Phytoplankton species turnover controlled by physical forcing at different time scales

2008 ◽  
Vol 65 (1) ◽  
pp. 47-60 ◽  
Author(s):  
Alexandrine Pannard ◽  
Myriam Bormans ◽  
Yvan Lagadeuc
Keyword(s):  
Species Composition ◽  
Time Scale ◽  
Phytoplankton Community ◽  
Diversity Index ◽  
Species Turnover ◽  
Rate Of Change ◽  
Original Structure ◽  
Short Term ◽  
Physical Forcing ◽  
Physical And Chemical

Changes in the physical and chemical environment induced by forcing events such as wind and rain can control the short-term dynamics of the phytoplankton community of inland waters. In two temperate reservoirs, species composition, diversity index, and species dynamics were characterized over periods of 3 weeks during different seasons, in parallel with changes in the physical and chemical structure of the water column. Dominant species and diversity index were shown to be controlled by environmental factors fluctuating on a seasonal and weekly time scale, whereas some rarer species responded to wind events and were indicators of a very short-term environmental change. As a consequence of the response of indicator species, the rate of change in species composition increased following meteorological events. Shifts in species composition were observed during each sampling period, except during the strongest stratification period. The shifts were associated with a modification of resource availability or intensity of stratification. We found that the resistance of the phytoplankton community to short-term physical forcing by wind increased with intensity of stratification. After the forcing event, the community did not return to its original structure because of modifications of the physical and chemical conditions induced by meteorological forcing on a weekly time scale.

scholarly journals Seaweed Species Composition, Abundance and Diversity in Drini and Kondang Merak Beach, Java

2018 ◽  
Vol 47 ◽  
pp. 03006
Author(s):  
Taufiq Ahmad Romdoni ◽  
Ajeng Ristiani ◽  
Maria Dyah Nur Meinita ◽  
Bintang Marhaeni ◽  
Setijanto
Keyword(s):  
Species Composition ◽  
Diversity Index ◽  
Sampling Technique ◽  
Survey Method ◽  
Enteromorpha Flexuosa ◽  
Transect Sampling ◽  
Abundance And Diversity ◽  
Different Characteristics ◽  
Physical And Chemical ◽  
Beach Survey

The different characteristics of subtrate might give influence on species composition, abundance and diversity of seaweed. Kondang Merak and Drini Beach are two beaches in Java Island which have different subtrate characteristic. The aim of this study is to investigate seaweed composition, abundance and diversity in Drini Beach and Kondang Merak Beach. Survey method and quadrant transect sampling technique were applied in this study. The result showed that 13 species of seaweed were found at Drini Beach and 18 species of seaweed were found in Kondang Merak Beach. The composition of the seaweed at Drini Beach and Kondang Merak Beach were dominated by Rhodophyta (69% and 56%). Enteromorpha flexuosa was the most abundant seaweed at Drini Beach, while at Kondang Merak Beach was dominated by Chaetomorpha crassa. The seaweed diversity index of Kondang Merak Beach (2,08) was higher than Drini Beach (1,27). Physical and chemical parameters were categorized as the optimal for the growth of the seaweed.

scholarly journals On the Role of Resonant Interactions in the Short-Term Evolution of Deep-Water Ocean Spectra

2007 ◽  
Vol 37 (4) ◽  
pp. 1022-1036 ◽  
Author(s):  
Mitsuhiro Tanaka
Keyword(s):  
Deep Water ◽  
Time Scale ◽  
Rate Of Change ◽  
Short Term ◽  
Random Surface ◽  
Resonant Interactions ◽  
Nonlinear Energy Transfer ◽  
Term Evolution ◽  
Ordinary Time

Abstract The temporal evolution of the energy spectrum of a field of random surface gravity waves in deep water is investigated by means of direct numerical simulations of the deterministic primitive equations. The detected rate of change of the spectrum is shown to be proportional to the cubic power of the energy density and to agree very well with the nonlinear energy transfer Snl as predicted by Hasselmann. Despite the fact that use of various asymptotic relations that are valid only for t → ∞ or integration with respect to time over a time scale much longer than O[period × (ak)−2] is necessary in the derivation of Hasselmann’s Snl, it is clearly demonstrated that the rate of change of the spectrum given by the numerical simulation agrees very well with Hasselmann’s Snl at every instance of ordinary time scale comparable to the period. The result implies that the four-wave resonant interactions control the evolution of the spectrum at every instant of time, whereas nonresonant interactions do not make any significant contribution even in a short-term evolution. It is also pointed out that the result may call for a reexamination of the process of derivation of the kinetic equation for the spectrum.

Variations in the contribution of transport to changes in planktonic animal abundance: a study of the flux of fish larvae in Conception Bay, Newfoundland

1995 ◽  
Vol 52 (7) ◽  
pp. 1475-1486 ◽  
Author(s):  
P. Pepin ◽  
J. A. Helbig ◽  
R. Laprise ◽  
E. Colbourne ◽  
T. H. Shears
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
Estimation Error ◽  
Mortality Rates ◽  
Rate Of Change ◽  
Short Term ◽  
Physical Forcing ◽  
Daily Rate ◽  
Conception Bay ◽  
And Diffusion

We investigated the magnitude of short-term variations in the flux of several species of fish larvae in Conception Bay, Newfoundland, determined the contribution of these fluxes to changes in the abundance of these species, and assessed the factors that may be causing the variations in these fluxes. The net effect of transport ranged from a daily influx of 5.8% to a daily efflux of 6.2% from the population. Short-term variations in transport were associated with variations in wind stress. The contribution of transport to variations in population abundance ranged from 12 to more than 75% of the average daily rate of change in numbers for the different species. The contribution of physical processes to estimated mortality rates is variable and can have a significant impact on the investigation and interpretation of potential biological processes (e.g., predation and starvation) influencing the survival of larval fish. We predicted that the average correction to the instantaneous mortality rate due to advection and diffusion should be proportional to A−1/2, where A is the area of system under study. This highlights the susceptibility of small systems to estimation error of mortality rates caused by short-term variations in physical forcing.

Responses of Diatom and Chrysophyte Assemblages in Lake 227 Sediments to Experimental Eutrophication

1994 ◽  
Vol 51 (10) ◽  
pp. 2300-2311 ◽  
Author(s):  
Barbara A. Zeeb ◽  
Catherine E. Christie ◽  
John P. Smol ◽  
David L. Findlay ◽  
Hedy J. Kling ◽  
...  
Keyword(s):  
Species Composition ◽  
Relative Abundance ◽  
Nutrient Availability ◽  
Lake Water ◽  
Rate Of Change ◽  
Short Term ◽  
Chemical Changes ◽  
Chrysophyte Cysts ◽  
Ph Values ◽  
Lakewater Chemistry

We examined the diatom and chrysophyte assemblages preserved in Lake 227 sediments prior to, during, and following the annual additions of phosphorus (P) and nitrogen (N) (from 1969–1989). Premanipulation (1957–1968) diatom and chrysophyte assemblages were dominated by taxa characteristic of acidic, unproductive lake conditions. In 1969, the assemblages immediately shifted in response to increased nutrient availability and/or increased pH values in the epilimnion. Large increases in the relative abundance of Synedra PIRLA 2 and S. rumpens var. familiaris, Mallomonas crassisquama, M. doignonii var. tenuicostis, and cysts 1, 15, 29, 233, and 120 largely replaced the prefertilization assemblages. From 1970–1990, the diatom assemblage was dominated by alkaliphilic or pH-indifferent taxa. A second chrysophyte assemblage shift, which coincided with a lowering of the N:P addition ratio in 1975, was characterized by decreases in M. crassisquama and cysts 1, 15, 29, 233, and 120, and corresponding increases in Synura sphagnicola Korshikov scales and cysts 62 and 33. The stratigraphical analyses and numerical rate-of-change analyses clearly showed that diatom and chrysophyte species composition, particularly chrysophyte cysts, closely tracked short-term changes in lakewater chemistry. The amount of variance in the stratigraphic assemblages explained by lake-water chemical changes was high (68–90%), indicating the close algae–chemistry relationships in Lake 227 from 1969–1989.

scholarly journals Phytoplankton composition and diversity of Taninthayi coastal waters, Myanmar

2020 ◽  
Vol 3 (3) ◽  
Keyword(s):  
Species Composition ◽  
Coastal Waters ◽  
Phytoplankton Community ◽  
Diversity Index ◽  
Marine Phytoplankton ◽  
Phytoplankton Composition ◽  
Species Diversity Index ◽  
Species Composition And Distribution ◽  
Richness Index ◽  
High Diversity

Water samples collected by R/V DR. FRIDTJOF NANSEN during Myanmar ecosystem survey 2018 were analyzed to determine the species composition and distribution of phytoplankton. A total of one hundred and eighty-eight taxa of marine phytoplankton were identified and comprised of 116 taxa of diatoms, 67 taxa of dinoflagellates, 2 taxa of silicoflagellates and 3 taxa of cyanobacteria. Phytoplankton community was dominated by diatoms with 61.7% of total samples, followed by 35.6% of dinoflagellates. Species composition and abundance was found to be highest at station 799 with 90 species (2147no/m3) and lowest at station 846 with 36 species (673no/m3). The index values encountered from Taninthayi coastal waters ranged between 3.97 and 3.31 for species diversity index (H’), between 0.94 and 0.05 for evenness index (E’) and between 13.76 and 6.69 for species richness index (D’). High diversity index values (H’, E’, and D’) were recorded at the nearshore stations. The density and diversity of phytoplankton were positively correlated with the nutrients (chlorophyll a, nitrate, nitrite, silicate, phosphate) and negatively correlated with the temperature and salinity.

Short-term variability of the phytoplankton community in coastal ecosystem in response to physical and chemical conditions' changes

2008 ◽  
Vol 80 (2) ◽  
pp. 212-224 ◽  
Author(s):  
Alexandrine Pannard ◽  
Pascal Claquin ◽  
Cécile Klein ◽  
Bertrand Le Roy ◽  
Benoît Véron
Keyword(s):  
Phytoplankton Community ◽  
Coastal Ecosystem ◽  
Short Term ◽  
Chemical Conditions ◽  
Physical And Chemical ◽  
Short Term Variability

Carabidae of Barnaul city parks: ecological characteristics and species composition

2018 ◽  
Vol 8 (2) ◽  
pp. 348-353
Author(s):  
E. A. Kuchina ◽  
N. D. Ovcharenko ◽  
L. D. Vasileva
Keyword(s):  
Species Composition ◽  
Diversity Index ◽  
Similarity Index ◽  
Life Forms ◽  
Ground Beetles ◽  
Forest Steppe ◽  
Ecological Groups ◽  
Dominant Group ◽  
Species Diversity Index ◽  
Steppe Species

<p>Anthropogenic impact on the population of ground beetles leads to a change in their numbers, structure of dominance, density, species composition, spectrum of life forms. This makes the beetles Carabidae a convenient and informative bioindicator of the ecological state of biocenoses. The material for this work was the Carabidae collections conducted in June-August 2016-2017 in the park zone of different regions of Barnaul, differing in location, area, hydrological regime, vegetation cover, purpose and anthropogenic load. When processing the material, the quantitative, species and generic composition of the carabidae was determined, calculations were made for such indicators as the Berger-Parker dominance index, the Shannon species diversity index (Hs), and the Jacquard species similarity index. The fauna (Coleoptera, Carabidae) of the park zone of Barnaul is represented by 55 species belonging to 20 genera. The dominant group is represented by species belonging to steppe, forest and polyzonal groups. Forest-steppe species of ground beetles as dominants have not been identified in any of the investigated territories. The greatest variety of ecological groups was noted on the territory of the Yubileyny рark, which is explained by the presence of zones with various microclimatic conditions, the presence of a birch grove that flows through the park with the Pivovarka River, and a wide log in the park. Registered species belong to eight groups of life forms belonging to two classes - zoophagous and myxophytophagous. On the numerical and species abundance, zoophages predominate. The spectrum of life forms corresponds to the zonal spectrum characteristic of the forest-steppe zone.</p><p> </p>

Development of a Technique for Short-Term Prediction of Hydrometeors Using Advection and Physical Forcing.

1983 ◽  
Author(s):  
Gregory S. Forbes ◽  
John J. Cahir ◽  
Paul B. Dorian ◽  
Walter D. Lottes ◽  
Kathy Chapman
Keyword(s):  
Short Term ◽  
Physical Forcing ◽  
Term Prediction ◽  
Short Term Prediction

scholarly journals Selection Response in Finite Populations

Genetics ◽  
1996 ◽  
Vol 144 (4) ◽  
pp. 1961-1974 ◽  
Author(s):  
Ming Wei ◽  
Armando Caballero ◽  
William G Hill
Keyword(s):  
Linkage Disequilibrium ◽  
Inbreeding Depression ◽  
Genetic Variance ◽  
Relative Rate ◽  
Selection Response ◽  
Rate Of Change ◽  
Effective Population ◽  
Short Term ◽  
Model Account

Formulae were derived to predict genetic response under various selection schemes assuming an infinitesimal model. Account was taken of genetic drift, gametic (linkage) disequilibrium (Bulmer effect), inbreeding depression, common environmental variance, and both initial segregating variance within families (σAW02) and mutational (σM2) variance. The cumulative response to selection until generation t(CRt) can be approximated asCRt≈R0[t−β(1−σAW∞2σAW02)t24Ne]−Dt2Ne,where Ne is the effective population size, σAW∞2=NeσM2 is the genetic variance within families at the steady state (or one-half the genic variance, which is unaffected by selection), and D is the inbreeding depression per unit of inbreeding. R  0 is the selection response at generation 0 assuming preselection so that the linkage disequilibrium effect has stabilized. β is the derivative of the logarithm of the asymptotic response with respect to the logarithm of the within-family genetic variance, i.e., their relative rate of change. R  0 is the major determinant of the short term selection response, but σM2, Ne and β are also important for the long term. A selection method of high accuracy using family information gives a small Ne and will lead to a larger response in the short term and a smaller response in the long term, utilizing mutation less efficiently.

Diversity metrics, species turnovers and nestedness of bird assemblages in a deep karst sinkhole

2017 ◽  
Vol 63 (2) ◽  
pp. 8-16 ◽  
Author(s):  
Corrado Battisti ◽  
Marco Giardini ◽  
Francesca Marini ◽  
Lorena Di Rocco ◽  
Giuseppe Dodaro ◽  
...  
Keyword(s):  
Species Richness ◽  
Random Distribution ◽  
Diversity Index ◽  
Species Turnover ◽  
Floristic Composition ◽  
Bird Assemblages ◽  
Β Diversity ◽  
Stick Model ◽  
Karst Sinkhole

We reported a study on breeding birds occurring inside an 80 m-deep karst sinkhole, with the characterization of the assemblages recorded along its semi-vertical slopes from the upper edge until the bottom. The internal sides of the sinkhole have been vertically subdivided in four belts about 20 m high. The highest belt (at the upper edge of the cenote) showed the highest values in mean number of bird detections, mean and normalized species richness, and Shannon diversity index. The averaged values of number of detections and species richness significantly differ among belts. Species turnover (Cody’s β-diversity) was maximum between the highest belts. Whittaker plots showed a marked difference among assemblages shaping from broken-stick model to geometric series, and explicited a spatial progressive stress with a disruption in evenness towards the deepest belts. Bird assemblages evidenced a nested subset structure with deeper belts containing successive subsets of the species occurring in the upper belts. We hypothesize that, at least during the daytime in breeding season, the observed non-random distribution of species along the vertical stratification is likely due to (i) the progressive simplification both of the floristic composition and vegetation structure, and (ii) the paucity of sunlight as resources from the upper edge to the inner side of the cenote.

Sign in / Sign up

Export Citation Format

Share Document