Climate signals in carbon and oxygen isotope ratios of Pinus cembra tree‐ring cellulose from the Călimani Mountains, Romania

Abstract We analyze annually resolved tree-ring stable carbon (I´13C) and oxygen (I´18O) isotopic chronologies from Swiss stone pine (Pinus cembra L.) in Romania. The chronologies cover the period between 1876 and 2012 and integrate data from four individual trees from the Calimani Mts in the eastern Carpathians where climatic records are scarce and starts only from 1961. Calibration trials show that the I´13C values correlate with local April-May relative humidity and with regional to larger scale (European) summer precipitation. I´18O correlates significantly with local relative humidity, cloud cover, maximum temperature, as well as European scale drought conditions. In all cases, the cli…