The influence of estuary eutrophication on the benthic diatom community: a molecular approach

The ecological characteristics of benthic diatom genera from lakes and tarns in mountainous areas of Tasmania (76 lakes) and the South Island (65 lakes) and Stewart Island (6 lakes) of New Zealand were investigated. Community composition and diversity were mainly governed by gradients in calcium, pH and the monovalent/divalent ionic (M/D) ratio, with typical acidophilous and calciphilous communities present in both regions. Highest genus diversity occurred in the pH range between 5.5 and 7.5. Marked interregional differences were present in both calciphilous and acidophilous diatom community assemblages, which were at least partially related to variations in the concentration of the chloride, sodium, potassium and humic substances. Acidophilous communities in New Zealand were typically dominated by Frustulia, Brachysira and Kobayasiella, whereas Eunotia and Actinella dominated in Tasmania. Calciphilous communities in New Zealand were characterised by higher relative abundances of the genera Hantzschia, Diploneis, Nupela, Stauroneis and Synedra, whereas their Tasmanian counterparts were typified by the genera Amphora (subgenus Psammamphora), Biremis, Navicula and Psammothidium. The provinciality of the floras underscores the need for continued protection and conservation of high latitude aquatic ecosystems worldwide and in the Australasian region in particular.

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Determinants of Benthic Diatom Community Structurein Boreal Streams: the Role of Environmental and Spatial Factors at Different Scales

International Review of Hydrobiology ◽

10.1002/iroh.200310714 ◽

2004 ◽

Vol 89 (2) ◽

pp. 139-150 ◽

Cited By ~ 31

Author(s):

Janne Soininen

Keyword(s):

Benthic Diatom ◽

Diatom Community ◽

Spatial Factors ◽

Boreal Streams

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Benthic diatom community response to metal contamination from an abandoned Cu mine: Case study of the Gromolo Torrent (Italy)

Journal of Environmental Sciences ◽

10.1016/j.jes.2018.03.034 ◽

2019 ◽

Vol 75 ◽

pp. 233-246 ◽

Cited By ~ 10

Author(s):

Raffaella Tolotti ◽

Sirio Consani ◽

Cristina Carbone ◽

Greta Vagge ◽

Marco Capello ◽

...

Keyword(s):

Metal Contamination ◽

Community Response ◽

Benthic Diatom ◽

Diatom Community

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Intra-annual fluctuations dominating temporal dynamics of benthic diatom assemblages in a Chinese mountainous river

Annales de Limnologie - International Journal of Limnology ◽

10.1051/limn/2020020 ◽

2020 ◽

Vol 56 ◽

pp. 22

Author(s):

Shuhan Guo ◽

Fengzhi He ◽

Tao Tang ◽

Lu Tan ◽

Qinghua Cai

Keyword(s):

Community Dynamics ◽

Environmental Changes ◽

Temporal Dynamics ◽

Multivariate Time Series ◽

Multiple Scale ◽

Benthic Diatom ◽

Diatom Community ◽

Diatom Communities ◽

Mountainous River

Understanding temporal dynamics of community may provide insights on biological responses under environmental changes. However, our knowledge on temporal dynamics of river organisms is still limited. In the present study, we employed a multivariate time-series modeling approach with a long-term dataset (i.e. 72 consecutive months) to investigate temporal dynamics of benthic diatom communities in four sites located in a Chinese mountainous river network. We hypothesized that: (1) there are multi-scale temporal dynamics within the diatom community; (2) intra-annual fluctuations dominate the community dynamics; (3) diatom species composing the community respond distinctly to environmental changes. We found that intra-annual fluctuations with periodicities <12 months explained 8.1–16.1% of community variation. In contrast, fluctuations with periodicities of 13–36 months and 37–72 months only accounted for 1.1–5.9% and 2.8–9.7% of variance in diatom community dynamics, respectively. Taxa correlating significantly to each significant RDA axis (namely, RDA taxa group) displayed distinct temporal dynamics. Conductivity, total nitrogen, and pH were important to most RDA taxa groups across the four sites while their effects were group-specific. We concluded that intra-annual dynamics dominated temporal variation in diatom communities due to community responses to local environmental fluctuations. We suggest that long-term monitoring data are valuable for identifying multiple-scale temporal dynamics within biological communities.

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Eunotia rudis sp. nov., a new diatom (Bacillariophyta) from the Man and Biosphere Reserve at Yangambi, Democratic Republic of the Congo

Phytotaxa ◽

10.11646/phytotaxa.272.1.4 ◽

2016 ◽

Vol 272 (1) ◽

pp. 73 ◽

Cited By ~ 2

Author(s):

CHRISTINE COCQUYT ◽

MYRIAM DE HAAN ◽

EDIT LOKELE NDJOMBO

Keyword(s):

New Species ◽

Rain Forest ◽

Democratic Republic ◽

Central Africa ◽

Biosphere Reserve ◽

Benthic Diatom ◽

Congo Basin ◽

Diatom Community ◽

Republic Of The Congo ◽

Silica Wall

Eunotia rudis sp. nov. is described from material collected in acid rivers in an almost pristine tropical rain forest in the Congo Basin in Central Africa. The benthic diatom community was dominated by other Eunotia spp. and small naviculoid taxa. The morphological features of the new species are described and documented based on light and scanning electron microscopy investigations. Eunotia rudis sp. nov. can be distinguished from other taxa within the genus Eunotia by its typical slightly asymmetric valve shape with four dorsal undulations and the rough surface of the thick silica wall. In contrast to other Eunotia species, the number of dorsal undulations was constant in all observed populations. Differences between the new species and the related Eunotia garucisa and E. garucisa var. polydentula are discussed.

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