Altitudinal Gradients and Forest Response:
Climate, Hydrology and Isotope Variability
of a Mediterranean Ecosystem

Abstract:

In the ongoing scientific effort to improve the knowledge about climate change, paleoclimate proxies can provide crucial insights into past climatic conditions. This is especially important in the Mediterranean which is predicted to be strongly affected by climate change. Stable oxygen isotopes of tree rings can be used as one of those proxies but seem not to be readily interpretable on the island of Corsica. To fill this gap and identify potential influences on isotope content during the waters pathway from source in the oceans to sink in trees, climatology, dendroecology, isotope-hydrology and dendroisotope research have been united in a unique multi-disciplined project.

Abstract:

Paleoclimate proxies such as tree rings rely on stable isotope ratios for the reconstruction of past climatic conditions. Such information then allows the calibration of models that evaluate and predict ongoing and future effects of global climate change. A region expected to be widely affected is the North-western Mediterranean. In that region, the island of Corsica was subject to isotope hydrology and dendroisotope studies in the recent past. Based on the findings of these previous investigations the new project “CorsicArchive" was launched in 2017. The project is designed to integrate climate modeling, isotope hydrology, wood anatomy and dendroisotopes for a better understanding of key aspects within the hydrologic cycle and climate reconstruction. The project aims to trace the stable isotope ratios of water along its pathway in the hydrologic cycle from its vapor source over precipitation to the uptake by trees where the information is eventually stored. For these purposes we placed 10 rain collectors in an E-W transect over the islands central main mountain range. With this setup, and two additional automatic rain event samplers, we foresee high-resolution sampling to map spatial and temporal variations. Currently conducted sampling of precipitation and soil water in conjunction with xylem water samples from trees are promising to decipher the sources and fate of water from its source to the climatic archives. We will present preliminary results from this exciting study.