Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2017
Authors
Till SeehusenAbstract
No abstract has been registered
Authors
Annelene Pengerud Marie-France Dignac Giacomo Certini Line Tau Strand Claudia Forte Daniel RasseAbstract
Increased mineralization of the organic matter (OM) stored in permafrost is expected to constitute the largest additional global warming potential from terrestrial ecosystems exposed to a warmer climate. Chemical composition of permafrost OM is thought to be a key factor controlling the sensitivity of decomposition to warming. Our objective was to characterise OM from permafrost soils of the European Arctic: two mineral soils—Adventdalen, Svalbard, Norway and Vorkuta, northwest Russia— and a ‘‘palsa’’ (ice-cored peat mound patterning in heterogeneous permafrost landscapes) soil in Neiden, northern Norway, in terms of molecular composition and state of decomposition. At all sites, the OM stored in the permafrost was at an advanced stage of decomposition, although somewhat less so in the palsa peat. By comparing permafrost and active layers, we found no consistent effect of depth or permafrost on soil organic matter (SOM) chemistry across sites. The permafrost-affected palsa peat displayed better preservation of plant material in the deeper layer, as indicated by increasing contribution of lignin carbon to total carbon with depth, associated to decreasing acid (Ac) to aldehyde (Al) ratio of the syringyl (S) and vanillyl (V) units, and increasing S/V and contribution of plant-derived sugars. By contrast, in Adventdalen, the Ac/Al ratio of lignin and the Alkyl C to O-alkyl C ratio in the NMR spectra increased with depth, which suggests less oxidized SOM in the active layer compared to the permafrost layer. In Vorkuta, SOM characteristics in the permafrost profile did not change substantially with depth, probably due to mixing of soil layers by cryoturbation. The composition and state of decomposition of SOM appeared to be site-specific, in particular bound to the prevailing organic or mineral nature of soil when attempting to predict the SOM proneness to degradation. The occurrence of processes such as palsa formation in organic soils and cryoturbation should be considered when up-scaling and predicting the responses of OM to climate change in arctic soils.
Authors
Kjersti Holt HanssenAbstract
No abstract has been registered
Authors
Ingeborg Callesen Marjo M. Palviainen O. Janne Kjønaas Kȩstutis E. Armolaitis Charlotte RasmussenAbstract
Soil texture is a key soil physical property for soil quality and used in modeling studies through pedotransfer functions (PTF) for the prediction of physical, e.g. hydraulic, soil properties. Soil texture is quantified by a particle size distribution (PSD) of the fine earth fraction and often translated into a texture class using defined separates of clay (0 - 2 µm), silt (2 µm to 20 µm, 50 µm or 63 µm) and sand (20 µm, 50 µm or 63 µm up to 2 mm) illustrated in a texture triangle. Until now pretreatment methods (e.g. humus and carbonate removal and dispersion) followed by standardised sedimentation and sieving methods have been well-defined. From literature and a mini-survey, we know already that laser diffraction is a commonly used analytical method for soil PSD determination in scientific environmental studies that involve soils. A body of literature has documented that colloid-sized fraction results obtained by laser diffraction analysis of fine-textured soil samples are not comparable to those obtained with sedimentation and sieving methods, when translating to the traditional particle size limits clay, silt and sand. Also, operating procedures for pretreatment of soil samples are variable, and the analyzed sample volumes are small, adding to uncertainty. In this study we first compared PSD’s from three different instruments for a set of soil samples to study reproducibility using the analytical operating procedures developed by the owner institutions (Malvern Mastersizer 2000, University of Copenhagen, Coulter LS230, University of Helsinki, and Sympatec Helos, Aarhus University). Secondly, we compared the influence of 1 mm sieving and found decreased fraction standard deviation and improved repeatability of the PSD determination by laser diffraction on the Coulter LS230. 1 mm sieving should be corrected for if the mass is more than a few percent, but depending on study purpose. Thirdly, the laser diffraction PSD’s were compared with PSD’s obtained by sieving and hydrometer analysis showing well-known underestimation of colloids and fine fractions, that increased with colloid content. We conclude that PSD’s obtained by the laser diffraction method are repeatable and mostly reproducible given standardised pretreatment. Translation to texture class using traditional separates does not work well, and more work and new PTF’s for soils are needed that can translate a laser diffraction PSD into a texture class and its associated physical properties for further use in modeling studies.
Abstract
The statistical model MESAW (Matrix Equations for Source Apportionment on Watershed) was used to estimate the diffuse unit-area source emission coefficients of nitrogen in Estonian rivers. The input data included monitored riverine loads, point sources and land use categories from a total of 50 rivers/catchment areas. Two independent studies were conducted: the estimation of emission coefficients for the whole of Estonia and for a smaller study area near Tallinn. The results from both cases showed that drained peat soils were the highest diffuse source contributor in unit-area loads. The results show that the unit-area loads from drained peat soils were up to 2.3 times higher than from arable land. Moreover, a comparison of emission coefficients for the whole of Estonia and for the Tallinn catchment area indicated that coefficients can vary significantly between sources and single years. Additional detailed studies and monitoring are needed to support these conclusions.
Authors
Habtamu AlemAbstract
No abstract has been registered
Authors
Ole Martin Eklo Jens Kværner Eivind Solbakken Marianne Stenrød Roar Lågbu Randi Bolli Marit Almvik Sven R. Odenmarck Ivar Solberg Stein SorknesAbstract
No abstract has been registered
Authors
Erling Meisingset Leif Egil Loe Øystein Brekkum Richard Bischof Inger Maren Rivrud Unni Støbet Lande Barbara Zimmermann Vebjørn Veiberg Atle MysterudAbstract
1. Population-level management is difficult to achieve if wildlife routinely crosses administrative boundaries, as is particularly frequent for migratory populations. However, the degree of mismatch between management units and scales at which ecological processes operate has rarely been quantified. Such insight is vital for delimiting functional population units of partially migratory species common in northern forest ecosystems. 2. We combined an extensive dataset of 412 GPS-marked red deer (Cervus elaphus) across Norway with information on the size and borders of two administrative levels, the governmental level (municipality) and landowner level (local management units, LMUs), to determine the timing and scale of mismatch between animal space use and management units. We analysed how landscape characteristics affected the use of management units and the timing and likelihood of crossing borders between them, in an effort to delineate more appropriate units in various landscapes. 3. Median municipality size could potentially cover 70% of female and 62% of male annual ranges, while only 12% and 4% of LMUs were expansive enough to accommodate migratory routes in females and males, respectively. Red deer migrate along elevational gradients and are more likely to find both suitable lowland winter habitat and higher summer habitat within management units with variable topography. Consistent with this, the likelihood of border crossing decreased with increasing diversity of elevations. 4. Synthesis and applications. We demonstrate a considerable mismatch between animal space use and management units. Far-ranging movements and frequent administrative border crossings during autumn migration coincides with the period of active management (hunting season). Our study also highlights that, due to extensive movements of males, coordination of management aims may provide a more realistic avenue than increasing sizes of local management units. A more general insight is that the degree of mismatch between range use and management units depends on the season and landscape type. This needs to be accounted for when delimitating functional population units of migratory populations.
Authors
Annette Dathe Attila Nemes Esther Bloem Matthew Patterson Daniel Gimenez Anna Angyal Johannes Koestel Nicholas JarvisAbstract
No abstract has been registered
Authors
Annette Dathe Attila Nemes Esther Bloem Matthew Patterson Daniel Gimenez Julia Szocs Johannes Koestel Nicholas JarvisAbstract
No abstract has been registered