Gerd Helle

TL;DR: In this article, a comparison of nine European stable isotope laboratories' results of cellulose preparation resulted in data that generally agreed within the precision of the isotope ratio mass spectrometry (IRMS) method used.

TL;DR: It is demonstrated that the combined effects of increasing CO2 and climate change leading to soil drying have resulted in an accelerated increase in iWUE, which will help to reduce uncertainties in the land surface schemes of global climate models, where vegetation-climate feedbacks are currently still poorly constrained by observational data.

TL;DR: In this paper, the tree-ring δ18O of high-elevation junipers is used as an indicator of August precipitation in the southern Tibetan plateau, and the late 20th century was among the driest periods during the past 800 years, showing a tendency to slightly wetter conditions after AD 1990.

TL;DR: Focusing on dendrochronological examples, PCGA is shown to correctly determine population gradients and to be advantageous over other considered methods, and groups in each example allowed for enhancing the strength of a common underlying signal and comparably as hierarchical cluster analysis.

TL;DR: Rising temperatures and alterations in precipitation patterns during the past eight decades can account for the observed increase in drought stress of junipers at all altitudes.