Carbon and nitrogen supply to the underground orchid, <i>Rhizanthella gardneri</i>
Bibliographic record
Abstract
*Rhizanthella gardneri is a rare and fully subterranean orchid that is presumably obligately mycoheterotrophic. R. gardneri is thought to be linked via a common mycorrhizal fungus to co-occurring autotrophic shrubs, but there is no experimental evidence to support this supposition. *We used compartmentalized microcosms to investigate the R. gardneri tripartite relationship. (13)CO(2) was applied to foliage of Melaleuca scalena plants and [(13)C-(15)N]glycine was fed to the common mycorrhizal fungus, and both sources traced to R. gardneri plants. *In our microcosm trial, up to 5% of carbon (C) fed as (13)CO(2) to the autotrophic shrub was transferred to R. gardneri. R. gardneri also readily acquired soil C and nitrogen (N), where up to 6.2% of C and 22.5% of N fed as labelled glycine to soil was transferred via the fungus to R. gardneri after 240 h. *Our study confirms that R. gardneri is mycoheterotrophic and acquires nutrients via mycorrhizal fungus connections from an ectomycorrhizal autotrophic shrub and directly from the soil via the same fungus. This connection with a specific fungus is key to explaining why R. gardneri occurs exclusively under certain Melaleuca species at a very limited number of sites in Western Australia.
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) | 0.001 | 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".