Variation in the population dynamics of the invasive bryozoan Membranipora membranacea along a 450-km latitudinal gradient in Newfoundland and Labrador, Canada
Notice bibliographique
Résumé
The overall objective of this study was to quantify and compare seasonal (June to November) and inter-annual (2008 and 2009) variation in settlement, recruitment, and colony cover of the invasive bryozoan Membranipora membranacea on the kelp Saccharina longicruris across eight sites spanning a 450-km latitudinal gradient between the southwestern tip of Newfoundland and southeastern tip of Labrador. Thermal histories were calculated for each site to determine the extent that the observed variation was explained by sea temperature. Analysis of settlement data (Chapter II) indicated that (1) settler abundance varied both seasonally and annually with a sharp increase between August and September at warmer sites, and spatially with differences of up to three orders of magnitude between sites, (2) settler abundance and sea temperature were strongly correlated (r(2)=0.577), with maxima at mid-latitudes and minima at the northernmost and southernmost sites, and (3) exposure to waves, degree of kelp blade corrugations, and surface area of colonies of M. membranacea on kelp had little explanatory power on settler abundance across the study sites compared to sea temperature. Analysis of recruitment and colony cover data (Chapter III) indicated that (4) recruitment and colony cover varied seasonally, though variation generally decreased with increasing latitude, (5) temperature in the 76 days preceding measurements explained most [>60%] of the variation in recruitment within each month from late summer [September] to late fall [November] with the highest predictive capability (97%) in late fall, and (6) colony cover was strongly correlated (r(2)=0.524) to recruit abundance from late summer to late fall. Consistently low abundances of settlers, recruits, and colonies at the two northernmost sites suggested that M. membranacea is nearing its northern distribution limit in the northwest Atlantic. This study provides the first quantitative analysis of spatial and temporal variation in the abundance of M. membranacea in Newfoundland and Labrador since its introduction in the early 2000s. It strongly supports the general hypothesis that temperature is a key factor in regulating the population dynamics of this species, while suggesting that oceanographic phenomena such as upwelling and downwelling, which act on larval transport, also affect the dynamics at different spatial and temporal scales. A few inconsistencies both within the system studied and between the system studied and that of Nova Scotia indicate additional long-term observational and experimental studies are required to elucidate factors that regulate local and regional variation in the abundance of M. membranacea in cold temperate and subarctic environments.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».