Plant and vegetation preferences for a high and a moderate yielding Norwegian dairy cattle breed grazing semi-natural mountain pastures

Plant and vegetation preferences of two Norwegian cattle breeds grazing semi-natural mountain pastures were studied for two weeks at two farms during one summer. Two rather different grazing sites gave the opportunity to study the two breeds at different pasture qualities, as well as to test if there is any interaction between breeds and study sites. Each of the two herds consisted of the old, moderate yielding Norwegian dairy breed Blacksided Trønder and Nordland Cattle (STN) and the modern, high yielding dairy breed Norwegian Red (NRF). In order to measure the plant preferences of the animals, faeces samples were collected and analysed for plant fragments. In addition, GPS-data showed the terrain chosen by the herds, and vegetation maps were drawn to find the connections between the grazed vegetation and plant preferences. The study shows that on nutrient and especially species rich vegetation growing on base and nutrient rich soil, as at the first study site (Skåbu), the plant species, plant genera and plant groups analysed for in the faeces samples indicate that both the STN and NRF breeds graze very much the same vegetation. However, the results from the second study site (Valdres), where the soil is less fertile, the plant species diversity is lower and the plant species distribution less uniform, the moderate yielding NRF breed seems to cover its higher nutritious requirements by grazing in areas with more nutrient rich vegetation compared to the lower yielding breed, STN.Préférences en termes de couvert végétal et d'espèces végétales des races bovines norvégiennes à forte production laitière ou modérée pâturant des prairies d'altitude semi-naturelles. Les préférences alimentaires de deux races bovines norvégiennes pâturant des prairies d'altitude semi-naturelles ont été étudiées durant deux semaines dans deux fermes pendant un été. Deux sites de pâturage ont permis d'étudier les deux races face à différentes qualités de pâturage et de tester une éventuelle interaction entre les races et les sites d'étude. Chacun des deux troupeaux comprenait des bovins laitiers de race Blacksided Trønder et Nordland (STN, race norvégienne ancienne avec une production laitière modérée) et des bovins de race Pie rouge (NRF, race prédominante en Norvège avec une production laitière élevée). Pour mesurer les préférences alimentaires des animaux au pâturage, des échantillons de fèces ont été collectés et analysés. En outre, les données GPS ont permis de localiser le site privilégié de pâture des animaux et la cartographie de la végétation a eu pour but de déterminer les relations existantes entre la végétation pâturée et la préférence des animaux pour certaines espèces végétales. Sur un couvert végétal riche en éléments nutritifs et particulièrement riche en espèces végétales se développant sur un sol basique et riche en nutriments, comme sur le premier site d'étude (Skåbu), les espèces, les genres et les familles de plantes détectées dans les échantillons de fèces indiquent que les races STN et NRF pâturent la même végétation. Sur le second site (Valdres), où le sol est moins fertile, la diversité des espèces est inférieure et la distribution des espèces est moins uniforme, la race NRF semble couvrir ses besoins nutritifs plus élevés en pâturant les secteurs où la végétation est nutritivement la plus riche comparativement à la race STN

New Small Aperture Broadband Arrays in the European Arctic

As part of the EPOS-Norway infrastructure project, NORSAR received funding from the Research Council of Norway for a new regional seismic array on Bjørnøya (Bear Island) in the European Arctic. After along planning phase, a six-element broadband array was installed by NORSAR staff in August 2019 and has been providing data to NORSAR in near real-time since then. Due to several logistical and administrative constraints the 6-element array has an aperture of only 300 m. All sites are equipped with Kinemetrics MBB-2 sensors and Earth Data EDR-209 digitizers that are installed in near-surface vaults. Data are automatically copied to the Norwegian node of the European Integrated Data Archive (EIDA) and are openly available. Due to environmental restrictions less than the planned 9 array sites could be installed on Bjørnøya and the non-used instruments are now available to extend the broadband station Hornsund (HSPB), Southern Spitsbergen, to another small aperture broadband array, also with 6 sites. The array installation had to be postponed because of the ongoing pandemic and is now planned for the Arctic summer 2021.poste

Plutonium Isotope Ratios in the Yenisey and Ob Estuaries

Over the past 50 years, nuclear weapons' tests and releases from the nuclear industry have introduced anthropogenic plutonium into the environment. In the Arctic environment, the main source of plutonium is from the atmospheric weapons testing, but previous studies of plutonium in the Kara Sea have shown that, at certain sites, other releases can give rise to enhanced local concentrations. The present paper presents results from determination of plutonium concentrations and isotope ratios in the sediment samples collected during various expeditions to the Kara Sea, the Ob and Yenisey estuaries and their river systems. The data indicated a clear influence from a low240Pu:239Pu source in surface sediments collected from the Yenisey estuary, whereas plutonium in Ob estuary sediments is dominated by global fallout. The results also show an increase in plutonium concentration (from 0.003 to 11Bq/kg) and a decrease in240Pu:239Pu isotope ratio (from 0.16 to 0.05) going upstream from the Yenisey estuary towards the nuclear installation at Krashnoyarsk

Transport of low 240 Pu/ 239 Pu atom ratio plutonium-species in the Ob and Yenisey Rivers to the Kara Sea

Plutonium (Pu) isotope ratios can be used to differentiate between sources of Pu contamination such as nuclear weapon production, weapon fallout as well as accidental and routine releases from nuclear installations. To obtain information on the contamination level, speciation and sources of Pu in the Ob and Yenisey river systems (Siberia, Russia) and the adjacent Kara Sea, water was size fractionated onboard ship and the concentrations and atom ratios of 240Pu and 239Pu in obtained water fractions (i.e. particles, colloids and low molecular mass species) were determined by accelerator mass spectrometry (AMS). Results show a clear difference in speciation between high 240Pu/239Pu atom ratio Pu derived from global weapon fallout and low 240Pu/239Pu atom ratio Pu, presumably originating from weapons grade Pu. In particular, the 240Pu/239Pu atom ratios (mean 0.18 ± 0.06) for particles (> 0.45 μm) could not be distinguished from global fallout Pu (0.17-0.19), whereas for low molecular mass (LMM; < 8 kDa) species the Pu ratio was much lower than for global fallout Pu in both rivers. The difference was especially well pronounced in the Ob (mean 240Pu/239Pu atom ratio 0.052 ± 0.023), where the difference was statistically significant (paired t-test, P = 0.02, n = 4). The low 240Pu/239Pu atom ratios in filtered (< 0.45 μm) water and especially in the LMM fractions were observed at stations along the whole length of the two sampling transects, extending from the lower parts of the Ob and Yenisey Rivers and into the northern Kara Sea. This provides evidence of long-range transport of Pu from low burn-up or non-civil sources into the Arctic Ocean. Pu appears to be predominantly in a dissolved form (< 0.45 μm) throughout the investigated area. The colloidal fraction (8 kDa-0.45 μm) ranged within 24-78% in the river systems and 8-53% in the Kara Sea. Concentrations of 239,240Pu in filtered (< 0.45 μm) water were very low, ranging from 2.6 to 40.6 mBq m- 3 in the rivers, somewhat higher than in the open Kara Sea (2.4-7.7 mBq m- 3) in agreement with previously reported values

Evaluation of 137Cs, 133Xe and 3H activity concentrations monitored in the Arctic atmosphere

This paper provides a brief introduction to the Arctic atmospheric radioactivity monitoring network. A decade of monitoring results have shown the 137Cs background levels in Arctic air range from 0.05 to 1.50 μBq/m3. The monitoring stations have sufficient sensitivity to detect 137Cs brought to the atmosphere due to resuspension in local soil and reemissions from biomass burning in a daily temporal resolution. These observations can be used as tracers for atmospheric processes. The 133Xe measurements obtained at Yellowknife, Resolute and Spitsbergen could support other research into how air pollution problems arise across intercontinental distances. It will help develop and improve models capable of predicting the long-distance transport and deposition of trace gases in the Arctic. Rainwater monitoring data collected in Finnish Lapland since the 1960’s indicate that 3H radioactivity concentrations reached natural background levels in early 2000s, typically around 1–2 Bq/L monthly, with an annual seasonal variation cycle consistent with the observed of other cosmogenic radionuclides