19 research outputs found
Origin and fluxes of atmospheric REE entering an ombrotrophic peat bog in Black Forest (SW Germany): Evidence from snow, lichens and mosses
The fate of the Rare Earth Elements (REE) were investigated in different types of archives of atmospheric deposition in the Black Forest, Southern Germany: (1) a 70 cm snow pack collected on the domed part of a raised bog and representing 2 months of snow accumulation, (2) a snow sample collected close to the road about 500 m from the peat bog, (3) two species of lichens and (4) a peat profile representing 400 years of peat accumulation as well as a âpreanthropogenicâ sample and the living moss layer from the top of the core. REE concentrations in peat are significantly correlated to Ti which is a lithogenic conservative element suggesting that REE are immobile in peat bog environments. Snow, lichens and peat samples show similar PAAS (Post Archean Australian Shale) normalized REE distributions suggesting that the complete atmospheric REE signal is preserved in the peat profile. However, the annual flux of REE accumulated by the peat is ca. 10 times greater than that of the bulk winter flux of REE. This difference probably indicates that the REE concentrations in the snowpack are not representative of the average REE flux over the whole year. Despite the pronounced geological differences between this site (granite host-rock) and a previously studied peat bog in Switzerland (limestone host-rock) similar REE distribution patterns and accumulation rates were found at both sites. Given that both sites confirm an Upper Continental Crust signature, the data suggests both sites are influenced by regional and not local, soil-derived lithogenic aerosols
Recent atmospheric Pb deposition at a rural site in southern Germany assessed using a peat core and snowpack, and comparison with other archives
In a peat bog from Black Forest, Southern Germany, the rate of atmospheric Pb accumulation was quantified using a peat core dated by 210Pb and 14C. The most recent Pb accumulation rate (2.5 mg mâ2 yâ1) is similar to that obtained from a snowpack on the bog surface, which was sampled during the winter 2002 (1 to 4 mg mâ2 yâ1). The Pb accumulation rates recorded by the peat during the last 25 yr are also in agreement with published values of direct atmospheric fluxes in Black Forest. These values are 50 to 200 times greater than the ânaturalâ average background rate of atmospheric Pb accumulation (20 ÎŒg mâ2 yâ1) obtained using peat samples from the same bog dating from 3300 to 1300 cal. yr B.C. The isotopic composition of Pb was measured in both the modern and ancient peat samples as well as in the snow samples, and clearly shows that recent inputs are dominated by anthropogenic Pb. The chronology and isotopic composition of atmospheric Pb accumulation recorded by the peat from the Black Forest is similar to the chronologies reported earlier using peat cores from various peat bogs as well as herbarium samples of Sphagnum and point to a common Pb source to the region for the past 150 years. In contrast, Pb contamination occurring before 1850 in southwestern Germany, differs from the record published for Switzerland mainly due to the mining activity in Black Forest. Taken together, the results show that peat cores from ombrotrophic bogs can yield accurate records of atmospheric Pb deposition, provided that the cores are carefully collected, handled, prepared, and analysed using appropriate methods
Kriterien und VorschlĂ€ge fĂŒr einen Subventionsabbau: Kurzexpertise zur Strukturberichterstattung an den Bundesminister fĂŒr Wirtschaft
Zum Einfluà betrieblicher und sektoraler Differenzierung der Arbeitskosten und sonstiger Regelungen auf die BeschÀftigung im Strukturwandel
Eine zunehmende Spreizung der Arbeitseinkommen wird derzeit als ein zentraler wirtschaftspolitischer Beitrag zur Ăberwindung der BeschĂ€ftigungsprobleme gesehen. Ausgangspunkt der Untersuchung dieser ZusammenhĂ€nge ist eine Analyse der Tarifverhandlungen in Ost- und Westdeutschland. In diesem Kontext werden Entwicklung und sektorale Differenzierung der Tariflöhne und die Bedeutung der ĂŒbertariflichen Entlohnung fĂŒr den Effektivlohn dargestellt, wobei nach gesetzlichen, tarifvertraglichen bzw. betrieblichen EinfluĂfaktoren differenziert wird. Neben der Relevanz von Lohnniveau und Lohnstruktur rĂŒckt im Zuge eines generellen Umdenkens in der Arbeits- und Betriebszeitorganisation die zunehmende Bedeutung der Flexibilisierung von Arbeits- und Betriebszeiten fĂŒr den betrieblichen Erfolg immer mehr in den Vordergrund. So können durch geeignete Flexibilisierungsschritte in Verbindung mit einer kostenneutralen ArbeitszeitverkĂŒrzung positive Preis- und ProduktivitĂ€tseffekte erzielt werden.Die gesamtwirtschaftliche Analyse wird ergĂ€nzt durch eine innovative Untersuchung des Entlohnungs- und BeschĂ€ftigungsverhaltens von Betrieben. Auf Basis eines aus der BeschĂ€ftigtenstatistik abgeleiteten Mikrodatensatzes wird in einer LĂ€ngs-/Querschnittanalyse unternehmerisches Handeln auf der betrieblichen Ebene analysiert. Die Untersuchung zeigt, daĂ zwischen Betrieben erhebliche Lohndifferenzen auftreten, die mit Unterschieden in der Qualifikationsstruktur nicht zu erklĂ€ren sind