Abstract
Paleoclimatic reconstructions are carried out using natural archives as indicators of the past climate. The knowledge of the proxy-environment relationship is therefore necessary to investigate the climatic conditions. Comparing different proxies through a high-resolution approach allows achieving a more reliable climate reconstruction. To this purpose, tree rings and peat bogs have been widely used as environmental recorders since they are able to provide annual or few years resolution information, respectively.
Several proxies from ombrotrophic peat bogs can be related to the atmospheric conditions and can be used to evaluate the occurrence of dry/wet periods. Among them, subfossil trees, preserved in peat deposits over millennia, are used to reconstruct past temperature and water availability. However, the basic physiological mechanisms which affect the growth of peatland trees are not yet fully known. Generally, the water table depth affects the growth of trees living on a peat bog which are often characterized by narrow rings. In this study, we investigated the climatic drivers influencing two natural archives (peat bog and tree rings) in the South-Eastern Alps. In detail, we characterized tree rings and wood anatomical structure of peatland pine trees and their neighbours growing on a mineral soil. Peatland trees recorded a complex climatic signal, mainly related to summer temperature and precipitation, unstable over time making them unsuitable for long-term reconstructions. Geochemical and biological proxies extracted from the peat core showed changes in the bog conditions across 1500 years. Thanks to a multi-proxy approach, including peat bogs and tree-ring proxies, we were able to assess convergent responses to climatic drivers over time, highlighting a change towards warmer and drier conditions during the last decades.