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.
2024
Sammendrag
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Sammendrag
Climate change is and will continue to alter plant responses to their environment. This is especially prominent concerning the adaptive tracking in reproductive phenology. For wind pollinated plants, this will substantially influence their pollen seasonality, yet there are gaps in knowledge about how environmental variation influences pollen seasonality. To investigate this, we monitored daily atmospheric pollen concentrations of seven pollen types from ecologically, economically and allergenically important plants (alder, hazel, willow, birch, pine, grass and mugwort) in twelve Norwegian locations spanning the entire country for up to 28 years. Six daily meteorological variables (maximum temperature, precipitation, wind speed, relative humidity, solar radiation and atmospheric pressure) was obtained from the MET Nordic dataset with full data cover. The pollen seasonality was then modelled using four spatial, three temporal and the six meteorological variables in a generalized linear model approach with a negative binomial distribution to investigate how each variable group thematically and individually contribute to variation in pollen seasonality. We found that the full models explained the most variation, ranging from R2 = 20.3 % to 59.5 %. The models were also highly accurate, being able to predict 54.5 % to 99.1 % of daily pollen concentrations to within 20.1 pollen grains/m3. Overall, the temporal variables were able to explain more variation than spatial and meteorological variables for most pollen types. Month, altitude and maximum temperature were the most important single variables for each category. The importance of each variable could be traced back to their individual effects of reproductive phenology, plant metabolism, species distributions and pollen release processes. We further emphasise the importance of source maps and atmospheric regional transport models in further model improvements. By understanding the relevance of environmental variation to pollen seasonality we can make better predictions regarding the consequences of climate change on plant populations.
Sammendrag
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Sammendrag
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Sammendrag
Only approximately 2% of the land area in Northern Norway is suitable for agricultural purposes. The short growing season and cold climate impose limitations for what can be produced. Agriculture still takes place here, with forage crops for livestock being the most important. On free rangeland areas, including both semi-natural and natural habitats, livestock grazing is common. The biomass production on some of these rangelands is presumed to be high, although little is known about the actual fodder potential. In 2022 a preliminary study was performed to determine abundance and variety of wild pasture plants, dry matter yield (DM) and feed quality in the (presumed) highest yielding Vegetation types. Results showed an average of 1520 kg DM ha–1 in spring and 5380 kg DM ha–1 in autumn. Early season feed quality was high, but with rapidly decreasing trends. The number of pasture plants was also high. Our results show that in sub-arctic Northern Norway grazing animals can harvest substantial amounts of ‘free’ fodder of good quality, yet the official statistics show that only 14% of this resource is utilised. Continuous grazing is needed to maintain production and fodder quality in these areas.
Sammendrag
Climate change is already reducing carbon sequestration in Central European forests dramatically through extensive droughts and bark beetle outbreaks. Further warming may threaten the enormous carbon reservoirs in the boreal forests in northern Europe unless disturbance risks can be reduced by adaptive forest management. The European spruce bark beetle (Ips typographus) is a major natural disturbance agent in spruce-dominated forests and can overwhelm the defences of healthy trees through pheromone-coordinated mass-attacks. We used an extensive dataset of bark beetle trap counts to quantify how climatic and management-related factors influence bark beetle population sizes in boreal forests. Trap data were collected during a period without outbreaks and can thus identify mechanisms that drive populations towards outbreak thresholds. The most significant predictors of bark beetle population size were the volume of mature spruce, the extent of newly exposed clearcut edges, temperature and soil moisture. For clearcut edge, temperature and soil moisture, a 3-year time lag produced the best model fit. We demonstrate how a model incorporating the most significant predictors, with a time lag, can be a useful management tool by allowing spatial prediction of future beetle population sizes. Synthesis and Applications: Some of the population drivers identified here, i,e., spruce volume and clearcut edges, can be targeted by adaptive management measures to reduce the risk of future bark beetle outbreaks. Implementing such measures may help preserve future carbon sequestration of European boreal forests.
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Sammendrag
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Rapporten er utarbeidet på oppdrag for Miljødirektoratet. Den gir en oversikt over kunnskapsgrunnlag for mulige tiltak for å redusere utslipp av klimagasser fra drenert organisk jordbruksjord i Norge, både ved restaurering og ved fortsatt jordbruksdrift. Vurdering av egnete arealer for tiltak, muligheter for bokføring i det nasjonale klimagassregnskapet, positive og negative effekter av tiltakene inngår også.