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- Lappalainen, Hanna K., et al.
(författare)
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Pan-Eurasian Experiment (PEEX) : towards a holistic understanding of the feedbacks and interactions in the land-atmosphere-ocean-society continuum in the northern Eurasian region
- 2016
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 16:22, s. 14421-14461
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Tidskriftsartikel (refereegranskat)abstract
- The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic-boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX), a multi-scale, multi-disciplinary and international program started in 2012 (https://www.atm.helsinki.fi/peex/). PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land-atmosphereaquatic-society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context.
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| 2. |
- Laurén, Ari, et al.
(författare)
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Nitrogen and Carbon Dynamics and the Role of Enchytraeid Worms in Decomposition of L, F and H Layers of Boreal Mor
- 2012
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Ingår i: Water, Air and Soil Pollution. - : Springer Science and Business Media LLC. - 0049-6979 .- 1573-2932. ; 223:7, s. 3701-3719
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Tidskriftsartikel (refereegranskat)abstract
- Decomposition of organic material releases carbon dioxide (CO2) into the atmosphere, and dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and ammonium (NH4-N) into soil water. Each of the decomposition products contributes differently to overall export of carbon (C) and nitrogen (N) to water courses. Our aim was to study the quantity and composition of the released C and N as affected by the organic material and soil fauna, represented by enchytraeid worms. We measured the release rate of carbon dioxide, and calculated the release rates for DOC and dissolved N in soil from repeated measurements of DOC and N pools during laboratory incubation of litter (L), fermented (F) and humus (H) layers of boreal forest mor. The intermediate decomposition products, DOC and DON, were characterised according to the molecule size. The release rate of the decomposition products was higher for fresh than for old organic material. The majority of N and C were released as NH4-N and CO2, respectively. The amount of extractable organic N in soil decreased by time but DON increased. Enchytraeids stimulated N mineralisation and the release of large molecule size DOC, particularly in L layer. The results suggest that organic N in extractable form biodegrades effectively, and that soil fauna have an important role in the decomposition. The results were interpreted from the water quality point of view and the implications of the results to modelling of decomposition and export of DOC and dissolved N to recipient water bodies are discussed. In the modelling context, the novelty of the study is the description of the intermediate decomposition products and the division of the dissolved organic compounds into low molecular weight and high molecular weight fractions.
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