RESUMEN
There is growing concern on the survival of Mediterranean forests under the projected near-future droughts as a result of anthropogenic climate change. Here we determine the resilience of Mediterranean forests across the entire range of climatic boundary conditions realized during the past 500 kyrs based on continuous pollen and geochemical records of (sub)centennial-scale resolution from drillcores from Tenaghi Philippon, Greece. Using convergent cross-mapping we provide empirical confirmation that global atmospheric carbon dioxide (CO2) may affect Mediterranean vegetation through forcing on moisture availability. Our analysis documents two stable vegetation regimes across the wide range of CO2 and moisture levels realized during the past four glacial-interglacial cycles, with abrupt shifts from forest to steppe biomes occurring when a threshold in precipitation is crossed. Our approach highlights that a CO2-driven moisture decrease in the near future may bear an impending risk for abrupt vegetation regime shifts prompting forest loss in the Mediterranean region.
RESUMEN
We here present high-resolution palynological data from the Füramoos peat bog, located in the alpine foreland of Southern Germany. The data represent raw pollen counts of major arboreal pollen as well as agricultural indicator taxa for the Late Glacial and Holocene (14.5 ka BP to present) at Füramoos with an average temporal resolution of 100 years (50 years during critical intervals). The data are also provided as percentages, which are calculated based on the total sum of pollen grains, excluding pollen grains of sedges (Cyperaceae) and strictly aquatic taxa. The data yield insight into the vegetation dynamics in Central Europe in response to climatic and anthropogenic forcing, which are an integral part of the original research article (Kern et al., 2021). Considering its high temporal resolution and the robust age-depth model, the dataset is ideally suited to be included in regional syntheses of vegetation dynamics in Central Europe from the Late Glacial onwards. In addition to the data, we provide a detailed description of the Füramoos site and detail the palynological processing and analysing techniques used.
RESUMEN
X-ray fluorescence core scanning (XRF-CS) has become a standard tool in paleoenvironmental studies. Allowing rapid, inexpensive and non-destructive analysis of the elemental composition of sediment cores at high spatial resolution, it is ideally suited for the reconstruction of short-term climatic change. However, its applicability to cores consisting of peat and other highly organic-rich sediments has yet remained poorly explored. We have therefore investigated the application of XRF-CS to two cores consisting of ombrotrophic peat and of fen peat and organic-rich muds of Late Glacial-Holocene and Eemian age, respectively, from a peat bog in Southern Germany using an Avaatech 4th-generation XRF core scanner. The XRF-CS-derived distributions of elements widely used in (paleo)environmental research (i.e., Al, Ca, Fe, K, Mg, Mn, S, Si, and Ti) were systematically compared to the results of inductively coupled plasma optical emission spectrometry analyses. For the Late Glacial-Holocene peat core, XRF-CS yielded reliable semiquantitative data for the majority of the investigated elements (i.e., Ca, Fe, K, Mn, S, Si, and Ti), with R2â¯≥â¯0.5. XRF-CS of the Eemian fen peat and organic-rich muds yielded reliable data for Al, K, S, and Ti (R2â¯≥â¯0.5) and, to a lesser extent, for Fe (R2â¯=â¯0.46). and Si (R2â¯=â¯0.25). This indicates that XRF-CS allows to semiquantitatively reconstruct the distribution of the majority of paleoclimatically relevant elements in peat and other highly organic-rich sediments. Hence, XRF-CS is well suited to complement the analytical toolbox for the paleoenvironmental study of such sediments.
