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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

To design the restoration plans requested by the EU Water Framework directive, local regulators need to implement technichally designed modifications of farming practices. Their main interest relies on the determination of which modifications are the most appropriate to the local conditions. To help this decision process, a selection grid has been built within the AgriBMPWater project(5th RTD Framework Program). The main interest of this grid is to allow comparision of different "best management practices regarding their environmental effectiveness, the associated costs and their acceptability. This paper presents the different steps of the method, some tools that have been used and their technical requirements, illustrated with some results the integrated tool that has been developed and provide key interpretation

Sammendrag

The uptake of chitosan based impregnation solutions were tested on Scots pine (Pinus sylvestris L), Beech (Fagus sylvatica L.), Downy birch (Betula pubescens Ehrh.) and Norway spruce (Picea abies L. Karst.) in longitudinal, radial and tangential directions separately. The four chitosans tested had a fraction of acetylated residues (FA) of 0.198 and average molecular weights ranging from 18 to 129kDalton. The kinetic viscosity of the 2.4% (weight/volume) solutions at pH 5.0 was in the range of 2.95 to 28.8mm2s-1. The general trend showed that there was an increase in uptake of chitosan based impregnation solutions with decreasing viscosity, and the chitosan solution with the lowest viscosity had almost comparable uptake with water for Pine and Beech in the longitudinal direction. In general, the lower the ability for uptake of impregnation solution, the more the viscosity influences the uptake.

Sammendrag

Det overordna målet med avhandlingen er å frembringe relevant kunnskap om urbane skoger i Norge. Artikkel I og II undersøker tilstand og forvaltningspraksis i urbane skoger. Jeg undersøker to faktorer som har vært viktig for forvaltningen av urbane skoger, folks preferanser for skog (Artikkel III) og naturskogens kontinuitet (Artikkel IV, V). Til slutt diskuterer jeg disse resultatene i forhold til Aldo Leopold ideer om hvordan estetikk og økologi kan integreres i forvaltningen (Artikkel VI, VII). Skog dekker dominerende arealer rundt de vel 900 byer og tettsteder i Norge, og urban skog dekker anslagsvis 2 % av det totale skogarealet. Selv om nesten 80 % av befolkningen har de urbane skogene som nærområde, angir avhandlingen at tilstand og forvaltning er ganske lik det øvrige skogarealet, og det fremkommer heller ingen vesentlig forskjell mellom byer og tettsteder. Tradisjonell forvaltningspraksis utviklet for landlige forhold dominerer også de urbane skogene. Avhandlingen diskuterer hvordan forvaltningen kan videreutvikles i urbane skoger, inkludert fokus på langsiktige visjoner for utvikling av urbane skoger ved bruk av en aktiv og dynamisk forvaltningstilnærming. Kunnskap fra preferanseundersøkelser kan brukes til å innarbeide generelle hensyn i skogskjøtselen. Folks preferanser for tilstander i naturskog er lite studert, men de studiene som finnes indikerer lav preferanseverdi. Avhandlingen diskuterer noen utfordringer i skogskjøtselen knyttet til konflikter mellom økologi og estetikk, der også forhold mellom skogens dynamikk og forvaltningen inngår. En konklusjon fra avhandlingen er at forvaltningen av urbane skoger bør videreutvikles på to nivåer: 1) generell soningsmodell for tilpasninger i forvaltningen til spekteret av verdier og funksjoner i urbane skoger, 2) stedstilpasset forvaltning, der skogeiere, forvaltere og lokalbefolkningen motiveres til en aktiv forvaltningspraksis som avtegner en signatur som klart viser at de bryr seg om stedet.

Sammendrag

A postal questionnaire survey about the forest situation and management in urban woodland was carried out around the three largest urban agglomerations in each of the five Nordic countries, Denmark, Finland, Iceland, Norway and Sweden. Twenty estate managements responded, giving a respondent rate of 54%. Our material from 13 cities includes 108,888ha productive forests, representing approximately 13% of all urban woodland areas in the Nordic region. The tree species composition in the urban woodland areas largely reflected the typical tree species distribution in the respective vegetation zones. It is expected that the percentage of Fagus sylvatica and Quercus spp. in the nemoral zone, and boreal hardwoods will increase in the future. The proportion of young and middle-aged forests is high in all urban woodlands, despite the focus on old forests in urban woodland management policy and research since the 1970s. Current silvicultural systems belonging to even-aged forestry prevail in most cities. However, the use of clear-cutting has decreased over the last 30 years. A conservative felling policy makes it likely that the proportion of old stands will increase. Various restrictions on forest management are briefly discussed. Reasons for changes in silvicultural practices differ from city to city, but recreation and conservation are most commonly reported.

Sammendrag

Root and needle litter are the most important sources of organic carbon in forest soils. Their decomposition is thus important for the long-term storage of C in, and release of CO2 from, the soil. Different components in the organic matter will decompose with different speeds. NIRS (Near InfraRed Spectroscopy) is a relatively simple and promising way of analysing the composition of organic matter, but its use in forest soil and litter studies has been limited up to now. We will present preliminary results from litter decomposition studies in two forest ecosystems: Picea abies stands (30 and 120 years old) from Nordmoen, Norway, and uneven-aged P. abies stands with a mean age of 90 years and under different N treatments at Gårdsjön, Sweden. ags with litter collected from the stands have been buried in the soil for different time periods and have been analysed using a CHN-analyzer and NIRS. Two aspects will be discussed: a) model calibration and validation for C and N concentrations, and b) assessment of decomposability using NIRS.