydrocarbon retention. HET is divides the processes of hydrocarbon expulsion into the various four stages.

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