Radiocarbon dating, pollen and non-pollen palynomorph analyses from a lake core were used to establish the timing and effects of farming activities around Lake Igaliku, Eastern Settlement, Greenland. The absence of agro-pastoral impact before the medieval colonization by Europeans provides an opportunity to understand the development of farming activity in a pristine landscape. The results show that the first phase of clearance and grazing pressure, without the expansion of the Norse apophyte (native plant, in habitats created by humans) Rumex acetosa type, could have occurred in the 9-10th century A.D. The presence of Norse settlers and livestock is clearly recorded from the 11-12th century A.D. with increasing frequencies of the Norse apophytes Rumex acetosa type and Ranunculus acris type, and coprophilous fungi. This colonization phase is followed by a period of decreasing human impact at the beginning of the 14th century, with a decrease in weeds, apophytes and coprophilous fungi suggesting a reduced grazing pressure. The regrowth of Salix and Betula and the disappearance of anthropogenic indicators except Rumex acetosa type between the 15th and 18th century demonstrate the abandonment of the settlement, until the development of contemporary agriculture in the 20th century.

The present study aims to document historical mining and smelting activities by means of geochemical and pollen analyses performed in a peat bog core collected around the Bibracte oppidum (Morvan, France), the largest settlement of the great Aeduan Celtic tribe (ca. 180 B.C. to 25 A.D.). The anthropogenic Pb profile indicates local mining operations starting from the Late Bronze Age, ca. cal. 1300 B.C. Lead inputs peaked at the height of Aeduan civilization and then decreased after the Roman conquest of Gaul, when the site was abandoned. Other phases of mining are recognized from the 11th century to modern times. They have all led to modifications in plant cover, probably related in part to forest clearances necessary to supply energy for mining and smelting. Zn, Sb, Cd, and Cu distributions may result from diffusional and biological processes or from the influence of groundwater and underlying mineral soil, precluding their interpretation for historical reconstruction. The abundance of mineral resources, in addition to the strategic location, might explain why early settlers founded the city of Bibracte at that particular place. About 20% of the anthropogenic lead record was accumulated before our era and about 50% before the 18th century, which constitutes a troublesome heritage. Any attempts to develop control strategies in accumulating environments should take into account past human activities in order to not overestimate the impact of contemporary pollution.

In the Sahel, with average annual precipitation in the order of 500 mm yr − 1 , wind erosion occurs mainly on cultivated millet fields whose surfaces are only partially covered by crop residues. The impact of these residues on wind erosion was not clearly established. The objective of this study is thus to quantify the actual amount of crop residues in traditional Sahelian fields and to determine their impacts on wind erosion by reference to a bare surface throughout the seasonal cycle over several years. At the beginning of the year during dry season, Sahelian farmers use to "clean" their fields, i.e. cut and lay flat on the soil surface any millet stalks still standing and yearly sprouts of shrubs. After this clearing, the crop residues cover (CRC) regularly decreases passing from 12% to less than 2% four months later. On traditional cultivated plot, crop residues efficiently prevent soil losses by wind erosion during the dry season and considerably reduce erosion fluxes at the beginning of the rainy season. However, for CRC lower than 2%, wind velocities were sufficient to produce important erosion even during dry season. A minimal cover rate of about 2% (100 kg ha − 1) thus appears as critical to reduce wind erosion. This reduction is driven by the higher aerodynamic roughness length which increases the wind erosion threshold velocity. If field clearing is made in January, as currently done, the CRC just after clearing should be about 800 kg ha − 1 to maintain CRC above 2% at beginning of the rainy season when wind velocities are the highest and wind erosion the most intense. Our results also demonstrate that during the second part of rainy season wind erosion is reduced, not so much due to vegetation development but rather to a decrease in the number and the intensity of high winds events. ©

A new and simple method is developed to efficiently quantify erosion and deposition rates based on stock unearthing measurements. This is applicable to spatial scales ranging from plot to hillslopes, and to time scales ranging from single hydrologic events to centennial scales. The method is applied to a plot area on vineyard hillslopes in Burgundy (Monthélie, France), with measurement of 4328 vine plants. A sediment budget established at the plot scale shows a mean soil lowering of 3.44 ± 1 cm over 20 years, involving a minimal erosion rate of 1.7 ± 0.5 mm yr − 1 . Locally, erosion rates can reach up to 8.2± 0.5 mm yr − 1 .This approach allows the sediment redistribution to be mapped and analyzed at 1-m resolution. It provides novel insights into the characterization of erosion patterns on pluri-decennial scales and into the analysis of spatial distribution of erosion processes on cultivated hillslopes.

This is the first integrated multiproxy study to investigate climate, catchment evolution and lake ecology in South Greenland. A 4-m-long sedimentary sequence from Lake Igaliku (618 00 0 N, 458 26 0 W, 15 m asl) documents major environmental and climatic changes in south Greenland during the last 10 ka. The chronology is based on a 210 Pb and 137 Cs profile and 28 radiocarbon dates. The paleoenvironmental history is interpreted on the basis of magnetic susceptibility, grain size, total organic carbon, total nitrogen and sulphur, sedimentation rates, pollen, and diatom assemblages. The basal radiocarbon date at ca. 10 cal ka BP provides a minimum age for the deglaciation of the basin, which is followed by *500 years of high sedimentation rates in a glaciomarine environment. After the glacio-isostatic emergence of the basin ca. 9.5 cal ka BP, limnological and terrestrial proxies suggests early warmth, which may have been interrupted by a cold, dry and windy period between 8.6 and 8.1 cal ka BP. A dry and windy event *5.3-4.8 cal ka BP preceded the Neoglacial transition at Lake Igaliku, which is characterized by a shift toward moister and perhaps cooler conditions *4.8 cal ka BP, causing major changes in terrestrial and aquatic ecological conditions. Significant cooling is documented after *3 cal ka BP. Since *1 cal ka BP the climatic-driven changes were overprinted by the human influence of Norse and recent agriculture.

The origins and biogeographical history of Vitis vinifera L. (domesticated grapevine) remain largely unknown. Shape and size have long been used as criteria to distinguish between wild and domesticated grape pips. Here we have analyzed variations of seed morphology in order to provide accurate criteria for the discrimination of different groups of varieties. Diversity in present-day cultivars and wild grapevines of Greek and east Mediterranean origin in relation to other Asiatic and European varieties and wild grapevines provides the basis for our analysis, which aims to allow the characterization of the ancient diversity of cultivated grapes in relation to present-day cultivars. Geometric morphometric analyses (Elliptic Fourier Transform method) have been used to characterize the seed shape and size of modern and archaeological material using 40 variables per seed. 197 archaeological grape pips from the 7th century BC sanctuary of Hera in Samos, Greece were compared with an extended reference collection of 269 modern cultivars and 83 wild populations, 10,518 seeds in total. Our study confirms the relationships between seed shape and domestication. Modern diversity is partly structured by the geographical origin of cultivars, but influence of other factors may play a significant role in clustering. The wide diversity of varieties offered at the Heraion of Samos during the Archaic Period, including cultivars growing on the island, imported grapes and wild morphotypes, is related to the history and geographical location of the island as well as to the diversity in the geographical range of pilgrims making offerings to the sanctuary.

Bonvalot, J. 1996 (June): Major palaeohydrographic changes in Alpine foreland during the Pliocene-Pleistocene. Boreas, VoI. 25, pp. 131 -143. Oslo. ISSN 0300-9483.The changing palaeogeographical pattern of Alpine deposits across the European forelands can be traced by identifying mineral assemblages and establishing the chronology of Pliocene-Pleistocene deposits in Alpine foreland. In the late Miocene, the upper courses of the Rhine and the Aar flowed east from the Swiss molasse plain towards the Danube. In the early Pliocene (Brunssumian, 5-3.2 Ma), these same rivers headed northwards towards the Rhine Graben of Alsace. In the early Reuverian, these streams were captured south of the Rhine Graben by the Doubs. They ceased their northward flow and headed west to feed the Bresse Graben. This phase is dated to the Lower and Middle Reuverian (3.2-2.6 Ma). From the Upper Reuverian (2.6 Ma) to the present day, the Rhine has adapted approximately its present course towards the North Sea, south to north along the Rhine Graben and across the Rhine Schist Massif to feed the Dutch Grabens. This changing pattern of capture and alteration of the hydrographic system of the upper reaches of the Rhine and the Aar can be explained by local tectonic movements.

The purpose of this paper is to provide a sediment-flux quantification in a vineyard context (Vosne-Romanée, Burgundy, France) where medium-term soil budget and sustainability are controlled by complex interactions between natural processes (rill erosion) and anthropogenic processes (earth supply transferred back into the rills by the winegrowers). Concentrated overland flows during the rainfall event resulted in the incision of 13 major rills in the inter-rows, carrying a sediment volume of about 4.77 m 3. Most of the rills were rectilinear and displayed a U shape with strong vertical walls. Rill incision began about 30 m from the upper plot boundary. In the buffer zone located at the lower border of the plot, seven fan systems developed from the material originating in one or two contributory rows. Accumulated volume is estimated at 1.6 m 3. Data from grain-size distribution, and rill and fan volumes, show that erosion is dominated by rilling (70% of the sediment yield) over sheet process (30% of the sediment yield). The net exported soil loss, corresponding to the balance between natural soil loss and anthropogenic supply, ranges between 24 ± 3 t ha − 1 and 48 t ha − 1 , over the plot during one hydrologic event. Analyses of the grain-size distribution in the reference soil sample and in the fans reveal that size selectivity has occurred, with preferential export of the fine material (b 63 μm) out of the plot, and preservation of the coarsest fractions (N 2 mm) in the fans. To evaluate the relative importance in grain-size distribution of natural processes (material loss) over anthropogenic processes (rill-filling by winegrowers), we simulated the temporal evolution of grain-size distribution in surface soil during five successive rainfall events. Our results clearly show that more than 30% of fine material in surface soil was lost in these few events, despite anthropogenic rill filling. This fine-fraction removal may have considerable impact on vineyard sustainability.