The Network of Ecological Compensation Areas in Switzerland

Since 1993, the Swiss law and Ordinance on Direct Payments for Agriculture (ODP) enables farmers to be compensated for ecological measures. A catalogue lists different possible measures which can be implemented at farm level both to create space for nature and biodiversity and to generate an alternative income for farmers. Measures include the maintenance of e. g. semi-natural structures in the landscape such as high-stem trees, hedges, pastures and meadows which are not intensively used (detailed catalogue: ART 2009). Succeeding a fast increase in the number of these areas, stagnation has been observed (BIODIVERSITYMONITORING 2009). Additionally, it has become evident, that many compensation areas are in unfavourable conditions for biodiversity and their quality, especially species richness, is low. This motivated the extension of the ODP with an additional ordinance which tackles two main points: Ordinance on Regional Promotion of Quality and Networking of Ecological Compensation Areas in Agriculture (OEQ 2001)

Wildflower strips to reduce lepidopteran pests in cabbage crops

Vegetable production systems are highly intensive and the periodic cultivations lead to un-favourable conditions for natural enemies. Using non-crops it is possible to create ecological infra-structure offering suitable food for natural enemies, and shelter from adverse conditions. On four organic farms in Western-Switzerland, we have tested in cabbage crops if wildflower strips are an appropriate tool to reduce lepidopteran pests. Analyses of wildflower strips on parasitism of caterpillars of Pieris rapae and Mamestra brassicae indicated a pest control potential. Grid trial using reared egg batches revealed no significant effect on parasitism of exposed M. brassicae and Plutella xylostella eggs in relation to the distance of the strip

Anbau transgener Pflanzen – Räumliche Aspekte der Koexistenz

Most of the farmers in Switzerland won’t apply GMO farming. Their organisations support a five-year ban for the marketing of transgenic plants. However, in Switzerland there is no political discussion on co-existence as in the European community and their member states. In this study, the spatial aspects of coexistence of transgenic, conventional and organic farming in Switzerland are investigated. It shows that there are only 28 communities of 2848 where all farmers are bound by different labels to produce GMO-free. Most of these communities are situated in high altitude regions. In contrast, in arable regions of Switzerland, few farmers produce organic crops. In most of the communities in Switzerland, the simultaneous production with and without transgenic plants will be a huge problem. Special attention must be devoted to neighbouring producers all along the national boundary

Jusqu'à quand restera-t-il des aliments non transgénetiques ?

L’Europe entière se demande si les agricultures transgéniques et non trans¬géniques peuvent vivre côte à côte. C’est un débat souvent très théorique, très éloigné du quotidien des agriculteurs. Une étude du FiBL mandatée par le WWF montre ce que l’autorisation des cultures transgéniques signifierait pour les entreprises agricoles suisses

Wie lange gibt es noch gentechfreie Lebensmittel?

Ganz Europa überlegt, ob eine Landwirtschaft mit und eine ohne gentech¬nisch veränderte Pflanzen nebeneinander existieren können. Dabei entsteht viel Theorie, weit weg vom Alltag der Landwirte. Das FiBL klärte im Auftrag des WWF ab, was der Anbau gentechnisch veränderter Pflanzen in der Landwirtschaft für die einzelnen Betriebe bedeuten würde

AIRBORNE EXPOSURE TO POLYCYCLIC AROMATIC HYDROCARBONS (PAHs) AND URINARY EXCRETION OF 1-HYDROXYPYRENE OF CARBON ANODE PLANT WORKERS

Workers in plants producing carbon anodes for aluminium electrolysis are exposed to PAHs containing coal tar pitch volatiles, pitch and coke. The aim of this study was to evaluate the suitability of urinary 1-hydroxypyrene to characterize respiratory exposure to PAH, which is most relevant for assessing individual health risks. Six workers in a carbon anode plant volunteered to take part in a personal air sampling and a biological monitoring programme lasting five consecutive 8-h shifts to determine occupational exposure to airborne PAHs and urinary excretion of l-hydroxypyrene. Exposure to total PAH for all worksites varied from 3.99 to 120.6 μg PAH m−3 and for benzo(a)pyrene (BaP) from 0.17 to 4.88 μg BaP m−3. The concentration of 1-hydroxypyrene in post- and pre-shift urine samples was in the range (0.5-61.8 μmol 1-OHP per mol creatinine) and depended on the worksite. The Spearman rank correlation test showed a low but significant (P<0.05) correlation of urinary 1-hydroxypyrene in the post- and pre-shift samples with respiratory pyrene exposure. The quantitative aspects of biological monitoring for the evaluation of respiratory PAH exposure were tested with a pharmacokinetic model. On the basis of individual pyrene exposure, excretion of urinary 1- hydroxypyrene during the working week was calculated for each worker. The results presented in this investigation indicate that biological monitoring of the pyrene metabolite 1-hydroxypyrene is a useful indicator of a general PAll exposure, but cannot replace personal air sampling for assessing the lung cancer risk of individuals. Copyright © 1996 BOHS. Published by Elsevier Science Lt

Funktionelle Biodiversität, Schädlingsregulation gezielt verbessern

Mit naturnahen Flächen werden Nützlinge als Teil des modernen biologischen Pflanzenschutzes gefördert. Um ihre Effizienz zu steigern, reicht die Förderung der generellen Biodiversität nicht aus; eine maßgeschneiderte,„funktionelle“ Biodiversität ist nötig

Ausbreitung des Rapsglanzkäfers innerhalb eines Feldes und in der Landschaft

Pollen beetles (Meligethes sp.) are important pests in oilseed rape (Brassica napus). In our study we wanted to determine which landscape structures have an influence on pollen beetle population in early spring. The dynamics of pollen beetle population and the damages on rape were studied on field scale level with 100 sampling points per field and on landscape scale level with 18 organic oilseed rape fields which differed by the complexity of the surrounding landscapes. The number of pollen beetle was strongly correlated with the distance to a forest. At the beginning of the flight period more pollen beetles were found close to the forest, later they migrated to the rest of the field. In addition, agricultural practices appeared to be determinant for pest control.Less pollen beetles per plant were found in fields with a higher density of rape plants

Turbulent ion heating in TCV tokamak plasmas

The Tokamak à configuration variable (TCV) features the highest electron cyclotron wave power density available to resonantly heat (ECRH) the electrons and to drive noninductive currents in a fusion grade plasma (ECCD). In more than 15 years of exploitation, much effort has been expended on real and velocity space engineering of the plasma electron energy distribution function and thus making electron physics a major research contribution of TCV. When a plasma was first subjected to ECCD, a surprising energisation of the ions, perpendicular to the confining magnetic field, was observed on the charge exchange spectrum measured with the vertical neutral particle analyser (VNPA). It was soon concluded that the ion acceleration was not due to power equipartition between electrons and ions, which, due to the absence of direct ion heating on TCV, has thus far been considered as the only mechanism heating the ions. However, although observed for more than ten years, little attention was paid to this phenomenon, whose cause has remained unexplained to date. The key subject of this thesis is the experimental study of this anomalous ion acceleration, the characterisation in terms of relevant parameters and the presentation of a model simulation of the potential process responsible for the appearance of fast ions. The installation of a new compact neutral particle analyser (CNPA) with an extended high energy range (≤ 50 keV) greatly improved the fast ion properties diagnosis. The CNPA was commissioned and the information derived from its measurement (ion temperature and density, isotopic plasma composition) was validated against other ion diagnostics, namely the active carbon charge exchange recombination spectroscopy system (CXRS) and a neutron counter. In ohmic plasmas, where the ion heating agrees with classical theory, the radial ion temperature profile was successfully reconstructed by vertically displacing the plasma across the horizontal CNPA line of sight. Active charge exchange measurements, by doping the plasma with ion neutralisation targets injected with the diagnostic neutral beam (DNBI), were used to absolutely calibrate the NPA. Advanced modelling of the measured hydrogenic charge exchange spectra with the neutralisation and neutral transport codes KN1D and DOUBLE-TCV permitted a calculation of the absolute neutral density profiles of the plasma species. The energisation and the properties of fast ions were studied in dedicated, low density, cold ion, hot electron plasmas, resonantly heated at the second harmonic of the electron cyclotron frequency. The ion acceleration occurs on a characteristic timescale in the sub-millisecond range and comprises up to 20 % of the plasma ions. The number of fast ions nis and their effective temperature Tis are found to depend strongly on the bulk and suprathermal electron parameters, in particular Tis ≤ Teb (electron bulk) and nis ∼ Vde (toroidal electron drift speed). The suprathermal electrons, abundantly generated in plasmas subjected to ECCD, are diagnosed with perpendicular and oblique viewing electron cyclotron emission (ECE) antennas and the measured frequency spectra are reconstructed with the relativistic ECE radiation balance code NOTEC-TCV. With steady-state ECRH and ECCD, the fast ion population reaches an equilibrium state. The spatial fast ion temperature profile is broad, of similar shape compared to the bulk ion temperature profile. The hottest suprathermal temperature observed is Tis ≤ 6 keV. Various potential ion acceleration mechanisms were examined for relevance in the TCV parameter range. The simultaneous wave–electron and wave–ion resonances of ion acoustic turbulence (IAT) show the best correlation with the available experimental knowledge. Ion acoustic waves are emitted by the weakly relativistic circulating electrons and are mainly Landau damped onto the ions. Destabilisation of IAT is markedly facilitated by the important degree of nonisothermicity Te/Ti ≥ 40 of X2 EC heated TCV plasmas. Efforts were undertaken to consistently model the experimental observations using a numerical experiment. The relevant physics describing IAT was implemented in a finite difference code solving the quasilinear diffusion equation describing the time evolution of the electron and ion distribution functions. The simulations, fed as far as possible with experimentally available information, confirm the growth and saturation of IAT. Electrons and ions are initially preferentially heated in the toroidal direction. As the ions gain energy, the ion waves are damped more efficiently and only modes propagating at oblique angles can still grow, thus accelerating ions into the radial perpendicular direction. The simulation shows that turbulence reaches a steady-state when the ions are sufficiently hot to permanently stabilise IAT. The parameters describing the tail of the modelled equilibrium ion distribution agree quantitatively well with the CNPA measurement. Preliminary studies investigated on the interaction of fast ions with the sawtooth instability. It is found that the fast ion population in sawtoothing plasmas is transiently enforced with each sawtooth collapse. It is presently thought that the toroidal electric reconnection field lowers the IAT stability threshold thus producing more suprathermal ions