Delayed greening of mountain birch leaves:Ecological and chemical correlates
Bibliographic record
Abstract
AbstractFlushing leaves of deciduous trees can be exposed to high herbivore pressure. Young foliage provides high quality food for herbivores, and therefore herbivore pressure is much higher in young than mature foliage. Plants may escape the effects of herbivory in time by delaying leaf greening. We measured delayed greening as an intensity of redness in leaves in mountain birch at bud burst. Furthermore, we analyzed covariation of leaf redness with leaf growth and leaf consumption by the autumnal moth, Epirrita autumnata (Bkh.), a major defoliator of mountain birch. We also analyzed concentrations of amino acids, sugars and phenolic compounds of leaves. Leaf redness was positively associated with leaf growth, and consumption by E. autumnata indicated reduced leaf resistance against herbivores. Concentrations of protein-bound amino acids and gallotannins in young leaves were closely and positively correlated with leaf redness. Concentrations of glucose exhibited close positive correlations with leaf redness at the beginning of the season, whereas the correlation was negligible in mature leaves. Concentrations of other sugars increased with increasing degree of leaf redness towards the end of leaf development. This may be one reason for high leaf biomass losses in trees with delayed greening.RésuméLes feuilles des arbres décidus peuvent être exposées à une forte pression par les herbivores lors de leur développement. Le jeune feuillage fournit une nourriture de très grande qualité aux herbivores; la pression exercée par les herbivores sera donc plus élevée chez le feuillage jeune que chez le feuillage mature. Les plantes peuvent échapper aux effets de l’herbivorie en retardant le verdissement des feuilles. Nous avons mesuré le retard de verdissement à l’aide de l’intensité de rougeur des feuilles du Bouleau pubescent lors du débourrement. De plus, nous avons analysé la covariance entre la rougeur du feuillage, la croissance des feuilles et la consommation des feuilles par Epirrita autumnata (Bkh.), un défoliateur important du Bouleau pubescent. Nous avons également mesuré les concentrations en acides aminés, en sucres et en composés phénoliques des feuilles. La rougeur des feuilles est positivement corrélée avec la croissance des feuilles; leur consommation par E. autumnata indique une résistance plus faible face aux herbivores. Les concentrations en acides aminés protéiques et en gallotannins chez les jeunes feuilles sont fortement et positivement corrélées avec le niveau de rougeur des feuilles. Les concentrations en glucose présentent des corrélations positives fortes avec la rougeur des feuilles au début de la saison de croissance, alors que la corrélation est négligeable chez les feuilles matures. Les concentrations des autres sucres augmentent avec le niveau de rougeur des feuilles vers la fin de leur période de développement. Ceci pourrait expliquer les pertes élevées de biomasse foliaire chez les arbres présentant un délai de verdissement.Key Words: BirchDelayed greeningHerbivoryEpirritaLeaf chemistryMots-clés: BouleauDélai de verdissementHerbivorieEpirritaChimie des feuilles
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 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 | 0.001 |
| 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".