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
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.
Forfattere
T. Larssen E. Lydersen D. Tang Yi He Jixi Gao H. Liu Lei Duan H.M. Seip R.D. Vogt Jan Mulder M. Shao Yan-Hui Wang H. Shang X. Zhang Svein Solberg Wenche Aas Tonje Økland O. Eilertsen V. Angell Quanru Liu D. Zhao Renjun Xiang J. Xiao J. LuoSammendrag
Acid rain emerged as an important environmental problem in China in the late 1970s. Many years of record economic growth have been accompanied by increased energy demand, greater coal combustion, and larger emissions of pollutants. As a result of significant emissions and subsequent deposition of sulfur, widespread acid rain is observed in southern and southwestern China. In fact, the deposition of sulfur is in some places higher than what was reported from the ?black triangle? in central Europe in the early 1980s. In addition, nitrogen is emitted from agriculture, power production, and a rapidly increasing number of cars. As a result, considerable deposition of pollutants occurs in forested areas previously thought to be pristine. Little is known about the effects of acid deposition on terrestrial and aquatic ecosystems in China. In this article, we present the current situation and what to expect in the future, largely on the basis of results from a five-year Chinese?Norwegian cooperative project. In the years ahead, new environmental challenges must be expected if proper countermeasures are not put into place.
Forfattere
Ole Martin EkloSammendrag
Det er ikke registrert sammendrag
Forfattere
Petter NilsenSammendrag
Det er ikke registrert sammendrag
Forfattere
Bal Ram Singh Zhihui Yang Sissel HansenSammendrag
Det er ikke registrert sammendrag
Sammendrag
For perioden 2001-2005 syner tal frå jordbruksstatistikken at heile 4,0 % av jordbruksarealet i Hordaland fylke har gått ut av drift, mens tilsvarande tal for Sogn og Fjordane er 2,8 %, Møre og Romsdal 2,1 % og for Agderfylka i overkant av 3 %. Statistikken synatr at det er kystkommunane og fleire av kommunane i bynære strok der tilgang på anna arbeid er god som er hardast råka. Utviklinga kjem som eit resultat av at når bruk vert lagt ned i desse områda står ikkje andre gardbrukarar lengre klar til å ta over drifta av arealet. I tillegg betyr dette at jordvernet er svekka, spesielt i by- og tettstadkommunar.Kystkommunane i Hordaland har såleis i perioden 2000-04 hatt ein nedgang på 10,4 %, der kommunar som Austevoll og Sund toppar statistikken med ein reduksjon på 34,8 og 36,3 %. Også i Sogn og Fjordane har kystkommunane hatt ein større samla nedgang (7,5 %), og kommunane Flora (-12,1), Hyllestad (-13,5), Bremanger (-14,5) og Vågsøy (-16,5) er her hardast råka. I Møre og Romsdal har utviklinga vore den same, der er jordbruksareal i drift langs kysten redusert med 4,9 %. Samtidig ser ein òg ein klår tendens til ei polarisering mellom tradisjonelt sterke jordbruksstrok og utkantstrok. Dette er spesielt tydeleg i Rogaland, som skil seg markert frå dei andre vestlandsfylka med ein netto auke i jordbruksareal (0,9%) og ein betydelig mindre reduksjon i husdyr. Jærkommunane Gjesdal og Time har t.d. hatt ein arealauke på høvesvis 5,7 og 5,4 %. Dette er kommunar med driftseiningar som tradisjonelt har vore større, desse har nytta omlegging av tilskottsystema med utflating av tilskottsatsar på tal dyr og areal til ytterlegare å styrke sitt produksjonsgrunnlag. Men, også i Rogaland finn vi kommunar der det har vore urovekkjande nedgang i jordbruksareal som til dømes i Sauda (-7,2 %) og Haugesund (-5,6 %).
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Alhaji S. Jeng Roshan M. Bajracharya Bed M. Dahal Bishal K. Sitaula Subodh ShermaSammendrag
Det er ikke registrert sammendrag
Forfattere
Alhaji Jeng R. M. Bajracharya B. M. Dahal B. K. Sitaula S. SharmaSammendrag
Det er ikke registrert sammendrag