We present a novel technique in which the carbon isotope ratio (delta(13)C) of soil CO(2) is measured from small gas samples (<5 mL) injected into a stream of CO(2)-free air flowing into a tunable diode laser absorption spectrometer (TDL). This new method extends the dynamic range of the TDL to measure CO(2) mole fractions ranging from ambient to pure CO(2), reduces the volume of sample require...

BaSO(4) precipitated from mixed salt solutions by common techniques for SO(4) (2-) isotopic analysis may contain quantities of H(2)O and NO(3) (-) that introduce errors in O isotope measurements. Experiments with synthetic solutions indicate that delta(18)O values of CO produced by decomposition of precipitated BaSO(4) in a carbon reactor may be either too low or too high, depending on the rela...

Understanding the patterns and drivers of carbon isotope discrimination in C(4) species is critical for predicting the effects of global change on C(3)/C(4) ratio of plant community and consequently on ecosystem functioning and services. Cleistogenes squarrosa (Trin.) Keng is a dominant C(4) perennial bunchgrass of arid and semi-arid ecosystems across the Mongolian plateau of the Eurasian stepp...

Active and passive sensors are available for ground-based, high-throughput phenotyping in the field. However, these sensor systems have seldom been compared with respect to their determination of plant water status and water use efficiency related parameters under drought conditions. In this study, five passive and active reflectance sensors, including a hyperspectral passive sensor, an active ...

BACKGROUND 'You are what you eat' is an accurate summary for humans and animals when it comes to carbon isotope abundance. In biological material, natural(13)C/(12)C ratio is subject to minute variations due to diet composition (mainly from ingestion of C3 and C4 metabolism plants) and to the discrimination between 'light' and 'heavy' isotopes during biochemical reactions (isotope effects and i...