Establishment patterns of saguaro cactus (<i>Carnegiea gigantea</i>) at the microsite scale help explain saguaro regeneration and distributions in heterogenous, regional habitats
Bibliographic record
Abstract
PREMISE: Establishment of long-lived perennial plants is a pivotal event that often leads to reproductive maturity. The population dynamics of the giant saguaro cactus (Carnegiea gigantea) have been investigated over large spatial areas, but establishment patterns have not been studied at the microsite (1 m) scale. Recent encroachment of non-native buffelgrass (Cenchrus ciliaris) has introduced an additional layer of complexity to our site at the Desert Lab on Tumamoc Hill in Tucson, Arizona, United States, with uncertain impact on saguaro establishment. We hypothesized that both biotic and abiotic microsite characteristics are correlated with saguaro establishment and that these correlations help explain saguaro distributions over larger spatial areas. METHODS: We investigated microsite characteristics correlated with saguaro establishment, the degree and direction of those correlations, and microsite effects on growth rate and saguaro abundance using 40 years of repeat survey data from saguaro plots at the Desert Lab. RESULTS: Saguaros established in microsites with higher native vegetation cover, intermediate rock cover, at more level sites, or sites closer to the north-south axis. Establishment was nearly zero in areas of high buffelgrass cover. The relative growth rate of young saguaros was determined in part by complex interactions of native vegetation cover with eastness and elevation. Abundance was positively affected by native vegetation cover and negatively by buffelgrass cover. CONCLUSIONS: Microsite characteristics help explain patterns in saguaro regeneration. Our results suggest that microsite characteristics be considered in future studies of the saguaro. Our findings will be useful for conservation, restoration, and management of saguaro populations.
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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 | 0.001 | 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".