Nutrient enrichment and flow regulation impair structure and function of a large river as revealed by aquatic hyphomycete species richness, biomass, and decomposition rates
Bibliographic record
Abstract
Diversity, sporulation rates, and biomass of aquatic hyphomycetes (Kingdom Fungi) on leaf litter were examined to assess the effects of nutrient enrichment and flow regulation on the ecological integrity of the Saint John River, New Brunswick, Canada. Leaf decomposition rate was used as an indicator of ecological function, whereas fungal abundance and diversity were chosen as structural indicators. Leaf-litter bags of yellow birch (Betula alleghaniensis) were deployed at 8 sites, periodically retrieved, and analyzed during 2 consecutive years in unregulated and regulated reaches. The interaction between nutrient enrichment and flow regulation regime significantly affected leaf decomposition rate and fungal sporulation during summer and autumn and fungal diversity during autumn. Flow regulation regime was the primary driver for fungal diversity during summer. In contrast, nutrient enrichment significantly affected fungal biomass. In general, this large 7th-order river responded to flow regulation and nutrient enrichment in the same manner as smaller rivers. Both factors increased decomposition rates, but only nutrient enrichment increased fungal biomass, diversity, and sporulation. Within the regulated reach, leaves in constantly covered litter bags had faster decomposition rates and more aquatic hyphomycete species, spore release, and biomass than in intermittently covered litter bags. Nutrient enrichment, flow regulation, and their interactions decreased ecosystem integrity by altering diversity and biomass of aquatic hyphomycetes and their function in the Saint John River.
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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 | 0.000 |
| 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 | 0.000 |
| Scholarly communication | 0.001 | 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".