Habitat dependent nurse effects of the dwarf-shrub<i>Dryas octopetala</i>on alpine and arctic plant community structure
Bibliographic record
Abstract
:Some species may increase community diversity by modifying the local environment for co-occurring species. This is most common in habitats of high abiotic stress. To explore whether the mat-forming dwarf shrub Dryas octopetala functions as a nurse plant in alpine and arctic plant communities of contrasting but generally stressful environmental conditions, we measured species diversity, richness, cover, and composition of different functional groups (vascular plants, bryophytes, and lichens) inside and outside Dryas mats at sites differing in environmental severity at Finse, alpine Norway, and in arctic Svalbard. Dryas appears to function as a nurse plant primarily for bryophytes, and mainly at the most severe sites in Svalbard. At the more benign sites at Finse, total diversity (Shannon’s index) and richness, and richness of all functional groups, were lower inside Dryas than outside, suggesting that Dryas has no nurse plant function on diversity parameters there. Species composition, however, differed inside and outside Dryas in all the communities, due to both presence/absence and abundance differences at Finse, and primarily due to differences in species abundances in Svalbard. This may suggest that Dryas functions as a nurse plant for individual species of all of the three functional groups in all the communities, even if competitive impacts of Dryas may overrule the positive effects on a whole-community level. Finally, our results show that Dryas may shift from being a nurse plant to being a competitor when its cover increases, but only under relatively low abiotic stress.
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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 | 0.000 |
| 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 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".