Long-term Limnological Changes in Six Lakes with Differing Human Impacts from a Limestone Region in Southwestern Ontario, Canada
Bibliographic record
Abstract
Diatom-based paleolimnological techniques have been used to track limnological changes over the last ~150 years in six oligomesotrophic, primarily shallow, hardwater lakes in southwestern Ontario. Three of the six lakes are located in national parks and consequently have had little-to-no direct human impacts in their watersheds, with the exception of logging following initial European settlement (A.D. ~1850–1910). The paleolimnological indicators suggest that these activities have led to subtle-to-moderate eutrophication and possibly a reduction of macrophyte abundances. Additional subtle limnological changes have been occurring over the last century even in the undisturbed control lakes. The marked increase of Cyclotella comensis suggests that alkalinity levels may have increased ~1950–1980. The remaining three lakes experienced additional disturbances following the 19th century logging. For example, a campsite has been located on the shore of Cyprus Lake since 1968, but study results indicate this minor disturbance did not significantly alter water quality. In contrast, the last two of the six study lakes have experienced significantly more intense human impact and showed markedly different trophic histories. For example, the catchment of Chesley Lake was heavily developed for agriculture, the shoreline was densely populated with cottages and macrophytes were deliberately removed from the littoral zone. The paleolimnological data recorded a reduction of the water quality following these disturbances. Cage aquaculture has been ongoing in Lake Wolsey since 1983. Diatom changes in the lake's recent sediment are consistent with increased nutrient concentrations. Collectively, these paleolimnological data provide lake managers with important historical data from which trajectories of past limnological changes can be inferred and realistic mitigation targets can be identified.
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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 | 0.002 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 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".