Symbiotic <i>Frankia</i> bacteria in <i>Alnus</i> forests in Mexico and the United States of America: is geographic location a good predictor of assemblage structure?
Bibliographic record
Abstract
While the biogeography of Alnus species is well characterized, that of their microbial symbionts remains less well understood. Little is known, for example, about how the genotypic richness of Alnus-associated Frankia bacteria varies at the continental scale, and the richness of Alnus-associated Frankia at tropical latitudes has yet to be explored. In this study, we conducted sequence-based analyses of the nifH gene comparing Frankia found in root nodules of two Alnus species in central Mexico with those associated with two Alnus species in the northwestern United States of America (USA). Similar to Frankia assemblages in northwestern USA and other geographic locations, genotypic richness within the Mexican samples was low, with five genotypes total using a ≥97% nifH sequence similarity cutoff. The vast majority of Mexican sequences belonged to genotypes also very common in northwestern USA Alnus forests, although two novel Mexican genotypes were identified. Phylogenetic analyses confirmed that all of the genotypes present in Mexico belong to larger clades of Alnus-associated Frankia. Genotype- and distance-based community analyses indicated that neither geographic location nor the phylogenetic relationships among hosts are strong predictors of Frankia assemblage structure. Our results suggest that factors other than classic biogeography are more influential in determining the continental-scale distribution and diversity of Alnus-associated Frankia.
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.001 |
| 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) | 0.000 | 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 teacher head, 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".