Microbial communities in the winter cover and the water column of an alpine lake: system connectivity and uncoupling
Bibliographic record
Abstract
AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 29:123-134 (2002) - doi:10.3354/ame029123 Microbial communities in the winter cover and the water column of an alpine lake: system connectivity and uncoupling Marisol Felip*, Anton Wille, Birgit Sattler, Roland Psenner Institut of Zoology and Limnology, University of Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria *Present address: Departament d¹Ecologia, Universitat de Barcelona, Avinguda Diagonal 645, 08028 Barcelona, Spain. E-mail: marisol@bio.ub.es ABSTRACT: Active microbial communities formed by autotrophic and heterotrophic flagellates, ciliates and bacteria, inhabit slush layers of the ice and snow cover of high mountain lakes. Our study of the ice and snow cover of Gossenköllesee (Tyrolean Alps) during 2 complete winter periods, with special emphasis on the relationship between slush layers and the water column, confirms the hypothesis that the drastic changes in the physical and chemical structure of the cover determine biomass and composition of microbial assemblages. The temporal pattern previously described in the Pyrenees applies to the Alps, and we could distinguish 3 periods of winter cover: formation, growth and ablation. During the formation period (November to December), the ice sheet forms and slush layers start to develop. In the growth period (January to May), slush layer assemblages are mainly influenced by organisms deriving from lake plankton, predominantly flagellated chrysophytes, which peaked at different times and depths. During the ablation period (May to June/July), however, the cover assemblages are shaped by organisms and processes in the catchment. Microbial communities are characterized by the appearance of new species, such as Gymnodinium sp., red volvocales and large ciliates. The mutual influence between lake water and winter cover assemblages affects only the upper 1 to 2 m of the water column, while changes in the microbial composition of deeper water layers are slow and poorly related to slush layer assemblages. The appearance of Œ2 systems in 1 lake¹ is restricted to ca. 6 mo yr-1 and the reciprocal influence seems to be even more limited by space and time. During the ablation phase, i.e. when the influence of the catchment is much stronger than that of lake plankton, the slush microbial communities in the Alps and the Pyrenees are more similar to each other than during the growth phase of the cover. Over the whole winter period, the ice and snow cover appeared to be more dynamic, vertically variable and sporadically richer in biomass than the water column. KEY WORDS: Phytoplankton · Bacteria · Protozoa · Slush · High-mountain lake Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 29, No. 2. Online publication date: September 23, 2002 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2002 Inter-Research.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".