Tree invasion constrains the influence of herbaceous structure in grassland bird habitats
Bibliographic record
Abstract
:Trees and other woody plants threaten grassland obligate birds, as well as the biological integrity of grasslands around the world. Bird species associated with grasslands of southern mixed-grass prairie of North America have declined in abundance, whereas species associated with shrub-stage and woodland habitats have increased. Recent increases in the extent of eastern redcedar (Juniperus virginiana) in the southern Great Plains of North America explain some of the change in bird assemblages in landscapes composed of patches of grassland fragmented by cropland and stands of eastern redcedar. In this study, we determined the influence of eastern redcedar, relative to the influence of structural attributes of the herbaceous layer, on bird assemblages within individual patches of grassland habitat. We indexed bird abundance within the breeding season with point counts on grassland patches with varying levels of invasion of eastern redcedar. Canopy cover of eastern redcedar explained a greater proportion of the composition of bird communities in these grasslands than structure of herbaceous vegetation. Species associated with grassland habitats generally declined in abundance, whereas species associated with shrub and woodland habitats increased as cover of eastern redcedar increased. Perhaps more important to conservation ecology, our data indicate that as canopy cover of eastern redcedar increased, variation in abundance of grassland birds decreased, indicating that canopy cover of eastern redcedar may constrain the local influence of herbaceous habitat structure on bird assemblages.
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 | 0.001 |
| 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 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".