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Paleolimnological data from varved sediments in Lake Holzmaar (Eifel, Germany) were combined with documentary data on human activities, long-term data from the Historical Climate Database (HISKLID) for Germany and with recent monitoring data to evaluate changes in deposition that arose from climatic and human influences. The sediment data included seasonal layer thickness in an established varve chronology (1608–1942 AD), subannual chemical element counts, and multiannual organic matter data (TOC, TN, δ 13C org), all combined on an annual scale. Indicators for detritus deposition (lithogenic element counts and detritus layers) determined the first principal component (PC1) of the sediment data. This detritus PC1 was compared to the first PCs of the seasonal precipitation and temperature from HISKLID. While no relation was found to precipitation, the correlation with the temperature PC1 determined by spring to fall temperatures was significant. From 1608 to 1870, a positive correlation of the PCs suggests an increase of detritus deposition in the lake center with increasing non-winter temperatures. These may be linked by lake-internal sediment redeposition that increases when the periods of winter stratification become shorter and that of lake circulation longer. The detritus deposition is modulated by external detritus input depending on the intensity of erosion-conducive land use (wood pasture, wood cutting, and rotational slash-and-burn cultivation). Detritus input diminished when land use slowed down with population decrease as the consequence of plague epidemics, warfare and emigration. After 1870, forest regeneration and improving agricultural practices led to a stabilization of the catchment. Erosion and detritus deposition decreased progressively. The negative correlation of detritus deposition with the gradually increasing temperature presumably mimics a cause-effect relation, although a link with decreasing freeze–thaw action is possible. The modernization of agriculture proceeded with manuring and fertilizing, which caused an increase of lake productivity as indicated by summer blooms of diatoms with enhanced nutrient demand, increased δ 13C org values and sulfur concentrations. Within this well established data base we found combinations of criteria that may be used to deduce natural climatic or anthropogenic influences. The quantitative attribution of these influences remains a challenging task in paleolimnology because their interaction makes the detection of linking mechanisms difficult even at high degree of detail and the processes themselves remain debatable. [ABSTRACT FROM AUTHOR]

In this study we investigate pollen and oxygen isotopes of moss cellulose from the peat bog ‘Dürres Maar’ in the Eifel low mountain range, Germany (450 m a.s.l.) to quantitatively infer mid-Holocene climate change for the period between ~7000 and 3800 cal. BP. Pollen was analysed on the same samples from which Sphagnum leaves were isolated to extract cellulose for the determination of its oxygen isotope composition (δ18OSphagnum). To quantitatively estimate January and July temperature and annual precipitation from the pollen data, we applied a probabilistic indicator taxa method (‘pdf-method’). The pollen-based reconstructions indicate July temperatures ~1°C higher around 6000 cal. BP than after ~5500 cal. BP, which is consistent with a ~1‰ decrease in δ18OSphagnum during the same period. While the pollen-based climate reconstructions indicate little variability in summer temperature after ~5500 cal. BP, winter temperature shows several pronounced cold excursions of ~2–4°C in this period, which was likely accompanied by changes in precipitation patterns. Test reconstructions leaving out specific taxa indicate that not only larger climate trends, but also relatively small-scale climate variability can robustly be reconstructed with the pdf-method. This is of particular importance for reliable reconstructions of climate variability not only during the Holocene, but also in former interglacials, for which archives are rare and pollen is often the only suitable proxy in terrestrial records. The stable isotope values agree with the reconstructions based on pollen for the time between ~4500 and 3500 cal. BP, but not for the period before 4500 cal. BP. We explain this difference by atmospheric circulation patterns being different in the mid and late Holocene, respectively. [ABSTRACT FROM PUBLISHER]

Objectives. To determine the potential of eotaxin-3 as a diagnostic marker for active disease and genetic susceptibility factor for Churg–Strauss syndrome (CSS).Methods. A total of 37 patients with active, relapsed or inactive CSS, 123 healthy controls and 138 disease controls were studied. Clinical data were collected and serum levels of eotaxin-3 were determined. Ex vivo stability of eotaxin-3 in serum samples was tested. Furthermore, the association of single nucleotide polymorphisms (SNPs) in the eotaxin-3 gene with CSS was determined in 161 CSS patients and 124 healthy controls.Results. Serum eotaxin-3 was highly elevated in active CSS patients. Neither eosinophilic diseases nor other small-vessel vasculitides were associated with high serum eotaxin-3 levels. Receiver operating characteristic curve analysis determined a sensitivity and specificity of 87.5 and 98.6% at a cut-off level of 80 pg/ml. None of the tested SNPs within the eotaxin-3 gene influenced the susceptibility to develop CSS.Conclusions. Serum eotaxin-3 is a sensitive and specific marker for the diagnosis of active CSS suitable for routine clinical practice. Previously described SNPs in the eotaxin-3 gene do not predict the risk of developing CSS. [ABSTRACT FROM PUBLISHER]

This paper presents a high resolution reconstruction of local growing season temperature (GST) anomalies at Dürres Maar, Germany, spanning the last two millennia. The GST anomalies were derived from a stable carbon isotope time series of cellulose chemically extracted from Sphagnum leaves (δ13Ccellulose) separated from a kettle-hole peat deposit of several metres thickness. The temperature reconstruction is based on the Sphagnum δ13Ccellulose/temperature dependency observed in calibration studies. Reconstructed GST anomalies show considerable centennial and decadal scale variability. A cold and presumably wet phase with below-average temperature is reconstructed between the 4th and 7th century AD which is in accordance with the so called European Migration Period, marking the transition from the Late Roman Period to the Early Middle Ages. At High Medieval Times, the amplitude in the reconstructed temperature variability is most likely overestimated; nevertheless, above-average temperatures are obvious during this time span, which are followed by a temperature decrease. On the contrary, a pronounced Late Roman Climate Optimum, often described as similarly warm or even warmer as medieval times, could not be detected. The temperature signal of the Little Ice Age (LIA) is not preserved in Dürres Maar due to considerable peat cutting that takes place in the first half of the 19th century. The local GST anomalies show a remarkable agreement to northern hemispheric temperature reconstructions based on tree-ring datasets and are also in accordance with climate reconstructions on the basis of lake sediments, glacier advances and retreats, and historical datasets. Most notably, e.g., during the Early Middle Ages and at High Medieval Times, temperatures were neither low nor high in general. Rather high frequency temperature variability with multiple narrow intervals of below- and above-average temperatures at maximum lasting a few decades are reconstructed. Especially the agreements between our estimated GST anomalies and temperature reconstructions derived from tree-ring chronologies indicate the great potential of Sphagnum δ13Ccellulose time series from peat deposits for palaeoclimate research. This is particularly the case, given that a quantitative δ13Ccellulose/temperature relationship has been found for several Sphagnum species. Although the time resolution of Sphagnum δ13Ccellulose datasets certainly wouldn't reach the annual resolution of tree-ring data, reconstructions of past temperature variability on the basis of this proxy hold one particular advantage: often due to relatively high peat accumulation rates, especially in kettle-hole bogs accumulated on temperate latitudes over periods of up to several millennia, they allow extending temperature reconstructions based on tree-ring series into the past to enhance our knowledge of natural climate variability during the Holocene. [ABSTRACT FROM AUTHOR]

Abstract: To investigate the potential of stable isotopes of Sphagnum peat deposits for palaeoclimate research and to inform sampling strategies, we present results from a study of selected Sphagnum plant constituents. We report a combined stable carbon and oxygen isotope record of cellulose separately extracted from Sphagnum branches and stem sections manually sampled from a ∼4000 year old peat, deposited in a small dry maar crater located in the Westeifel Volcanic Field, Germany. We have determined the species composition of each individual sample of Sphagnum branches to address the sensitivity of the stable isotope records to potential changes in Sphagnum assemblages. The youngest approximately 3000 years old peat section consists of scarcely decomposed Sphagnum plant material. From the bog''s surface to a depth of ∼60 cm the predominant species is Sphagnum magellanicum. Between ∼60 and ∼550 cm the peat predominantly consists of Sphagnum capillifolium var. rubellum. At greater depths the decomposition status increases, species identification is, however, solely achievable if the record under examination consists of moderately decomposed peat. The stable carbon and oxygen isotope values of cellulose from Sphagnum stem sections are significantly lighter than those of the branches. Both isotopic offsets between the different plant compounds exhibit a strong degree of correlation, are statistically highly significant and observable down-core. The stable carbon isotope offset averages to 1.5‰, however, presumably decreases with increasing age of the plant material. In contrast, the averaged oxygen isotope offset of 0.9‰ is consistent in time. Our results imply that if no differentiation into Sphagnum branches and stem sections prior to stable isotope analyses is possible, erroneous interpretations of the isotope records are likely, since down-core changes in the ratio of branches to stem sections in the peat profile are most likely. This also implies that the removal of all non-Sphagnum plants or plant fragments is insufficient to retrieve stable isotope signals from peat deposits exclusively reflecting palaeo-environmental conditions. Even isotopic records from bulk Sphagnum cellulose comprise of two different signals: firstly, an environmental signal based on the plant response to external controls. This signal is, however, masked by a second plant physiological signal originating from the isotopic offset between branches and stem sections. [Copyright &y& Elsevier]