Tree-ring–based summer mean temperature variations in the Adamello–Presanella Group (Italian Central Alps), 1610–2008 AD

Abstract. Climate records from remote mountain sites and for century-long periods are usually lacking for most continents and also for the European Alps. However, detailed reconstructions of climate parameters for pre-instrumental periods in mountain areas, suffering of glacial retreat caused by recent global warming, are needed in the view of a better comprehension of the environmental dynamics. We present here the first annually-resolved reconstruction of summer (JJA) mean temperature for the Adamello–Presanella Group (Central European Alps), one of the most glaciated mountain groups of the Italian Central Alps. The reconstruction has been based on four larch tree-ring width chronologies derived from living trees sampled in four valleys surrounding the Group. The reconstruction spans from 1610 to 2008 and the statistical verification of the reconstruction demonstrates the positive skill of the tree-ring dataset in tracking summer temperature variability also in the recent period

Dendroclimatic relevance of “Bosco Antico”, the most ancient living European larch wood in the southern Rhaetian Alps (Italy).

The ongoing increase in the global mean temperature at an unprecedented recorded rate is well documented. Nevertheless, knowledge of past climate variations is fundamental for a better understanding of ongoing climate change. This need is crucial in high mountain areas, where the effects of global warming are amplified and induce an accelerated glacial retreat. Thus, the use of climatic proxies such as tree-ring width offers tools to better understand the environmental dynamics in remote, sensitive sites. Here, we present the “Bosco Antico” site chronology, a six-century long dataset from the most ancient living stand in the Val di Sole area (southern Rhaetian Alps, Italy), and its relationship with summer mean temperatures. The analyses were performed on earlywood and latewood separately, as well as on tree-ring widths using static and moving correlations. The results showed that tree-rings and earlywood width are linked with June temperatures, whereas latewood width is mainly driven by July temperatures. All the analysed series were greatly influenced by June to July and June to August temperatures. Finally, a mean summer latewood-based temperature reconstruction since 1525 is proposed. It highlighted that during the last six hundred years, the summer temperatures span between -2.3 to +1.9 °C compared to the 1960–90 mean temperature (between 6.2 and 10.4 °C at the stand elevation). The coolest phase is recorded in the 1810s-20s underlining the strongest pulse of the Little Ice Age; other phases of negative anomalies are recorded in the first half of the 17th century, around 1700, and 1900 and during the 1970s. Our results add an important dataset for a specific climatic area, providing new information that will contribute to a better understanding of the climate dynamics for the study site as well as on a larger scale