Observations on Holocene subfossil tree remains from high-elevation sites in the Italian Alps

Abstract

Subfossil tree remains from 38 high-elevation sites in the eastern Alps, which were mostly located in the province of Trentino, Italy, were dendrochronologically analysed. A total of 909 samples were collected, 497 of which were dated to calendar years through dendrochronology and separated into six groups. A further tree-ring series of 20 samples were cross-dated into two groups and their ages established by means of radiocarbon dating. The new Trentino Chronology that was established on the basis of these samples covers more than 80% of the last ca. 11,500 years. The uneven distribution of wood samples through time is most likely caused by different factors, for example, climatic and anthropogenic factors. According to our observations, the trees fell at the sites where they were found. The tree-ring series show that trees often died after a period of pronounced growth decline, for example, as a consequence of variations in groundwater levels. A comparison of the Holocene sample distribution of the new Trentino Chronology with contemporaneous records of other European tree-ring chronologies suggests that, at least partly, the greater scale of climatic variability influenced the depositional frequency. The new data contribute to our understanding of past climatic variability and environmental dynamics.