To compare natural variability and trends in a developed estuary with human-influenced patterns, stable isotope ratios ( C and N) were measured in sediments from five piston cores collected in Chesapeake Bay. Mixing of terrestrial and algal carbon sources primarily controls patterns of Corg profiles, so this proxy shows changes in estuary productivity and in delivery of terrestrial carbon to th...

The ability to distinguish between ‘light’ and ‘heavy’ forms of carbon dioxide in the atmosphere has proven to be a useful tool in the study of plant ecology and the role of terrestrial ecosystems in the global carbon cycle. Plant processes imprint unique isotopic signatures on atmospheric CO 2 such that measurements of the ratio of heavy to light carbon in CO 2 can provide a means of detecting...

Soil is an integral part of terrestrial ecosystems. Many soil ecologists interested in soil ecosystem functioning rely, to some degree, on stable isotope methodologies. The study of the natural abundance of carbon isotopes, especially (13)C but also (14)C, in the environment and the use of stable carbon isotope tracers have proved very useful in investigating the soil carbon cycle and soil trop...

While all members of the Orchidaceae are fully dependent on mycorrhizal fungi during their achlorophyllous juvenile stages, mature plants may remain fully myco-heterotrophic, become fully autotrophic or develop a nutritional mode where the carbon gain through photosynthesis is complemented by organic carbon from fungal partners. This so-called partial myco-heterotrophy is intriguingly complex. ...

Biological transfer of nutrients and materials between linked ecosystems influences global carbon budgets and ecosystem structure and function. Identifying the organisms or functional groups that are responsible for nutrient transfer, and quantifying their influence on ecosystem structure and carbon capture is an essential step for informed management of ecosystems in physically distant, but ec...

[1] Stable isotope tracer budget results suggest the transport to vertical diffusivity ratio for Antarctic Bottom Water (AABW) in the Atlantic was higher at the Last Glacial Maximum (LGM). Reduced mixing across the upper boundary of AABW is consistent with movement of this surface away from the seafloor and may be a factor in sequestering CO2 in the abyssal Atlantic. Two key unknowns in the bud...

Winter habitat use and the magnitude of migratory connectivity are important parameters when assessing drivers of the marked declines in avian migrants. Such information is unavailable for most species. We use a stable isotope approach to assess these factors for three declining African-Eurasian migrants whose winter ecology is poorly known: wood warbler Phylloscopus sibilatrix, house martin De...

[1] Oxygen and carbon stable-isotope compositions of modern benthic foraminifera in the Kara and Pechora estuarine regions of the Arctic continental shelf were compared with water dO, dCDIC, temperature, and salinity. The foraminiferal dO distribution is mostly similar to that of equilibrium calcite, primarily controlled by mixing of runoff and seawater in near-estuarine areas (depth < 15–20 m)...

a detailed study of ostracoda changes against the stable isotopes of carbon and oxygen acrossthe cenomanian-turonian boundary mass extinction has been fully documented in one section, the south ofengland. this section comprises the uppermost cenomanian to lowermost turonian strata. the comparisonbetween the results obtained in this research and two rival models for the cenomanian-turonian bound...

Moderate elevated vertical methane (CH4) flux is associated with sediment accretion and raised fluid expulsion at the Hikurangi subduction margin, located along the northeast coast of New Zealand. This focused CH4 flux contributes to the cycling of inorganic and organic carbon in solid phase sediment and pore water. Along a 7 km offshore transect across the Porangahau Ridge, vertical CH4 flux r...