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.
2022
Forfattere
Laura D. Ngau Sim S. Fong Kho L. Khoon Elisa Rumpang Harri Vasander Jyrki Jauhiainen Kim Yrjälä Hanna Marika SilvennoinenSammendrag
Water table conditions in drained peatlands affect peat decomposition, fluvial carbon and greenhouse gas emissions, and plant growth in oil palm plantations. This study illustrates the spatial heterogeneity of soil moisture profiles in cultivated tropical peat under oil palm plantation and uncultivated secondary forest, using maps. At a study plot under each land use the geographical coordinates of sampling points, tree locations and other features were recorded. Peat soil samples were taken at depths of 0–50 cm, 50–100 cm, 100–150 cm and 150–200 cm, and their moisture contents were determined. Overall, soil moisture content was higher in secondary forest than in oil palm plantation due to land management activities such as drainage and peat compaction in the latter. Significant differences were observed between the topsoil (0–50 cm) and deeper soil layers under both land uses. Soil moisture maps of the study plots interpolated using geographical information system (GIS) software were used to visualise the spatial distributions of moisture content in soil layers at different depths (0–50 cm, 50–100 cm, 100–150 cm, 150–200 cm). Moisture content in the 0–50 cm soil layer appeared to be inversely related to elevation, but the correlation was not statistically significant. On the other hand, there was a significant positive correlation between soil moisture content and the diameters of oil palm trunks. Palm trees with negative growth of trunk diameter were mostly located in subplots which were relatively dry and/or located near drains. The results of this study indicate that soil moisture mapping using GIS could be a useful tool in improving the management of peatland to promote oil palm growth.
Forfattere
Nils-Otto Kitterød Jens Kværner Per Aagaard Jurga Arustiene Jānis Bikše Atle Dagestad Pål Gundersen Birgitte Hansen Árni Hjartarson Enn Karro Maris Klavins Andres Marandi Rasa Radiene Inga Retike Pekka M. Rossi Lærke ThorlingSammendrag
Det er ikke registrert sammendrag
Forfattere
YeonKyeong Lee Payel Bhattacharjee Marcos Viejo Gareth Benjamin Gillard Simen Rød Sandve Torgeir Rhoden Hvidsten Ole Christian Lind Brit Salbu Dag Anders Brede Jorunn Elisabeth OlsenSammendrag
Det er ikke registrert sammendrag
Forfattere
Mateusz Liziniewicz Mats Berlin Thomas Solvin Henrik R. Hallingbäck Matti Haapanen Seppo Ruotsalainen Arne SteffenremSammendrag
Norway spruce is a major industrial tree species in Fennoscandia and future productivity of the species must be secured by matching the variation in adaptation of the species with suitable sites for optimized performance. An appropriate transfer model for forest reproductive material (FRM) is crucial for regeneration of productive forests in the changing climatic conditions that are predicted to occur in Fennoscandia. We have developed a transfer model for prediction of height of Norway spruce in Norway, Sweden, and Finland, using data acquired from 438 progeny and provenance trials with 1919 genetic entries of local and transferred origins. Transfer of genetic material at a given site was expressed in terms of the difference in daylength (photoperiod) between the site and its origin. This variable best reflected the nonlinear response to transfer that has been commonly reported in previous studies. Apart from the transfer variable, the height prediction model included the age of material when height measurements were acquired, annual temperature sum over 5 °C, precipitation during the vegetation period, and interaction terms between test site and transfer variables. The results show that long northward transfers (4-5° latitude) seem to be optimal for relatively mild sites in southern parts of the countries where growing season is longer, and shorter northward transfers (2-4° latitude) for harsher northern sites with shorter growing seasons. The transfer model also predicts that southward transfers of Norway spruce would result in height growth reductions. The developed model provides foundations for development of common or national recommendations for genetically improving Norway spruce material in Fennoscandia.
Sammendrag
Norway’s most common tree species, Picea abies (L.) Karst. (Norway spruce), is often infected with Heterobasidion parviporum Niemelä & Korhonen and Heterobasidion annosum (Fr.) Bref.. Because Pinus sylvestris L. (Scots pine) is less susceptible to rot, it is worth considering if converting rot-infested spruce stands to pine improves economic performance. We examined the economically optimal choice between planting Norway spruce and Scots pine for previously spruce-dominated clear-cut sites of different site indexes with initial rot levels varying from 0% to 100% of stumps on the site. While it is optimal to continue to plant Norway spruce in regions with low rot levels, shifting to Scots pine pays off when rot levels get higher. The threshold rot level for changing from Norway spruce to Scots pine increases with the site index. We present a case study demonstrating a practical method (“Precision forestry”) for determining the tree species in a stand at the pixel level when the stand is heterogeneous both in site indexes and rot levels. This method is consistent with the concept of Precision forestry, which aims to plan and execute site-specific forest management activities to improve the quality of wood products while minimising waste, increasing profits, and maintaining environmental quality. The material for the study includes data on rot levels and site indexes in 71 clear-cut stands. Compared to planting the entire stand with a single species, pixel-level optimised species selection increases the net present value in almost every stand, with average increase of approximately 6%.
Redaktører
Heidi KnutsenSammendrag
«Utsyn over norsk landbruk» kom første gang i 1995, og blir i 2022 utgitt for 27. gang. Formålet med publikasjonen er å samle en del av den informasjonen som årlig blir publisert innenfor landbruksområdet, fra blant annet Statistisk sentralbyrå, Budsjettnemnda for jordbruket og NIBIO. Felles for mye av informasjonen som er samlet i «Utsyn over norsk landbruk», er at den i første rekke er utarbeidet til spesielle formål og rettet mot de institusjoner og personer som arbeider med landbruksspørsmål til daglig. «Utsyn over norsk landbruk» retter seg mot et bredere publikum; forvaltning, politikere, journalister, studenter, skoleelever og andre med interesse for norsk landbruk. Utsynet vil også være et nyttig oppslagsverk for dem som trenger oppdaterte data og beskrivelser av de viktigste utviklingstrekkene i norsk landbruk.
Forfattere
Haftamu Gebretsadik Gebrehiwot Jens Bernt Aune Ole Martin Eklo Torfinn Torp Lars Olav BrandsæterSammendrag
Field experiments were conducted in 2015 and 2016 to study the effect of tillage frequency, seed rate, and glyphosate on teff and weeds. The experiments were arranged in a split plot design with three replications consisting of tillage frequency (conventional, minimum, and zero tillage) as the main plot and the combination of seed rate (5, 15, and 25 kg ha−1) and glyphosate (with and without) as subplots. Results showed that zero tillage reduced teff biomass yield by 15% compared to minimum tillage and by 26% compared to conventional tillage. Zero tillage and minimum tillage also diminished grain yield by 21% and 13%, respectively, compared to conventional tillage. Lowering the seed rate to 5 kg ha−1 reduced biomass yield by 22% and 26% compared to 15 and 25 kg ha−1, respectively. It also reduced the grain yield by around 21% compared to 15 and 25 kg ha−1 seed rates. Conventional tillage significantly diminished weed density, dry weight, and cover by 19%, 29%, and 33%, respectively, compared to zero tillage. The highest seed rate significantly reduced total weed density, dry weight, and cover by 18%, 19%, and 15%, respectively, compared to the lowest seed rate. Glyphosate did not affect weed density but reduced weed dry weight by 14% and cover by 15%. Generally, sowing teff using minimum tillage combined with glyphosate application and seed rate of 15 kg ha−1 enhanced its productivity and minimized weed effects.
Forfattere
Ágota Horel Tibor Zsigmond Csilla Farkas Györgyi Gelybó Eszter Tóth Anikó Kern Zsófia BakacsiSammendrag
Land use and management affect soil hydrological processes, and the impacts can be further enhanced and accelerated due to climate change. In this study, we analyzed the possible long-term effects of different land use types on soil hydrological processes based on future climatic scenarios. Soil moisture and temperature probes were installed at four land use sites, a cropland, a vineyard, a meadow, and a forest area. Based on modeling of long-term changes in soil water content (SWC) using the HYDRUS 1D model, we found that changes in precipitation have a more pronounced effect on soil water content than changes in air temperature. Cropland is at the highest risk of inland water and SWC values above field capacity (FC). The number of days when the average SWC values are above FC is expected to increase up to 109.5 days/year from the current 52.4 days/year by 2081–2090 for the cropland. Our calculations highlight that the forest soil has the highest number of days per year where the SWC is below the wilting point (99.7 days/year), and based on the worst-case scenario, it can increase up to 224.7 days/year. However, general scenario-based estimates showed that vineyards are the most vulnerable to projected climate change in this area. Our study highlights the limitations of potential land use change for specific agricultural areas, and emphasizes the need to implement water retention measures to keep these agricultural settings sustainable.
Forfattere
Randika K. Makumbura Miyuru Gunathilake Jayanga T. Samarasinghe Remegio Confesor Nitin Muttil Upaka RathnayakeSammendrag
Hydrologic models are indispensable tools for water resource planning and management. Accurate model predictions are critical for better water resource development and management decisions. Single-site model calibration and calibrating a watershed model at the watershed outlet are commonly adopted strategies. In the present study, for the first time, a multi-site calibration for the Soil and Water Assessment Tool (SWAT) in the Kelani River Basin with a catchment area of about 2340 km2 was carried out. The SWAT model was calibrated at five streamflow gauging stations, Deraniyagala, Kithulgala, Holombuwa, Glencourse, and Hanwella, with drainage areas of 183, 383, 155, 1463, and 1782 km2, respectively, using three distinct calibration strategies. These strategies were, utilizing (1) data from downstream and (2) data from upstream, both categorized here as single-site calibration, and (3) data from downstream and upstream (multi-site calibration). Considering the performance of the model during the calibration period, which was examined using the statistical indices R2 and NSE, the model performance at Holombuwa was upgraded from “good” to “very good” with the multi-site calibration technique. Simultaneously, the PBIAS at Hanwella and Kithulgala improved from “unsatisfactory” to “satisfactory” and “satisfactory” to “good” model performance, while the RSR improved from “good” to “very good” model performance at Deraniyagala, indicating the innovative multi-site calibration approach demonstrated a significant improvement in the results. Hence, this study will provide valuable insights for hydrological modelers to determine the most appropriate calibration strategy for their large-scale watersheds, considering the spatial variation of the watershed characteristics, thereby reducing the uncertainty in hydrologic predictions.
Sammendrag
Data compilation of groundwater chemistry and freshwater abstraction documents the importance of groundwater as an economical resource in the Nordic Region. Management of groundwater require chemical monitoring to minimize risks for contamination, and mitigation is needed to identify anthropogenic and geogenic hazards related to groundwater quality (Kitterød et al, 2022). The interaction between groundwater and surface water is crucial for important ecological systems in the Nordic Region, and the impacts of climate change is a big challenge for hydrological and environmental research. The increased net global energy influx has impact on average temperature, seasonality, precipitation, and runoff, but issues related to water quality and groundwater have received less attention. The interaction between surface water and groundwater chemistry is embraced in the term hydrogeochemistry. In this context the geological framework plays a cardinal role in combination with residence time of water in the subsurface. Extensive sampling of hydrogeochemical variables have been undertaken in the Nordic Region and results are made available in public databases. Such data deserve more attention from the research community, and a pertinent challenge is to include geochemical variables in water balance studies and regional hydrological modeling. Reference: Kitterød, N-O, Kværner, J., Aagaard, P, Arustienė, J, de Beer, H, Bikše, J, Dagestad, A, Gundersen, P, Hansen, B, Hjartarson, Á, Karro, E, Klavins, M, Marandi, A, Putys, P, Radienė, R, Retiķe, I, Rossi, P M, and Thorling, L: Hydrogeology and Groundwater Quality in the Nordic Region. Submitted to Hydrology Research, 2022. Keywords: Hydrogeochemsitry; groundwater quality; surface water quality.