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.
2005
Sammendrag
The suitability of shell sand as a P sorbent has been tested both with laboratory batch experiments as well as in a sub-surface flow (SSF) meso-scale constructed sand filter treating municipal wastewater from a single household. The batch experiments suggest that retention of P in shell sand occurs both as sorption and precipitation. The soil-water ratio was found to be a crucial parameter when performing laboratory batch experiments. The maximum retention capacity was about 8000 and 800 mg P kg-1 sand, and the Kd was 33.7 and 82.9 L kg-1 for soil-water ratios of 5 g "75 mL and 50 g " 50 mL, re-spectively. The average total accumulated P concentration in samples from the SSF sand filter was 335 mg P kg-1. The Kd value based on [PO43-] and accumulated concentration of inorganic P in the SSF filter was 89.8 L kg-1. Thus the batch experiments overestimated the retention capacity of shell sand in real sand filter systems, however, a ratio of 50-50 gave a more reasonable estimate than a ratio of 5-75. The Kd value from batch samples with a ratio of 50-50 also gave a good estimate of the Kd value in the constructed sand filter. Ca-P was found to be the predominant form of P mineral in samples col-lected from the SSF sand filter. Some Al-P, loosely bounded P and occluded P were also present in the sand.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Maria Herrero Arild SlettenSammendrag
I 1993 ble det oppdaget en ny Phytophthora-art i Nederland og Tyskland. Denne arten var årsak til problemer i Rhododendron. Den angrep greiner og blad, og kunne i noen tilfeller drepe planter. I 2001 fikk patogenet det vitenskapelig navnet P. ramorum. I 1995 var det i California (USA) stor dødelighet i noen typer amerikansk eik (Lithocarpus densiflorus) og diverse Quercus spp. Problemet fikk epidemiske dimensjoner, og tusenvis av trær døde de følgende årene. Sykdommen ble kalt sudden oak death (SOD). Først i 2000 ble det klart at problemene i de Californiske skogene var foråsaket av P. ramorum. Etter at dette var klarlagt har P. ramorum vært vurdert som en potensiell fare for skog også i Europa, og underlagt bekjempelse av plantehelsemyngidhetene i de enkelte land. Patogenet er allerede utbredt i mange områder i Europa. Hittil er det hovedsakelig et problem i planteskoler. De mest utsatte vertplantene er arter i slektene Rhododendron og Vibrunun. Det er funnet også i parker, og noen trær er drept av patogenet. I Norge ble P. ramorum opåvist for første gang høsten 2002. Til nå er den funnet i 11 fylker, hovedsakelig på importerte Rhododendron, men også på Pieris og Kalmia.
Forfattere
Maria Herrero Ole Billing HansenSammendrag
I løpet av 2004 ble det påvist angrep av plantesykdommen Phytophthora ramorum i 27 norkse hagesentre og planteskoler og i to hageanlegg. I de aller fleste tilfeller var påvisning på rhododendron, men også pieris og kalmia var smittet i enkelte tilfeller. Dette er en ny skadegjøre her i landet.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
In 2004, damages resembling those caused by Phytophthora spp. were observed on three different fir species in Norway. Isolations were carried out from all the host plants on the Phytophthora selective medium PARP (with and without hymexazol added). In a nordmann fir (Abies nordmanniana) Christmas tree field at the southwestern coast of Norway, approximately 70 % of the plants died within a few months after planting. The massive infestation in a field previously used for grass production over decades, left no doubt that the disease had followed the imported transplants. Symptoms included poorly developed roots and discoloration under the bark from the stem basis downwards. The foliage had different stages of drought symptoms; pale green, yellow or brown. Isolations were carried out from the area between healthy and diseased tissue, both from roots and stem base, and a Phytophthora sp. was isolated. The culture produced nonpapillate sporangia with internal proliferation. The sexual stage was observed in water, but not on agar. The oogonia were large. The oospores were aplerotic and the anteridia predominantly amphigynous. ITS rDNA sequences of the isolate were obtained and found to be most similar to P. inundata. Samples were examined from diseased 15-year-old noble fir (A. procera) grown in a bough plantation at the southwestern coast of Norway. Approximately 25 % of the trees were dead or dying. The foliage had turned chlorotic to brown. On one tree a typical stem canker extending approximately 1.5 meters above ground on one side of the tree resulted in dead basal branches (flagging). Isolations were carried out from both roots and the cankered stem. Based on morphological characters (nonpapillate sporangia, internal proliferation, characteristic hyphal swellings, heterothallic culture) and ITS rDNA sequencing, the isolate was identified as P. cambivora. In a Christmas trees planting in southeastern Norway, several seven-year-old trees of subalpine fir (A. lasiocarpa) were dying. The tree loss was estimated to 25 %. Typical Phytophthora canker was found at the base of several trees. Isolations resulted in a culture that readily produced oogonia. The average diameter of the oogonia was 48 "m. The oospores were aplerotic with an average diamerter of 40 "m. The antheridia were paragynous, but a few amphigynous antheridia were also observed. The culture produced nonpapillate sporangia with internal proliferation ITS rDNA sequences matched P. megasperma. A pathogenesis test to fulfil Koch"s postulate was carried out on all three species of fir, each of them inoculated with the respective isolate. After seven weeks, root growth was poor on all the inoculated plants, and canker symptoms had developed in the lower part of the stem. Reisolated culture from noble fir was ITS rDNA sequenced and found identical to the original culture used for inoculation. Results from the ITS rDNA sequencing of the other two reisolated cultures are not yet available.
Sammendrag
Intensive monitoring plots of the ICP Forests gathered an amount of data about the ground vegetation in forest ecosystems throughout Europe. Each Country, applying different field techniques, conform to common rules of procedure, under the suggestions of a dedicated Expert Panel which implemented a Unified Coded Flora and comparability targets. Data series are foreseen to contribute to: definition of the forest ecosystem state and changes evaluation; assessment of the specific plant diversity at the ecosystems level. The contribution to scientific knowledge and to Global and Pan-European biodiversity initiatives and networks (ICP-IM, MCPFE, CBD, Forest BIOTA, ALTER-net, etc.) are also underlined. In spite of site-related data, first results (more than 670 plots, with large differences in plant diversity) depict the linkages with temperature, precipitation, dominant tree species and actual soil acidity. Nitrogen deposition seems to have some significant influence, which claims to further studies. Plant data series from ICP Forest’s plot, can be used for on-site confirmation of models including biodiversity k-factors and environment relations.
Forfattere
Hege Hovd Arnfinn SkogenSammendrag
Plant species composition and species number were studied in two types of field margins: 31 arable field margins and 33 road verges. Both field margin types were adjacent to intensively managed grass or cereal fields. Effects of eight variables on field margin vegetation were studied. Despite having many plant species in common, composition and species number differed between the two field margin types, due to different ecological conditions and margin management. Arable field margins were composed of tall and/or nutrient demanding ubiquitous species and were characterised by species of later successional stages than those of road verges. The vegetation of road verges was lower and species numbers were higher than in arable field margins. The road verges contained several semi-natural meadow species that are declining in abundance. A CCA ordination of the field margins and the recorded variables showed that plant species composition was significantly affected by thickness of litter, slope, width, moisture level and type of crop in the adjacent field. Number of plant species was significantly higher in mown than unmown margins and generally higher in margins adjacent to fields with mainly grass production than in margins adjacent to fields with mainly cereal crops. In order to preserve botanical diversity in this agricultural landscape, the maintenance of regularly mown road verges should be prioritized.
Forfattere
Løes, Anne-Kristin McKinnon, KirstySammendrag
Det er ikke registrert sammendrag
Forfattere
Hilde Aarnseth KirkbakSammendrag
Det er ikke registrert sammendrag