Tropospheric ozone (O3) is a secondary atmospheric pollutant, generated from oxides of nitrogen and volatile organic compounds reacting in the presence of sunlight. It has been recognized as an ...increasing and damaging agent to plants (Karnosky et al. 2005). The effects of O3 on plant growth and development at different structural and functional levels of the aboveground parts have been studied extensively (Matyssek and Sandermann 2003), while the relative inaccessibility of plant roots and mycorrhiza has hampered efforts to understand effects of O3 below ground (Andersen 2003; Schloter et al. 2005). O3 triggers physiological changes in leaves that affect carbon source strength, i.e., the amount of carbon available for allocation to sink tissues. Decreased carbon assimilation, increased metabolic costs for repair mechanisms, and decreased phloem loading, all lead to decreased carbon allocation below ground, thus affecting roots, root symbionts, rhizodeposition, litter quality and quantity, and consequently the whole soil food web (Andersen 2003).
Forest soils are the major stocks of organic carbon in terrestrial ecosystems.The dynamics of carbon in soil is closely related to soil (micro)organisms, predominantly symbiotic organisms. Key ...symbionts in forest soils regarding their taxonomic and functional diversity are ectomycorrhizal fungi. In the present study, we have analysed ectomycorrhizal community in beech dominated forest stands using morphological and molecular identification of ectomycorrhizae. Several new types were discovered and briefly described in soil samples taken in beech forest stands, down to 20 cm deep. Based on ectomycorrhizal type abundance, we have calculated the (static)content of total carbon in each of the type. Quantities of carbon stored in ectomycorrhizae were compared with modelled quantities of total carbon in forest soils. We summarise the role and importance of ectomycorrhizae for carbon dynamics in beech dominated forest ecosystems.
Presents an abridged report on the results of research conducted as a part of the Harm Reduction Phare Project at the U of Ljubljana School of Social Work in Slovenia. The bulk of the material on ...which this report is based consists of interviews with users, often in their own words: the project's methodology, data processing, & final report consistently take into account the users' perspective. Results are used to construct a portrait of users & map their practices in different regions of Slovenia. Main topics include knowledge & perception of drug use in the wider community; accessibility of drugs; geographical placement of drug users; & characteristics of drug-using groups in terms of health issues, violence, employment, accommodation, contacts with relatives, peer groupings, career, drug dealing, risks of injecting & overdose, sex & drugs, prostitution, & evaluation of services. The research is unique in its focus on the social aspects of harm reduction. 1 Map, 16 References. Adapted from the source document.
Ectomycorrhizal fungi are of main significance for establishment, growth and survival of most trees in temperate and boreal forests. Mycelium of ectomycorrhizal fungi presents the main component of ...forestry ecosystems which links biotic with abiotic factors. Since ectomyocrrhizae are significant and beneficial for their host, the aim of this work was to describe and identify types of ectomycorrhizae in selected white poplar (Populus alba L.) stand in vicinity of Novi Sad, Vojvodina (Serbia). Identification of fungal partner in ectomycorrhiza was done by combining morphological and anatomical characters with molecular methods (RFLP and sequencing of ITS regions in ribosomal DNK). Six types of ectomycorrhizae were observed. They were photographed and described according to morphological, anatomical and molecular characteristics. Two fungal partners were identified to the species level: Tuber rufum and Inocybe squamata, two to the genus level: Tomentella sp. and Inocybe sp., the last two fungi were determinated as members of families Cortinariaceae and Thelephoraceae. Further research is needed in order to achieve better insight into diversity and richness of ectomycorrhizal fungi that leave on white poplars.
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