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.
2017
Sammendrag
The use of digital aerial photogrammetry (DAP) for forest inventory purposes has been widely studied and can produce comparable accuracy compared with airborne laser scanning (ALS) in small, homogeneous areas. However, the accuracy of DAP for large scale applications with heterogeneous terrain and forest vegetation has not yet been reported. In this study we examined the accuracy of timber volume, biomass and basal area prediction models based on DAP and national forest inventory (NFI) data on a large area in central Norway. Two separate point clouds were derived from aerial image acquisitions of 2010 and 2013. Vegetation heights were extracted by subtracting terrain elevation derived from ALS. A large number of NFI sample plots (483) measured between 2010 and 2014 were used as reference data to fit linear models for timber volume, biomass and basal area with height metrics derived from the DAP data as explanatory variables. Variables describing the heterogeneous environmental and image acquisition conditions were calculated and their influence on the model accuracy was tested. The results showed that forest parameter prediction using DAP works well when applied to a large area. The model fits of the timber volume, biomass and basal area models were good with R2 of 0.80, 0.81, 0.81 and RMSEs of 41.43 m3 ha−1 (55% of the mean observed value), 32.49 t ha−1 (47%), 5.19 m2 ha−1 (41%), respectively. Only a small proportion of the variation could be attributed to the heterogeneous conditions. The inclusion of the relative sun inclination led to an improvement of the model RMSEs by 2% of the mean observed values. The relatively low cost and stability across large areas make DAP an attractive source of auxiliary information for large scale forest inventories.
Sammendrag
Regionale klimamodeller for Norge gir grunnlag for regionale oversikter over forventede endringer i temperatur, nedbør og vind. Endringer i nedbørforholdene vil kunne få stor betydning for dreneringen og de andre av landbrukets hydrotekniske systemer som lukkingsanlegg, kanaler og behovet for erosjonssikring. Dreneringssystem som er anlagt i perioden 1960–1990 er dimensjonert etter klimaforholdene som fantes da.
Forfattere
Atle HaugeSammendrag
Rapporten går gjennom beregningsmetoder for dimensjonering av lukkingsanlegg i landbruket, med spesiell fokus på Vestfold, på bakgrunn av befaringer av eldre lukkingsanlegg i tre Vestfoldkommuner. En bruker den rasjonelle formel og ser hvilke opplysninger som må vurderes. I tillegg går en gjennom mulighetene NVEs internettløsning NEVINA gir for beregning av avrenning og gjentaksintervall.
Sammendrag
The aim of this study was to evaluate the natural occurrence of Beauveria spp. in soil, from infections in the stink bug Piezodorus guildinii, an important pest of common bean (Phaseolus vulgaris) and as endophytes in bean plant tissue. Twelve conventional and 12 organic common bean fields in the Villa Clara province, Cuba were sampled from September 2014 to April 2015. One hundred and fifty Beauveria isolates were obtained from soil samples, bean plant parts and stink bugs. The overall frequency of occurrence of Beauveria isolates in conventional fields (8.4%) was significantly lower than that in organic fields (23.6%). Beauveria were also obtained significantly more frequently from bean roots in organic fields (15.0%) compared to bean roots in conventional fields (3.3%). DNA sequencing of the intergenic Bloc region was performed for Beauveria species identification. All isolates where characterized as Beauveria bassiana (Balsamo-Crivelli) Vuillemin, and clustered with isolates of neotropical origin previously described as AFNEO_1. The Cuban B. bassiana isolates formed five clusters in the phylogeny. Isolates of two clusters originated from all four locations, organic and conventional fields, as well as soil, plants and stink bugs. Organic fields contained isolates of all five clusters while conventional fields only harbored isolates of the two most frequent ones. Mating type PCR assays revealed that mating type distribution was skewed, with MAT1/MAT2 proportion of 146/4, indicating limited potential for recombination. The present study is the first to report of B. bassiana as a naturally occurring endophyte in common bean. Further, it shows that B. bassiana occurs naturally in diverse environments of common bean fields, and constitutes a potential reservoir of natural enemies against pest insects particularly in organic fields.
Forfattere
Ingunn M. VågenSammendrag
Det er ikke registrert sammendrag
Forfattere
Nick Hutchings Isabelle Weindl C. F. E. Topp V. O. Snow A. Rotz H Raynal Şeyda Özkan Gülzari R Martin D. P. Holzworth A.-I. Graux P. Faverdin Agustin del Prado Richard Eckard André BanninkSammendrag
Det er ikke registrert sammendrag
Forfattere
Ingerd Skow HofgaardSammendrag
Det er ikke registrert sammendrag
Redaktører
Berit KristiansenSammendrag
Kort om undersøkinga Driftsgranskingane skal vise årlege resultat, og meir langsiktige utviklingslinjer, for økonomien i jordbruket. Undersøkinga er avgrensa til gardsbruk der inntekta frå jordbruket utgjer ein viktig del av den samla inntekta til brukarfamilien. Driftsgranskingane byggjer på skatterekneskapar som er omarbeidde til driftsrekneskapar. Rekneskapane kjem frå gardsbruk som er spreidde rundt i heile landet. For rekneskapsåret 2016 har 920 bruk teke del i driftsgranskingane i jordbruket. Av desse har 141 vore med i dei spesielle driftsgranskingane i skogbruket. Dessutan har 20 samdrifter innan kumjølkproduksjon levert data til undersøkinga. Driftsgranskingane omfattar gardsbruk med ei standard omsetning som minst svarer til kr 150 000.......
Forfattere
Gregory TaffSammendrag
Det er ikke registrert sammendrag
Forfattere
Lars Sandved DalenSammendrag
Det er ikke registrert sammendrag