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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.

2019

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Sammendrag

The nitrogen cycle has been radically changed by human activities1 . China consumes nearly one third of the world’s nitrogen fertilizers. The excessive application of fertilizers2,3 and increased nitrogen discharge from livestock, domestic and industrial sources have resulted in pervasive water pollution. Quantifying a nitrogen ‘boundary’4 in heterogeneous environments is important for the effective management of local water quality. Here we use a combination of water-quality observations and simulated nitrogen discharge from agricultural and other sources to estimate spatial patterns of nitrogen discharge into water bodies across China from 1955 to 2014. We find that the critical surface-water quality standard (1.0 milligrams of nitrogen per litre) was being exceeded in most provinces by the mid-1980s, and that current rates of anthropogenic nitrogen discharge (14.5 ± 3.1 megatonnes of nitrogen per year) to fresh water are about 2.7 times the estimated ‘safe’ nitrogen discharge threshold (5.2 ± 0.7 megatonnes of nitrogen per year). Current efforts to reduce pollution through wastewater treatment and by improving cropland nitrogen management can partially remedy this situation. Domestic wastewater treatment has helped to reduce net discharge by 0.7 ± 0.1 megatonnes in 2014, but at high monetary and energy costs. Improved cropland nitrogen management could remove another 2.3 ± 0.3 megatonnes of nitrogen per year—about 25 per cent of the excess discharge to fresh water. Successfully restoring a clean water environment in China will further require transformational changes to boost the national nutrient recycling rate from its current average of 36 per cent to about 87 per cent, which is a level typical of traditional Chinese agriculture. Although ambitious, such a high level of nitrogen recycling is technologically achievable at an estimated capital cost of approximately 100 billion US dollars and operating costs of 18–29 billion US dollars per year, and could provide co-benefits such as recycled wastewater for crop irrigation and improved environmental quality and ecosystem services.

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Sammendrag

Soil is one of the most species-rich habitats and plays a crucial role in the functioning of terrestrial ecosystems. It is acknowledged that soils and their biota deliver many ecosystem services. However, up to now, cultural ecosystem services (CES) provided by soil biodiversity remained virtually unknown. Here we present a multilingual and multisubject literature review on cultural benefits provided by belowground biota in European forests. We found 226 papers mentioning impact of soil biota on the cultural aspects of human life. According to the reviewed literature, soil organisms contribute to all CES. Impact on CES, as reflected in literature, was highest for fungi and lowest for microorganisms and mesofauna. Cultural benefits provided by soil biota clearly prevailed in the total of the reviewed references, but there were also negative effects mentioned in six CES. The same organism groups or even individual species may have negative impacts within one CES and at the same time act as an ecosystem service provider for another CES. The CES were found to be supported at several levels of ecosystem service provision: from single species to two or more functional/taxonomical groups and in some cases morphological diversity acted as a surrogate for species diversity. Impact of soil biota on CES may be both direct – by providing the benefits (or dis-benefits) and indirect – through the use of the products or services obtained from these benefits. The CES from soil biota interacted among themselves and with other ES, but more than often, they did not create bundles, because there exist temporal fluctuations in value of CES and a time lag between direct and indirect benefits. Strong regionality was noted for most of CES underpinned by soil biota: the same organism group or species may have strong impact on CES (positive, negative or both) in some regions while no, minor or opposite effects in others. Contrarily to the CES based on landscapes, in the CES provided by soil biota distance between the ecosystem and its CES benefiting area is shorter (CES based on landscapes are used less by local people and more by visitors, meanwhile CES based on species or organism groups are used mainly by local people). Our review revealed the existence of a considerable amount of spatially fragmented and semantically rich information highlighting cultural values provided by forest soil biota in Europe.

Sammendrag

A complete diallel cross was made among nine Betula pendula trees growing in a natural population and a trial was planted on agricultural soil at one site. This exceptional trial has provided estimates of genetic parameters that can only be estimated in complete diallels. Traits measured were height and diameter during a period of 37 years, and assessments were made of bud burst, leaf abscission and rust infection at the early ages. All traits showed genetic variation and the variance components of general combining ability (GCA) effects were dominating, with heritability estimates of 0.16 and 0.23 for height and diameter at age six years. The best-growing families could be identified at that age. At age 37 years, when the trial had been thinned twice, the offspring from the highest and lowest ranked parent for growth contributed with 19% and 6% of the total volume of the stand, respectively. The GCA effects were also highly significant for the assessment traits, but with an interaction with year for bud burst. High values of estimates of genetic correlations proved that bud burst, leaf abscission and rust infection are interrelated, and also to some extent with growth traits. Families with an early bud burst were tallest, were less affected by the rust fungus and kept their leaves later in the autumn.

Sammendrag

We investigated dissipation, earthworm and plant accumulation of organic contaminants in soil amended with three types of sewage sludge in the presence and absence of plants. After 3 months, soil, plants and earthworms were analyzed for their content of organic contaminants. The results showed that the presence of plant roots did not affect dissipation rates, except for galaxolide. Transfer of galaxolide and triclosan to earthworms was significant, with transfer factors of 10–60 for galaxolide and 140–620 for triclosan in the presence of plants. In the absence of plants, transfer factors were 2–9 times higher. The reduced transfer to worms in the presence of plants was most likely due to roots serving as an alternative food source. Nonylphenol monoethoxylate rapidly dissipated in soil, but initial exposure resulted in uptake in worms, which was detected even 3 months after sewage sludge application. These values were higher than the soil concentration at the start of the exposure period. This indicates that a chemical's short half-life in soil is no guarantee that it poses a minimal environmental risk, as even short-term exposure may cause bioaccumulation and risks for chronic or even transgenerational effects.