Seasonal variations in the structure of copepod assemblages in tropical marine and estuarine waters, Coleroon, south-east India

2013 ◽  
Vol 94 (3) ◽  
pp. 521-535 ◽  
Author(s):  
M. Rajkumar ◽  
Jun Sun ◽  
I. R. Jenkinson ◽  
M.M. Rahman
Keyword(s):  
Community Structure ◽  
Species Diversity ◽  
Environmental Factors ◽  
Seasonal Patterns ◽  
Dissolved Oxygen Concentration ◽  
Copepod Community ◽  
Factors Affecting ◽  
Abundance And Diversity ◽  
High Diversity ◽  
Coleroon Estuary

A twelve-month investigation was undertaken on how copepod community structure varied in relation to environmental factors in the Coleroon estuary, south-east India. Sampling was monthly, from Station 1 in the sea to Station 4 in the Vettar backwaters. Canonical correspondence analysis (CCA) was applied to elucidate the environmental factors affecting the copepod community. A total of 104 copepod species in 38 genera and 26 families were recorded, with the Calanoids, Acartia erythraea and Oithona brevicornis being the most dominant. At all four stations, both these species loaded near the intercept of CCA axes 1 and 2, perhaps reflecting that they were autochthonous. Most species occurred in distinct seasonal patterns. Abundances ranged from 13 × 103 to 215 × 103 (ind. m−3). Coleroon waters showed high diversity (bits/ind.), from 5.29 at Station 3 to 4.97 at Station 4. Abundance correlated positively with temperature and salinity and negatively with rainfall, dissolved oxygen concentration (DO) and pH. Species diversity correlated strongly with abundance (P < 0.01). Abundance and diversity were highest during the summer, and both correlated positively with salinity. Temperatures (air and water), salinity, pH and DO varied in the ranges 26–36°C, 25–34.2°C, 9–38, 7.0–8.7 and 3.0–6.8 ml l-1, respectively. Nitrate, nitrite, phosphate and silicate (µM) varied in the ranges: 4.7–64.5, 0.4–14.1, 0.2–12.9 and 9.3–148, respectively.

Diversity and community structure of Ephemeroptera in freshwater stream of Megamalai hills, Tamil Nadu, India

ENTOMON ◽  
2021 ◽  
Vol 46 (4) ◽  
pp. 279-284
Author(s):  
S. Barathy ◽  
T. Sivaruban ◽  
Srinivasan Pandiarajan ◽  
Isack Rajasekaran ◽  
M. Bernath Rosi
Keyword(s):  
Community Structure ◽  
Species Diversity ◽  
Air Temperature ◽  
Tamil Nadu ◽  
Dominant Species ◽  
Diversity Indices ◽  
Low Diversity ◽  
Freshwater Stream ◽  
Species Diversity Indices ◽  
High Diversity

In the study on the diversity and community structure of Ephemeroptera in the freshwater stream of Chinnasuruli falls on Megamalai hills, a total of 523 specimens belonging to thirteen genera and five families were collected in six month periods. Of the five families, Teloganodidae and Leptophlebiidae exhibited high diversity and Caenidae showed low diversity. Choroterpes alagarensis (Leptophlebiidae) is the most dominant species. Diversity indices such as Shannon and Simpson indices showed that diversity was maximum in November and December and it was minimum in August and January. Canonical Correspondence Analysis revealed that rainfall, water flow, turbidity, and air temperature were the major stressors in affecting the Ephemeropteran community structure.

scholarly journals Soil Microbial Community Variation With Time and Soil Depth in Eurasian Steppe (Inner Mongolia, China)

2021 ◽  
Author(s):  
Hongbin Zhao ◽  
Wenling Zheng ◽  
Shengwei Zhang ◽  
Wenlong Gao ◽  
Yueyue Fan
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Environmental Factors ◽  
Soil Microbial Community ◽  
Soil Depth ◽  
Microbial Community Composition ◽  
Spatial Transformation ◽  
Soil Microbial ◽  
Abundance And Diversity ◽  
Bacteria And Fungi

Abstract BackgroundSoil microorganisms play an indispensable role in the material and energy cycle of grassland ecosystem, and were affected by many environmental factors, such as time and space changes. However, there are few studies on the temporal and spatial transformation of soil microbial community in typical degraded steppe. We analyzed the community structure and diversity of soil bacteria and fungi and the effects of environmental factors on the community structure in Xilingol degraded steppe. ResultsThe abundance and diversity of bacteria and fungi were significantly affected by depth. Bacteria and fungi diversity of 10 cm was higher than that of 20 cm and 30 cm. The abundance of Acidobacteria, Proteobacteria, Actinomycetes, Ascomycetes and Basidiomycetes varies significantly with depth. What’s more, soil pH increased significantly with depth increasing, while SOM, AN, VWC and ST decreased significantly with increasing depth. In addition, Depth, TOC and AN had significant impact on the bacterial and fungi communities (p < 0.05). ConclusionsSpatial heterogeneity (depth) is more important than temporal (month) in predicting changes in microbial community composition and soil properties. And the abundance of Acidobacteria, Proteobacteria, Actinomycetes, Ascomycetes and Basidiomycetes varies significantly with depth. We speculate that SOM and VWC account for the abundance variations of Acidobacteria and Proteobacteria, and pH cause the abundance changes of Actinomycetes, Ascomycetes and Basidiomycota.

scholarly journals Conditions of Coral Reef in Bunaken Island North Sulawesi Province

2014 ◽  
Vol 2 (1) ◽  
pp. 19
Author(s):  
Alex Denny Kambey
Keyword(s):  
Community Structure ◽  
Coral Reef ◽  
Species Diversity ◽  
Coral Reefs ◽  
Good Condition ◽  
Species Abundance ◽  
North Sulawesi ◽  
Abundance And Diversity

Community structure of corals were analyzed to understand their response to different conditions of coral reefs in several places of Bunaken island. This study focused on species abundance and diversity including Shannon-Wiener’s species diversity (H’) respectively. The result recorded 67 species and 29 genera of corals. In general, the condition of coral reefs in Bunaken Island in good condition.   Keywords: Community structure, coral reef.   A B S T R A K   Struktur komunitas karang dianalisis untuk memahami respon   terhadap perbedaan kondisi  terumbu karang di beberapa tempat pulau Bunaken. Penelitian ini difokuskan pada kelimpahan dan keragaman spesies termasuk keragaman Shannon-Wiener spesies (H') masing-masing. Hasilnya mencatat 67 spesies dan 29 genera karang. Secara umum, kondisi terumbu karang di Pulau Bunaken dalam kondisi baik.   Kata kunci : Komunitas struktur, terumbu karang.

scholarly journals Bryophyte communities and seston in a karst stream (Jankovac Stream, Papuk Nature Park, Croatia)

2012 ◽  
Vol 48 (1) ◽  
pp. 125-138 ◽  
Author(s):  
Maria Špoljar ◽  
Tvrtko Dražina ◽  
Ana Ostojić ◽  
Marko Miliša ◽  
Marija Gligora Udovič ◽  
...  
Keyword(s):  
Organic Matter ◽  
Community Structure ◽  
Environmental Factors ◽  
Environmental Parameters ◽  
Community Diversity ◽  
Nature Park ◽  
Community Assemblages ◽  
Abundance And Diversity ◽  
Bottom Cover ◽  
Source Site

An investigation into bryophyte communities in karst Jankovac Stream (Papuk Nature Park, Croatia) was carried out once a month from July 2008 to June 2009. Samples were taken from two lotic microhabitats: (i) Jankovac Spring (JS), a hypocrenal habitat with dense bryophyte clusters (90% bottom cover) and (ii) Jankovac Waterfall (JW), with scattered bryophyte clusters (50% bottom cover). At the same time, seston samples were collected during the spring as the source site and after the JW, as the outflow site. The goals of this study were to understand the (i) algal, protozoan and metazoan bryophyte community assemblages in these two lotic microhabitats, (ii) influence of environmental factors on the structuring of the bryophyte community and (iii) structure of seston along the longitudinal profile. A total of 172 taxa were determined: 68 algae, 55 protozoa, 24 meiofauna and 25 macroinvertebrates. Statistically significant differences between two microhabitats differing in percentage of bryophyte cover were established testing 13 environmental parameters. In dense bryophyte clusters, community structure was determined by flow velocity and pH, and macroinvertebrates achieved higher diversity and abundance. On the contrary, in scattered bryophyte coverage algae, protozoa and meiofauna reached higher abundance and diversity governed by the amount of suspended organic matter and epiphyton. In contrast to previous studies, the inverse ratio of community diversity and abundanceversuspercentage of bryophyte cover was established. We assume this to be the result of an enrichment of the scattered bryophyte clusters by upstream seston. Additionally, the effects of anthropogenic hydromorphological disturbance are reflected in macroinvertebrate diversity and abundance reduction.

scholarly journals Environmental factors affecting community structure of Sasa kurilensis in the understory of a beech forest

2019 ◽  
Vol 45 (1) ◽  
pp. 103-108 ◽  
Author(s):  
WU Chongyang ◽  
TANAKA Ryota ◽  
FUJIYOSHI Kyohei ◽  
HATTORI Itsuka ◽  
AKAJI Yasuaki ◽  
...  
Keyword(s):  
Community Structure ◽  
Environmental Factors ◽  
Beech Forest ◽  
Factors Affecting ◽  
Sasa Kurilensis

scholarly journals Water Properties Influencing the Abundance and Diversity of Denitrifiers onEichhornia crassipesRoots: A Comparative Study from Different Effluents around Dianchi Lake, China

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Neng Yi ◽  
Yan Gao ◽  
Zhenhua Zhang ◽  
Hongbo Shao ◽  
Shaohua Yan
Keyword(s):  
Nitrous Oxide ◽  
Community Structure ◽  
Environmental Factors ◽  
Environmental Conditions ◽  
Redundancy Analysis ◽  
Eichhornia Crassipes ◽  
Dianchi Lake ◽  
Gene Copies ◽  
Abundance And Diversity ◽  
Denitrifier Communities

To evaluate effects of environmental conditions on the abundance and communities of three denitrifying genes coding for nitrite (nirK, nirS) reductase and nitrous oxide (nosZ) reductase on the roots ofEichhornia crassipesfrom 11 rivers flowing into the northern part of Dianchi Lake. The results showed that the abundance and community composition of denitrifying genes onE. crassipesroot varied with different rivers. ThenirKgene copies abundance was always greater than that ofnirSgene on the roots ofE. crassipes, suggesting that the surface ofE. crassipesroots growth in Dianchi Lake was more suitable for the growth ofnirK-type denitrifying bacteria. The DGGE results showed significant differences in diversity of denitrifying genes on the roots ofE. crassipesamong the 11 rivers. Using redundancy analysis (RDA), the correlations of denitrifying microbial community compositions with environmental factors revealed that water temperature (T), dissolved oxygen (DO), and pH were relatively important environmental factors to modifying the community structure of the denitrifying genes attached to the root ofE. crassipes. The results indicated that the specific environmental conditions related to different source of rivers would have a stronger impact on the development of denitrifier communities onE. crassipesroots.

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