Top-down vs. bottom-up effects on the planktonic microbial food web of a maritime Antarctic lake
Bibliographic record
Abstract
Abstract This study evaluated the influence of nutrient (bottom-up) and biological (top-down) controls on the planktonic microbial food web of Lake Limnopolar, an oligotrophic lake in maritime Antarctica. Using a factorial experiment, we manipulated nutrient levels (nitrogen and phosphorus) and macrozooplankton abundance (absence/presence, and abundance increased by 30×) to simulate environmental variations. Nutrient additions led to moderate phytoplankton growth in the absence of zooplankton, indicating nutrient limitation. The presence of zooplankton enhanced algal growth, favoured chlorophytes over diatoms, and significantly increased bacterial abundance while reducing particularly ciliates. These results indicate a cascading effect typical of biological control and they highlight the role of biotic interactions, even in extreme environments where abiotic factors are thought to dominate. Understanding biological controls in such extreme environments is essential, as it underscores the complexity of ecosystem functioning in the polar regions, which are increasingly seen as early indicators of global change.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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 teacher head, 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".