Distinguishing trophic variation from seasonal and size-based isotopic (δ<sup>15</sup>N) variation of zooplankton
Bibliographic record
Abstract
We measured the δ15N of particulate organic matter (POM), Daphnia pulex (D), Holopedium gibberum (H), Leptodiaptomus tyrelli (LT), Epischura nevadensis (E), and Chaoborus trivittatus (C) over an annual cycle in Council Lake, a pristine, oligotrophic, fishless lake. Annual averages of the δ15N of plankton (C, LT, E > D, H > POM) matched expected differences in trophic position, but seasonal patterns differed among species. During midsummer, the δ15N of D, H, and LT increased above the δ15N of E and C, despite little temporal or spatial variation in the δ15N of POM (<41 µm). Larger size fractions of POM (41–200 µm) helped explain some of the temporal variability of zooplankton δ15N. Body size of zooplankton was correlated with δ15N for D, C, and E, which could indicate size-based, trophic-level variation; selective feeding; or physiological differences in 15N enrichment. We propose that detailed time series of δ15N for multiple zooplankton species can help determine the seasonal variability of trophic structure in zooplankton assemblages.
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| 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".