Potential of environmental DNA for tracing land-use based sediment sources
Notice bibliographique
Résumé
Environmental DNA (eDNA) is a complex mixture of genetic material extracted from environmental samples like soil, water or sediment in order to obtain reliable information on the past and current biological communities. In recent years, the eDNA technique was successfully applied to sediment accumulated in lakes for providing information on past land use and land cover changes in their drainage areas. Recently, the potential of eDNA for providing detailed information on the plant species found in sediment sources was investigated. These research highlight the powerful potential of this method for improving our ability to detect the vegetal communities causing erosion and sediment delivery. Nevertheless, some fundamental questions remain like for example the DNA memory effect of soils. How long the plant signature can persist in soils? Are we recording the last species cultivated or a mixture of past plants in agricultural areas? These issues are of prime importance for examining the potential of eDNA as a new sediment tracer. To answer these questions, two contrasted sites located in intensively cultivated environments in France were studied. In the first site, soil samples were collected (n=30) in plots for which the crop rotation history was well documented since 1975. In particular, crops cultivated only once during the rotation were used as potential chronological markers. The impact of agricultural practices on eDNA preservation was also investigated comparing soil signatures under conventional and conservation farming. In the second site, samples were collected (n=40) to compare the abundance of currently observed taxa versus detected taxa in cropland, grassland, woodland and river channel banks. The results showed that the last cultivated crop was detected in 100% of the samples as the most abundant taxa under conventional farming and 75% under no-tillage. The last cultivated species was the most abundant in 80% of the studied plots. Interestingly, grapevine was detected in 46% of the cultivated plots of the second site, although this plant is no longer cultivated in this catchment. In addition, a large variety of weeds were detected in both sites in addition to the cultivated species. eDNA results provided by the current research illustrate the potential of this method for identifying the recent (<7 years) land cover history of soils which may allow to improve our understanding of sediment mobilization and transfer processes over short timescales.
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 | 0,001 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,002 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,001 |
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 ».