Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2006
Forfattere
Sonja Klemsdal A. Haghanizadeh Oleif ElenSammendrag
A fungal endochitinase gene, ech42 from Trichoderma atroviride, has been incerted in barley resulting in increased resistance towards Fusarium culmorum infection. The F. culmorum resistance was found to be stable when tested in the T3 generation
Forfattere
Bernard Slippers Rimvis Vasiliauskas Brett Hurley Jan Stenlid Michael J. WingfieldSammendrag
The Forestry and Agricultural Biotechnology Institute, University of Pretoria and the Department of Forest Mycology and Pathology, Swedish University of Agricultural Biotechnology Institute, Uppsala, Sweden are collaborating on a study of the Siricid-Fungal symbiosis, and its parasites. This project aims to address questions in two general areas, namely (a) the evolution and biology of mutualistic symbiosis and (b) the monitoring and control of wood inhabiting pests and pathogens that threaten biodiversity and forest production in introduced and native environments...
Forfattere
Andreas TreuSammendrag
Det er ikke registrert sammendrag
Sammendrag
A new compact wastewater treatment system for use in single houses has been constructed in eastern Norway. The system is based on the principles of sub-surface flow constructed wetlands using various types of Filtralite as filter media. It consists of a septic tank followed by an aerobic biofilter succeeded by an upflow saturated filter. The aerobic biofilter is essential to remove organic matter and achieve nitrification, while the upflow filter polishes the wastewater and removes microorganisms and phosphorus. During the first 3 years of operation, the system has show stable and high removal with the following average values measured from the outlet of septic tank to the outlet of the upflow filter: 97.0%-BOD7, 30%-N, 99.4%-P, and 70.8%-SS. No Escherichia coli or somatic coliphages have been detected in the effluent. Due to considerable removal of organic mater, nutrients, and pathogens, the effluent will not negatively affect water and soil ecosystems. The system requires low maintenance and is designed to remove phosphorus for 5 years before renewal of the upflow filter media. When saturated with phosphorus, the media is a suitable fertilizer for plant production. (c) 2006 Elsevier B.V. All rights reserved.
Forfattere
Audun KorsæthSammendrag
Det er ikke registrert sammendrag
Forfattere
Arild Vatn Lars Bakken Marina A. Bleken Ole Hans Baadshaug Haldor Fykse Lars E. Haugen Helge Lundekvam John Morken Eirik Romstad Per Kristian Rørstad Arne O. Skjelvåg Trine SognSammendrag
This paper presents a methodology for analyzing the effect of policies focused at reducing pollution from agriculture. Such a methodology must take into account that agricultural pollution is an effect of a large set of interacting processes, covers many different substances, and may vary substantially due to shifts in natural and economic conditions.
Sammendrag
Detailed analyses of thresholded ecological interactions can improve our understanding of the transition from aperiodic to periodic dynamics. We develop a threshold model of the population dynamics of outbreaking bark beetle populations that alternate between non-epidemic and epidemic behavior. The model involves accumulation of resources during low-density periods and depletion during outbreaks. The transition between the two regimes is caused by disturbance events in the form of major tree felling by wind. The model is analyzed with particular reference to the population dynamics of the spruce bark beetle (Ips typographus) in Scandinavia for which a comprehensive literature allows full parameterization. The fairly constant outbreak lengths and the highly variable waiting time between outbreaks that are seen in the historical records of this species agree well with the predictions of the model. The thresholded resource-depletion dynamics result in substantial variation in the degree of periodicity between stochastic realizations. The completely aperiodic tree colonizations are partly predictable when the timing of the irregular windfall events are known. However, the predictability of inter-outbreak periods is low due to the large variation of cases falling most frequently in the middle between the extremes of purely nonperiodic (erratic) and periodic (cyclic) fluctuations.
Forfattere
John Jensen Neal Sorokin Liesbet Dirven-van Breemen Tobias Bogolte Elisabeth Erlacher George Archibald Clark Ehlers Thomas ter Laak Thomas Hartnik Johan Bierkens Michiel Rutgers Miranda MesmanSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor Håkon Sivertsen Janis GailisSammendrag
A web-base system for administrating data from a network of agro meteorological stations is presented, especially the module containing the documentation of the instruments. The quality concept of meteorological data is presented. The system development practice is recently changing from a traditional in-house and vendor controlled system to the global software development in a highly distributed and heterogeneous environments. This can be highly challenging for system development practices related to specific domain activities like collection, control and correction of meteorological and biological data, since the number of involved actor-networks can become large and the interactions between actor-networks then tends to be complex. To utilize the meteorological and biological data in scientific models that has practical implications for the users, and to make the data accessible and representative in different contexts, a large set of actor-networks has to be considered. To illustrate the variety of interactions between actor-networks in the process of the development of a web-based system, the actor-network theory , ANT, (Law, 1992; Latour, 2005; Latour and Woolgar, 1986) is shortly introduced. The actor-network dealing with collection, administration, control, correction and presentation of values of both measured ( by sensors) and derived parameters, is described in a detailed manner. Also the role of the formal and informal specifications is discussed ( Frias et al., 2005) for the actor-networks involved in the process of development. A heterogeneous engineering approach is suggested for the further development of the web-based system, especially the control and correction of the meteorological and biological data. Some features of another system for documentation of instruments, called `Sensor Model Language" is didcussed and commented. We ask, if using ANT to describe the social patterns uncovered during the system development process, can this increase the usability and dynamical features for various actor-networks involved? References: Latour, B., & Woolgar, S.,(1986), Laboratory Life : The construction of scientific facts; Princeton; Princetn university Press. Fries, A. F., Lopez Pombo, C.G., Baum, G.A., Aguirre, N.M., & Maibaum, T.S.E., (2005), Reasoning about static and dynamic properties in alloy: A purely relational approach, ACM Transactions on software engineering and methology, Vol. 14., No 4, October 2005, p. 478-526 Law, J., (1992), Notes on the theory of the actor-network: Ordering, strategy, and heterogeneity, systemiv practice and action research,Springer Netherlands, ISSN: 1094-429x ( Paper) 1573-9295 ( online), D01: 10.1007/BF01059830, Issue: Volume 5, Number 4, August 1992, p. 379-393 Latour, B., (2005), Reassembling the social: An introduction to Actor-network theory; Oxford; Oxford University Press Sivertsen, T.H., 2005, Implementation of a General Documentation System for web-based administration and use of historical series of meteorological and biological data, Physics and Chemistry of the Earth Special Issue: Agrometeorology 2003, Vol 30/1-3 pp 217-222 Sivertsen, T.H., 2005, Discussing scientific methods and the quality of meteorological data, in `Use and Availability of Meteorological Information from Different Sources as Input in Agrometeorological Models", COST ACTIONS 718 `Meteorological Applications for Agriculture", Edited by G. Maracchi, A. Mestre, L. Toulios and B. Gozzini. Sivertsen, T.H, 2005, ", Reflections on the Theme of Classifying, Documenting and Exchanging Meteorological Data", Atmospheric Science Letters, Vol.6 , Issue 3, p 171-175, John Wiley & Son
Forfattere
Ievina Sturite Marianne Vileid Uleberg Marit Jørgensen Trond Henriksen Anne Kjersti Bakken Tor Arvid BrelandSammendrag
In order to improve the basis for utilising nitrogen (N) fixed by white clover (Trifolium repens L.) in northern agriculture, we studied how defoliation stress affected the N contents of major plant organs in late autumn, N losses during the winter and N accumulation in the following spring. Plants were established from stolon cuttings and transplanted to pots that were dug into the field at Apelsvoll Research Centre (60 degrees 42'N, 10 degrees 51' E) and at Holt Research Centre (69 degrees 40' N, 18 degrees 56' E) in spring 2001 and 2002. During the first growing season, the plants were totally stripped of leaves down to the stolon basis, cut at 4 cm height or left undisturbed. The plants were sampled destructively in late autumn, early spring the second year and after 6 weeks of new spring growth. The plant material was sorted into leaves, stolons and roots. Defoliation regime did not influence the total amount of leaf N harvested during and at the end of the first growing season. However, for intensively defoliated plants, the repeated leaf removal and subsequent regrowth occurred at the expense of stolon and root development and resulted in a 61-85% reduction in the total plant N present in late autumn and a 21-59% reduction in total accumulation of plant N (plant N present in autumn + previously harvested leaf N). During the winter, the net N loss from leaf tissue (N not recovered in living nor dead leaves in the spring) ranged from 57% to 74% of the N present in living leaves in the autumn, while N stored in stolons and roots was much better conserved. However, the winter loss of stolon N from severely defoliated plants (19%) was significantly larger than from leniently defoliated (12%) and non-defoliated plants (6%). Moreover, the fraction of stolon N determined as dead in the spring was 63% for severely defoliated as compared to 14% for non-defoliated plants. Accumulation in absolute terms of new leaf N during the spring was highly correlated to total plant N in early spring (R-2 = 0.86), but the growth rates relative to plant N present in early spring were not and, consequently, were similar for all treatments. The amount of inorganic N in the soil after snowmelt and the N uptake in plant root simulator probes (PRS (TM)) during the spring were small, suggesting that microbial immobilisation, leaching and gas emissions may have been important pathways for N lost from plant tissue.