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.
2008
Forfattere
Christian Uhlig Bernhard Kratutzer Wilhelm Graiss Albin BlaschkaSammendrag
Though revegetation material and methods getting progressively standardized throughout Europe comparable little attention is paid to assess long-term effects of revegetation efforts. One obvious reason, beside others, is the in general short-time character of the majority of the research projects. Other possible reasons may include an insufficient documentation of earlier applied materials and methods and deficiencies in recording site-specific key factors. The generally individual developed evaluation methods and procedures make it often difficult, if not impossible, to compare study sites in time and space. Thus, the aim of this paper is to suggest the development of a commonly applicable evaluation scheme for the assessment of revegetation efforts. Beside the need for a detailed documentation of the original site-specific conditions and the applied materials and methods, the here proposed scheme includes a concise qualitative and quantitative assessment of a) general soil properties, b) soil erosion, c) soil erosion control mats and mulching material, e) plant growth and development and d) post management efforts.
Forfattere
Christian UhligSammendrag
This study reassessed the long-term effects (10 years) of different revegetation methods for the reclamation of a steep sandy slope under sub-arctic conditions. Four different organic based erosion control mats a) coconut, b) straw, c) coconut/ straw and d) wool in combination with the three propagated native plant species i) Poa pratensis (seeds), ii) Festuca rubra (seeds) and iii) Betula nana (transplants) and fertilizer treatments were studied. An assessment three years after establishment of the experiment indicated that the majority of the selected materials and methods gave satisfying results. However, reassessment after 10 years gave a rather opposite result. With exception of the wool mat none of the erosion control mats gave any long-term advantages. The coconut mat had not changed in physical appearance and represented a hinder rather than an advantage for plant establishment and soil development. In contrary few remains of the straw and straw/ coconut mats could be found and there were no obvious signs of any beneficial effect of these materials. None of the seeded native grass species were alive after ten years, but the majority of the Betula nana transplants had survived. Apart from increased survival and growth rates of B. nana, the most obvious effect of mineral fertilization was a higher appearance of Polytrichum sp. Consequently, results from this study clearly emphasizes the importance of repeatedly reassessment of revegetation efforts to avoid recommendations of short-time operational but long-time inappropriate revegetation materials ands methods.
Forfattere
Knut Anders Hovstad Silje Borkvik Mikael OhlsonSammendrag
Epizoochorous seed dispersal on the red fox was examined by walking a fox dummy through a semi-natural grassland and comparing seeds found on the dummy to estimated seed availability in the vegetation. The potential for seed attachment in different species were compared using an index, Iseed, defined as the number of seeds on dummy after a fixed distance, divided by seed density (1000 seeds sq-m) in the vegetation. Seed attachment was related to plant and seed traits by fitting a zero-inflated negative binomial model. Only species with mature seeds, i.e. seeds that could be dispersed naturally, were included in the analysis and the results presented are means from ten independent runs. Twenty-nine species with mature seeds were observed in the vegetation and 19 of these species (4500 seeds in total) were found on the fox. Most of the seeds that attached to the coat originated from a few species. The most common seeds on the dummy were from the grasses Deschampsia cespitosa (84.2 %) and Agrostis capillaris (6.2 %), whereas the most abundant herb seeds on the dummy were Rumex acetosa (2.9%) and Ranunculus acris (1.9 %). The number of seeds available in the vegetation differed greatly among species, and when adjusted for seed availability, Geum rivale and Festuca ovina had the highest potential for seed attachment as judged by the index Iseed. In some species, Iseed displayed large variations due to a patchy distribution. Seed attachment was positively related to plant height, and bristle and hooked seed appendages, whereas it was negatively related to winged appendages, seed mass, and round seed-shape. However, also species without specific seed traits supposed to enhance epizoochory, attached some seeds on the fox, and our results support the view that a wide range of seed types can be dispersed in the fur of mammals. In summary, the results suggest that red fox can be an important seed dispersal vector in the agricultural landscape. A complete description of the experiments and results will appear in Journal of Vegetation Science in 2009.
Forfattere
Knut Anders HovstadSammendrag
This study examines the impact of plant litter on seedling establishment in a semi-natural grassland. In a field experiment, seeds of six forbs were sown in plots subjected to either different litter quantities or addition of water extracts of litter. The response to plant litter was species specific. High quantities of litter resulted in a negative response in all species except Anthriscus sylvestris. In some of the species, the response shifted from positive or neutral at intermediate litter quantities, to negative at high litter quantities. This suggests that facilitative effects were present, although inhibitory effects dominated at high litter quantities. The physical effects were generally stronger than the chemical effects. However, water extract of litter inhibited emergence in three of the six species. Filtration using activated carbon removed the negative effect of litter extract, which suggests that the effect was caused by inhibitory compounds adsorbed by activated carbon (e.g. polyphenols) rather than by increased competition in response to nutrients added via the extract.
Sammendrag
Samandrag av kunnskap frå forsøk utført i Noreg.
Sammendrag
Artikkelen gjev eit oversyn over arbeid med bitterote på eple under lagring i Noreg.
Sammendrag
Bitterrote på søtkirsebær er rapportert frå Sveits, Ungarn og Norge. Det er lite publisert kunnskap om sjukdomen på søtkirsebær. Artikkelen gjev eit oversyn over arbeid gjort i Noreg.
Forfattere
Reidun PommerescheSammendrag
Foredrag om jordlivet, men fokus på jordarbeiding som pakking, pløying og ugrasregulering. Videom om jordlivet og oppgaver som deltakerne skulle løse
Forfattere
Reidun Pommeresche Maud GrøttaSammendrag
Miniseminar for økologiske gardbrukere, men foredrag om jordliv i forhold til jordarbeiding og gjødsling. Vising av en videofilm om jorddyr. Praktiske oppgaver ute med å grave i jorda og tolke jordprofil og se etter meitemark og nitrogenfikserende knoller på kløverrøtter
Sammendrag
This study compares diversity an abundance of spiders in barley with different sub crops and in young ley. Spiders were sampled from 14 cereal and 4 grass-clover fields distributed within three different sites in eastern and central Norway. Two sites were long term experimental field trials and one was an organically managed farm. Pitfall traps were used to sample spiders from May to Sept 2004. In total 4130 spiders were found. The density and number of species varied between fields. More individuals of both Linyphiidae and Lycosidae were trapped in fields with leys compared to fields with cereals. There was no clear difference in total density of spiders according to type of sub-crop, but more Lycosidae were found in cereal fields undersown with ley than in fields undersown with ryegrass. A higher density of Linyphiidae was found in the cereal fields at the farm than at the two experimental sites, whereas the frequency of Lycosidae was about the same at the three sites. Only minor differences in number of species were found, but an ordination technique of multivariate analysis reveals differences in the spider community structures.