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
Forfattere
Jogeir N. StoklandSammendrag
Det er ikke registrert sammendrag
Sammendrag
Changes in forest management have been suggested as a government policy to mitigate climate change in Norway. Tree species change is one of the major strategies considered, with the aim to increase the annual uptake of CO2 as well as the long-term storage of carbon (C) in forests. The strategy includes replacing native, deciduous species with fast-growing species, mainly Norway spruce. Forests in western Norway host some of the largest soil C pools in Scandinavia, and may potentially function as a long-term C reservoir as well as a large source of atmospheric CO2 through decomposition. The project BalanC was initiated in 2016 in order to estimate the C storage potential related to tree species in a total of 15 parallel plots of birch and planted Norway spruce at 5 locations in western Norway. In addition to estimates of C stocks in biomass and soils, we investigate soil C processes, soil fungal and earthworm diversity, albedo, and wood product life-cycles. The current presentation focuses on C stocks in soils relative to trees, soil respiration, and soil climate data. Preliminary results indicate that the soil respiration in spruce was 85 % of the respiration in birch, with a span ranging from 55-151%. The preliminary soil temperature and soil moisture data of the spruce stands were 97 and 73%, respectively, of the birch stands, indicating cooler and drier conditions under spruce which may affect decomposition and C accumulation rates. We expect C allocation in the soil to be affected by tree species, with larger C stocks in the forest floor of spruce stands compared to the mineral soil. Consistent differences in the bulk density of soils under each tree species are likely to be observed, pointing out the need to compare soil C stocks based on equal soil mass. The magnitude of the combined C stock in biomass and soil may increase with planting of spruce, however, we also expect an impact on C stability that will affect the overall mitigation effect of this measure.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Ingeborg Callesen Marjo M. Palviainen O. Janne Kjønaas Kȩstutis E. Armolaitis Charlotte RasmussenSammendrag
Soil texture is a key soil physical property for soil quality and used in modeling studies through pedotransfer functions (PTF) for the prediction of physical, e.g. hydraulic, soil properties. Soil texture is quantified by a particle size distribution (PSD) of the fine earth fraction and often translated into a texture class using defined separates of clay (0 - 2 µm), silt (2 µm to 20 µm, 50 µm or 63 µm) and sand (20 µm, 50 µm or 63 µm up to 2 mm) illustrated in a texture triangle. Until now pretreatment methods (e.g. humus and carbonate removal and dispersion) followed by standardised sedimentation and sieving methods have been well-defined. From literature and a mini-survey, we know already that laser diffraction is a commonly used analytical method for soil PSD determination in scientific environmental studies that involve soils. A body of literature has documented that colloid-sized fraction results obtained by laser diffraction analysis of fine-textured soil samples are not comparable to those obtained with sedimentation and sieving methods, when translating to the traditional particle size limits clay, silt and sand. Also, operating procedures for pretreatment of soil samples are variable, and the analyzed sample volumes are small, adding to uncertainty. In this study we first compared PSD’s from three different instruments for a set of soil samples to study reproducibility using the analytical operating procedures developed by the owner institutions (Malvern Mastersizer 2000, University of Copenhagen, Coulter LS230, University of Helsinki, and Sympatec Helos, Aarhus University). Secondly, we compared the influence of 1 mm sieving and found decreased fraction standard deviation and improved repeatability of the PSD determination by laser diffraction on the Coulter LS230. 1 mm sieving should be corrected for if the mass is more than a few percent, but depending on study purpose. Thirdly, the laser diffraction PSD’s were compared with PSD’s obtained by sieving and hydrometer analysis showing well-known underestimation of colloids and fine fractions, that increased with colloid content. We conclude that PSD’s obtained by the laser diffraction method are repeatable and mostly reproducible given standardised pretreatment. Translation to texture class using traditional separates does not work well, and more work and new PTF’s for soils are needed that can translate a laser diffraction PSD into a texture class and its associated physical properties for further use in modeling studies.
Forfattere
Belachew Gizachew Zeleke Rasmus Astrup Pål Olav Vedeld Eliakimu M. Zahabu Lalisa A. DugumaSammendrag
REDD+, a climate change mitigation mechanism that values carbon in tropical forests, is expected to provide Africa with a range of environmental and socio-economic benefits. Drawing on a vast array of literature and personal experiences, this review analyzed particular features and challenges that REDD+ implementation has faced on the continent. The distinct contexts and major challenges regarding governance, finance and technical capacities are discussed, and mechanisms to fill these gaps are suggested. Radical land tenure reform and a perfect safeguard mechanism that transfers forest land and carbon to the communities are unlikely. REDD+ should rather look for systems that respect local institutional arrangements, and allow forest-based communities to participate in decision-making and benefit sharing, particularly benefits from emerging REDD+. Finances for REDD+ infrastructure and the results-based payment are in short supply. While negotiating for potential external sources in the short term, Africa should generate domestic financial resources and look for additional payments for ecosystem services. Africa should also negotiate for forest monitoring capacity building, while strengthening local community forest monitoring. This review contributes to an improved understanding of the contexts and challenges to consider in the capacity and policy development for REDD+ implementation.
Forfattere
Gunnhild SøgaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Gunnhild SøgaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Gunnhild SøgaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Gunnhild SøgaardSammendrag
Det er ikke registrert sammendrag
Sammendrag
Klimagassutslipp knyttet til torvuttak er en del av Norges klimagassregnskap under FNs klimakonvensjon (UNFCCC), og rapporteres i sektoren arealbruk, arealbruksendringer og skogbruk (LULUCF-sektoren). Norge har valgt å bruke 2013 Supplement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories: Wetlands (IPCC 2014) for beregning av klimagassutslipp fra drenert torvjord («on-site emissions»). For torvuttak rapporteres i tillegg til utslipp fra de drenerte arealene, utslipp fra det volumet torv som høstes årlig («off-site emissions». Det kom ikke nye retningslinjer for dette i 2013 Wetlands Supplement, så for å beregne utslipp fra dette volumet brukes metodikk beskrevet i 2006 IPCC Guidelines for National Greenhouse Gas Inventories (IPCC 2006). I denne rapporten beskrives det datagrunnlaget og den metoden som er brukt for å beregne klimagassutslipp fra torvproduksjon i Norges klimagassregnskap under FNs klimakonvensjon (UNFCCC) i National Inventory Report 2017..........