scholarly journals Hydrologic processes influence diatom community composition in Dry Valley streams

2011 ◽  
Vol 30 (4) ◽  
pp. 1057-1073 ◽  
Author(s):  
Lee F Stanish ◽  
Diana R Nemergut ◽  
Diane M McKnight
Keyword(s):  
Community Composition ◽  
Diatom Community ◽  
Hydrologic Processes ◽  
Dry Valley ◽  
Diatom Community Composition

Extreme streams: flow intermittency as a control on diatom communities in meltwater streams in the McMurdo Dry Valleys, Antarctica1This article is derived from a special session entitled “A New Hydrology: Inflow Effects on Ecosystem Form and Functioning” that took place at the February 2011 ASLO Aquatic Sciences conference in San Juan, Puerto Rico.

2012 ◽  
Vol 69 (8) ◽  
pp. 1405-1419 ◽  
Author(s):  
Lee F. Stanish ◽  
Tyler J. Kohler ◽  
Rhea M.M. Esposito ◽  
Breana L. Simmons ◽  
Uffe N. Nielsen ◽  
...  
Keyword(s):  
Community Composition ◽  
Endemic Species ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Intermittent Streams ◽  
Diatom Community ◽  
Diatom Communities ◽  
Dry Valley ◽  
Flow Intermittency ◽  
Diatom Community Composition

In the McMurdo Dry Valleys of Antarctica, stream biota is limited by the brief availability of liquid water. The benthic microbial mats harbor diatoms that have adapted to hydrologic stresses, including numerous endemic species. We found a strong relationship between diatom community composition and flow intermittency in a data set including seven streams that spanned a gradient in flow intermittency. In particular, two genera represented by numerous endemic species in Dry Valley habitats, Hantzschia and Luticola , had high abundances in moderately and highly intermittent streams, respectively. The Shannon Index of diversity was greatest in streams with intermediate flow intermittency, with lower diversity in more stable streams resulting from lower evenness, and lower diversity in highly intermittent streams resulting from lower richness. These results indicate that multiple metrics of biodiversity may be useful in assessing the response of diatom communities to changing hydrologic regime. We propose that flow intermittency acts as a species filter that increases habitat heterogeneity in Dry Valley streams and may allow endemic species to persist. Future Antarctic warming may alter diatom community composition and habitats that act as refugia for desiccation-tolerant taxa.

Frustule-related gene transcription and the influence of diatom community composition on silica precipitation in an iron-limited environment

2012 ◽  
Vol 57 (6) ◽  
pp. 1619-1633 ◽  
Author(s):  
Colleen A. Durkin ◽  
Adrian Marchetti ◽  
Sara J. Bender ◽  
Tiffany Truong ◽  
Rhonda Morales ◽  
...  
Keyword(s):  
Community Composition ◽  
Gene Transcription ◽  
Related Gene ◽  
Diatom Community ◽  
Silica Precipitation ◽  
Diatom Community Composition

scholarly journals Vulnerability of diatom communities in the Peace–Athabasca Delta to environmental change

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5447
Author(s):  
Stephanie J. Connor ◽  
Alexa C. Alexander-Trusiak ◽  
Donald J. Baird
Keyword(s):  
Community Composition ◽  
Gradient Analysis ◽  
Habitat Degradation ◽  
Region Of Interest ◽  
Specific Conductance ◽  
Environmental Drivers ◽  
Limited Information ◽  
Diatom Community ◽  
Dissolved Phosphorus ◽  
Diatom Community Composition

Habitat degradation associated with resource development is a major ecological concern, particularly in Canada’s boreal zone where limited information on biodiversity is available. Habitat degradation can lead to reductions in biodiversity and ecosystem function, especially when drivers of variability and diversity patterns have not been identified for a region of interest. In this study, the distribution of diatom genera in the Peace–Athabasca Delta in northeastern Alberta was examined in relation to seasonal, geographic, and alkalinity gradients. Grab samples of six abiotic variables (total dissolved nitrogen, total dissolved phosphorus, dissolved iron, turbidity, pH, and specific conductance (SPC)) were taken from 12 remote wetlands over three sampling periods, and regressed against an ordination of diatom community composition to identify key environmental drivers of diatom community variation. Indirect gradient analysis identified two major gradients among sites. First, separation of sites among sampling periods showed successional seasonal changes in diatom community composition. Second, separation of sites from the Peace sub-delta and Birch sub-delta showed a gradient of geographic separation. Direct gradient analysis failed to explain the underlying drivers of these two gradients, but did show that alkalinity is a key driver of diatom community composition in the Embarras sub-delta, and that these sites could be particularly vulnerable to community changes associated with acidification.

scholarly journals DNA metabarcoding and morphological methods show complementary patterns in the metacommunity organization of lentic epiphytic diatoms

2021 ◽  
Vol 4 ◽  
Author(s):  
Alejandro Nistal ◽  
Pedro Garcia ◽  
Jorge Garcia ◽  
María Borrego ◽  
Saúl Blanco ◽  
...  
Keyword(s):  
Community Composition ◽  
High Throughput Sequencing ◽  
Freshwater Ecosystems ◽  
Reference Database ◽  
Compositional Variation ◽  
Diatom Community ◽  
Morphological Method ◽  
Dna Metabarcoding ◽  
Geographical Distances ◽  
Diatom Community Composition

Diatoms are important organisms in freshwater ecosystems due to their position as primary producers and therefore, analyzing their communities provides relevant information on ecosystem functioning. Diatoms have historically been identified based on morphological traits, which is time-consuming and requires well-trained specialists. Nevertheless, DNA barcoding offers an alternative approach to overcome some limitations of the morphological method. Here, we assess if both approaches are comparable methods to study patterns and mechanisms (including environmental filtering and dispersal limitation) of epiphytic diatom metacommunities using a comprehensive dataset from 22 Mediterranean ponds at different taxonomic resolutions. We used a fragment of rbcL barcode gene combined with High-Throughput Sequencing to infer diatom community composition. The overall degree of correspondence between both approaches was assessed by Procrustean rotation analysis and Procrustean randomization tests, whereas the role of local environmental variables and geographical distances was studied using a comprehensive combination of BIOENV, Mantel tests and distance-based redundancy analysis. Our results showed a relatively poor correspondence in the compositional variation of diatom metacommunity between both approaches. We speculate that the incompleteness of the reference database and the bioinformatics processing are the biases most likely affecting the molecular approach, whereas the limited counting effort and the presence of cryptic species are presumably the major biases related with the morphological method. On the other hand, variation in diatom community composition detected with both approaches was strongly related to the environmental template, which may be related with the narrow ecological niche and the strong preferences for particular substrata of some diatom species. Nevertheless, we found no significant relationship between compositional variation and geographical distances at regional extent. Overall, our work highlights the importance of DNA metabarcoding to address empirical research questions of community ecology in freshwaters, especially once the reference databases include most genotypes of occurring taxa and bioinformatics biases are overcome.

Light, nutrients and grazing interact to determine stream diatom community composition and functional group structure

2010 ◽  
Vol 56 (2) ◽  
pp. 264-278 ◽  
Author(s):  
KATHARINA LANGE ◽  
ANTONIA LIESS ◽  
JEREMY J. PIGGOTT ◽  
COLIN R. TOWNSEND ◽  
CHRISTOPH D. MATTHAEI
Keyword(s):  
Community Composition ◽  
Functional Group ◽  
Group Structure ◽  
Diatom Community ◽  
Diatom Community Composition

scholarly journals Substrate type selection in diatom based lake water quality assessment

2021 ◽  
pp. 21
Author(s):  
Ivana S. Trbojević ◽  
Slađana S. Popović ◽  
Vanja V. Milovanović ◽  
Dragana D. Predojević ◽  
Gordana V. Subakov Simić ◽  
...  
Keyword(s):  
Water Quality ◽  
Quality Assessment ◽  
Community Composition ◽  
Lake Water ◽  
Water Quality Assessment ◽  
Diatom Community ◽  
Substrate Type ◽  
Lake Water Quality ◽  
Diatom Indices ◽  
Diatom Community Composition

Various studies report contrasting results on the substrate-type effect on diatom community composition, but the particularly important question is whether or not it affects diatom-based assessments of water quality. We investigated whether the substrate type is a significant predictor of the diatom community composition and if it affects lake water quality assessment based on diatom indices. This study took place in Sava Lake (Serbia). We used glass, ceramic, willow and yew tree tiles as artificial substrates for periphyton development, and pebbles from the lake littoral as natural substrate. Results revealed differences in both the diatom community composition and diatom indices values related to the substrates. A distinction was recognized between natural, artificial wooden, and artificial inert substrates. However, the final lake quality assessment based on diatom indices was more or less similar in all substrate types in our study, and depended on value ranges associated with water quality classification and on diatom index choices. Artificial substrates in our study did show potential as an alternative for natural substrate, but further studies are required, particularly in various types of lentic ecosystems to confirm our findings and support artificial substrate employment in lake water quality assessment.

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