Simple competition indices and environmental variables do little to improve predictions of natural population fluctuations
Bibliographic record
Abstract
The debate about the relative importance of interspecific competition and environmental factors in annual population fluctuations has persisted in ecology for many decades. Ecologists face the challenge of determining the extent to which interspecific competition and environmental factors impact population growth rates. We assess the predictive ability of models with and without interspecific competition and environmental covariates to predict population size one year beyond the model-building data. For 5 of 14 datasets a model with interspecific competition and/or environmental factors make better mean ‘absolute’ prediction error. However, none of the models with interspecific competition and/or environmental variables make predictions that are statistically significantly superior to the random walk model. We conclude that there is limited evidence that incorporating interspecific competition and/or environmental covariates leads to improved model predictive ability.
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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 | 0.009 | 0.021 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.005 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.003 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
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".