Spatial and seasonal variations of large tintinnid ciliates in Shenhu Bay of China

2014 ◽  
Vol 43 (3) ◽  
Author(s):  
Yibo Wang ◽  
Wenjing Zhang ◽  
Yuanshao Lin ◽  
Lianming Zheng ◽  
Wenqing Cao ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Seasonal Variations ◽  
Redundancy Analysis ◽  
Dominant Species ◽  
Abiotic Factors ◽  
Seasonal Pattern ◽  
Taxonomic Composition ◽  
Nutrient Level ◽  
Spearman Correlation ◽  
Factors Affecting

AbstractIn this study, the spatial distribution and seasonal variation of large tintinnids (>76 μm) were investigated in Shenhu Bay during three seasons of 2012. Of the 36 species identified, 9 were dominant (i.e. Tintinnopsis radix, Leprotintinnus simplex, Tintinnopsis japonica, Tintinnopsis tubulosoides, Leprotintinnus nordqvisti, Tintinnopsis beroidea, Stenosemella parvicollis, Tintinnidium primitivum, Tintinnopsis nana). A clear seasonal shift of the taxonomic composition as well as the lorica size of the dominant species was observed. The highest numbers of tintinnid species occurred in spring, while the highest abundance and biomass occurred in summer. Clustering indicated that the seasonal variations of the community structure were more obvious than spatial variations. Spearman correlation analysis revealed that density of phytoplankton prey had a significant impact on the tintinnid abundance. Redundancy analysis (RDA) illustrated that temperature, salinity and the nutrient level were the most important abiotic factors affecting the spatial and seasonal pattern of tintinnid communities in Shenhu Bay.

scholarly journals A cross-sectional study of factors affecting seasonality in bipolar disorder

2014 ◽  
Vol 20 (2) ◽  
pp. 2 ◽  
Author(s):  
Pankaj Kumar Mittal ◽  
Shubham Mehta ◽  
Ram Kumar Solanki ◽  
Mukesh Kumar Swami ◽  
Parth Singh Meena
Keyword(s):  
Bipolar Disorder ◽  
Seasonal Variations ◽  
Affective Disorders ◽  
Seasonal Pattern ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Factors Affecting ◽  
Behavioural Patterns ◽  
Assessment Questionnaire

<p><strong>Background.</strong> Researchers have evinced interest in the effect of seasonal variations on mood and behavioural patterns in affective disorders. </p><p><strong>Objective. </strong>To study seasonality in bipolar disorder (BD) patients and also the factors affecting this seasonality. </p><p><strong>Method. </strong>Forty-nine patients with BD in euthymic phase were recruited and analysed using<strong> </strong>the<strong> </strong>Seasonal Pattern Assessment Questionnaire and Morningness-Eveningness Questionnaire. </p><p><strong>Results. </strong>Most of the patients were morning types but chronotype had no influence on seasonality. Age of patient and number of episodes were the most important factors affecting seasonality in BD. </p><p><strong>Conclusion. </strong>Seasonality and its influencing factors must be considered while managing bipolar disorder.</p>

scholarly journals Diversity and Copepods’composition off Moroccan Atlantic Coast (Northwest Africa): A Review

2017 ◽  
Vol 13 (18) ◽  
pp. 272
Author(s):  
Laila El Arraj ◽  
Ouadiaa Tazi ◽  
Laila Somoue ◽  
Karim Hilmi ◽  
Mansour Serghini ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Species Composition ◽  
Seasonal Variability ◽  
Dominant Species ◽  
Atlantic Coast ◽  
Taxonomic Composition ◽  
Factorial Correspondence Analysis ◽  
Northwest Africa ◽  
Acartia Clausi ◽  
Paracalanus Parvus

This overview sums up the results of main investigations and knowledge about zooplankton off Moroccan Atlantic coast. Copepods diversity, spatial distribution, seasonal variability and hydrology off Moroccan Atlantic coast are given. A compilation of taxonomic list of copepods’ species found therein was established from published studies, they accounted for 210. Diversity and richness varied strongly between seasons, an onshore offshore gradient was observed as well. Species composition differed from northern to southern Moroccan Atlantic coast although most dominant species off Morocco’s coasts were Calanus helgolandicus, Paracalanus parvus, Acartia clausi and Corycaeus typicus. In addition, the largest number of species was found in upwelling regions. A synthesis study was established in order to spatial distribution of copepods along Moroccan Atlantic coast. The Factorial Correspondence Analysis of copepod species characterizing the most important sectors has shown different patterns of copepods distribution across Moroccan Atlantic coast; three main areas were clearly segregated according to their taxonomic composition (Northern, Central and Southern Atlantic).

Biotic and abiotic factors affecting seasonal and spatial distribution of meiofauna and macrophytobenthos in transitional coastal waters

2019 ◽  
Vol 219 ◽  
pp. 328-340 ◽  
Author(s):  
Federica Semprucci ◽  
Chiara Facca ◽  
Federica Ferrigno ◽  
Maria Balsamo ◽  
Adriano Sfriso ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Coastal Waters ◽  
Abiotic Factors ◽  
Factors Affecting ◽  
Biotic And Abiotic Factors

Large-scale mapping of the catenas vegetation in Subarctic tundra

1995 ◽  
pp. 3-21
Author(s):  
S. S. Kholod
Keyword(s):  
Spatial Distribution ◽  
Vegetation Cover ◽  
Large Scale ◽  
Block Diagram ◽  
Abiotic Factors ◽  
Ecological Factors ◽  
Spatial Arrangement ◽  
Geological Time ◽  
Ecological Barriers ◽  
Functional Zones

One of the most difficult tasks in large-scale vegetation mapping is the clarification of mechanisms of the internal integration of vegetation cover territorial units. Traditional way of searching such mechanisms is the study of ecological factors controlling the space heterogeneity of vegetation cover. In essence, this is autecological analysis of vegetation. We propose another way of searching the mechanisms of territorial integration of vegetation. It is connected with intracoenotic interrelation, in particular, with the changing role of edificator synusium in a community along the altitudinal gradient. This way of searching is illustrated in the model-plot in subarctic tundra of Central Chukotka. Our further suggestion concerns the way of depicting these mechanisms on large-scale vegetation map. As a model object we chose the catena, that is the landscape formation including all geomorphjc positions of a slope, joint by the process of moving the material down the slope. The process of peneplanation of a mountain system for a long geological time favours to the levelling the lower (accumulative) parts of slopes. The colonization of these parts of the slope by the vegetation variants, corresponding to the lowest part of catena is the result of peneplanation. Vegetation of this part of catena makes a certain biogeocoenotic work which is the levelling of the small infralandscape limits and of the boundaries in vegetation cover. This process we name as the continualization on catena. In this process the variants of vegetation in the lower part of catena are being broken into separate synusiums. This is the process of decumbation of layers described by V. B. Sochava. Up to the slope the edificator power of the shrub synusiums sharply decreases. Moss and herb synusium have "to seek" the habitats similar to those under the shrub canopy. The competition between the synusium arises resulting in arrangement of a certain spatial assemblage of vegetation cover elements. In such assemblage the position of each element is determined by both biotic (interrelation with other coenotic elements) and abiotic (presence of appropriate habitats) factors. Taking into account the biogeocoenotic character of the process of continualization on catena we name such spatial assemblage an exolutionary-biogeocoenotic series. The space within each evolutionary-biogeocoenotic series is divided by ecological barriers into some functional zones. In each of the such zones the struggle between synusiums has its individual expression and direction. In the start zone of catena (extensive pediment) the interrelations of synusiums and layers control the mutual spatial arrangement of these elements at the largest extent. Here, as a rule, there predominate edificator synusiums of low and dwarfshrubs. In the first order limit zone (the bend of pediment to the above part of the slope) one-species herb and moss synusiums, oftenly substituting each other in similar habitats, get prevalence. In the zone of active colonization of slope (denudation slope) the coenotic factor has the least role in the spatial distribution of the vegetation cover elements. In particular, phytocoenotic interactions take place only within separate microcoenoses of herbs, mosses and lichens. In the zone of the attenuation of continualization process (the upper most parts of slope, crests) phytocoenotic interactions are almost absent and the spatial distribution of vegetation cover elements depends exclusively on the abiotic factors. The principal scheme of the distribution of vegetation cover elements and the disposition of functional zones on catena are shown on block-diagram (fig. 1).

scholarly journals Spatio-temporal distribution patterns of Plutella xylostella (Lepidoptera: Plutellidae) in a fine-scale agricultural landscape based on geostatistical analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jian-Yu Li ◽  
Yan-Ting Chen ◽  
Meng-Zhu Shi ◽  
Jian-Wei Li ◽  
Rui-Bin Xu ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Plutella Xylostella ◽  
Agricultural Landscape ◽  
Seasonal Pattern ◽  
Distribution Patterns ◽  
Geostatistical Analysis ◽  
Distribution Model ◽  
Detailed Knowledge ◽  
Fine Scale ◽  
Spatio Temporal

AbstractA detailed knowledge on the spatial distribution of pests is crucial for predicting population outbreaks or developing control strategies and sustainable management plans. The diamondback moth, Plutella xylostella, is one of the most destructive pests of cruciferous crops worldwide. Despite the abundant research on the species’s ecology, little is known about the spatio-temporal pattern of P. xylostella in an agricultural landscape. Therefore, in this study, the spatial distribution of P. xylostella was characterized to assess the effect of landscape elements in a fine-scale agricultural landscape by geostatistical analysis. The P. xylostella adults captured by pheromone-baited traps showed a seasonal pattern of population fluctuation from October 2015 to September 2017, with a marked peak in spring, suggesting that mild temperatures, 15–25 °C, are favorable for P. xylostella. Geostatistics (GS) correlograms fitted with spherical and Gaussian models showed an aggregated distribution in 21 of the 47 cases interpolation contour maps. This result highlighted that spatial distribution of P. xylostella was not limited to the Brassica vegetable field, but presence was the highest there. Nevertheless, population aggregations also showed a seasonal variation associated with the growing stage of host plants. GS model analysis showed higher abundances in cruciferous fields than in any other patches of the landscape, indicating a strong host plant dependency. We demonstrate that Brassica vegetables distribution and growth stage, have dominant impacts on the spatial distribution of P. xylostella in a fine-scale landscape. This work clarified the spatio-temporal dynamic and distribution patterns of P. xylostella in an agricultural landscape, and the distribution model developed by geostatistical analysis can provide a scientific basis for precise targeting and localized control of P. xylostella.

Factors affecting the spatial distribution and co‐occurrence of two sympatric mountain ungulates in southern Mongolia

2021 ◽  
Author(s):  
C. Odonjavkhlan ◽  
J.S. Alexsander ◽  
C. Mishra ◽  
G. Samelius ◽  
K. Sharma ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Factors Affecting ◽  
Mountain Ungulates

scholarly journals Spatial distribution and survival rate of waterfrog tadpoles in relation to biotic and abiotic factors: a field experiment

2001 ◽  
Vol 22 (1) ◽  
pp. 21-32 ◽  
Author(s):  
Sylvie Thurnheer ◽  
Heinz-Ulrich Reyer
Keyword(s):  
Spatial Distribution ◽  
Community Dynamics ◽  
Abiotic Factors ◽  
Rana Esculenta ◽  
Natural Conditions ◽  
Major Purpose ◽  
Biotic And Abiotic Factors ◽  
Lab Experiments ◽  
Shallow Zone ◽  
Population And Community Dynamics

AbstractPredictions about population and community dynamics are usually based on lab experiments. Because the results are difficult to transfer to natural conditions, the major purpose of this study was to test the effects of biotic and abiotic factors on tadpole populations in a natural environment. We stocked six ponds, created the previous year, with known numbers of Rana esculenta and R. lessonae tadpoles and followed their development over several months. When compared among ponds, tadpole density correlated positively with the nitrate:phosphate ratio. This suggests that water chemistry may have affected survival, either directly or indirectly via productivity. Within ponds, both species showed a clear preference for the shallow zone. This behavior probably reflects a preference for warm water close to the surface, rather than avoidance of predators, because relative densities of odonates also increased from deep to shallow zones. This study is one of few that not only considers the distribution of the anuran tadpoles but the distribution of their predators as well.

scholarly journals Abiotic factors affecting habitat selection by two invasive gammarids Dikerogammarus villosus and Pontogammarus robustoides

Hydrobiologia ◽  
2017 ◽  
Vol 797 (1) ◽  
pp. 247-263 ◽  
Author(s):  
Jarosław Kobak ◽  
Łukasz Jermacz ◽  
Joanna Marcińczyk ◽  
Ewa Bartoszyńska ◽  
Daria Rutkowska ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Abiotic Factors ◽  
Factors Affecting ◽  
Dikerogammarus Villosus ◽  
Pontogammarus Robustoides
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