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.
2003
Forfattere
Halvor B. Gjærum Mary Namaganda Kåre LyeSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor Håkon SivertsenSammendrag
The main elements of a web-based system for administrating data from a network of automated agro meteorological stations are presented. The concept of quality of meteorological data is then discussed. `Controlling the measurements" is one element contained in the concept of `quality of data". An automatic system for controlling the meteorological data is introduced as mainly a control of the functioning of the instruments. Each instrument is explicitly and uniquely defined in this system, and the different meteorological parameters are uniquely coupled to these instruments. The procedures for automatic control is dependent on the information mentioned above, as well as information dependent on the climate on each site, giving us the expected variation of each parameter through the year. The system also allows automated correction of measured parameter values dependent on the type of instrument used in each case.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
This report contains all papers presented at the OECD Expert meeting in Oslo October 7th - 9th 2002, in addition to the list of participants. The topic of the meeting was the development of landscape indicators. In brief, the Expert Meeting agreed that interested OECD Member countries should consider the following recommendations; • Invest in the scientific understanding and further development of an indicator framework for agricultural landscapes, representing the linkages between landscape structure, function and management, • Build upon the existing national and international experiences in policy monitoring, evaluation and predictive scenarios, • Encourage pro-active collaboration, information exchange and methodological integration, • Contribute to, and cooperate with, other international initiatives related to developing agricultural landscape indicators, • Establish an informal expert network to follow up recommendations of the meeting.
Forfattere
Helge Lundekvam Eirik Romstad Lillian ØygardenSammendrag
Norwegian agriculture depends heavily on governmental subsidies, due to small farming units and high costs. Due to a limited home market, many agricultural productions are also quantum regulated. Milk and grain production was regulated starting in the 1950 using region specific prices. At the level of three counties in south-eastern Norway, this policy resulted in an increase in the grain producing area from 30 to 80% of total agricultural area causing a similar reduction in grassland area over a'30 year period. The change in land use caused by this policy more than doubled the estimated soil losses by water erosion. During the late; seventies extensive land levelling in the same region stimulated by subsidies lead to an estimated two-three fold increase in soil erosion. The increase was especially high when former ravine landscapes used for pasture were levelled and turned into arable land that was ploughed in autumn. Very visible erosion and increasing negative offsite effects on water quality together with overproduction put an end to the subsidies for land levelling. Erosion research was started around 1980 and the results from this research lead to the introduction of several kinds of payments in the early 1990 to encourage more sustainable agricultural production. Since the policy changed there has been changes in cultivating systems and a reduction in soil erosion has been estimated. Thus, farmers' behaviour and soil erosion in Norway is strongly influenced by agricultural and environmental policy.
Forfattere
Randi Berland FrøsethSammendrag
Det er ikke registrert sammendrag
Forfattere
Randi Berland Martha Ebbesvik Thor Johannes Rogneby Ragnar EltunSammendrag
For bønder som ønskjer å produsere korn økologisk er det viktig å få god informasjon om korleis andre gardbrukarar får det til i praksis. Femten gardar rundt omkring i Noreg er plukka ut som eksempel på korleis det får an å dyrke korn under ulike naturgjevne forhold og i ulike økologiske driftssystem. Dyrkingsmetode og erfaringar på desse bruka er kartlagt gjennom eit intervju. Denne informasjonen vert skriven i artikkelform og gjeve ut på markdagar og andre fagsamlingar der målgruppa er produsentar. Arbeidet med demonstrasjonsgardar med korn er ein del av det nasjonale prosjektet "Storskalaforsøk i økologisk korndyrking".
Forfattere
Nina TrandemSammendrag
Innlegget tar for seg konsekvensene av de siste års bortfall av kjemiske insekt- og middmidler, med utgangspunkt i situasjonen for frukt og bær. Dyrkerne vil om få år ha ingen eller ett godkjent plantevernmiddel igjen å bruke mot en rekke skadedyr dersom det ikke blir godkjent nye preparater/bruksområder. Dette gjelder rognebærmøll, kirsebærflue, rotsnutebiller, eplevikler, spinnmidd, jordbærmidd og flere andre betydelige skadedyr. Situasjonen er vanskeligst i frukt, der den integrerte produksjonen har vært bygd på kunnskap om bruk av organofosfater som nå forsvinner, og hvor pyretroider ikke blir brukt. Dersom ingenting gjøres, vil dyrkerne få betydelige økonomiske tap, og det er også stor risko for oppbygging av resistens mot de få gjenværende midlene. Innlegget lister så opp mulighetene for å avhjelpe situasjonen, og påpeker at samtlige innbærer økte kostnader på en eller annen måte.
Forfattere
Celine ReboursSammendrag
Det er ikke registrert sammendrag
Sammendrag
The rationale for stand growth modelling is often either grounded in a search for improved scientific understanding or in support for management decisions. The ultimate goal under the first task is seen in mechanistic models, i.e. models that represent the stand structure realistically and predict future growth as a function of the current status of the stand. Such mechanistic models tend to be over-parameterized with respect to the data actually available for a given stand. Calibration of these models may lead to non-unique representations and unreliable predictions. Empirical models, the second major line of growth modelling, typically match available data sets as well as do process-based models. They have less degrees of freedom, hence mitigate the problem of non-unique calibration results, but they employ often parameters without physiological or physical meaning. That is why empirical models cannot be extrapolated beyond the existing conditions of observations. Here we argue that this widespread dilemma can be overcome by using interactive models as an alternative approach to mechanistic (algorithmic) models. Interactive models can be used at two levels: a) the interactions among trees of a species or ecosystem and b) the interactions between forest management and a stand structure, e.g. in thinning trials. In such a model data from a range of sources (scientific, administrative, empirical) can be incorporated into consistent growth reconstructions. Interactive selection among such growth reconstructions may be theoretically more powerful than algorithmic automatic selection. We suggest a modelling approach in which this theoretical conjecture can be put to a practical test. To this end growth models need to be equipped with interactive visualization interfaces in order to be utilized as input devices for silvicultural expertise. Interactive models will not affect the difficulties of predicting forest growth, but may be at their best in documenting and disseminating silvicultural competence in forestry.