In this paper the results from a workshop of the OSPAR Intersessional Correspondence Group on Eutrophication Modelling (ICG-EMO) held in Lowestoft in 2007 are presented. The aim of the workshop was to compare the results of a number of North Sea ecosystem models under different reduction scenarios. In order to achieve comparability of model results the participants were requested to use a minimum spin-up time, common boundary conditions which were derived from a wider-domain model, and a set of common forcing data, with special emphasis on a complete coverage of river nutrient loads. Based on the OSPAR requirements river loads were derived, taking into account the reductions already achieved between 1985 and 2002 for each country. First, for the year 2002, for which the Comprehensive Procedure was applied, the different horizontal distributions of net primary production are compared. Furthermore, the differences in the net primary production between the hindcast run and the 50% nutrient reduction runs are displayed. In order to compare local results, the hindcast and reduction runs are presented for selected target areas and scored against the Comprehensive Procedure assessment levels for the parameters DIN, DIP and chlorophyll. Finally, the temporal development of the assessment parameter bottom oxygen concentration from several models is compared with data from the Dutch monitoring station Terschelling 135. The conclusion from the workshop was that models are useful to support the application of the OSPAR Comprehensive Procedure. The comparative exercise formulated specifically for the workshop required models to be evaluated for pre-defined target areas previously classified as problem areas according to the first application of the Comprehensive Procedure. The responsiveness of the modelled assessment parameters varied between different models but in general the parameter showed a larger response in coastal rather than in offshore waters, which in some cases lead to the goal to achieve a non-problem status. Therefore, the application of the Comprehensive Procedure on model results for parameter assessment opens a new potential in testing eutrophication reduction measures within the North Sea catchment. As a result of the workshop further work was proposed to confirm and bolster confidence in the results. One general field of difficulty appeared to be the model forcing with SPM data in order to achieve realistic levels of light attenuation. Finally, effects of the prescribed spin-up procedure are compared against a long-term run over many years and consequences on the resulting initial nutrient concentrations are highlighted.
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The large-scale excavation at the prehistoric site of Tell el-Iswid made it possible to undertake a systematic archaeobotanical study of different structures covering the Predynastic and Early Dynastic period (Lower Egyptian Cultures (Buto II) to Naqada III Culture. Here we present the results of the analysis of carpological remains preserved mostly in charred state and coming from 62 samples processed by manual flotation, with total volume of 615 litres and containing a total of 9672 identifiable and quantifiable items. Further ca. 650 wood fragments (or woody vegetative remains) were subject to anthracological analysis. Besides the aim of overall characterising and exploring the plant economy of the site, the macrobotanical assemblages were also considered in relation to the structures from which they were uncovered. The study revealed that the agricultural economy of both studied periods relied on emmer, barley, lentils, and pea, but from the Early Dynastic times onwards also flax and condiments (like Anethum graveolens and cf. Origanum sp.) played a certain role. Together with the cultivated fields also the surrounding wetlands were an important part of the plant resources utilized at site. The stems of Phragmites are also the most common among the anthracological remains, together with a small proportion of Tamarix and Acacia charcoal fragments. The overall composition of the plant assemblages (charred and mineralised chaff, small weed or wild growing seeds capable to pass the herbivore digestion, dung fragments, awns) suggest that the major source of the retrieved plant remains was dung fuel.
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RBINS Staff Publications 2023 OA
