24 resultados para Project of wood
Resumo:
Radiocarbon offers a unique possibility for unambiguous source apportionment of carbonaceous particles due to a direct distinction of non-fossil and fossil carbon. In this work, particulate matter of different size fractions was collected at 4 sites in Switzerland to examine whether fine and coarse carbonaceous particles exhibit different fossil and contemporary sources. Elemental carbon (EC) and organic carbon (OC) as well as water-soluble OC (WSOC) and water-insoluble OC (WINSOC) were separated and determined for subsequent 14C measurement. In general, both fossil and non-fossil fractions in OC and EC were found more abundant in the fine than in the coarse mode. However, a substantial fraction (~20 ± 5%) of fossil EC was found in coarse particles, which could be attributed to traffic-induced non-exhaust emissions. The contribution of biomass burning to coarse-mode EC in winter was relatively high, which is likely associated to the coating of EC with organic and/or inorganic substances emitted from intensive wood burning. Further, fossil OC (i.e. from vehicle emissions) was found to be smaller than non-fossil OC due to the presence of primary biogenic OC and/or growing in size of wood-burning OC particles during aging processes. 14C content in WSOC indicated that the second organic carbon rather stems from non-fossil precursors for all samples. Interestingly, both fossil and non-fossil WINSOC concentrations were found to be higher in fine particles than in coarse particles in winter, which is likely due to primary wood burning emissions and/or secondary formation of WINSOC.
Resumo:
The presence of soluble carbohydrates in the cambial zone, either from sugars recently produced during photosynthesis or from starch remobilized from storage organs, is necessary for radial tree growth. However, considerable uncertainties on carbohydrate dynamics and the consequences on tree productivity exist. This study aims to better understand the variation in different carbon pools at intra-annual resolution by quantifying how cambial zone sugar and starch concentrations fluctuate over the season and in relation to cambial phenology. A comparison between two physiologically different species growing at the same site, i.e., the evergreen Picea abies Karst. and the deciduous Larix decidua Mill., and between L. decidua from two contrasting elevations, is presented to identify mechanisms of growth limitation. Results indicate that the annual cycle of sugar concentration within the cambial zone is coupled to the process of wood formation. The highest sugar concentration is observed when the number of cells in secondary wall formation and lignification stages is at a maximum, subsequent to most radial growth. Starch disappears in winter, while other freeze-resistant non-structural carbohydrates (NSCs) increase. Slight differences in NSC concentration between species are consistent with the differing climate sensitivity of the evergreen and deciduous species investigated. The general absence of differences between elevations suggests that the cambial activity of trees growing at the treeline was not limited by the availability of carbohydrates at the cambial zone but instead by environmental controls on the growing season duration.
Resumo:
The technical definition of ‘wood’ is well accepted, but its botanical understanding remains vague. Different degrees and amounts of lignification in plants and their imprecise description, together with a conceptually doubtful life form catalog including trees, shrubs and herbs further complicate our understanding of ‘wood’. Here, we use permanent micro sections to demonstrate that the xylem and bark of terrestrial plants can vary from one tissue with a few lignified cells to an almost fully lignified tissue. This universal principle of plant growth and stabilization, accounting for all taxonomic units within vascular plants, suggests that the classical life form separation into herbs, shrubs and trees is not valid. An anatomical-based differentiation between ‘wood’, ‘woody’ and ‘woodiness’ is also only meaningful if supplemented by insight on the particular plant section and its lignified proportion. We therefore recommend utilizing the botanically more neutral term ‘stem anatomy’ instead of ‘wood anatomy’, which further implies integration of the xylem and bark of all terrestrial plants. Since dendrochronology considers shrubs, dwarf shrubs and perennial herbs in addition to trees, its semantic expansion toward ‘xylemchronology’ might be worthwhile considering.
Resumo:
Cultural protectionism has been an element of national and foreign policies, as an extension of state sovereignty expressed both in a defensive and offensive manner. While the generic protectionist formula in the sense of restraining trade between states through measures such as import tariffs or quotas and through privileging domestic production has somewhat disintegrated over time under the rationale for free trade and the strong practical evidence of its benefits, the particular case of cultural protectionism has persevered. As we reveal in this paper, however, it has been modified, or at least its rhetoric has changed. The enquiry into the notion of cultural protectionism or cultural diversity, as the current political jargon would have it, is but one of the paper’s objectives. Its second and certainly more ambitious goal is the search for the normative dimensions of cultural diversity policies in the global digital space, asking what adjustments are needed and how feasible the entire project of diversity regulation in this environment may be. Taking into account the specificities of cyberspace and in a forward-looking manner, we propose some adjustments to current media policy practices that could better serve the goal of a sustainably diverse cultural environment.
Resumo:
This article traces the history of a group of Zambian broadcasters who established the first radio station in the country and made their mark on broadcasting for years to come. It describes their contribution to modern Zambian culture and to nationalist mobilisation. African broadcasters developed formats, ways of presenting and choices of music that appealed to Zambian listeners and established new, authentically local styles. While radio quickly established itself as an integral part of everyday life and culture in the colony, its effect was highly ambivalent. Broadcasters at the same time undermined and enforced the colonial project of using the medium as a transmitter of modernisation ideology. The article explores Thomas Turino’s characterisation of this team as ‘cosmopolitans’ and shows how they were influenced by BBC ideas of journalism and modernisation ideology. To do so, it analyses the relationships African broadcasters had with Europeans in senior positions and with colonial and postcolonial governments. This shared value system brought these Zambian broadcasters into conflict with the post-independence government and its plans to bureaucratise radio, despite their nationalist commitment and strong support for the United National Independence Party (UNIP) before independence.
Resumo:
Over the last decade European democracies have been facing a challenge by the rising force of new populist movements. The emergence of the financial and sovereign debt crisis in Europe created new fertile soil for the strengthening of old-established – and the development of new – populist parties in several EU-member states. José Manuel Barroso, president of the European Commission, emphasized his increased unease concerning these developments when he was speaking at the annual Brussels Think Tank Forum on 22. April 2013: “I am deeply concerned about the divisions that we see emerging: political extremes and populism tearing apart the political support and the social fabric that we need to deal with the crisis; […]” (Barroso 2013). Indeed, European elites seem to be increasingly worried by these recent developments which are perceived as an impending stress test of the Union and the project of European integration as a whole (Hartleb 2013). Sure enough, the results of the recent European Parliament Elections 2014 revealed a great support for populist political parties in many societies of EU-member countries. To understand the success of populist parties in Europe it is crucial to first shed light on the nature of populist party communication itself. Significant communicative differences may explain the varying success of populist parties between and within countries, while a pure demand-side approach (i.e. a focus on the preferences of the electorate) often fails to do so (Mudde 2010). The aim of this study is therefore to analyse what different types of populist communication styles emerge during the EP election campaign 2014 and under which conditions populist communication styles are selected by political parties. So far, the empirical measurement of populism has received only scarce attention (Rooduijn & Pauwels 2011). Besides, most of the existing empirical investigations of populism are single case studies (Albertazzi & McDonnell 2008) and scholars have not yet developed systematic methods to measure populism in a comparative way (Rooduijn & Pauwels 2011). This is a consequence of a lack of conceptual clarity which goes along with populism (Taggart 2000; Barr 2009; Canovan 1999) due to its contextual sensitivity. Hence, populism in Europe should be analysed in a way that clarifies the concept of populism and moreover takes into account that the Europeanization of politics has an influence on the type of populist party communication, which is intended in the course of that study.
Resumo:
Epixylic bryophytes are important components of forest vegetation but are currently endangered by increment of wood harvest and intensive forest management. In this paper we present a study about the relationship between forest management, deadwood abundance, deadwood attributes and species richness of epixylic bryophytes on 30 plots comprising three forest types (managed coniferous, managed deciduous and unmanaged deciduous forests) in three regions in Germany. Additionally we analyzed the relations between deadwood attributes (wood species, decay, deadwood type, size) and bryophytes on deadwood items (n = 799) and calculated species interaction networks of wood species and bryophytes. Overall, species richness of epixylic bryophytes was positively related to deadwood abundance and diversity. The mean deadwood abundance was lowest in unmanaged forests (9.7 m3 ha-1) compared with 15.0 m3 ha-1 in managed deciduous and 25.1 m3 ha-1 in managed coniferous forests. Accordingly, epixylic bryophyte species richness per plot increased from 7 species per 400 m 2 in unmanaged, 10 in managed deciduous and 16 in managed coniferous forests. The interaction network provided evidence of importance of tree-species diversity for bryophyte diversity and the relevance of particular wood species for rare bryophytes.
Generally, the results demonstrate a considerable lack of deadwood in all forest types, even in unmanaged forests. Species richness of epixylic bryophytes was strongly limited by available substrates within the observed deadwood abundance ranging up to only 60 m3 ha-1. Altogether, this suggests a high demand to increase both abundance and diversity of deadwood in forests.
Resumo:
Many things have been said about literature after postmodernism, but one point there seems to be some agreement on is that it does not turn its back radically on its postmodernist forerunner, but rather generally continues to heed and value their insights. There seems to be something strikingly non-oedipal about the recent aesthetic shift. It is a project of reconstruction that remains deeply rooted in postmodernist tenets. Such an essentially non-oedipal attitude, I would argue, is central to the nature of the reconstructive shift. This, however, also raises questions about the wider cultural context from which such an aesthetic stance arises. If postmodernism was nurtured by the revolutionary spirits of the late 1960s, reconstruction faces a different world with different strategies. Instead of the postmodernist urge to subvert, expose and undermine, reconstruction yearns towards tentative and fragile intersubjective understanding, towards responsibility and community. Instead of revolt and rebellion it explores reconciliation and compromise. One instance in which this becomes visible in reconstructive narratives is the recurring figure of the lost father. Missing father figures abound in recent novels by authors like Mark Z. Danielewski, Dave Eggers, Yann Mantel, David Mitchell etc. It almost seems like a younger generation is yearning for the fathers which postmodernism has struggled hard to do away with. My paper will focus on one particularly striking example to explore the implications of this development: Daniel Wallace’s novel Big Fish and Tim Burton’s well-known film adaptation of the same. In their negotiation of fact and fiction, of doubt and belief, of freedom and responsibility, all of which converge in a father-son relationship, they serve well to illustrate central characteristics and concerns of recent attempts to leave postmodernism behind.
Resumo:
Eight species of wood-inhabiting basidiomycetes (Laurilia sulcata, Peniophora aurantiaca, Resinicium bicolor, Scytinostroma galactinum, Terana caerulea, Trichaptum abietinum, T. biforme and T. fuscoviolaceum) were used in a spore-trapping test to evaluate their individual ability for long-distance spore dispersal. Petri dishes with single spore mycelia were used as baits. In the experiment, carried out at the Botanical Institute in Göteborg, spores from the air were regularly captured. Surprisingly, spores were captured from species whose nearest known natural occurrence was located quite far from Göteborg. The closest population of Peniophora aurantiaca is about 1000 km south of Göteborg. The results from this experiment support the hypothesis that fungal spores are widely and efficiently dispersed. Such a broad and extensive dispersal ability is of vital importance, especially for wood-inhabiting species which are highly dependent on a substrate which is onlv temporarily available.