Calcicole plant diversity in Switzerland may reflect a variety of habitat templets

The study of the disparity concerning the sizes of calcicole and calcifuge floras in Central Europe is a surprisingly young scientific branch. Accordingly, explanations of the patterns have not yet been consolidated. In this paper, we comment on the solution of the "calcareous riddle' proposed by JörgEwald (Folia Geobot. 38: 357-366, 2003). On the basis of flora and vegetation data bases, we tested the phenomenon of calcicole richness by analyzing the forest vegetation and the flora of Switzerland and found corresponding patterns. A clear overbalance of calcareous forest habitats contrasts with an overbalance of acidic topsoils, as derived from a large representative sample in Swiss forests. Calcicole/calcifuge ratios reveal an overbalance of calcicoles in most mapping units of the distribution atlas of vascular plants in Switzerland. Central crystalline parts of the Alps, however, show a clear overbalance of calcifuges. Patterns from the different community and regional scales are explained by (micro-)habitat diversity. With respect to the "calcareous riddle”, we question several assumptions, e.g. the time considered before the Pleistocene bottleneck, the area considered for speciation/extinction, and the role of habitat diversity rather than two substrate classe

Ethical and social issues of personalized medicine

A medicina personalizada tem como objetivo integrar a informação genética do indivíduo, os fatores ambientais a que este está exposto e o seu estilo de vida para identificar a sua predisposição à doença e as medidas preventivas, de promoção da saúde e terapêuticas que lhe serão mais eficazes ou que evitem reações adversas. As doenças raras, a oncologia e a farmacogenómica são áreas onde se tem assistido a avanços da medicina personalizada. Embora, na sua conceção, este modelo de medicina cumpra os princípios éticos da beneficência e da não-maleficência, cria alguns desafios éticos e sociais. Serão abordadas algumas questões relativas à privacidade e confidencialidade dos dados pessoais, ao seu potencial para a discriminação e estigmatização, ao consentimento informado para investigação e diagnóstico genético, à maior necessidade de literacia em saúde, à mudança na relação médico-doente e, principalmente, questões de justiça distributiva e equidade em saúde.Personalized medicine aims to integrate the genetic variabilit y of each person with environmental and lifest yle factors to bet ter identif y individual predisposition to disease and the most ef fective preventive, health promotion and therapeutic measures for that individual. Rare diseases, oncology and pharmacogenomics have witnessed the greatest advances in personalized medicine. Although this model of medicine, in its concept, complies with the ethical principles of beneficence and nonmaleficence, it also creates ethical and social challenges. Herein, it will be discussed questions related to the personal data confidentialit y and privacy, its potential for discrimination and stigmatization, the informed consent for genetic research and genomic medicine, the need for health literacy, the change in physician-patient relationship, and the challenges regarding distributive justice and health equit y.info:eu-repo/semantics/publishedVersio

Erstnachweis der Verworrenen Armleuchteralge für Sachsen-Anhalt

Trotz ihres auffälligen, an Schachtelhalme oder Hornkraut erinnernden Erscheinungsbildes bleibt die Gruppe der Armleuchteralgen (Characeae) vielfach unbeachtet. Dabei liefert sie wichtige Hinweise zur Beurteilung des Erhaltungszustandes von Gewässern und zur Bewertung ihrer naturschutzfachlichen Bedeutung. Die Armleuchteralgen sind habituell auch mit bloßem Auge leicht erkennbar und eine streng in sich geschlossene Artengruppe. Neuere deutschsprachige Bestimmungsschlüssel liefern KRAUSE (1976, 1997), ROTHMALER (1984) und VAHLE (1990). Angaben zu den Standortansprüchen der Arten findet man unter anderem bei KRAUSE (1997), SCHMIDT et al. (1996) und VAHLE (1990)

Translational sensitivity of the Escherichia coli genome to fluctuating tRNA availability

The synthesis of protein from messenger RNA during translation is a highly dynamic process that plays a key role in controlling the efficiency and fidelity of genome-wide protein expression. The availability of aminoacylated transfer RNA (tRNA) is a major factor influencing the speed of ribosomal movement, which depending on codon choices, varies considerably along a transcript. Furthermore, it has been shown experimentally that tRNA availability can vary signifi-cantly under different growth and stress conditions, offering the cell a way to adapt translational dynamics across the genome. Existing models of translation have neglected fluctuations of tRNA pools, instead assuming fixed tRNA availabilities over time. This has lead to an incomplete under-standing of this process. Here, we show for the entire Escherichia coli genome how and to what extent translational speed profiles, which capture local aspects of translational elongation, respond to measured shifts in tRNA availability. We find that translational profiles across the genome are affected to differing degrees, with genes that are essential or related to fundamental processes such as transla-tion, being more robust than those linked to regula-tion. Furthermore, we reveal how fluctuating tRNA availability influences profiles of specific sequences known to play a significant role in translational control of gene expression

Land-use and climate change effects in forest compositional trajectories in a dry Central-Alpine valley

• Increased mortality of Scots pine (Pinus sylvestris L.) and spreading of deciduous trees are observed in the Swiss Rhone valley. Previous research identified climate change effects as main drivers of this trend. On the local scale, we hypothesize that legacies from past anthropogenic disturbances are superimposed on climate effects. • We reconstructed land-use history and quantified changes in tree species composition from 1930 to 1994 on 9468 ha of forested land. The aim was to analyze the contribution of anthropogenic disturbances to the observed changes and to disentangle human impact from climate change effects. • At altitudes below 1 200 m a.s.l. we found a shift from pine (−11.4%) to deciduous trees (+11%) with significantly lower increase of deciduous trees in stands formerly used for grazing and/or litter collecting. Conversely, pine decrease was not correlated with former anthropogenic disturbances. We interpret pine mortality as an effect of increased drought stress due to climate change while spread of deciduous trees is driven by land-use change. Grazing and litter collecting hindered deciduous tree regeneration and it was not until their abandonment a few decades ago that forest composition started to change. At higher elevations the shift from Norway spruce (Picea abies; −8.5%) to European larch (Larix decidua; +8.2%) corresponds to silvicultural management schemes, aimed at promoting larch recruitment. • Our study illustrates the importance of disentangling climate from land-use change effects for understanding shifts in forest composition. The findings are relevant for other regions in the European Alps where forests undergo comparable environmental change

Impacts of salvage-logging on the status of deadwood after windthrow in Swiss forests

Downed and standing deadwood (DW) is a key resource for maintaining forest biodiversity. Although extreme events such as windthrow and fires produce large quantities of DW, this substrate is often drastically reduced by logging activities. To elucidate the respecting consequences of salvage-logging, we assessed both quantity and quality of storm-derived DW (storms Vivian 1990 and Lothar 1999) in Swiss forests using a sample of 90 windthrow sites with ≥3ha complete windthrow and at elevations ranging from 350 to 1,800m a.s.l. The majority had been salvage-logged (SL) a few years after the windthrow. On each site, we recorded DW amount and quality on six circular sample plots 20 or 50m2 in size. DW volume on SL sites was surprisingly high, with 76.4m3 ha−1 on average 20years after Vivian and 73.8m3 ha−1 10years after Lothar. In comparison, DW volumes on unsalvaged sites, that is, with no post-windthrow intervention (NI), amounted to 270m3 ha−1. A wide variety of wood decay stages and diameter classes (10 to ≥70cm) was found on both NI and SL sites, suggesting considerable habitat diversity for DW-associated species irrespective of the treatment. The considerable amounts of DW left after salvage-logging distinctly exceed the minimum DW volumes in forest stands proposed by Müller and Bütler (Eur J For Res 129: 981-992, 2010) in a conservation context, which demonstrates the importance of wind disturbance for biodiversity. Further studies should quantify DW of individual tree species, since habitat requirements are species-specifi

Ground vegetation monitoring in Swiss forests: comparison of survey methods and implications for trend assessments

At Swiss long-term forest ecosystem research sites, ground vegetation was assessed during the period 1994-2003/2008 following two approaches: (1) visual assessment of the cover of species occurring in sixteen 1m2 quadrats, distributed over a 43 × 43m area, and (2) phytosociological relevés in concentric circular plots of 30, 200, and 500m2. We first compared the two approaches with respect to diversity assessment. The number of species recorded in the 16 quadrats was in general higher than in the 30m2 plot and it represented 42% to 108% of the number of species recorded in the 500m2 plot. In a second step, we tested whether any temporal trends were apparent. In a few cases, a decrease or increase in Landolt's mean indicator values for light, nitrogen availability, soil pH, soil moisture, or temperature was found to be significant. However, these changes were usually restricted to one approach or one area. The only clear trend was detected in an unmanaged former coppice beech stand, for which all survey approaches indicated canopy closure. At another site, vegetation reacted to the local opening of the canopy following windthrow. In a third step, we compared the leaf area index (LAI), measured with an LAI-2000 instrument (Licor, Inc.) over each quadrat, with the indicator value of the vegetation for light (L). Within a site, there was no clear relationship between LAI and L values per quadrat. In contrast, across all sites, the relationship between LAI and L, averaged per site for all available years, was highly significan

Ectomycorrhiza succession patterns in Pinus sylvestris forests after stand-replacing fire in the Central Alps

Fires shape fundamental properties of many forest ecosystems and climate change will increase their relevance in regions where fires occur infrequently today. In ecosystems that are not adapted to fire, post-fire tree recruitment is often sparse, a fact that might be attributed to a transient lack of mycorrhizae. Ectomycorrhizal (EcM) fungi play an important role for recruitment by enhancing nutrient and water uptake of their hosts. The questions arise whether and for how long the EcM community is transformed by fire. We investigated the resistance and resilience of EcM fungal communities on a chronosequence of 12 Pinus sylvestris stands in Valais (Switzerland) and Val d'Aosta (Italy) affected by fire between 1990 and 2006. Soil samples from burnt and non-burnt forests were analyzed with respect to EcM fungi by means of a bioassay. The number of EcM species was significantly lower in samples from recently (2-5years) burnt sites than non-burnt forest, and increased with time since fire reaching levels of adjacent forests after 15-18years. Community composition changed after fire but did not converge to that of non-burnt sites over the 18year period. Only Rhizopogon roseolus and Cenococcum geophilum were abundant in both burnt sites and adjacent forest. Our data indicate fire resistance of some EcM fungal species as well as rapid resilience in terms of species number, but not in species composition. As long as the function of different EcM species for seedling establishment is unknown, the consequences of long-term shifts in EcM community composition for tree recruitment remain unclea