Island Studies Journal 10(2), Book Reviews
Notice bibliographique
Résumé
This book is based on the author's PhD thesis, which examines the changes in the ecoenvironment of the Xisha archipelago (also known as the Paracel islands) in the central South China Sea over the last 2000 years.All the islands of the archipelago are coral islands in a tropical ocean.So far, the Xisha Islands have been well preserved and they remain in a relatively pristine condition due to their distance from mainland China and restrictions on traveling to the area imposed by the Chinese government.Changes in seawater temperature, animal migration and human activities, therefore, may bring ecological risks and may substantially impact the vulnerable ecosystem of the islands.The main objective of this study is to explain interactions between the climate system, marine environments, seabirds and coral islands.Furthermore, it aims to provide data to predict future ecological responses to climate change.DNA barcoding and elemental, isotopic, geochemical, and biochemical analyses of the ornithogenic sediments from the Xisha Islands are used to track changes in the island ecology, along with multi-proxy analyses and regional comparisons.Soils that are ornithogenic -literally, originating from birds -consist of a welldefined layer of bird excrement, or guano, resting on mineral layers.In order to find out about environments on the Xisha archipelago, Xu's research selected various biological materials such as sediments and seabird remains (bones, guano).Seabirds inhabit these islets in large numbers and have played a central role in the development of the ecosystem.Seabird occupation leads to the accumulation of high levels of guano in the soil, which supports the development of flora: a great number of trees and shrubs flourish on guano-rich islands.The thriving vegetation, in turn, provides an ideal habitat for the seabirds.This case study shows that, besides nutrients (phosphorus and nitrogen), seabirds may also deliver significant quantities of contaminants and metal pollutants to a pristine and fragile island eco-environment.Regarding mercury, for instance, this happens, as Xu suggests that the dry and wet deposition of mercury from the atmosphere above the South China Sea "could be absorbed by the extremely productive oceanic phytoplankton" (p.106).Mercury is then further transferred to fish and then to birds as their predators.Collected soil samples consisted of a sediment mixture including plant humus, seabird guano and coral sand with remains of bird and fish bones.In order to trace elements in the soil and guano, elemental and isotopic analyses were carried out.However, the main method used in this study is a multi-proxy analysis which includes determining the age of ornithogenic sediments in the coral sand.Chemical analyses and radiometric dating techniques used include lead ( 210 Pb) and radiocarbon ( 14 C) chronology analyses.The long half-life of radiocarbon (more than 5000 years) means it is well suited to determining the age of ancient carbonbearing materials (such as bird and fish bones from hundreds to 50,000 years old).Several other radionuclides -or unstable, radioactive atom nuclei -were detected in ornithogenic coral sand sediment cores collected from five different islands of the Xisha archipelago, including radium ( 226 Ra) and caesium ( 137 Cs).Seabirds may have a significant impact on radionuclide concentrations in their immediate surroundings.However, peaks of 137 Cs were discovered in 1963 and 1986.The former were identified as a record of the 1963 fallout
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,006 | 0,004 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,004 | 0,001 |
| Communication savante | 0,000 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 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 tête enseignante, 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 ».