Found 9830 publications. Showing page 388 of 394:
Volatile and persistent emissions from traffic and power production on Svalbard. VETAPOS. NILU OR
Volatile organic compounds (VOC) including Benzene-Toluene-Xylene (BTX) related compounds were monitored in ambient air samples during Spring (April-Mai) and Autumn (October) 2010 as a follow-up of an earlier BTX ambient air monitoring program in 2007 (Reimann et al 2007) at the Research park in Longyearbyen (Forskningsparken). In addition, BTX related compounds were measured in 18 ¿headspace¿ samples above collected surface soil along snowmobile tracks in Longyeardalen, Adventdalen, Todalen as well as Sassendalen (Fredheim). In addition, during the 2010 VETAPOS in a parallel surface soil sampling campaign 18 samples were analysed for 15 priority PAH compounds.
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2006
Volatile organic compounds in the museum environment - a PTR-TOF pilot study on canvas samples. NILU F
2013
2013
Fungus-farming termites cultivate a Termitomyces fungus monoculture in enclosed gardens (combs) free of other fungi, except during colony declines, where Pseudoxylaria spp. stowaway fungi appear and take over combs. Here, we determined Volatile Organic Compounds (VOCs) of healthy Macrotermes bellicosus nests in nature and VOC changes associated with comb decay during Pseudoxylaria takeover. We identified 443 VOCs and unique volatilomes across samples and nest volatilomes that were mainly composed of fungus comb VOCs with termite contributions. Few comb VOCs were linked to chemical changes during decay, but longipinocarvone and longiverbenone were only emitted during comb decay. These terpenes may be involved in Termitomyces defence against antagonistic fungi or in fungus-termite signalling of comb state. Both comb and Pseudoxylaria biomass volatilomes contained many VOCs with antimicrobial activity that may serve in maintaining healthy Termitomyces monocultures or aid in the antagonistic takeover by Pseudoxylaria during colony decline. We further observed a series of oxylipins with known functions in the regulation of fungus germination, growth, and secondary metabolite production. Our volatilome map of the fungus-farming termite symbiosis provides new insights into the chemistry regulating complex interactions and serves as a valuable guide for future work on the roles of VOCs in symbioses.
John Wiley & Sons
2025
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2014
Extreme winter events that damage vegetation are considered an important climatic cause of arctic browning—a reversal of the greening trend of the region—and possibly reduce the carbon uptake of northern ecosystems. Confirmation of a reduction in CO2 uptake due to winter damage, however, remains elusive due to a lack of flux measurements from affected ecosystems. In this study, we report eddy covariance fluxes of CO2 from a peatland in northern Norway and show that vegetation CO2 uptake was delayed and reduced in the summer of 2014 following an extreme winter event earlier that year. Strong frost in the absence of a protective snow cover—its combined intensity unprecedented in the local climate record—caused severe dieback of the dwarf shrub species Calluna vulgaris and Empetrum nigrum. Similar vegetation damage was reported at the time along ~1000 km of coastal Norway, showing the widespread impact of this event. Our results indicate that gross primary production (GPP) exhibited a delayed response to temperature following snowmelt. From snowmelt up to the peak of summer, this reduced carbon uptake by 14 (0–24) g C m−2 (~12% of GPP in that period)—similar to the effect of interannual variations in summer weather. Concurrently, remotely-sensed NDVI dropped to the lowest level in more than a decade. However, bulk photosynthesis was eventually stimulated by the warm and sunny summer, raising total GPP. Species other than the vulnerable shrubs were probably resilient to the extreme winter event. The warm summer also increased ecosystem respiration, which limited net carbon uptake. This study shows that damage from a single extreme winter event can have an ecosystem-wide impact on CO2 uptake, and highlights the importance of including winter-induced shrub damage in terrestrial ecosystem models to accurately predict trends in vegetation productivity and carbon sequestration in the Arctic and sub-Arctic.
2018
Vurdering av CLEO for norske reindriftsutøvere
Denne rapporten er en evaluering av Local Environmental Observer (LEO) Network ved bruk av erfaringene fra pilottestene utført i perioden 2016-2020 av arktiske akademikere, urfolksinstitusjoner og samisk samfunn i Norge. Rapporten prøver å finne svar på hvordan man kan tilrettelegge for innrapportering av observasjoner på lokale miljøendringer blant norske reindriftsutøvere samt opprettholde en utstrakt bruk. Dette for å skape engasjement, bevisstgjøring, forsterke lokale stemmer og identifisere svar på viktige miljøutfordringer og mulige handlinger, og søke konstruktive og respektfulle måter å dele informasjon og samarbeid mellom ulike kunnskapssystemer.
Rapporten konkluderer med at for å gjøre det mulig for norske reindriftsutøvere å rapportere inn observasjoner av klimaendringer i miljøet, og legge til rette for en utstrakt og kontinuerlig bruk, bør det bygges en egen Sápmi løsning.
NILU
2021