Analysis of the Structure and Diversity of Prosopis africana (G. et Perr.) Taub. Tree Stands in the Southeastern Niger
Bibliographic record
Abstract
All parts of Prosopis africana are used by rural people in Niger, and this exposes it to degradation and a regeneration problems. The objective of this study was to determine the structure and regeneration of P. africana stands in the southern regions of Maradi and Zinder, Niger. Data were collected in plots, following transects after stratified sampling. Trunk diameter of all woody species was recorded in 126 plots. The diversity was analyzed and diameter structure and regeneration rates were determined. P. africana was the predominant species in both Maradi and Zinder: frequency = 40.35% and 43.95% of all species, respectively in Maradi and Zinder; importance value index = 40.57% in Maradi and 48.60% in Zinder. The Shannon diversity index was 2.82 in Maradi and 2.40 in Zinder and the Sorensen similarity index between the two regions was 0.73. According to the diameter structure, the stands were degraded in Zinder but regenerating in Maradi. The density of P. africana per hectare for trees with trunk diameter > 5 cm and < 5 cm, respectively was 16 and 51 in Maradi, and 30 and 12 in Zinder. The regeneration rate of P. africana was low compared with the general woody population. These results show the need for reforestation operations, using appropriate techniques, to avoid local extinction of the species.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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".