Climate sensitivity of a millennium-long pine chronology from Albania

Considerable progress has been made in assessing European climate variations of the last millennium, but little is known about the Mediterranean region and particularly its eastern part including the Balkan Peninsula. This area, however, will be particularly vulnerable to a predicted temperature increase and precipitation decrease, likely resulting in amplified drought extremes and episodes. Here we present a well-replicated composite tree-ring width chronology of millennial length from Albania, Balkan Peninsula. The Pinus heldreichii Christ dataset contains 302 series from 217 living and dead trees from 3 high-elevation sites, and spans the years 968-2008. Signal strength and growth-climate relationships were investigated using subsets according to location, age class, and growth level, as well as differently detrended chronology versions. Growth comparisons amongst the 3 sites' chronologies, between age classes and between growth-rate groups reveal an overall strong common signal. Growth-climate relationships over the last 100 yr, however, indicate that tree-ring formation does not depend on one single dominant factor, but rather on various combinations of summer precipitation and temperature resulting in temporally varying drought sensitivity. Our results emphasize a mixed and variable climate signal, corresponding with findings from other P. heldreichii sites across the Balkan Peninsula and Southern Italy.