2021
Authors
Gaute Velle Lennart Edsman Charlotte Evangelista Stein Ivar Johnsen Martin Malmstrøm Trude Vrålstad Hugo de Boer Katrine Eldegard Kjetil Hindar Lars Robert Hole Kyrre Linné Kausrud Johanna Järnegren Inger Elisabeth Måren Erlend Birkeland Nilsen Eli Knispel Rueness Eva Bonsak Thorstad Anders NielsenAbstract
No abstract has been registered
Authors
Mladen Ognjenovic Ivan Seletkovic Nenad Potocic M. Perčec-Tadić R. Sokol Jurković M. Marušić K. Sever D. Ugarković Volkmar Timmermann Pasi Rautio Mathieu JonardAbstract
No abstract has been registered
Authors
Ikumi Umetani Eshetu Janka Wakjera Michal Sposob Christopher Jonathan Hulatt Synne Kleiven Rune BakkeAbstract
No abstract has been registered
Abstract
Population fluctuations of small rodents are often synchronized over larger areas (>100 km) than what could be explained by dispersal, suggesting that the synchronizing factor is weather-related and possibly mediated through changes in food quality. Because bank vole (Myodes glareolus) populations usually peak 1 year after peaks in reproduction of the staple winter food plant bilberry (Vaccinium myrtillus), we tested for a possible link between food and spatial synchrony by comparing the synchrony in bank vole population indices and bilberry seed production indices between three study areas across about 20,000 km2 in South Norway during a four decade period (1979–2019). There were subperiods of spatial synchrony and asynchrony between the study areas in the fluctuations of bank vole numbers and bilberry seed production, with the latter part of the study period displaying more pronounced synchrony than the first and middle part. However, with a few marked exceptions, when vole fluctuations were spatially out of phase across study areas so was bilberry seed production. Thus, we conclude that bilberry seed production to a large extent explained the spatiotemporal synchronicity in bank vole population fluctuations. Although bilberry seed production seems to be a causal driver of vole fluctuations, it remains to be seen to what extent the chemical composition of bilberry plants influences vole performance. Finally, certain weather factors may still influence voles directly, or indirectly by triggering bilberry seed production.
Abstract
No abstract has been registered
Abstract
Communication to JordPro AS about the research status regarding the use of biochar as an ingredient in organic fertilizer products.
Authors
Naseer Muhammad Tomas Persson Isabella Righini Cecilia Stanghellini Henk Maessen Michel VerheulAbstract
No abstract has been registered
Authors
Naseer MuhammadAbstract
No abstract has been registered
Authors
Michel VerheulAbstract
No abstract has been registered
Abstract
Organisms use circadian rhythms to anticipate and exploit daily environmental oscillations. While circadian rhythms are of clear importance for inhabitants of tropic and temperate latitudes, its role for permanent residents of the polar regions is less well understood. The high Arctic Svalbard ptarmigan shows behavioral rhythmicity in presence of light-dark cycles but is arrhythmic during the polar day and polar night. This has been suggested to be an adaptation to the unique light environment of the Arctic. In this study, we examined regulatory aspects of the circadian control system in the Svalbard ptarmigan by recording core body temperature (Tb) alongside locomotor activity in captive birds under different photoperiods. We show that Tb and activity are rhythmic with a 24-h period under short (SP; L:D 6:18) and long photoperiod (LP; L:D 16:8). Under constant light and constant darkness, rhythmicity in Tb attenuates and activity shows signs of ultradian rhythmicity. Birds under SP also showed a rise in Tb preceding the light-on signal and any rise in activity, which proves that the light-on signal can be anticipated, most likely by a circadian system.