11 resultados para Stand Management

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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Genomic variations influencing response to pharmacotherapy of pain are currently under investigation. Drug-metabolizing enzymes represent a major target of ongoing research in order to identify associations between an individual's drug response and genetic profile. Polymorphisms of the cytochrome P450 enzymes (CYP2D6) influence metabolism of codeine, tramadol, hydrocodone, oxycodone and tricyclic antidepressants. Blood concentrations of some NSAIDs depend on CYP2C9 and/or CYP2C8 activity. Genomic variants of these genes associate well with NSAIDs' side effect profile. Other candidate genes, such as those encoding (opioid) receptors, transporters and other molecules important for pharmacotherapy in pain management, are discussed; however, study results are often equivocal. Besides genetic variants, further variables, for example, age, disease, comorbidity, concomitant medication, organ function as well as patients' compliance, may have an impact on pharmacotherapy and need to be addressed when pain therapists prescribe medication. Although pharmacogenetics as a diagnostic tool has the potential to improve patient therapy, well-designed studies are needed to demonstrate superiority to conventional dosing regimes.

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Lichens are a key component of forest biodiversity. However, a comprehensive study analyzing lichen species richness in relation to several management types, extending over different regions and forest stages and including information on site conditions is missing for temperate European forests. In three German regions (Schwäbische Alb, Hainich-Dün, Schorfheide-Chorin), the so-called Biodiversity Exploratories, we studied lichen species richness in 631 forest plots of 400 m2 comprising different management types (unmanaged, selection cutting, deciduous and coniferous age-class forests resulting from clear cutting or shelterwood logging), various stand ages, and site conditions, typical for large parts of temperate Europe. We analyzed how lichen species richness responds to management and habitat variables (standing biomass, cover of deadwood, cover of rocks). We found strong regional differences with highest lichen species richness in the Schwäbische Alb, probably driven by regional differences in former air pollution, and in precipitation and habitat variables. Overall, unmanaged forests harbored 22% more threatened lichen species than managed age-class forests. In general, total, corticolous, and threatened lichen species richness did not differ among management types of deciduous forests. However, in the Schwäbische-Alb region, deciduous forests had 61% more lichen species than coniferous forests and they had 279% more threatened and 76% more corticolous lichen species. Old deciduous age classes were richer in corticolous lichen species than young ones, while old coniferous age-classes were poorer than young ones. Overall, our findings highlight the importance of stand continuity for conservation. To increase total and threatened lichen species richness we suggest (1) conserving unmanaged forests, (2) promoting silvicultural methods assuring stand continuity, (3) conserving old trees in managed forests, (4) promoting stands of native deciduous tree species instead of coniferous plantations, and (5) increasing the amount of deadwood in forests.

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Für die an der SWX kotierten Unternehmen besteht seit dem 1. Juli 2005 die Pflicht, Transaktionen in Bezug auf Beteiligungsrechte des Emittenten, welche Angehörige von dessen Management durchführen, der SWX anzuzeigen. In einem ersten Schritt wird die Bedeutung dieser spezifischen Offenlegungspflicht im Zusammenhang sonstiger Ad-hoc-Publizitätspflichten sowie im weiteren Kontext von Corporate Governance erörtert; anschliessend werden Geltungsgrund und normative Reichweite der schweizerischen Regelung vor dem Hintergrund vergleichbarer Regelungen im europäischen Ausland und in den USA analysiert. Abschliessend wird kritisch hinterfragt, ob sich die Verpflichtung zur Offenlegung von Director's Dealings tatsächlich durch die Signal- oder Indikatorfunktion rechtfertigen lässt.

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There is a wealth of smaller-scale studies on the effects of forest management on plant diversity. However, studies comparing plant species diversity in forests with different management types and intensity, extending over different regions and forest stages, and including detailed information on site conditions are missing. We studied vascular plants on 1500 20 m × 20 m forest plots in three regions of Germany (Schwäbische Alb, Hainich-Dün, Schorfheide-Chorin). In all regions, our study plots comprised different management types (unmanaged, selection cutting, deciduous and coniferous age-class forests, which resulted from clear cutting or shelterwood logging), various stand ages, site conditions, and levels of management-related disturbances. We analyzed how overall richness and richness of different plant functional groups (trees, shrubs, herbs, herbaceous species typically growing in forests and herbaceous light-demanding species) responded to the different management types. On average, plant species richness was 13% higher in age-class than in unmanaged forests, and did not differ between deciduous age-class and selection forests. In age-class forests of the Schwäbische Alb and Hainich-Dün, coniferous stands had higher species richness than deciduous stands. Among age-class forests, older stands with large quantities of standing biomass were slightly poorer in shrub and light-demanding herb species than younger stands. Among deciduous forests, the richness of herbaceous forest species was generally lower in unmanaged than in managed forests, and it was even 20% lower in unmanaged than in selection forests in Hainich-Dün. Overall, these findings show that disturbances by management generally increase plant species richness. This suggests that total plant species richness is not suited as an indicator for the conservation status of forests, but rather indicates disturbances.

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Der Beitrag gibt einen Überblick über den Stand der Forschung zur staatlichen Gründungsfinanzierung, speziell in Deutschland. Dabei steht die Frage im Vordergrund, ob eine öffentliche Gründungsfinanzierung aus wirtschaftspolitischer Sicht zu rechtfertigen ist. Konkret werden vier Forschungsfragen untersucht. Die erste Frage lautet, ob Unternehmensgründungen für eine Wirtschaft überhaupt Nutzen stiften. Die zweite Frage lautet, ob auf dem Markt der Finanzierung von Gründungsunternehmen Unvollkommenheiten bzw. Marktversagen feststellbar sind. Die dritte Frage lautet, ob staatliche Maßnahmen der Gründungsfinanzierung einzelwirtschaftlich effektiv sind, dass sich also geförderte Unternehmen als erfolgreicher erweisen als nicht geförderte. Die vierte Frage lautet, ob eine staatliche Gründungsfinanzierung die angestrebten wirtschaftspolitischen Ziele zu den niedrigstmöglichen Kosten erreicht, also effizient ist. Die Antworten sind durchweg negativ und zeigen, dass die bisherige Forschung keine ausreichende Rechtfertigung für eine staatliche Gründungsfinanzierung bieten kann.

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Forest management is known to influence species diversity of various taxa but inconsistent or even contrasting effects are reported for arthropods. Regional differences in management as well as differences in regional species pools might be responsible for these inconsistencies, but, inter-regional replicated studies that account for regional variability are rare. We investigated the effect of forest type on the abundance, diversity, community structure and composition of two important ground-dwelling beetle families, Carabidae and Staphylinidae, in 149 forest stands distributed over three regions in Germany. In particular we focused on recent forestry history, stand age and dominant tree species, in addition to a number of environmental descriptors. Overall management effects on beetle communities were small and mainly mediated by structural habitat parameters such as the cover of forest canopy or the plant diversity on forest stands. The general response of both beetle taxa to forest management was similar in all regions: abundance and species richness of beetles was higher in older than in younger stands and species richness was lower in unmanaged than in managed stands. The abundance ratio of forest species-to-open habitat species differed between regions, but generally increased from young to old stands, from coniferous to deciduous stands and from managed to unmanaged stands. The response of both beetle families to dominant tree species was variable among regions and staphylinid richness varied in the response to recent forestry history. Our results suggest that current forest management practices change the composition of ground-dwelling beetle communities mainly by favoring generalists and open habitat species. To protect important forest beetle communities and thus the ecosystem functions and services provided by them, we suggest to shelter remaining ancient forests and to develop near-to-nature management strategies by prolonging rotation periods and increasing structural diversity of managed forests. Possible geographic variations in the response of beetle communities need to be considered in conservation-orientated forest management strategies.

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Slow growth, branch dieback and scarce acorn yield are visible symptoms of decay in abandoned Quercus pyrenaica coppices. A hypothetical root-to-shoot (R:S) imbalance provoked by historical coppicing is investigated as the underlying driver of stand degradation. After stem genotyping, 12 stems belonging to two clones covering 81 and 16 m2 were harvested and excavated to measure above- and below-ground biomass and nonstructural carbohydrate (NSC) pools. To study root system functionality, root connections and root longevity were assessed by radiocarbon analysis. Seasonality of NSC was monitored on five additional clones. NSC pools, R:S biomass ratio and fine roots-to-foliage ratio were higher in the large clone, whose centennial root system, estimated to be 550 years old, maintained large amounts of sapwood (51.8%) for NSC storage. 248 root connections were observed within the large clone, whereas the small clone showed comparatively simpler root structure (26 connections). NSC concentrations were higher in spring (before bud burst) and autumn (before leaf fall), and lower in summer (after complete leaf expansion); they were always higher in roots than in stems or twigs. The persistence of massive and highly inter-connected root systems after coppicing may lead to increasing R:S biomass ratios and root NSC pools over time. We highlight the need of surveying belowground organs to understand aboveground dynamics of Q. pyrenaica, and suggest that enhanced belowground NSC storage and consumption reflect a trade-off between clonal vegetative resilience and aboveground performance.

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Our knowledge about the effect of single-tree influence areas on the physicochemical properties of the underlying mineral soil in forest ecosystems is still limited. This restricts our ability to adequately estimate future changes in soil functioning due to forest management practices. We studied the stand scale spatial variation of different soil organic matter species investigated by 13C NMR spectroscopy, lignin phenol and neutral sugar analysis under an unmanaged mountainous high-elevation Norway spruce (Picea abies L.) forest in central Europe. Multivariate geostatistical approaches were applied to relate the spatial patterns of the different soil organic matter species to topographic parameters, bulk density, oxalate- and dithionite-extractable iron, pH, and the impact of tree distribution. Soil samples were taken from the mineral top soil. Generally, the stand scale distribution patterns of different soil organic matter compounds could be divided into two groups: Those compounds, which were significantly spatially correlated with topography/altitude and those with small scale spatial pattern (range ≤ 10 m) that was closely related to tree distribution. The concentration of plant-derived soil organic matter components, such as lignin, at a given sampling point was significantly spatially related to the distance of the nearest tree (p ≤ 0.05). In contrast, the spatial distribution of mainly microbial-derived compounds (e.g. galactose and mannose) could be attributed to the dominating impact of small-scale topography and the contribution of poorly crystalline iron oxides that were significantly larger in the central depression of the study site compared to crest and slope positions. Our results demonstrate that topographic parameters dominate the distribution of overall topsoil organic carbon (OC) stocks at temperate high-elevation forest ecosystems, particularly in sloped terrain. However, trees superimpose topography-controlled OC biogeochemistry beneath their crown by releasing litter and changing soil conditions in comparison to open areas. This may lead to distinct zones with different mechanisms of soil organic matter degradation and also stabilization in forest stands.