From organismal physiology to ecological processes: Effects of nutrient enrichment and salinity variation in a freshwater ecosystem
Bibliographic record
Abstract
Abstract Environmental stressors have profound implications for species, communities, and ecosystems by altering fundamental processes. With increasing human impacts on aquatic ecosystems, two main scenarios have been reported: (1) the spatiotemporal superposition of multiple stressors, leading to interactions among them and (2) intensifying environmental gradients, leading to threshold responses. However, studies designed to assess the effects of multiple stressors (e.g., pulse stressors) along environmental gradients (e.g., press stressors) are uncommon, and interactions between pulse and press stressors may cause abrupt changes in biological responses. We conducted a laboratory experiment to investigate the effects of osmotic stress along a nutrient enrichment gradient on a freshwater community composed of periphyton, microorganisms, and zebra mussels (Dreissena polymorpha). Our objectives were to (1) quantify the individual and combined effects of stressors, (2) delineate thresholds along the nutrient gradient (press) in the absence and presence of osmotic stress (pulse), and (3) test for interactions between the two stressors. We evaluated effects on metabolic rates in D. polymorpha and on microbial activity, as well as phototrophic periphyton biomass and physiological status. We observed interactions between the two stressors for metabolic rates in D. polymorpha and periphytic phaeopigments. In contrast, we found an individual effect of osmotic stress on microbial activity and chlorophyll a content. Thresholds were only identified in the presence of osmotic stress for metabolic rates in D. polymorpha. Our work highlights the importance of combining multiple stressors with environmental gradients and the need to consider multiple biological compartments when evaluating the impacts of stressors on ecosystems.
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 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 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".