No abstract

Modern pollen samples provide an invaluable research tool for helping to interpret the quaternary fossil pollen record, allowing investigation of the relationship between pollen as the proxy and the environmental parameters such as vegetation, land-use, and climate that the pollen proxy represents. The European Modern Pollen Database (EMPD) is a new initiative within the European Pollen Database (EPD) to establish a publicly accessible repository of modern (surface sample) pollen data. This new database will complement the EPD, which at present holds only fossil sedimentary pollen data. The EMPD is freely available online to the scientific community and currently has information on almost 5,000 pollen samples from throughout the Euro-Siberian and Mediterranean regions, contributed by over 40 individuals and research groups. Here we describe how the EMPD was constructed, the various tables and their fields, problems and errors, quality controls, and continuing efforts to improve the available data

words)A 19-meter-long sedimentary record retrieved in Lake Aydat (French Massif Central) covers the last 6700 yrs at a high-resolution. A multi-proxy approach (density, magnetic susceptibility, XRF, Rock-Eval, pollen and non-pollen palynomorph analyses and a historical archives study) was used to characterise and propose a model of sedimentation. The high 2 deposition rate results from the combined effects of the high suspension load of the river, autochthonous production and the narrow shape of the incised fluvial valley dammed by a lava flow ca. 8550 years ago. Two contrasted periods (6700±200 -3180±90 cal. BP, and 1770±60 cal. BP-now) were characterized. The lower unit (mid-Holocene) displays a fine and regular lamination and holds a single, major, flood deposit. This unit is capped by an erosive mass wasting deposit triggered ca. 1770±60 cal. BP. The upper unit (late-Holocene) is made of organic rich and fine grained faintly laminated sediment, with numerous interbedded flood deposits and diatom blooms. The sedimentation was principally controlled by climatic forcings until ca. 1100 cal. BP, accompanied by detrital events linked to human activities around the lake. Then, a more detrital input attested by numerous and recurrent flood deposits can be linked to the intensification of a persistent anthropogenic impact on the catchment.Two phases of lake eutrophication are highlighted: 1200-1130 cal. BP, as a result of increased anthropogenic pressure, and the current phase that could have started ca. 150 cal. BP.