Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2012
Abstract
The flight responses of 750 female Calliphora vicina Robineau-Desvoidy, 1830 (Diptera: Calliphoridae) are investigated in a wind tunnel bioassay. The attraction of C. vicina towards dead mice and seven different synthetic lures made from dimethyl trisulphide, mercaptoethanol and O-cresol is compared. Responses towards natural odours and the three-component synthetic kairomones depend on the flies' ovarian egg developmental status. The natural and three-component lures also induce similar age-dependent responses, although the dead mice lure yields a significantly higher attraction. Oriented flight increases with the number of chemicals in the synthetic kairomone; one-, two- and three-compound lures induce 13–25%, 32–43% and 62% attraction, respectively. Responses to one-component lures are not significantly influenced by egg developmental status, whereas blends of two or three components are. Attraction levels increase in a stepwise manner both across egg developmental categories and with the number of compounds. The results suggest that the attractiveness of synthetic kairomones is influenced not only by the blowflies' physiological state, but also by the complexity of the lure.
Authors
H.J. van der Fels-Klerx P.W Goedhart Oleif Elen T. Börjesson V Hietaniemi C.J.H BooijAbstract
Climate change will affect mycotoxin contamination of feed and food. Mathematical models for predicting mycotoxin concentrations in cereal grains are useful for estimating the impact of climate change on these toxins. The objective of the current study was to construct a descriptive model to estimate climate change impacts on deoxynivalenol (DON) contamination of mature wheat grown in northwestern Europe. Observational data from 717 wheat fields in Norway, Sweden, Finland, and The Netherlands were analyzed, including the DON concentrations in mature wheat, agronomical practices, and local weather. Multiple regression analyses were conducted, and the best set of explanatory variables, mainly including weather factors, was selected. The final model included the following variables: flowering date, length of time between flowering and harvest, wheat resistance to Fusarium infection, and several climatic variables related to relative humidity, temperature, and rainfall during critical stages of wheat cultivation. The model accounted for 50 % of the variance, which was sufficient to make this model useful for estimating the trends of climate change on DON contamination of wheat in northwestern Europe. Application of the model in possible climate change scenarios is illustrated.
Abstract
No abstract has been registered
Authors
Daniela Sauer Peter Finke Rolf Sørensen Ragnhild Sperstad Isabelle Schülli-Maurer Helge I. Høeg Karl StahrAbstract
The first results of modeling soil development in marine sediments in S Norway using the model SoilGen are compared to measured properties of two soil chronosequences, on the western and eastern side of Oslofjord, respectively. The aim of this work is to test how well soil development under well-defined environmental conditions can be modeled. Such testing reveals to what degree soil-forming processes are understood, allowing formulation of adequate calculations reflecting these processes. The model predicts particle size distribution reasonably well, although clay depletion in the upper parts of the soils as a result of clay migration is overestimated. The model tends to underestimate contents of organic carbon and CEC in the A horizons: below, modeled CEC matches well with measured CEC. Base saturation is overestimated in the upper 40 cm and underestimated below. Apparently, leaching of bases proceeds less rapidly in reality than is predicted by the model, due to strong soil structure of the B horizons, causing preferential flow and base leaching around the aggregates, whereas bases inside the aggregates are only slightly affected by leaching. Difficulties and possibilities for improvements are identified, some related to model input data and some to the model itself. Input data could be improved by determining the amounts of organic carbon in organic surface horizons and by quantifying effects of bioturbation. A big challenge is the implementation of soil structure formation in the model. Quantitative data on the development of soil structure with time that can be included in a model are required. Amounts, distribution and connectivity of macro pores need to be defined for each stage of soil development, and zones of low and high base leaching need to be distinguished in the model for each time step. The long-term aim of this work is to model soil development with different sets of soil-forming factors, e.g. different climatic conditions in order to reliably predict soil development under different climate scenarios and related sets of soil-forming factors. The results of the first model runs and the identified possible improvements suggest that this aim is generally achievable.
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Authors
Wen You Paul D. Mitchell Rodolfo M. Jr. NaygaAbstract
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Authors
DJ Sargent T Passey N Surbanovski E. Lopez Girona P Kuchta Jahn Davik R. Harrison A Passey AB Whitehouse DW SimpsonAbstract
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Abstract
No abstract has been registered