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.
2024
Abstract
Orchardgrass (Dactylis glomerata L.) is an important forage seed crop, but unlike other cool-season grasses, seed yields have not increased over time. Seed yield increases in orchardgrass may be possible with plant growth regulators (PGRs) such as trinexapac-ethyl (TE) and chlormequat chloride (CCC). Field trials were conducted at Hyslop Experimental Farm near Corvallis, Oregon, over three crop years (2017–2019) to examine the effects of spring nitrogen (N) and PGRs on seed production characteristics in orchardgrass. Spring N treatments included 0, 112, 157, and 202 kg N ha−1 and PGR applications were timed using the BBCH (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) scale. Four PGR treatments included an untreated control, 210 g TE ha−1 at BBCH 32, 210 g TE ha−1 at BBCH 51, and 105 g TE ha−1 + 1500 g CCC ha−1 at BBCH 32. An interaction of spring N and PGR increased seed yields in 2 years, while spring N and PGR increased seed yield independently in the other year. The combination of TE and CCC PGRs did not increase seed yield over TE alone. Seed yield increases from spring N were due to an increase in seed number m−2, while increases in seed yield attributable to PGRs were the result of increased seed number m−2 and harvest index. This study suggests that the combination of 112 kg ha−1 spring N and 210 g ha−1 TE PGR is the best practice to maximize seed yield in orchardgrass.
Authors
Virve Ravolainen Ingrid Marie Garfelt Paulsen Isabell Eischeid Jennifer Sorensen Forbey Eva Fuglei Tomás Hájek Brage Bremset Hansen Leif Egil Loe Petr Macek Jesper Madsen Eeva M Soininen James David Mervyn Speed Audun Stien Hans Tømmervik Åshild Ønvik PedersenAbstract
Herbivores play a crucial role in shaping tundra ecosystems through their effects on vegetation, nutrient cycling, and soil abiotic factors. Understanding their habitat use, co-occurrence, and overlap is therefore essential for informing ecosystem-based management and conservation. In the High Arctic, only a marginal proportion of the land area is vegetated, and climate change is impacting herbivore population sizes and their habitats. In this study, we assessed the spatial habitat overlap of a vertebrate herbivore community based on: 1) regional predictive summer habitat suitability models for the resident Svalbard reindeer (Rangifer tarandus platyrhynchus), resident Svalbard rock ptarmigan (Lagopus muta hyperborea), and the migratory pink-footed goose (Anser brachyrhynchus), and 2) presence of fecal pellets, reflecting the annual habitat use of reindeer, ptarmigan, and geese, including the pink-footed goose and barnacle goose (Branta leucopsis). Our findings revealed that only small proportions of the available land cover (~ 12516 km2; all land area excluding glaciers and freshwater) are suitable for each of the species (habitat suitability [HS] > 0.5): reindeer (22%), ptarmigan (11%), and pink-footed goose (4%). Overlapping suitable habitat [HS > 0.5] for reindeer and goose accounted for only 3% of the total vegetated area (~ 8848 km2) and was primarily found in heath and moist habitats dominated by mosses, graminoids, and herbaceous plants. The overlapping suitable habitat for reindeer and ptarmigan covered 8% of the vegetated area, predominantly in higher elevation ridges with vegetation on drier substrates. The shared habitat for ptarmigan and goose, and all three species of herbivores, was less than 1% of the vegetated area. Additionally, an assessment of fecal pellets suggested that the highest overlap in habitat use among reindeer and goose occurred in bird cliff moss tundra, followed by moss tundra and heath habitats. The small proportion of the vegetated area suitable for all three herbivores indicates a high degree of habitat differentiation. Therefore, different habitats need to be considered for the management and conservation of resident and migratory herbivore species in this High Arctic Archipelago. Moreover, our results underscore the importance of the small but productive parts of the landscape that were used by all herbivores. Goose, habitat suitability, management, ptarmigan, reindeer
Authors
Isabell EischeidAbstract
No abstract has been registered
Authors
Isabell EischeidAbstract
No abstract has been registered
Authors
Malin Olsen Wedaa Stine Samsonstuen Helge Bonesmo Bente Aspeholen Åby Erland Kjesbu Magne Bergfjord Rune OkstadAbstract
No abstract has been registered
Authors
Erlend Hustad Honningdalsnes Erik Stensrud Marstein Dag Lindholm Helge Bonesmo Heine Nygard RiiseAbstract
No abstract has been registered
Authors
Randi Berland FrøsethAbstract
No abstract has been registered
Authors
Randi Berland FrøsethAbstract
No abstract has been registered
Authors
Randi Berland FrøsethAbstract
No abstract has been registered
Authors
Till SeehusenAbstract
No abstract has been registered