Vertical distribution of attached algae in shallow fishponds of different trophic status

Biologia ◽  
2006 ◽  
Vol 61 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Aloisie Poulíčková ◽  
Miloslav Kitner ◽  
Petr Hašler

AbstractSpring and summer vertical distributions of attached algae were studied on artificial substrates (glass cover slips) in shallow fishponds of different trophic status. Differences were found in colonization process between two fishponds, two seasons and between two sites at each fishpond (central part, fishpond shore). Oligotrophic fishpond U třech krátkých can be characterized by better light conditions and lower temperatures. While equal vertical distribution of periphytic algae was observed at oligotrophic site, their relative cover decreased continuously in spring and strongly in summer with the increasing depth at eutrophic site. Oligotrophic fishpond can be characterized by very slow colonization rate and increasing abundance of Chrysophyceae. On the other hand Cyanobacteria were more frequent in eutrophic fishpond where periphyton displayed high colonization rate. Diatom species richness was the highest at oligotrophic site during spring experiments. The sites near the fishpond shore compared to sites in the central part of the fishpond can be characterized by higher rate of colonization, higher periphyton relative cover, lower proportion of Chrysophyceae and higher proportions of diatoms and cyanophytes indicating probably higher trophic level.

2017 ◽  
Author(s):  
Chengzhi Xing ◽  
Cheng Liu ◽  
Shanshan Wang ◽  
Ka Lok Chan ◽  
Yang Gao ◽  
...  

Abstract. Ground based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) and lidar measurements were performed in Shanghai, China during May 2016 to investigate the summertime atmospheric pollutants vertical distribution. In this study, vertical profiles of aerosol extinction coefficient, nitrogen dioxide (NO2) and formaldehyde (HCHO) concentrations were retrieved from MAX-DOAS measurement using the Heidelberg Profile (HeiPro) algorithm, while vertical distribution of ozone (O3) was obtained from an ozone lidar. Sensitivity study of the MAX-DOAS aerosol profile retrieval shows that the a priori aerosol profile shape has significant influences on the aerosol profile retrieval. Aerosol profiles retrieved from MAX-DOAS measurements with Gaussian a priori demonstrate the best agreements with simultaneous lidar measurements and vehicle-based tethered-balloon observations among all a priori aerosol profiles. MAX-DOAS measured tropospheric NO2Vertical Column Densities (VCDs) show a good agreement with OMI satellite observations with Pearson correlation coefficient (R) of 0.95. In addition, measurements of the O3 vertical distribution indicate that the ozone productions do not only occur at surface level but also at higher altitudes (about 1.1 km). Planetary boundary layer (PBL) height, horizontal and vertical wind fields information were integrated to discuss the ozone formation at upper altitudes. The results reveal that enhanced ozone concentrations at ground and upper altitudes are not directly related to horizontal and vertical transportations. Similar patterns of O3 and HCHO vertical distributions were observed during this campaign, which implies that the ozone productions near to the surface and at higher altitudes are mainly influenced by the abundance of volatile organic compounds (VOCs) in the lower troposphere.


Author(s):  
F. S. Russell

1. The diurnal behaviour of Sagitta of different sizes is shown as a result of collections made with the 2-metre stramin ring-trawl throughout 24 hours on July 15th–16th, 1924, and on June 3rd–4th, 1926.2. The younger stages of Sagitta elegans appear to withstand higher intensities of light in the daytime than do the older stages, and they migrate first to the surface at dusk, as do those of Sagitta setosa. The older stages leave the surface first at dawn.3. Diagrams are given showing the curves of equal intensities of light beneath the sea surface throughout 24 hours as calculated from air intensities obtained in June, with a reflection loss of 15%; (a) assuming a coefficient of absorption of 0·200 at all depths, and (b) assuming a coefficient of absorption of 0·100 at all depths.4. It appears, from a comparison of the behaviour of Sagitta elegans with the calculated light conditions beneath the surface, that the older Sagitta at any rate are more sensitive to light in the early morning after the darkness of the night and can become adapted to light of higher intensities later in the day.5. Previously published observations on the behaviour of Sagitta sp. on June 17th–18th–19th, 1925, show quite a different type of behaviour from the above, possibly due to more transparent water, the Sagitta only appearing abundantly above 30 metres in the dark. They had again migrated to below 30 m. before there was any appreciable light.


2019 ◽  
Vol 41 ◽  
pp. e45872 ◽  
Author(s):  
Nilce Svarcz Jungles de Camargo ◽  
Atsler Luana Lehun ◽  
Jonathan Rosa ◽  
Ana Carolina de Deus Bueno-Krawczyk

The objective of this research was to validate the colonization process on natural and artificial substrates by benthic invertebrates in a tropical stream in South Brazil. The samples were performed in July and August-2012, and 32 samplers were used, being 16 natural and 16 artificial substrates. In each sample, two replicas were taken for each substrate at the 2th, 4th, 7th, 14th, 21th 28th, 35th and 42th days of colonization. The organisms were identified to the lowest possible taxonomic level. In both substrates 3,070 benthic invertebrates were detected, of which 1,753 individuals were collected on the natural substrate, and 1,317 on the artificial substrate. From the identified taxa 8.5% were not dominant (Anacroneuria, Orthocladiinae, Tupiara, Smicridea, Baetodes, Tupiperla, Macrogynoplax, Gripopteryx, Cylloepus, Macrelmis, Microcylloepus, Hetaerina, Argia, Coryphaeschna, Atopsyche, Pomacea, Corydalus, Leptohyphes and Eccoptura), and 31.5% were dominant (Tanypodinae, Chironominae, and Paragripopteryx). The genus Simulium was very common, dominant and abundant, representing 65% of the collected individuals. No significant difference was found in the abundance and species composition between artificial and natural substrates. On the natural substrate, the higher colonization index was at the 35th day with 459 individuals, and the lowest was at the 14th day, with 87. On the artificial substrate the highest index was at the 42th day with 337 individuals, and the lowest was at the 4th day, with 85. Both natural and artificial substrates are efficient in characterizing the benthic community. In the evaluation of the ecological succession, it was not possible to observe a pattern that described the process, since the composition was nearly constant throughout the study period.


2003 ◽  
Vol 60 (6) ◽  
pp. 1342-1351 ◽  
Author(s):  
Henrik Jensen ◽  
Peter J Wright ◽  
Peter Munk

Abstract Vertical distribution patterns of larval and juvenile sandeels were investigated at four locations in the North Sea. Sandeels between 6 and 65 mm were found to depths of 80 m, with vertical distributions dependent on both length and environmental factors. At one location with a stratified water column, the highest densities were found during the day in midwater where food concentration was also highest. In areas without marked vertical hydrographic gradients, larvae were relatively more abundant in surface waters during the day. At all locations, larvae of all sizes were generally more homogeneously distributed in the water column during night than during day. The extent of vertical migration, as measured by the standard deviation of the mean depth, increased generally with length. Gear avoidance was evident for larvae ≥20 mm. Catch efficiency generally depended on both length class and surface light intensity. A simulated drift pattern of larvae, based on ADCP current measurements from two locations, predicts that the horizontal drift trajectory would only be affected slightly by the vertical positioning of the larvae in the water column during the time of sampling. The implication of vertical migrations for dispersal of larvae away from the spawning grounds is discussed.


2017 ◽  
Vol 17 (9) ◽  
pp. 5973-5989 ◽  
Author(s):  
Yinghui Liu ◽  
Matthew D. Shupe ◽  
Zhien Wang ◽  
Gerald Mace

Abstract. Detailed and accurate vertical distributions of cloud properties (such as cloud fraction, cloud phase, and cloud water content) and their changes are essential to accurately calculate the surface radiative flux and to depict the mean climate state. Surface and space-based active sensors including radar and lidar are ideal to provide this information because of their superior capability to detect clouds and retrieve cloud microphysical properties. In this study, we compare the annual cycles of cloud property vertical distributions from space-based active sensors and surface-based active sensors at two Arctic atmospheric observatories, Barrow and Eureka. Based on the comparisons, we identify the sensors' respective strengths and limitations, and develop a blended cloud property vertical distribution by combining both sets of observations. Results show that surface-based observations offer a more complete cloud property vertical distribution from the surface up to 11 km above mean sea level (a.m.s.l.) with limitations in the middle and high altitudes; the annual mean total cloud fraction from space-based observations shows 25–40 % fewer clouds below 0.5 km than from surface-based observations, and space-based observations also show much fewer ice clouds and mixed-phase clouds, and slightly more liquid clouds, from the surface to 1 km. In general, space-based observations show comparable cloud fractions between 1 and 2 km a.m.s.l., and larger cloud fractions above 2 km a.m.s.l. than from surface-based observations. A blended product combines the strengths of both products to provide a more reliable annual cycle of cloud property vertical distributions from the surface to 11 km a.m.s.l. This information can be valuable for deriving an accurate surface radiative budget in the Arctic and for cloud parameterization evaluation in weather and climate models. Cloud annual cycles show similar evolutions in total cloud fraction and ice cloud fraction, and lower liquid-containing cloud fraction at Eureka than at Barrow; the differences can be attributed to the generally colder and drier conditions at Eureka relative to Barrow.


2014 ◽  
Vol 955-959 ◽  
pp. 3581-3585
Author(s):  
Xiao Tong Wu ◽  
Ya Ting Dai ◽  
Yu Qin Shao ◽  
Jia Yin Lu ◽  
Miao Miao Hou

The study investigated the vertical distribution of soil microorganism on Caragana rhizosphere at Hobq of ORDOS. The result showed that microbial vertical distribution was obvious. The order of vertical distribution in number of aerobic bacteria were 0-10cm>20-30cm>10-20cm>30-40cm, and there were significant differences between microorganisms in 0-10cm, 10-20cm and 30-40cm underground; the number of aerobic bacteria in 0-10cm underground was higher than 10-20cm, 20-30cm and 30-40cm by 1.48,1.41 and 1.86. The order of vertical distribution in number of fungi were 0-10cm>10-20cm>20-30cm>30-40cm, and there were significant differences between 0-10 cm and 20-30cm、30-40cm, and between 10-20 cm and 20-30cm、30-40cm. the number of fungi in 0-10cm underground was higher than 10-20cm, 20-30cm and 30-40cm by 1.01, 3.60 and 5.37. The order of vertical distribution in number of Actinomycetes was 0-10cm>10-20cm>20-30cm>30-40cm, and the differences between 0-10 cm and 10-20cm, 20-30cm, 30-40cm were significant; the number of Actinomycetes in 0-10cm underground was higher than 10-20cm, 20-30cm and 30-40cm by 1.54,1.66 and 2.60. The distribution and quantity of soil microorganisms might be influenced by organic matter contents.


2021 ◽  
Vol 29 (1) ◽  
pp. 10-16
Author(s):  
N. M. Mineeva

Long-term observations are necessary to analyze and predict changes occurring in biological communities under global and regional climatic changes. The data on seasonal and long-term dynamics of chlorophyll in plankton of the Rybinsk Reservoir (Upper Volga, Russia) obtained in May – October 2009–2019 at six standard stations using the fluorescence method are presented. In the years with contrasting hydroclimatic conditions and water regime, the chlorophyll content varied from 1–3 to >100 μg/L. The significant variability of mean seasonal values (7.9 ± 0.5 μg/L in 2009 to 27.6 ± 1.7 μg/L in 2013 with variation coefficients of 52–134%) indicates the low resistance of the community. The total chlorophyll content is associated with the development of three main phytoplankton divisions i.e., diatoms, cyanoprokaryots, and green algae. The trophic status of the reservoir was characterized as mesotrophic in 2009 and 2017, eutrophic in 2011–2014, and moderately eutrophic in other years. In the long-term seasonal cycle of phytoplankton, there are five periods with stable temperature conditions and transparency, but variable chlorophyll content. A moderate positive relationship was found between the seasonal dynamics of chlorophyll and water temperature, but a moderate negative relationship with transparency. The priority factors regulating the long-term dynamics of chlorophyll include the NAO indices, Wolf numbers, temperature, and underwater light conditions, as well as the inflow volume and water level. Water regime limits the development of phytoplankton.


1985 ◽  
Vol 42 (6) ◽  
pp. 1178-1188 ◽  
Author(s):  
Lars G. Rudstam ◽  
John J. Magnuson

We develop a model based on fish behavior in temperature and oxygen gradients that yields quantitative predictions of the vertical distribution of a fish population throughout the water column. The model was tested against observed vertical distributions of cisco, Coregonus artedii, and yellow perch, Perca flavescens, in 1981 and 1982 from five Wisconsin lakes. In some cases, the model seemed adequate for cisco, but in most cases, they occupied a temperature lower than their final preferendum. Occupation of lower temperature is consistent with a response to less than ad libitum food rations expected in these oligotrophy to mesotrophic lakes. In Lake Mendota, which is eutrophic with an anaerobic hypolimnion, cisco occupied temperatures higher than predicted by the model. For perch distributions, avoidance of high light intensities appears important. We did not observe effects of interspecific segregation between cisco and perch in their vertical distributions beyond that expected from differences in their preferred temperatures. Deviations of actual distributions from predictions of our relatively simplistic two-factor model can be used to help identify and evaluate other important physical and biotic factors influencing vertical distributions.


2013 ◽  
Vol 58 (1) ◽  
pp. 89-105 ◽  
Author(s):  
Lili Daneshvar Saein ◽  
Iraj Rasa ◽  
Nematolah Rashidnejad Omran ◽  
Parviz Moarefvand ◽  
Peyman Afzal ◽  
...  

Determination of the vertical distribution of geochemical elemental concentrations is of fundamental importance in mineral exploration. In this paper, eight mineralized boreholes from the Nowchun Cu-Mo porphyry deposit, SE Iran, were used to identify of the vertical distribution directional properties of Cu and Mo values using number-size (N-S) fractal model. The vertical distributions of Cu and Mo in the mineralized boreholes show a positively skewed distribution in the former and a multimodal distribution in the latter types. Elemental threshold values for the mineralized boreholes were computed by fractal model and compared with the statistical methods based on the data obtained from chemical analysis of samples. Elemental distributions are not normal in these boreholes and their median equal to Cu and Mo thresholds. The results of N-S fractal analysis reveal that Cu and Mo values in mineralized boreholes are multifractals in nature. There are at least three geochemical populations for Cu and Mo in the boreholes and Cu and Mo thresholds have ranges between 0.07%-0.3% and 50-200 ppm, respectively. The results obtained by N-S fractal model were compared with geological observations in the boreholes. Major Cu and Mo enrichment correlated by monzonitic rocks and high amounts of observed Cu and Mo ores (Chalcopyrite and molybdenite) in the boreholes.


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