Search results for "δ15N"
showing 10 items of 40 documents
The history and impacts of farming activities in south Greenland: an insight from lake deposits.
2013
International audience; Agriculture in southern Greenland has a two-phase history: with the Norse, who first settled and farmed the region between 985ad and circa 1450ad, and with the recent reintroduction of sheep farming (1920ad to the present). The agricultural sector in Greenland is expected to grow over the next century as anticipated climate warming extends the length of the growing season and increases productivity. This article presents a synthesis of results from a well-dated 1500-year lake sediment record from Lake Igaliku, south Greenland (61°00′N, 45°26′W, 15m asl) that demonstrates the relative impacts of modern and Norse agricultural activities. Pollen, non-pollen palynomorphs…
A combined dietary approach using isotope and dental buccal-microwear analysis of human remains from the Neolithic, Roman and Medieval periods from t…
2016
Stable isotope and dental-microwear analysis are methods commonly used to reconstruct dietary habits in modern and ancient human populations. However, it is rare that they are both used together in the same study, and here both methods are combined to obtain information on human dietary habits from the site of Tossal de les Basses (Alicante, Spain) through time. Middle Neolithic, Late Roman and Medieval (Islamic) individuals have been analyzed for carbon and nitrogen stable isotope ratios of bone collagen, as well as for buccal-dental microwear. Overall, δ13C and δ15N isotopic values show that for all periods the diet was mainly based on C3 terrestrial resources. However, the isotopic signa…
Diet and mobility during the Christian conquest of Iberia: The multi-isotopic investigation of a 12th-13th century military order in Évora, Portugal
2020
Abstract The Kingdom of Portugal was established with the help of military-monastic orders, which provided important defence against Muslim armies during the 12th–13th century Christian conquest. While historical sources document the main events of this period, this research seeks to elucidate individual lifestyles and movement, aspects typically absent from written records. A multi-isotopic approach was used on skeletal material from eight Christian and two Muslim burials from Evora, Portugal (11th–13th centuries). Anthropological and archaeological evidence suggests the Christian adults belonged to the Evora Militia, which we seek to confirm through the reconstructed diet and mobility of …
Anthropic resource exploitation and use of the territory at the onset of social complexity in the Neolithic-Chalcolithic Western Pyrenees: a multi-is…
2018
Carbon (δ13C) and nitrogen (δ15N) stable isotope analyses from bone collagen provide information about the dietary protein input, while strontium isotopes (87Sr/86Sr) from tooth enamel give us data about provenance and potential territorial mobility of past populations. To date, isotopic results on the prehistory of the Western Pyrenees are scarce. In this article, we report human and faunal values of the mentioned isotopes from the Early-Middle Neolithic site of Fuente Hoz (Anuntzeta) and the Late Neolithic/Early Chalcolithic site of Kurtzebide (Letona, Zigoitia). The main objectives of this work are to analyse the dietary and territorial mobility patterns of these populations. Furthermore…
Spatial variability of soft-bottom macrobenthic communities in northern Sicily (Western Mediterranean): Contrasting trawled vs. untrawled areas
2016
13 páginas, 9 tablas, 5 figuras
Periphyton support for littoral secondary production in a highly humic boreal lake
2016
Steep stratification and poor light penetration in highly humic lakes typically restrict oxygenated littoral areas to narrow lake margins. However, in some instances, surrounding floating vegetation mats can sustain highly productive periphyton and more diverse invertebrate communities than pelagic areas. Little is known about how these littoral food webs function or the extent to which the pelagic and littoral food webs are coupled. We added 15N-labeled ammonium nitrate to the floating moss mat surrounding the littoral zone of Mekkojärvi, a small highly humic and fishless lake in southern Finland. Our goal was to increase the δ15N values of periphyton to investigate the diets of littoral i…
Ecological implications of purple sea urchin (Heliocidaris crassispina, Agassiz, 1864) enhancement on the coastal benthic food web: evidence from sta…
2020
A responsible approach to marine stock enhancement is an effective approach to restore fishery resources. While the release strategy of target species has been well investigated, the impacts on local ecological equilibrium and habitat qualities have only been poorly considered. In the present study, we evaluated how the macro-benthic food web in Daya Bay was affected by purple sea urchin (Heliocidaris crassispina (Agassiz, 1864) stock enhancement using stable isotope analyses (δ13C and δ15N). Our results indicated that the distribution of local species and trophic diversity were influenced to a certain degree by release of purple sea urchins and changes in the feeding habit of the urchins w…
Whole-lake dissolved inorganic 13C additions reveal seasonal shifts in zooplankton diet.
2008
Sustained whole-lake additions of 13C-enriched dissolved inorganic carbon (DIC), intended to increase experimentally the delta13C of DIC in the epilimnion of a small lake with high dissolved organic carbon (DOC), were made during three seasonal periods (spring, summer, and autumn). Coupled with carbon and nitrogen stable isotope analysis of zooplankton and several of their putative food sources, these additions were used to investigate seasonal changes in the relative contributions of different food sources to zooplankton diet in the lake. Four main potential food sources were considered: phytoplankton, heterotrophic bacteria (HB), methanotrophic bacteria (MOB), and green sulfur bacteria (G…
Pre and post-settlement movements of juvenile green turtles in the Southwestern Atlantic Ocean
2018
Abstract Detailed knowledge on migratory routes connecting distant breeding, developmental and foraging areas is a key prerequisite for the successful management of marine vertebrates. The present study combines stable isotopes analysis of carapace scutes and satellite tracking of juvenile green turtles as an experimental approach to understand the pre and post settlement (recruit to neritic habitats) movements in the Southwestern Atlantic Ocean. To this end, carapace scute biopsies were collected from 20 turtles foraging on coastal rocky outcrops in East Uruguay and sliced in successive 30-μm layers using a cryostat. The δ15N and δ13C values of the newest layer increased significantly with…
δ15N in deployed macroalgae as a tool to monitor nutrient input driven by tourism activities in Mediterranean islands
2020
Abstract Mediterranean Sea is among the world's leading tourist destinations; however, the sharp increase in tourists during the high season may affect coastal seawater. The main aim of this study was to evaluate the occurrence and temporal variation of anthropogenic nutrients in coastal seawater in relation to tourist flows in three Mediterranean islands (Cyprus, Sicily and Rhodes), through short-term macroalgae deployments, coupled with δ15N analysis and GIS mapping. In all islands, an overall increase in macroalgae δ15N occurred over the deployment carried out in August in the tourist sites, suggesting the presence of anthropogenic nutrients. Decreasing δ15N values occurred at increasing…