Earthworms often constitute an important component of agricultural foodwebs. As such, knowledge of their feeding preferences is relevant to the sustainable management of carbon and nutrient cycling in agroecosystems. We used natural abundances of stable isotopes (δ13C and δ15N) in earthworms and two of their putative food sources soil and leaf litter to test hypotheses regarding the feeding pla...

Blood stable isotope compositions in birds reflect the dietary isotopic signature at the time of the cellular blood synthesis. Several studies suggest that stable isotope ratios of some elements such as nitrogen (δ15N) can change in response to individual metabolic and physiological conditions. Using a wind tunnel experiment we tested if endurance flight in birds alters the metabolic state and ...

To clarify the effect of irrigation drainage from paddy fields on an estuarine tidal flat (Ushibashi Estuary, Miyagi Prefecture),we investigated carbon and nitrogen stable isotope ratios (δ13C δ15N) organic matters within fields, agricultural channels (rivers),and flats, those 18 species benthic consumers March to December 2020. The sediments had lower δ13C δ15N at riverward station (δ13C: -27....

Isotopic paleoecology (δ13c, δ18o) of mammals from the late Pleistocene–Holocene Ituaçu, Bahia, Brazil. In this paper, isotopic (δ13C, δ18O) fossils Alouatta sp., Cebus Myocastor coypus, Dicotyles tajacu, Tamandua tetradactyla, and Tapirus terrestris collected in Lapa do Bode cave, Ituaçu Municipality, State is described. Radiocarbon ages 6,480–6,653 Cal yr. BP (14C collagen = 5,790±25 years) w...

Carbon stable isotopes (δ13C) are widely used in ecological studies to understand diet, food web dynamics, and movements of marine fishes. Still, δ13C is influenced by lipid content often requires chemical extraction or mathematical correction. Here, we developed a species-specific correction for white muscle tissue yellowfin tuna (Thunnus albacares), highly migratory finfish considerable econo...

The travertine deposit springs are located on the southeast of the Damavand Volcano, 85 km northeast of Tehran Province. The deposits of these springs mainly outcropped with cascade, hill, conical, layered, calcareous Tufa and Fissure-Ridges morphologies. Travertine studies have usually been conducted based on field observations, geochemistry and hydrology. The tectonic activity of the region, ...

Emissions of carbon dioxide from fossil fuel combustion are reducing the ratio 13C/12C, δ13C, in atmospheric CO2 and ocean terrestrial biosphere that exchanges with atmosphere on timescales decades to centuries. Future changes emissions vary across different scenarios may cause decreases more than 6% δ13CO2 between 1850 2100. The effects these potential three-dimensional distribution δ13C have ...

Carbonate and organic matter deposited during the latest Paleocene thermal maximum is characterized by a remarkable –2.5‰ excursion in δ13C that occurred over ~104 yr and returned to near initial values in an exponential pattern over ~2 × 105 yr. It has been hypothesized that this excursion signifies transfer of 1.4 to 2.8 × 1018 g of CH4 from oceanic hydrates to the combined ocean-atmosphere i...

Stable carbon isotopic compositions of water-soluble organic carbon (WSOC) and organic molecular markers were measured to investigate the relative contributions of the sea-surface sources to the water-soluble 15 fraction of submicron organic aerosols collected over the eastern equatorial Pacific during the Tropical Ocean tRoposphere Exchange of Reactive halogens and Oxygenated VOCs (TORERO)/KA-...