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.
2023
Sammendrag
More than 2/3rds of Norway’s agricultural area are grassland, and more than half of it is over 5 years old. Renewing old grassland increases annual yield but causes yield loss during renewal. Parts of the increased yield is due to replacement of low-productive species with high production species and cultivars, replacing biodiversity with productivity. Finding the optimal rate of renewal requires long term experiments to compare the sustainability of different strategies. Therefore, three field experiments were established to investigate the effect of difference renewal and harvest strategies on grass yield and quality, on similar mineral soil at Særheim (58.5°N, 5.6°E) in 1968 and Fureneset (61.3°N,5.0°E) in 1974, and on peat soil at Svanhovd (69.5°N,30.0°E) in 1968. Until 1991, the experiment included non-renewed treatments, and renewal every 3rd or 6th year. It was cut either two or three times a year, with autumn grazing on parts of the two-cut regime. The experiment was simplified in 1992, with the establishment of another non-renewed treatment, all treatments being cut 3 times a year (2 at Svanhovd), no grazing but contrasting slurry and compound fertilizer applications. This phase lasted until 2011, followed by period with no renewal and minimal registration. The third phase started in 2016, with renewal of all treatments at Fureneset and Særheim, except the permanent grassland from 1968/1974. Duration between renewals was doubled, and fertilizer applications revised. Presenting results from the third phase, we show that five to six years are required to recoup and significantly over-yield the non-renewed grassland. We will use soil chemical and physical properties, fertilizer application and yield gaps as well as ecological succession from sown seed mixture in 2017 till 2022 grassland to discuss the why we needed six years for all renewed treatments to over-yield permanent grassland from 1974.
Forfattere
Jian LiuSammendrag
Det er ikke registrert sammendrag
Forfattere
Arne Verstraeten Peter Waldner Aldo Marchetto Andreas Schmitz Nicholas Clarke Anne Thimonier Catherine Hilgers Anne-Katrin Prescher Karin HansenSammendrag
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Forfattere
Ludmila Sromek Eeva Ylinen Mervi Kunnasranta Simo Maduna Tuula Sinisalo Craig T. Michell Kit M. Kovacs Christian Lydersen Evgeny Ieshko Elena Andrievskaya Vyacheslav Alexeev Sonja Leidenberger Snorre Hagen Tommi NymanSammendrag
Studies on host–parasite systems that have experienced distributional shifts, range fragmentation, and population declines in the past can provide information regarding how parasite community richness and genetic diversity will change as a result of anthropogenic environmental changes in the future. Here, we studied how sequential postglacial colonization, shifts in habitat, and reduced host population sizes have influenced species richness and genetic diversity of Corynosoma (Acanthocephala: Polymorphidae) parasites in northern European marine, brackish, and freshwater seal populations. We collected Corynosoma population samples from Arctic, Baltic, Ladoga, and Saimaa ringed seal subspecies and Baltic gray seals, and then applied COI barcoding and triple-enzyme restriction-site associated DNA (3RAD) sequencing to delimit species, clarify their distributions and community structures, and elucidate patterns of intraspecific gene flow and genetic diversity. Our results showed that Corynosoma species diversity reflected host colonization histories and population sizes, with four species being present in the Arctic, three in the Baltic Sea, two in Lake Ladoga, and only one in Lake Saimaa. We found statistically significant population-genetic differentiation within all three Corynosoma species that occur in more than one seal (sub)species. Genetic diversity tended to be high in Corynosoma populations originating from Arctic ringed seals and low in the landlocked populations. Our results indicate that acanthocephalan communities in landlocked seal populations are impoverished with respect to both species and intraspecific genetic diversity. Interestingly, the loss of genetic diversity within Corynosoma species seems to have been less drastic than in their seal hosts, possibly due to their large local effective population sizes resulting from high infection intensities and effective intra-host population mixing. Our study highlights the utility of genomic methods in investigations of community composition and genetic diversity of understudied parasites.
Forfattere
Stig Strandli GezeliusSammendrag
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Forfattere
Sandra Rojas-Botero Leonardo H. Teixeira Johannes KollmannSammendrag
Urban grasslands are crucial for biodiversity and ecosystem services in cities, while little is known about their multifunctionality under climate change. Thus, we investigated the effects of simulated climate change, i.e., increased [CO2] and temperature, and reduced precipitation, on individual functions and overall multifunctionality in mesocosm grasslands sown with forbs and grasses in four different proportions aiming at mimicking road verge grassland patches. Climate change scenarios RCP2.6 (control) and RCP8.5 (worst-case) were simulated in walk-in climate chambers of an ecotron facility, and watering was manipulated for normal vs. reduced precipitation. We measured eight indicator variables of ecosystem functions based on below- and aboveground characteristics. The young grassland communities responded to higher [CO2] and warmer conditions with increased vegetation cover, height, flower production, and soil respiration. Lower precipitation affected carbon cycling in the ecosystem by reducing biomass production and soil respiration. In turn, the water regulation capacity of the grasslands depended on precipitation interacting with climate change scenario, given the enhanced water efficiency resulting from increased [CO2] under RCP8.5. Multifunctionality was negatively affected by reduced precipitation, especially under RCP2.6. Trade-offs arose among single functions that performed best in either grass- or forb-dominated grasslands. Grasslands with an even ratio of plant functional types coped better with climate change and thus are good options for increasing the benefits of urban green infrastructure. Overall, the study provides experimental evidence of the effects of climate change on the functionality of urban ecosystems. Designing the composition of urban grasslands based on ecological theory may increase their resilience to global change.
Forfattere
Kjersti Holt HanssenSammendrag
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Forfattere
Gunnhild SøgaardSammendrag
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Sammendrag
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Sammendrag
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