Using the Vaganov-Shaskin growth model to infer climate limitations of tree growth

Category: Time:
Wednesday, March 15, 2023 - 12:00 to 13:00
Room: URL: Speaker:
Cristina Valeriano PeƱas
Technical University of Madrid (UPM), Spain
Kiyomi Morino
Extreme droughts are among the most obvious consequences of current climate change and they are deeply affecting forest ecosystems. The Mediterranean region is one of the most affected areas by climate change. Warmer conditions and increased evapotranspiration rates are amplifying drought stress and causing more severe dieback and mortality episodes. Process-based growth models such as the Vaganov-Shaskin (VS) model can be used to: (i) determine growth departures from a climate baseline and (ii) infer the main climate constraints of radial growth. The VS model simulates daily integral growth rates (Gr) as a function of temperature and soil moisture. I illustrate the use of the VS model: (i) to investigate differences in growth rates and patterns between coexisting declining and non-declining Pinus pinaster trees, (ii) to search for early-warning signals of impending dieback in conifers (several pine species and silver fir), and (iii) how growth bimodality changes along climatic gradients (pine and juniper species). I also discuss how facultative bimodality could be an advantageous response to overcome summer drought in Mediterranean forests and to revert the negative impacts of aridification.