Are we ready to conserve species complexes? Insights from morphometrics and distribution of the <i>Poidium</i> complex (Poaceae)
Bibliographic record
Abstract
Abstract Conservation strategies rely on precise taxonomic delimitation, yet delineating species complexes remains challenging. Despite these difficulties, it is crucial to protect vulnerable complexes. We examined the Poidium complex, comprising five morphologically similar taxa that co-occur in the highland grasslands of northeast Rio Grande do Sul, Brazil. Our goals were to assess whether morphological characters distinguish taxa or groups within the complex, evaluate correlations with environmental and geographic patterns, and inform conservation priorities. Using uni- and multivariate analyses of morphometric and environmental data, we identified three main groups within the complex, each defined by distinctive palea and lemma surface traits. Quantitative spikelet and lemma characters significantly differentiate these groups, and environmental and morphometric variables help characterize subgroups within the clusters. The majority of subgroups are concentrated in Northeast Rio Grande do Sul. Our results support circumscribing Poidium juergensii as having only strigose lemmas and no infraspecific delimitation, as well as treating individuals with glabrous lemmas at the species level, as Poidium tricholepis sp. nov. In addition, we highlight the weak morphological distinction between Poidium calotheca and Poidium ambiguum in sympatric areas. This study underscores the uniqueness of the South Brazilian highland grasslands and the relevance of including species complexes in conservation efforts.
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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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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".