Sprecher
Beschreibung
Reconstructing past continental climates is a major objective in palaeobotany, and fossil plants constitute one of the most effective proxies for this purpose. Paleoclimate reconstructions using fossil leaf assemblages can be based either on taxonomic affinities or on physiognomic approaches. These approaches rely on relationships between leaf morphology and climate established from modern calibration datasets. However, the quality of the results obtained through physiognomic approaches depends heavily on the climatic coverage of the current calibrations. While the CLAMP (Climate Leaf Analysis Multivariate Program) method relies on extensive modern datasets comprising more than 370 sites worldwide, several climatic regions remain underrepresented, especially Mediterranean climates. In contrast, for other plant organs, especially wood, the associated methods and calibrations still need to be developed. Here, we present two studies addressing these calibration challenges. First, we explore ways to improve CLAMP climatic reconstructions through the addition of 11 new sites, mainly from Mediterranean environments. Second, we present a preliminary study toward the development of a wood–climate calibration dataset based on three plant groups sampled from field collections and the Montpellier xylarium, including material from Brittany (France), sub-Saharan Africa, and French Guiana. These two studies provide an opportunity to discuss broader methodological questions related to palaeoclimatic calibrations, including the number and climatic distribution of calibration sites, specimen selection strategies, and data collection protocols.