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.
2021
Forfattere
Cerena J. Brewen John-Pascal Berrill Martin W. Ritchie Kevin Boston Christa M. Dagley Bobette Jones Michelle Coppoletta Coye L. BurnettSammendrag
Quaking aspen (Populus tremuloides) is a valued, minor component on northeastern California landscapes. It provides a wide range of ecosystem services and has been in decline throughout the region for the last century. This decline may be explained partially by the lack of fire on the landscape due to heavier fire suppression, as aspen benefit from fire that eliminates conifer competition and stimulates reproduction through root suckering. However, there is little known about how aspen stand area changes in response to overlapping fire. Our study area in northeastern California on the Lassen, Modoc and Plumas National Forests has experienced recent large mixed-severity wildfires where aspen was present, providing an opportunity to study the re-introduction of fire. We observed two time periods; a 52-year absence of fire from 1941 to 1993 preceding a 24-year period of wildfire activity from 1993 to 2017. We utilized aerial photos and satellite imagery to delineate aspen stands and assess conifer cover percent. We chose aspen stands in areas where wildfires overlapped (twice-burned), where only a single wildfire burned, and areas that did not burn within the recent 24-year period. We observed these same stands within the first period of fire exclusion for comparison (i.e., 1941–1993). In the absence of fire, all aspen stand areas declined and all stands experienced increases in conifer composition. After wildfire, stands that burned experienced a release from conifer competition and increased in stand area. Stands that burned twice or at high severity experienced a larger removal of conifer competition than stands that burned once at low severity, promoting expansion of aspen stand area. Stands with less edge:area ratio also expanded in area more with fire present. Across both time periods, stand movement, where aspen stand footprints were mostly in new areas compared to footprints of previous years, was highest in smaller stands. In the fire exclusion period, smaller stands exhibited greater loss of area and changes in location (movement) than in the return of fire period, highlighting their vulnerability to loss via succession to conifers in the absence of disturbances that provide adequate growing space for aspen over time.
Sammendrag
There is an increasing use of carcass detection dogs to find remains of dead livestock in Norwegian rangelands. But how effective are these dogs actually? • We compared the efficiency of approved carcass detection dog equipages (CDEs, i.e., dog and man) with people searching for sheep carcasses without dogs. • CDEs found significantly more carcasses than people without dogs, and kilometers traveled and minutes spent per carcass detection indicated that dogs were >3x as effective in their search. However, CDEs found only 1 in 4 of the carcasses laid out experimentally. • The training program for CDEs in Norway is now adjusted to improve the quality of the equipages. • The effort of sheep CDEs is important to Norwegian sheep farmers applying for compensation because of the increase in percentage of proven losses caused by protected carnivores. • In the future carcass detection dogs in Norway could be used for wildlife conservation and management tasks.
Forfattere
Marit HaukenSammendrag
Program for jord- og vannovervåking i landbruket (JOVA) ledes av NIBIO divisjon for miljø og naturressurser og gjennomføres i samarbeid med Divisjon for bioteknologi og plantehelse, flere av forskningsstasjonene i NIBIO og andre institusjoner. JOVA overvåker jordbruksdominerte nedbørfelt over hele landet, og feltene representerer ulike driftsformer og ulike jordbunns-, hydrologiske og klimatiske forhold. JOVA rapporterer årlig om jordbruksdrift, avrenning og tap av partikler, næringsstoffer og plantevernmidler for hvert nedbørfelt. Tap av partikler og næringsstoffer rapporteres for agrohydrologisk år, 1. mai – 1. mai, og tap av plantevernmidler for kalenderår.
Forfattere
Paal Krokene Bjørn Arild Hatteland Christer Magnusson Daniel Flø Iben Margrete Thomsen Johan A. Stenberg May Bente Brurberg Per Hans Micael Wendell Mogens Nicolaisen Simeon Rossmann Venche Talgø Beatrix Alsanius Sandra A.I. Wright Trond RafossSammendrag
Det er ikke registrert sammendrag
Sammendrag
Undersøkelsen av kunstsnø ble gjennomført fordi vi tidligere har påvist flere Phytophthora-arter i og nært Sørkedalselva som brukes som vannkilde for produksjon av kunstsnø; P. cryptogea, P.gonapodyides, P. lacustris, P. plurivora, P. rosaecearum, P. taxon raspberry and P. uniformis. Man fryktet at snøen kunne spre smitte av Phytophthora til skianlegg i Oslo-området via små partikler fra jord og planter, men smitte via svermesporer var utelukket på grunn av lav temperatur i vannet. Phytophthora ble påvist med en hurtigtest av en grannål fra grovfilteret til en snøkanon, men ikke ved isolering fra finmaska filter som den smelta snøen ble filtrert gjennom. En DNA-analyse av filtrene som vannprøvene ble sugd gjennom, noe som er en mer sensetiv metode enn isolering på agar, ga heller ikke utslag for Phytophthora.
Sammendrag
Denne rapporten gir resultater fra første år i prosjektet ‘ROBO-GOLF: Bedre gresskvalitet, redusert gjødselkostnad og mindre bruk av fossil energi ved bruk av robotklipper på fairway og semi-rough’ I arbeidspakke (WP) 1 ble forsøk med sammenlikning av robotklipper og manuell klipper (sylinder-klipper på fairway, 15 mm klippehøyde; rotorklipper på semi-rough, 35 mm klippehøyde) til ulike grasarter anlagt på NIBIO Landvik i 2020. Foreløpige resultater fra perioden 11.august - 30.oktober 2020 (etter at grasdekket var etablert) viste bedre helhetsinntrykk med robotklipping enn med manuell klipping på fairway, spesielt i engkvein (Agrostis capillaris) som ble mindre angrepet av mikrodochiumflekk. På semi-rough var derimot skuddtettheten mindre og bladbredden større, og engrapp (Poa pratensis) ble mer invadert av tunrapp og mer angrepet av rust ved robotklipping enn ved manuell klipping.
Forfattere
Gry Alfredsen Christian Brischke Brendan N. Marais Robert F. A. Stein Katrin Zimmer Miha HumarSammendrag
To evaluate the performance of new wood-based products, reference wood species with known performances are included in laboratory and field trials. However, different wood species vary in their durability performance, and there will also be a within-species variation. The primary aim of this paper was to compare the material resistance against decay fungi and moisture performance of three European reference wood species, i.e., Scots pine sapwood (Pinus sylvestris), Norway spruce (Picea abies), and European beech (Fagus sylvatica). Wood material was collected from 43 locations all over Europe and exposed to brown rot (Rhodonia placenta), white rot (Trametes versicolor) or soft rot fungi. In addition, five different moisture performance characteristics were analyzed. The main results were the two factors accounting for the wetting ability (kwa) and the inherent protective properties of wood (kinh), factors for conversion between Norway spruce vs. Scots pine sapwood or European beech for the three decay types and four moisture tests, and material resistance dose (DRd) per wood species. The data illustrate that the differences between the three European reference wood species were minor, both with regard to decay and moisture performance. The results also highlight the importance of defined boundaries for density and annual ring width when comparing materials within and between experiments. It was concluded that with the factors obtained, existing, and future test data, where only one or two of the mentioned reference species were used, can be transferred to models and prediction tools that use another of the reference species
Sammendrag
There is a need for mapping of forest areas with young stands under regeneration in Norway, as a basis for conducting tending, or precommercial thinning (PCT), whenever necessary. The main objective of this article is to show the potential of multitemporal Sentinel-1 (S-1) and Sentinel-2 (S-2) data for characterization and detection of forest stands under regeneration. We identify the most powerful radar and optical features for discrimination of forest stands under regeneration versus other forest stands. A number of optical and radar features derived from multitemporal S-1 and S-2 data were used for the class separability and cross-correlation analysis. The analysis was performed on forest resource maps consisting of the forest development classes and age in two study sites from south-eastern Norway. Important features were used to train the classical random forest (RF) classification algorithm. A comparative study of performance of the algorithm was used in three cases: I) using only S-1 features, II) using only S-2 optical bands, and III) using combination of S-1 and S-2 features. RF classification results pointed to increased class discrimination when using S-1 and S-2 data in relation to S-1 or S-2 data only. The study shows that forest stands under regeneration in the height interval for PCT can be detected with a detection rate of 91% and F-1 score of 73.2% in case III as most accurate, while tree density and broadleaf fraction could be estimated with coefficient of determination ( R2 ) of about 0.70 and 0.80, respectively.
Forfattere
Aurita Butkeviciute Mindaugas Liaudanskas Darius Kviklys Dalia Gelvonauskiene Valdimaras JanulisSammendrag
The interest in old cultivars of apple trees, their fruit and processed products is growing worldwide. Studies on the qualitative and quantitative composition of biological compounds are important for the evaluation of the quality and nutritional properties of apple fruit. A variation in the qualitative and quantitative composition of triterpenic compounds was found in the fruit of apple cultivars included in the collection of National Plant Genetic Resources. A high-performance liquid chromatography (HPLC) analysis showed that the fruit of the cultivar ‘Birutės pepinas’ had the highest total amount (5.17 ± 0.86 mg g-1) of triterpenic compounds. Higher total amounts of triterpenic compounds were also found in the fruit of apple cultivars ‘Tabokinė’ and ‘Panemunės baltasis’ (3.72 ± 0.57 and 4.25 ± 0.17 mg g-1, respectively). By the quantitative composition, triterpenic compounds in apple fruit were ranked in the following order: ursolic acid > oleanolic acid > corosolic acid > betulinic acid. The old apple cultivars ‘Birutės pepinas’, ‘Panemunės baltasis’ and ‘Tabokinė’ included in the collection of National Plant Genetic Resources have a potential for cultivation in industrial orchards and for the use of their apples, and processed apple products as natural functional foods rich in triterpenic compounds and adapted for medical purposes, including the prevention of various diseases. Key words: apple, old cultivars, triterpenic compounds.
Forfattere
Callum Aidan Stephen Hill Michael Altgen Lauri RautkariSammendrag
Thermal modification is a well-established commercial technology for improving the dimensional stability and durability of timber. Numerous reviews of thermally modified timber (TMT) are to be found in the scientific literature, but until now a review of the influence of cell wall moisture content during the modification process on the properties of TMT has been lacking. This paper reviews the current state of knowledge regarding the hygroscopic and dimensional behaviour of TMT modified under dry (cell wall at nearly zero moisture content) and wet (cell wall contains moisture) conditions. After an overview of the topic area, the review explores the literature on the thermal degradation of the polysaccharidic and lignin components of the cell wall, as well as the role of extractives. The properties of TMT modified under wet and dry conditions are compared including mass loss, hygroscopic behaviour and dimensional stability. The role of hydroxyl groups in determining the hygroscopicity is discussed, as well as the importance of considering the mobility of the cell wall polymers and crosslinking when interpreting sorption behaviour. TMT produced under wet processing conditions exhibits behaviour that changes when the wood is subjected to water leaching post-treatment, which includes further weight loss, changes in sorption behaviour and dimensional stability, but without any further change in accessible hydroxyl (OH) content. This raises serious questions regarding the role that OH groups play in sorption behaviour.