Degree of tapering of xylem conduits in stems and roots of small <i>Pinus cembra</i> and <i>Larix decidua</i> trees
Bibliographic record
Abstract
Xylem conduits increase in size from the apex downwards. While conduit tapering in the stem has often been reported to converge towards a common pattern among all plants, information on conduit tapering in small plants and roots is extremely scarce. We selected 10 small trees (height < 3 m) of Pinus cembra L. and Larix decidua Miller along an altitudinal gradient and measured diameter and conduit dimensions along stems and roots in the last annual ring. Sections of 10 µm were cut from wooden disks taken at different heights in the stem and in the roots and then stained with safranine. Slides were observed under a microscope, the lumen areas of conduits were measured and mean hydraulic diameters (Dh) calculated. Dh increased from stem tip (Dh at 1 cm from the apex averaged 10.75 µm; s = 2.33) to base (Dh from 20.70 to 30.54 µm), following a power trajectory (i.e., Dh = a·Lb, with L being the distance from the tip). Such degrees of conduit tapering may have a considerable effect in minimizing the hydraulic constraints. Despite trees at the treeline being older and smaller than in the subalpine forest (age: 28–70 years at the treeline; 18–39 years in the subalpine forest), conduit tapering did not differ significantly between sites, suggesting that tree height is the main factor controlling the basipetal increase in conduit lumens. In the roots, the increase in conduit dimensions continued towards their tips, even more steeply than in the stem. The widest conduits were measured around the root tips (around 40 µm). Conduit tapering resulted as a stable structural feature in small plants as well as in tall trees.
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 | 0.001 | 0.000 |
| 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) | 0.001 | 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".