scholarly journals Influence of environmental parameters on the community structure of phytoplankton from river confluence of Cuddalore, Tamil Nadu, India

2022 ◽  
pp. 100170
Author(s):  
Sagaya John Paul Joseph ◽  
Priya Darshini Gunasekaran ◽  
Nagaraj Subramani
Keyword(s):  
Community Structure ◽  
Tamil Nadu ◽  
Environmental Parameters ◽  
River Confluence

scholarly journals Micro-Landscape Dependent Changes in Arbuscular Mycorrhizal Fungal Community Structure

2021 ◽  
Vol 11 (11) ◽  
pp. 5297
Author(s):  
Stavros D. Veresoglou ◽  
Leonie Grünfeld ◽  
Magkdi Mola
Keyword(s):  
Community Structure ◽  
Mycorrhizal Fungi ◽  
Root Colonization ◽  
Environmental Parameters ◽  
Arbuscular Mycorrhizal ◽  
Fungal Community Structure ◽  
High Connectivity ◽  
Spatio Temporal ◽  
Arbuscular Mycorrhizal Fungal ◽  
Colonization Rates

The roots of most plants host diverse assemblages of arbuscular mycorrhizal fungi (AMF), which benefit the plant hosts in diverse ways. Even though we understand that such AMF assemblages are non-random, we do not fully appreciate whether and how environmental settings can make them more or less predictable in time and space. Here we present results from three controlled experiments, where we manipulated two environmental parameters, habitat connectance and habitat quality, to address the degree to which plant roots in archipelagos of high connectivity and invariable habitats are colonized with (i) less diverse and (ii) easier to predict AMF assemblages. We observed no differences in diversity across our manipulations. We show, however, that mixing habitats and varying connectivity render AMF assemblages less predictable, which we could only detect within and not between our experimental units. We also demonstrate that none of our manipulations favoured any specific AMF taxa. We present here evidence that the community structure of AMF is less responsive to spatio-temporal manipulations than root colonization rates which is a facet of the symbiosis which we currently poorly understand.

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.

Macrobenthic community structure in tropical estuaries: the effect of sieve mesh-size and sampling depth on estimated abundance, biomass and composition

2013 ◽  
Vol 93 (6) ◽  
pp. 1441-1456 ◽  
Author(s):  
Ana Paula Maria Cavalcanti Valença ◽  
Paulo Jorge Parreira dos Santos
Keyword(s):  
Community Structure ◽  
Mesh Size ◽  
Environmental Parameters ◽  
Total Biomass ◽  
Sampling Depth ◽  
Total N ◽  
The Status ◽  
Sieve Mesh Size ◽  
The Difference ◽  
Sampling Procedures

Macrobenthic data from estuaries along the Pernambuco coast in north-eastern Brazil were analysed to evaluate the effect of sieve mesh size (1.0 mm × 0.5 mm) and sampling depth (0–10 cm × 0–20 cm) on the description of infaunal communities, in an attempt to discuss standardized sampling procedures for different ecological studies objectives in these ecosystems. In general, the difference in sieve retention was less evident for biomass but was important for abundance: the 1.0 mm sieve retained only 27% of total individuals but 77% of total biomass. Regarding sampling depth, the 0–10 cm layer contained most individuals (94%) but contributed just 64% of the overall biomass. Although no strong differences in community structure were observed at most sites with the use of different sieves, the correlations among community dissimilarity using different meshes with environmental parameters (organic matter, total-N and microphytobenthos) indicated that the use of the 0.5 mm sieve will allow a better evaluation of the status of these estuaries. The results also highlight the importance of taking the vertical distribution of tropical macrofauna into account for quantitative estimates: for taxa composition and abundance the top layer is clearly essential, whereas for biomass the deeper layers should also be considered.

scholarly journals Microbial Diversity in Engineered Haloalkaline Environments Shaped by Shared Geochemical Drivers Observed in Natural Analogues

2015 ◽  
Vol 81 (15) ◽  
pp. 5026-5036 ◽  
Author(s):  
Talitha C. Santini ◽  
Lesley A. Warren ◽  
Kathryn E. Kendra
Keyword(s):  
Community Structure ◽  
Microbial Diversity ◽  
Fungal Community ◽  
Soda Lakes ◽  
Bauxite Residue ◽  
Environmental Parameters ◽  
Total Alkalinity ◽  
Content Type ◽  
Natural Analogues ◽  
Bauxite Residues

ABSTRACTMicrobial communities in engineered terrestrial haloalkaline environments have been poorly characterized relative to their natural counterparts and are geologically recent in formation, offering opportunities to explore microbial diversity and assembly in dynamic, geochemically comparable contexts. In this study, the microbial community structure and geochemical characteristics of three geographically dispersed bauxite residue environments along a remediation gradient were assessed and subsequently compared with other engineered and natural haloalkaline systems. In bauxite residues, bacterial communities were similar at the phylum level (dominated byProteobacteriaandFirmicutes) to those found in soda lakes, oil sands tailings, and nuclear wastes; however, they differed at lower taxonomic levels, with only 23% of operational taxonomic units (OTUs) shared with other haloalkaline environments. Although being less diverse than natural analogues, bauxite residue harbored substantial novel bacterial taxa, with 90% of OTUs nonmatchable to cultured representative sequences. Fungal communities were dominated byAscomycotaandBasidiomycota, consistent with previous studies of hypersaline environments, and also harbored substantial novel (73% of OTUs) taxa. In bauxite residues, community structure was clearly linked to geochemical and physical environmental parameters, with 84% of variation in bacterial and 73% of variation in fungal community structures explained by environmental parameters. The major driver of bacterial community structure (salinity) was consistent across natural and engineered environments; however, drivers differed for fungal community structure between natural (pH) and engineered (total alkalinity) environments. This study demonstrates that both engineered and natural terrestrial haloalkaline environments host substantial repositories of microbial diversity, which are strongly shaped by geochemical drivers.

scholarly journals Community structure and condition of seagrass meadows in Ayau Islands, Raja Ampat Regency

2020 ◽  
Vol 45 (1) ◽  
pp. 13-24
Author(s):  
Andri Irawan ◽  
Muhammad Hafizt ◽  
Udhi Eko Hernawan
Keyword(s):  
Community Structure ◽  
Environmental Parameters ◽  
Water Clarity ◽  
Well Being ◽  
Common Species ◽  
Thalassia Hemprichii ◽  
Seagrass Meadows ◽  
Halophila Ovalis ◽  
Seagrass Cover ◽  
Baseline Information

Seagrass meadows are an important component of coastal ecosystems, providing many ecosystem services beneficial for human well-being. Basic information about seagrass meadows in Indonesia is relatively limited, particularly in the eastern part of Indonesia, such as the remote Ayau Islands in Raja Ampat. In this paper, we reported the community structure and condition of seagrass meadows in Ayau Islands surveyed during Nusa Manggala Expedition in November 2018. We conducted the seagrass survey using quadrat transect method at five locations, i.e. Reni, Rutum, Abidon, Kanober, and Dorehkar. In the survey, we assessed parameters of community structure, including habitat extent, species composition, seagrass cover, seagrass density, macroalgae and epiphyte cover. We also recorded environmental parameters, i.e. substrate types, water clarity, salinity, water temperature, and nutrient (phosphate and nitrate). Our study showed that seagrass meadows in Ayau Islands are multispecies meadows, composed of two to five species. In overall, five species recorded in Ayau Islands are Cymodocea rotundata, Enhalus acoroides, Halodule pinifolia, Halophila ovalis, and Thalassia hemprichii. The most common species is T. hemprichii as it can be found in all locations. Meadows in Reni, Rutum, and Dorehkar are in a healthy condition, while in Abidon and Kanober are in less healthy condition. This information is of significance as baseline information needed for seagrass conservation planning.

scholarly journals Diversity Patterns and Community Structure of the Ground-Associated Macrofauna along the Beach-Inland Transition Zone of Small Tropical Islands

Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 377
Author(s):  
Sebastian Steibl ◽  
Robert Sigl ◽  
Paul E. Bräumer ◽  
Victoria Clauß ◽  
Simon Goddemeier ◽  
...  
Keyword(s):  
Community Structure ◽  
Transition Zone ◽  
Environmental Parameters ◽  
Gradual Change ◽  
Small Islands ◽  
Tropical Islands ◽  
Diversity Patterns ◽  
Transition Zones ◽  
Taxa Richness ◽  
Insular Ecosystems

Biodiversity follows distinct and observable patterns. Where two systems meet, biodiversity is often increased, due to overlapping occurrence ranges and the presence of specialized species that can tolerate the dynamic conditions of the transition zone. One of the most pronounced transition zones occurs at shores, where oceans and terrestrial habitat collide, forming the shore–inland transition zone. The relevance of this transition zone in shaping a system’s community structure is particularly pronounced on small islands due to their high shore-to-inland-area ratio. However, the community structure of insular faunas along this transition zone is unknown. Here, we investigated the diversity patterns along the beach–inland transition zone of small islands and tested the hypothesis that species diversity increases toward the transition zone where beach and interior habitat meet. By measuring environmental parameters, resource availability, and ground-associated macrofauna diversity along transects running across the beach–inland transition zone, we show that a gradual change in species composition from beach to the inland exists, but neither taxa richness, diversity, nor overall abundance changed significantly. These findings offer important insights into insular community structure at the transition zone from sea to land that are relevant to better understand the dynamic and unique characteristics of insular ecosystems.

Analysis of Microbial Community Structure in an Ecological Remediation Process of the River Water

2013 ◽  
Vol 864-867 ◽  
pp. 339-342
Author(s):  
Ji Hua Wang ◽  
Jan Fei Guan ◽  
Di Cui ◽  
Ang Li ◽  
Xiang Liu ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Microbial Community Composition ◽  
Environmental Parameters ◽  
Molecular Data ◽  
Vital Role ◽  
Structure Changes ◽  
And Function ◽  
Ecological Remediation

In urban river ecosystem, microorganism plays a vital role in maintaining ecological balance. Microbial community structure changes triggered with the river remediation progress. However, the change process in different sites from ecological remediation river has not been explored deeply before. We used polymerase chain reaction-denaturing gradient gelelectrophoresis (PCR-DGGE) to examine bacterial diversity of ecological remediated river in Changzhou City, China, and with rarely and severely contaminated rivers which from the same regions as reference. Molecular data were related to environmental parameters through multivariate analysis to investigate the relationship between potential impact of water quality and microbial community structure. As the ecological remediated river, NH3-N and TP were the important environmental variables influencing microbial community composition. After remediation, the microbial community structure showed a good consistency in each site, the microbial diversity and function were greatly improved, too.

Benthic Meiofaunal Diversity in Four Zones of Pichavaram Mangrove Forest, India

2021 ◽  
Vol 51 (4) ◽  
pp. 294-307
Author(s):  
Rengasamy Punniyamoorthy ◽  
Perumal Murugesan ◽  
Gopalan Mahadevan ◽  
Alberto Sanchez
Keyword(s):  
Organic Matter ◽  
Community Structure ◽  
Mangrove Forest ◽  
Environmental Parameters ◽  
The Other ◽  
Sediment Texture ◽  
Field Sampling ◽  
Key Variables ◽  
Sediment Ph ◽  
Richness Index

ABSTRACT The community structure of meiofauna was assessed relative to environmental parameters in four zones (non-mangrove, Avicennia zone, mixed zone, and Rhizophora zone) of Pichavaram Mangrove Forest, which is located along the southeast coast of India. Field sampling was carried out from June 2016–May 2017. The meiofaunal data were evaluated using univariate and multivariate statistics. The highest abundance of meiofauna (434 ind/10 cm−2) was recorded in the Rhizophora zone and the lowest (270 ind/10 cm−2) in the non-mangrove zone. A total of 62 species representing four meiofaunal groups were recorded, including 38 species of foraminifera, 12 species of nematodes, seven species of ostracods, and five species of harpacticoids. Diversity (Shannon H′) mostly ranged from 3–4, and was highest (3.86±0.26) in the Avicennia zone and averaged ∼3.3 in the other three zones. The Margalef richness index was ∼6 in the Avicennia and Rhizophora zones and ∼5 in the non-mangrove and mixed zones. The BIO-ENV and CCA analyses identified sediment texture and organic matter as key variables influencing the distribution of meiofauna, while % calcium carbonate, salinity, and sediment pH were also important. Monitoring studies of meiofaunal taxa may help elucidate their roles in coastal blue-carbon cycling and will also contribute to understanding how mangrove-associated habitats influence meiofaunal distributions.

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