Regeneration niches of Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis> [L.] Karst.) saplings in small canopy gaps in mixed mountain forests of the Bavarian Limestone Alps

Natural regeneration measurements are the main silvicultural objective in overaged protective forests of the Bavarian Limestone Alps. While manifold problems with these stands, especially the impact of browsing, are widely recognised, the regeneration niches of Norway spruce (Picea abies [L.] Karst.) are insufficiently known. The purpose of this study was to determine favourable combinations of site factors for the development of spruce in small, unfenced canopy gaps, located on Aposerido-Fagetum caricetosum albae forest sites. We recorded the occurrence of spruce saplings (as dependent variable) and of six site factors (as independent variables) on 480 0.5 m²-subplots. In addition, we estimated the coverage of six acid adapted plant species to determine correlations with the humus depth. A binary logistic regression analysis was used to predict the probability of the occurrence of a spruce sapling in dependency of the different site factors. Supported by other studies, we assumed that the supply of solar radiation was adequate for the sufficient regeneration of spruce within the canopy gaps. Other site factors significantly determined the regeneration niches of spruce saplings. More spruce saplings were found near hindrances and on rough surfaces than would be expected from a random occurrence of saplings. These microsite types may have characteristics, especially protection against snow gliding that promotes spruce establishment. A calculated “hindrance index”, which accounted for the number, and the distance of surrounding hindrances might be a good specific value to describe the influence of hindrances on steep slopes. The sapling establishment decreased on thin humus layers. Our assumption for the sites was that thick organic layers might represent a good seedbed for spruce. Decayed dead wood was scarce, but was exceedingly favoured by spruce saplings. Results obtained suggest that the natural regeneration establishment of spruce on steep slopes can be successfully influenced by site factors which inhibit the influence of snow gliding. According to a “positive microsite” concept, we recommend for artificial regeneration measurements with spruce, microsites close to hindrances (e.g. stumps, downed trees) and Vaccinium myrtillus as a predictor for thick, acid humus layers.     

Southern Hemisphere and deep-sea warming led deglacial atmospheric CO2 rise and tropical warming

Establishing what caused Earth's largest climatic changes in the past requires a precise knowledge of both the forcing and the regional responses. We determined the chronology of high- and low-latitude climate change at the last glacial termination by radiocarbon dating benthic and planktonic foraminiferal stable isotope and magnesium/calcium records from a marine core collected in the western tropical Pacific. Deep-sea temperatures warmed by approximately 2 degrees C between 19 and 17 thousand years before the present (ky B.P.), leading the rise in atmospheric CO2 and tropical-surface-ocean warming by approximately 1000 years. The cause of this deglacial deep-water warming does not lie within the tropics, nor can its early onset between 19 and 17 ky B.P. be attributed to CO2 forcing. Increasing austral-spring insolation combined with sea-ice albedo feedbacks appear to be the key factors responsible for this warming.     

Common Kibra alleles are associated with human memory performance

Human memory is a polygenic trait. We performed a genome-wide screen to identify memory-related gene variants. A genomic locus encoding the brain protein KIBRA was significantly associated with memory performance in three independent, cognitively normal cohorts from Switzerland and the United States. Gene expression studies showed that KIBRA was expressed in memory-related brain structures. Functional magnetic resonance imaging detected KIBRA allele-dependent differences in hippocampal activations during memory retrieval. Evidence from these experiments suggests a role for KIBRA in human memory.     

Fecal Indicator and Pathogen Reduction in Vegetation Microcosms

Municipal wastewater has been applied as a fertilizer to coniferous forest in northern Sweden with the additional aims to purify the wastewater and reduce the treatment costs. This practice has the potential to introduce pathogenic microorganisms from the applied wastewater or sludge to the environment, with a subsequent risk of transmission to exposed humans or animals. Seasonality and climatological conditions, in particular low temperature, humidity and low sun intensity will furthermore affect the persistence of pathogens in the forest in northern Scandinavia and may therefore enhance the survival and thereby the exposure risk. The survival of two pathogens (Salmonella senftenberg and Campylobacter coli) and four fecal indicator organisms; bacteria strains (E. coli and E. fecalis) and bacteriophages (S. typhimurium phage 28 B and ?x174), used here as viral models, was evaluated in microcosms (60 Litre terrariums) with two vegetation regimes (characterized as moss and lichen) at selected temperatures (+3^?C to +27^?C) and artificial light exposure (light and dark). Salmonella persisted in high numbers after 35 days in the vegetation, indicating a potential risk for further transmission. Neither the vegetation regime nor temperature or light exposure as independent factors governed the reduction of the indicator bacteria and the bacteriophages. The persistence of the indicator organisms was generally best supported in the moss vegetation at low temperature in the dark, where the time for a 90% reduction (T₉₀) was in the range from 8 days (E. coli) to 31 days (Salmonella phage). The die-off characteristics found in this study provide baseline values for further validations in the field and verify that the purification and reuse of municipal wastewater in coniferous forest could potentially be responsible for transmission of fecal pathogens to humans and animals.     

Entwicklung und gestaltung gehölzreicher weidelandschaften auf reliefiertem niedermoor

Die drastische Reduzierung der Besatzstärke an Rindern auf 0,5–1 GV/ha LF nach der politischen Wende in Ostdeutschland schafft interessante Möglichkeiten der Neugestaltung von Weiden. Um stärker und gleichmäßiger wechselnde Aufenthaltsplätze in der Fläche zu induzieren, könnten Extensivweiden in einer Art aufgelockerter Parklandschaft gestaltet werden. Die Eignung verschiedener Baum‐ und Straucharten für Niedermoore wurde in der Forschungsstation Paulinenaue, nordwestlich von Berlin, analysiert.

Untersuchungen zeigten, daß zukünftig insbesondere ausländische Rinderrassen vor zu starker UV‐Belastung geschützt werden sollten. Die heutigen ausgeräumten Weidelandschaften bieten nicht genügend Schatten und auch nicht ausreichend Windund Wetterschutz während des Winters. Die Entwicklung von vielfältig strukturierten Weiden verbessert das Wohlbefinden der Tiere als auch die Biodiversität des gesamten Ökosystems. Die Landschaft gewinnt durch die Variation von Landschaftselementen, der Stoffkreislauf wird geregelter und die Akzeptanz für den ländlichen Raum in der Bevölkerung steigt.     

Implications of soil substrate and land use for properties of fen soils in North-East Germany Part III: Soil quality for grassland use

Abstract

The aim of the study was to analyse aspects of fen soil quality for grassland use with regard to the different topsoil structure and their status of earthification/moorshification (degradation). Fifty fens of different origin, structural status and land use intensity were sampled, analysed and scored by different methods: Visual Soil Assessment, Peerlkamp test and Muencheberg Soil Quality Rating. Suitable soil structure scores were found at different land use intensities with the exception of stock tracks on pastures. These had lower water and air permeability and lower soil strength. Highest visual scores of macrostructure were found where the water table was deeper; while highest overall soil quality scores occurred where the water table was optimum. The accelerated status of moorshification had no effect on the soil quality scores and on the crop yield. At lower levels of soil development (earthification) the crop yield was slightly lower due to higher proportions of inedible plants. It may be concluded that degraded peat soils will have no loss of soil quality and have relatively high soil quality for grassland use if the water table can be managed in a suitable range and the sward quality is maintained.     

Variation in phenotypic characters of pale flax (<Emphasis Type="Italic">Linum bienne</Emphasis> Mill.) from Turkey

The diversity of pale flax (Linum bienne Mill.) as the progenitor of cultivated flax (L. usitatissimum L.) has not been well documented and the domestication syndromes in cultivated flax are poorly understood. An attempt was made to characterize 34 pale flax accessions and six cultivated flax accessions collected during 2007 summer in Turkey. A total of 12 quantitative and 7 qualitative characters covering vegetative and generative plant parts, including phenological traits, were assessed. The occurrence of yellow anthers well known in cultivated flax is reported for the first time in pale flax. Pale flax displayed larger variation in vegetative plant parts and growth habit than the cultivated flax and more heterogeneity within accessions. Within pale flax, a higher degree of variation was observed in many generative parts such as the flower characters than in the capsule and seed characters. Based on the assayed characters, the pale flax from Turkey was grouped into three clusters and these clusters were associated with site elevation and longitude, further confirming local genetic differentiation in pale flax from Turkey. These findings are significant for further studies of flax domestication history and useful for further exploitation of wild flax in genetic improvement of cultivated flax.     

Progesterone and pregnanediol-glucuronid concentrations in saliva, milk and urine of female alpacas and their application in pregnancy diagnosis

The objective of the present study was the measurement of the pregnancy associated hormones progesterone (P4) and pregnanediol-glucuronide (PdG) in saliva, milk and urine of alpacas and their potential use in pregnancy diagnosis. Sample of blood, saliva, milk and urine were obtained from 36 female alpacas before mating and throughout the pregnancy. Concentrations of P4 and PdG were determined using an enzyme immunoassay (EIA). Pregnancy was checked by ultrasonography at any sampling time. The milk samples were also tested using a commercial on-farm progesterone kit which was designed for dairy cattle. EIA-Concentrations of P4 in blood, milk and urine and urine PdG concentrations were significantly higher in pregnant than in not pregnant alpacas. There was no difference in concentrations of P4 or PdG in saliva. The accuracy of the progesterone kit was 90% for diagnosis of pregnancy and 69% for non-pregnancy. However, 70% of the false positive results also showed relatively high P4 milk concentrations in the EIA. Values of P4 in blood and PdG in urine are comparable to previous reports in alpacas and therefore can be confirmed as an indicator for pregnancy. Saliva seems unsuitable in pregnancy diagnosis in alpacas, whereas milk seems to be an adequate alternative. The use of milk and urine would simplify the pregnancy diagnosis in alpacas since in contrast to the current methods (e. g. blood progesterone) the owners can take the samples. The avoidance of blood sampling results in a considerable stress reduction for the animals. P4 measurement in milk and PdG measurement in urine are good alternatives in pregnancy diagnosis during the first month of pregnancy, when a trans-abdominal ultrasonographic examination is not yet reliable. However, since high values of P4 and PdG only show the presence of active luteal tissue and therefore are indirect markers of pregnancy the diagnosis should be confirmed using ultrasound later in pregnancy.     

Effect of adjacent agricultural habitat on the distribution of passerines in natural grasslands

Habitat heterogeneity has often been acknowledged as a key factor determining which species occur in a landscape, but we still know little on the nature and relative importance of the processes controlling species distribution and abundance within complex landscape mosaics. We used a framework defined by the compensation, supplementation and complementation models to study the distribution of four species of passerines typical of steppe habitats and identify the degree to which landscape context accounts for their distribution in the steppe-agriculture mosaic of the Crau, southern France. Steppe habitat was the best predictor of species distribution in all cases and that densities were highest in steppe. One of these species, the Calandra lark, is strictly tied to the natural steppe habitats independently of its context. For another species, the Tawny pipit, we document a significant positive effect of the presence, near steppe habitat, of extensive pastoral habitats, such as fallows and grazed crops. Finally, the abundance of the two remaining species, Skylark and Short-toed lark, was negatively affected by the presence of non-herbaceous habitats in the vicinity of steppe habitat. This suggests that the quality of the steppe habitat, as perceived by these species is conditional to the nature of adjacent habitats. Our results suggest that the management of the context in which steppe habitat is imbedded will significantly affect the distribution and abundance of this group of passerines and determine both habitat quality and conservation value at a landscape scale.