Carbon cycle disturbance associated with mass extinction at the end of the Permian Period continued through the Early Triassic, an interval of approximately 5 million years. Coincidence of carbon cycle stabilization with accelerated Middle Triassic biotic recovery suggests a link between carbon cycling and biodiversity, but the cause of Early Triassic carbon isotope excursions remains poorly un...

environmental variables, including soil water content (swc), act as constraints on crop growth and productivity. therefore, open air (e0), perforated (e1) and non-perforated (e2) plastic housings were used with well-watered (w0), moderately-watered (w1) and water-stressed (w2) bush bean plants to explore the relationships between water-use efficiency (wue), carbon isotope discrimination (δ) and...

Photosynthetic carbon isotope discrimination is a non-destructive tool for investigating C4 metabolism. Tuneable diode laser absorption spectroscopy provides new opportunities for making rapid, concurrent measurements of carbon isotope discrimination and CO2 assimilation over a range of environmental conditions, and this has facilitated the use of carbon isotope discrimination as a probe of C4 ...

The decrease in the average magnitude of carbon isotope excursions in marine carbonates over Phanerozoic time is a longstanding unresolved problem. In addition, carbon isotope excursions commonly co-occur with oxygen isotope excursions of the same sign, implying the existence of a longstanding link between organic carbon burial fluxes and temperature. It was proposed that this connection was pr...

Stable isotope analysis has been utilized in archaeology since the 1970s, yet standardized protocols for terminology, sampling, pretreatment evaluation, calibration, quality assurance and control, data presentation, and graphical or statistical treatment still remain lacking in archaeological applications. Here, we present recommendations and requirements for each of these in the archaeological...

Carbon and hydrogen isotope ratios of cellulose nitrate and oxygen isotope ratios of cellulose from species of greenhouse plants having different photosynthetic modes were determined. When hydrogen isotope ratios are plotted against carbon isotope ratios, four clusters of points are discernible, each representing different photosynthetic modes: C(3) plants, C(4) plants, CAM plants, and C(3) pla...

The concentration of atmospheric methane is strongly linked to variations in Earth’s climate. Currently, we can directly reconstruct the total atmospheric concentration of methane, but not individual terms of the methane cycle. Northern wetlands, dominated by Sphagnum, are an important contributor of atmospheric methane, and we seek to understand the methane cycle in these systems. We present a...

The application of stable isotope analysis (SIA) has become a standard scientific approach in Agricultural and Ecological researches and, more in general, in several disciplines such as biology, botany, zoology, organic chemistry, climatology, and nutrition. The main objectives of this paper are (1) to provide a simple definition of stable isotopes and (2) to illustrate analytical measurement m...

[1] Eocene Thermal Maximum 2 (ETM2; ∼53.7 Ma) occurred approximately 2 Myr after the Paleocene‐ Eocene Thermal Maximum (∼55.5 Ma) and was characterized by a deep‐sea warming of >3°C, associated with massive release of carbon into the ocean‐atmosphere system. We performed single‐specimen stable isotope analyses of the planktic foraminiferal genera Acarinina (surface dweller) and Subbotina (therm...

Studies in freshwater ecosystems are seeking to improve understanding of carbon flow in food webs and stable isotopes have been influential in this work. However, variation in isotopic values of basal production sources could either be an asset or a hindrance depending on study objectives. We assessed the potential for basin geology and local limnological conditions to predict stable carbon and...