TY - JOUR A1 - van Schaik, Loes A1 - Palm, Juliane A1 - Klaus, Julian A1 - Zehe, Erwin A1 - Schroeder, Boris T1 - Potential effects of tillage and field borders on within-field spatial distribution patterns of earthworms JF - Biological chemistry N2 - Earthworms play a key role in regulating soil ecosystem functions and services. The small scale variability in earthworm abundance is often found to be very high, which is a problem for representative sampling of earthworm abundance at larger scales. In agricultural fields, soil tillage may influence both the average earthworm abundance as well as the spatial distribution of earthworms. Therefore we studied the abundance and spatial pattern of the different ecological earthworm types, i.e. endogeic, epigeic and anecic earthworms, in four agricultural fields differing in soil tillage (two fields with regular tillage and two fields with conservation tillage) and surrounding land use (other cropped fields or apple orchard and forest). To this aim we sampled earthworms on a total number of 430 plots (50 x 50 cm(2)) using a combination of extraction with mustard solution and hand sorting. The results exhibit large differences in average earthworm abundance between the four fields. Only one of the two fields with conservation tillage had a comparatively very high overall abundance of earthworms. Furthermore, we found a high spatial variability of earthworms within the field scale often exhibiting a patchy distribution. We detected a trend of decreasing earthworm abundances from the field border into the field for different earthworm groups on each of the fields. In three fields with low total earthworm abundance (and only very few epigeic earthworms) there was a short scale autocorrelation with ranges varying strongly for the endogeic earthworms (37.9 m, 62.6 m, and 85.2 m) compared to anecic earthworms (19.8 m, 22.8 m, and 27.4 m). In the field with high abundance, after trend removal, the variogram models for anecic and endogeic earthworms were rejected based on their negative explained variances. On this field, we found only a short scale autocorrelation for the epigeic earthworms with a range of 143 m. Based on these results it seems that ploughing alone cannot explain the differences in abundance and range of autocorrelation found on the four fields. The trend of strongly decreasing earthworm abundance from the field border into the field in the one field with high abundance does indicate that the field border or surrounding land use may also influence the recolonization of fields, but more research is required to provide further evidence for this hypothesis. Due to the very different patterns of earthworm distributions in the fields it remains difficult to recommend an optimal number and distance of samples to obtain a representative earthworm abundance for the field scale. (C) 2016 Elsevier B.V. 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KW - Earthworms KW - Spatial distribution KW - Autocorrelation KW - Agricultural fields KW - Soil tillage Y1 - 2016 U6 - https://doi.org/10.1016/j.agee.2016.05.015 SN - 0167-8809 SN - 1873-2305 VL - 228 SP - 82 EP - 90 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Kruckenberg, Helmut A1 - Müller, Thomas A1 - Freuling, Conrad A1 - Mühle, Ralf-Udo A1 - Globig, Anja A1 - Schirrmeier, Horst A1 - Buss, Melanie A1 - Harder, Timm A1 - Kramer, Matthias A1 - Teske, Kathrin A1 - Polderdijk, Kees A1 - Wallschläger, Hans-Dieter A1 - Hlinak, Andreas T1 - Serological and virological survey and resighting of marked wild geese in Germany JF - European journal of wildlife research N2 - In order to investigate the potential role of arctic geese in the epidemiology, the spatial and temporal spread of selected avian diseases, in autumn 2002, a virological and serological survey designed as capture-mark-resighting study was conducted in one of the most important coastal resting sites for migratory waterfowl in Germany. Orophatyngeal, cloacal swabs and blood samples were collected from a total of 147 birds comprising of three different arctic geese species including White-fronted Goose (Anser albifrons), Tundra Bean Goose (Anser fabalis rossicus), Pink-footed Goose (Anser brachyrhynchus) as well as from 29 non-migratory Canada Geese (Branta canadensis). Altogether, six adeno-like viruses (ALV; 95% CI, 1.74-9.92%) and two avian paramyxoviruses (APMV-4; 95% Cl, 0.19-5.53%) were isolated mainly from juvenile White-fronted Geese. In addition, four Canada Geese were infected with lentogenic APMV-1 (95% CI, 3.89-31.66%) at the date of sampling. No avian influenza viruses, reo-like viruses could be isolated despite serological evidence. Likewise, no evidence of current or previous infection by West Nile virus was found. Of the 147 birds tagged in the following years, 137 birds were resighted between 2002 and 2008 accumulating to 1925 sightings. About 90% of all sightings were reported from the main wintering and resting sites in Germany and The Netherlands. Eight of the resighted geese were virus positive (ALV and APMV-4) at the time point of sampling in 2002. KW - Wild geese KW - Anser albifrons KW - White-fronted goose KW - Disease KW - Spatial distribution KW - Winter KW - Distribution KW - Branta canadensis KW - Canada goose KW - Virus KW - Infection KW - Neckbanding Y1 - 2011 U6 - https://doi.org/10.1007/s10344-011-0514-1 SN - 1612-4642 VL - 57 IS - 5 SP - 1025 EP - 1032 PB - Springer CY - New York ER -