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.
2020
Forfattere
D. Balasubramanian Wen-Jun Zhou Hong-Li Ji John Grace Xiao-Long Bai Qing-Hai Song Yun-Tong Liu Li-Qing Sha Xue-Hai Fei Xiang Zhang Junbin Zhao Jun-Fu Zhao Zheng-Hong Tan Yi-Ping ZhangSammendrag
In order to predict the effects of climate change on the global carbon cycle, it is crucial to understand the environmental factors that affect soil carbon storage in grasslands. In the present study, we attempted to explain the relationships between the distribution of soil carbon storage with climate, soil types, soil properties and topographical factors across different types of grasslands with different grazing regimes. We measured soil organic carbon in 92 locations at different soil depth increments, from 0 to 100 cm in southwestern China. Among soil types, brown earth soils (Luvisols) had the highest carbon storage with 19.5 ± 2.5 kg m−2, while chernozem soils had the lowest with 6.8 ± 1.2 kg m−2. Mean annual temperature and precipitation, exerted a significant, but, contrasting effects on soil carbon storage. Soil carbon storage increased as mean annual temperature decreased and as mean annual precipitation increased. Across different grassland types, the mean carbon storage for the top 100 cm varied from 7.6 ± 1.3 kg m−2 for temperate desert to 17.3 ± 2.9 kg m−2 for alpine meadow. Grazing/cutting regimes significantly affected soil carbon storage with lowest value (7.9 ± 1.5 kg m−2) recorded for cutting grass, while seasonal (11.4 ± 1.3 kg m−2) and year-long (12.2 ± 1.9 kg m−2) grazing increased carbon storage. The highest carbon storage was found in the completely ungrazed areas (16.7 ± 2.9 kg m−2). Climatic factors, along with soil types and topographical factors, controlled soil carbon density along a soil depth in grasslands. Environmental factors alone explained about 60% of the total variation in soil carbon storage. The actual depth-wise distribution of soil carbon contents was significantly influenced by the grazing intensity and topographical factors. Overall, policy-makers should focus on reducing the grazing intensity and land conversion for the sustainable management of grasslands and C sequestration.
Sammendrag
Tap av leveområder er den viktigste trusselen mot pollinatorer i dag. Det er derfor viktig å ivareta de gode leveområdene som finnes i kulturlandskapet. Målet med dette prosjektet er å gi kunnskap om hvilke areal i et vanlig jordbrukslandskap som er gode leveområder for pollinatorer og evaluere skjøtselmetoder som er egnet for å ivareta pollinatorer. Denne kunnskapen kan brukes til å utforme eller fortsette med tiltak som sikrer og opprettholder et nettverk av gode leveområder i kulturlandskapet...
Sammendrag
Forskrift til gjødslingsplanlegging stiller krav til at næringen tar ut representative jordprøver og at analyseresultatene benyttes for å lage en gjødslingsplan. Denne rapporten beskriver status for de jordprøver som tas ut i regi av næringen. Rapporten foreslår en standardisert datafangst av jordprøvene og en standardisert dataforvaltning av analyseresultatene.....
Sammendrag
Rapporten gir status for husdyrrasene som er med i Produksjonstilskudd for bevaringsverdige husdyrraser. Rapporten trekker fram aktuelle problemstillinger for utviklingen av disse rasene. Alle de aktuelle rasene viser en økende trend, samtidig som hver art har ulike problemstillinger som det kan være aktuelt å få mer kunnskap om for å opprettholde den positive trender.
Sammendrag
kunnskap om hjortens arealbruk på indre Sunnmøre til grunnlag for hjorteforvaltningen i regionen. Rapporten tar også for seg påkjørsler av hjort i studieområdet og det er gjennomført analyser av risiko for påkjørsler. Rapporten oppsummerer resultatene fra prosjektet og diskuterer disse i lys av hjorteforvaltningen.
Sammendrag
Soil respiration is an important ecosystem process that releases carbon dioxide into the atmosphere. While soil respiration can be measured continuously at high temporal resolutions, gaps in the dataset are inevitable, leading to uncertainties in carbon budget estimations. Therefore, robust methods used to fill the gaps are needed. The process-based non-linear least squares (NLS) regression is the most widely used gap-filling method, which utilizes the established relationship between the soil respiration and temperature. In addition to NLS, we also implemented three other methods based on: 1) artificial neural networks (ANN), driven by temperature and moisture measurements, 2) singular spectrum analysis (SSA), relying only on the time series itself, and 3) the expectation-maximization (EM) approach, referencing to parallel flux measurements in the spatial vicinity. Six soil respiration datasets (2017–2019) from two boreal forests were used for benchmarking. Artificial gaps were randomly introduced into the datasets and then filled using the four methods. The time-series-based methods, SSA and EM, showed higher accuracies than NLS and ANN in small gaps (<1 day). In larger gaps (15 days), the performance was similar among NLS, SSA and EM; however, ANN showed large errors in gaps that coincided with precipitation events. Compared to the observations, gap-filled data by SSA showed similar degree of variances and those filled by EM were associated with similar first-order autocorrelation coefficients. In contrast, data filled by both NLS and ANN exhibited lower variance and higher autocorrelation than the observations. For estimations of the annual soil respiration budget, NLS, SSA and EM resulted in errors between −3.7% and 5.8% given the budgets ranged from 463 to 1152 g C m−2 year−1, while ANN exhibited larger errors from −11.3 to 16.0%. Our study highlights the two time-series-based methods which showed great potential in gap-filling carbon flux data, especially when environmental variables are unavailable.
Sammendrag
Genetic selection in commercial sheep production has mainly focussed on production traits and to a large extent ignoring behavioural traits, such as response towards predators. The Icelandic leadersheep is a sheep breed selected and known for its special behavioural traits, such as leading the flock and bringing it home from pasture in case of danger. Those traits are also said to be beneficial in areas with a high predator pressure. In this study, it was investigated if there are behavioural differences in sheep flocks with and without a leadersheep present. Behaviour of sheep flocks was observed before, during and after a predator test, in small groups of Icelandic sheep with or without a leadersheep in the group. Eleven groups of Icelandic sheep with six ewes in each group were observed in a test arena while a human, a dog and a drone passed through the pasture. Six of the groups included a leadersheep and the remaining five did not. Groups including a leadersheep spent more time grazing after both the human and dog test, indicating a faster recovering to normal behaviour. They were also located close to the exit during the dog test compared to groups without a leadersheep, fitting well with the assertion that leadersheep bring the flock home in case of danger. During the drone test, groups with a leadersheep however spent more time moving around compared to the other groups. Since the sheep had experienced both humans and dogs before, but not drones, this may indicate that groups with leadersheep recovered quickly from the figurants they had experienced before, but tended to react more in the test which was a new situation. In conclusion, it appears likely that the earlier selection for leader traits in the leadersheep have indeed changed both their own behaviour and also that this has an effect on the behaviour of group members.
Sammendrag
Young forest stands and clearcuts in the boreal forest created by modern forestry practices along with meadows of abandoned summer farms may contribute as feeding areas for beef cattle. The patchy distribution and varying quality and diversity of forage on such unimproved lands may affect cattle productivity. Weight gain of 336 beef cows and 270 calves free-ranging during three summer grazing seasons was monitored in boreal forests of southeastern Norway, stocked at either high (0.16 cows ha-1) and low (0.04 cows ha-1) stocking densities. We used linear mixed effect models for assessing intrinsic correlates of weight gain in cows and calves in the two areas. Habitat use and home range size of a subsample of 53 cows were monitored by using GPS collars programmed to log locations at 5 min. intervals during the grazing season. Additional extrinsic correlates of weight gain for the subsampled cows using a linear mixed model were also tested. Average weight gain of beef cows grazing at the low stocking density was positive among cows of early maturing breeds (represented by Hereford) gaining 24 ± 2.8 kg ( ± SE), while cows of late maturing breeds (mainly represented by Charolais) had an average weight loss of 9 ± 8.4 kg. The average weight gain was negative for beef cows of both early (Herefords) and late maturing breeds (mainly represented by Charolais but also Limousin and Simmental) at the high stocking density. Within both breed groups, there was a negative relationship between breed-specific average weight of cows at turnout and weight gain during the grazing period, while a prolonged grazing period was slightly positively related to weight gain. There was no relationship between weight gain and home range size and proportion of grazing habitat for the 53 cows fitted with GPS collars. Higher weight gains in calves of the low compared to the high stocking density area was found. However, there was no breed effect of weight gain in calves. Across study areas, spring-born suckler calves gained more weight than autumn-born calves (92 ± 1.7 kg vs. 65 ± 4.4 kg). Also, there were higher weight gains for springborn bull-calves than spring-born heifers (100 ± 2.4 kg vs. 94 ± 2.2 kg). Overall, the results indicate that it is possible to achieve acceptable weight gains for cattle grazing coniferous forest by finding breeds suitable for these extensive areas and stocking at moderate densities.
Sammendrag
Wheat dwarf virus (WDV), a mastrevirus transmitted by the leafhopper Psammotettix alienus, causes a severe disease in cereal crops. Typical symptoms of wheat plants infected by WDV are yellowing and severe dwarfing. In this present study, RNA-Seq was used to perform gene expression analysis in wheat plants in response to WDV infection. Comparative transcriptome analysis indicated that a total of 1042 differentially expressed genes (DEGs) were identified in the comparison between mock and WDV-inoculated wheat plants. Genomes ontology (GO) annotation revealed a number of DEGs associated with different biological processes, such as phytohormone metabolism, photosynthesis, DNA metabolic process, response to biotic stimulus and defense response. Among these, DEGs involved in phytohormone and photosynthesis metabolism and response pathways were further enriched and analyzed, which indicated that hormone biosynthesis, signaling and chloroplast photosynthesis-related genes might play an important role in symptom development after WDV infection. These results illustrate the dynamic nature of the wheat-WDV interaction at the transcriptome level and confirm that symptom development is a complex process, providing a solid foundation to elucidate the pathogenesis of WDV.
Forfattere
Hans Martin Hanslin Trygve S. Aamlid J. Kollmann T. Lennartson Ellen Johanne Svalheim Eveliina KallioniemiSammendrag
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