Changes in the understory plant community and ecosystem properties along a shrub density gradient
Bibliographic record
Abstract
Climate warming is projected to alter the vegetation community composition of arctic and alpine ecosystems including an increase in the relative abundance and cover of deciduous shrubs. This change in plant functional group dominance will likely alter tundra ecosystem structure and function. We conducted an observational study to quantify how the understory vegetation community and ecosystem properties varied along a shrub density and altitudinal gradient in a tundra alpine ecosystem in south-west Yukon. Although there was weak association between shrub density and species richness of understory community, there were large differences in functional group abundance between the different shrub densities; forb cover increased at lower elevations with higher shrub density at the expense of cryptogam and dwarf shrub cover. Litter mass, light interception, and soil carbon:nitrogen ratios all increased with shrub density. Sites with shrubs had higher summer soil temperatures, lower summer soil moisture, and lower percent soil nitrogen than the shrub-free site, although there was no difference in available nutrients among sites. This study presents findings from a nonmanipulated, model system where shrubification has been documented and suggests that direct and indirect effects of increasing shrub dominance are likely to affect the surrounding vegetation and abiotic environment controls.
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 | 0.000 | 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 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".