Hopp til hovedinnholdet

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.

2017

Til dokument

Sammendrag

I dette kapitlet peker Ekspertrådet på hva vi mener er en fornuftig kurs for videre utvikling av fagsystemet. Vi omtaler problemer knyttet til manglende samordning, både med hensyn til begrepsbruk og definisjoner, og med hensyn til bruk av innsamlede data. Manglende felles tilnærming gjør at det kan oppstå unødvendige misforståelser som forsinker prosesser. Vi peker også på omfattende mangel på økologiske overvåkingsdata, og gir noen synspunkter på behovet for mer overvåking.

Sammendrag

In Norway the common ash (Fraxinus excelsior L.) has its northernmost distribution in Europe. It grows along the coastal range as small fragmented populations. The first occurrence of ash dieback caused by Hymenoscyphus fraxineus in Norway was reported in 2008. At that time, the disease had already spread through large areas of southern and south-eastern parts of Norway. Since then the disease continued spreading with a speed of about 50- 60 km per year along the western coastal range. To monitor the disease development over time, we established eight permanent monitoring plots in south-eastern and western Norway in 2009 and 2012, respectively. In all plots tree mortality was high, especially among the youngest trees in south-eastern Norway. The extent of crown damage has continually increased in all diameter classes for both regions. In 2009, 76.8 % of all trees on the five monitoring plots in south-eastern Norway were considered to be healthy or slightly damaged, and only 8.9 % to be severely damaged. In 2015, 51.7 % were dead, 13.5 % severely damaged and only 25.7 % remained healthy or slightly damaged. To assess the infection pressure and spore dispersal patterns of the pathogen, we used a Burkard volumetric spore sampler placed in an infested ash stand in southern Norway. We examined the airborne ascospores of H. fraxineus and H. albidus captured on the sampling tape microscopically and with real-time PCR assays specific to these fungi. We detected very few ascospores of H. albidus, whereas ascospores of H. fraxineus dominated throughout entire sampling periods of 2009, 2010 and 2011. Spore discharge occurred mainly between the hours of 5 and 8 a.m., though the distinctive sporulation had yearly variation between 5-7 a.m. We observed the same diurnal pattern throughout the entire sampling period, with a seasonal peak in spore liberation between mid-July and midAugust, after which the number of ascospores decreased substantially. Similar diurnal patterns were observed throughout the sampling period except that after mid-August the number of trapped ascospores substantially decreased. To compare the genetic pattern of common ash in the northern and central ranges of Europe we analyzed the Norwegian samples together with available samples from central Europe by using chloroplast and nuclear microsatellite markers. We found that the northern range of common ash was colonized via a single migration route that originated in eastern or south-eastern Europe with little influence originating from other southern or western European refugia. In the northern range margins, genetic diversity decreased and population differentiation increased, coherent with a post-glacial colonization history characterized by founder events and population fluctuations. Based on our findings we discuss the future management and conservational implications.

Til dokument

Sammendrag

This chapter presents an analysis of land cover changes in Eastern Europe between 1990 and 2006, assessed using CORINE (Co-ORdination of INformation on the Environment) Land Cover (CLC) datasets. The plethora of potential land cover change categories were condensed into seven categories of major land use change processes: urbanization, agricultural intensification, agricultural extensification, afforestation, deforestation, construction and management of water bodies, and other changes. The amounts of each change category and their spatial distributions are summarized, and the change categories were also mapped to show the relative amounts of change (per 3 × 3 km2) between 1990 and 2000 and between 2000 and 2006. The results showed that while more afforestation than deforestation was observed in the first period, the reverse was true in the second period, when deforestation outpaced afforestation. Urbanization and suburbanization were major processes in Eastern Europe, particularly around existing major cities, and the speed of this process generally increased from the first to the second period. Both the intensification and extensification of agriculture were common during both periods, but a larger effect was observed in the first period. Overall, land use changes were highest in central Europe and the Baltic countries and lowest in southeast Europe.