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.
2018
Forfattere
Synnøve RivedalSammendrag
No abstract has been registered
Forfattere
Synnøve RivedalSammendrag
No abstract has been registered
Sammendrag
There is increasing evidence that the impact of climate change on the productivity of grasslands will at least partly depend on their biodiversity. A high level of biodiversity may confer stability to grassland ecosystems against environmental change, but there are also direct effects of biodiversity on the quantity and quality of grassland productivity. To explain the manifold interactions, and to predict future climatic responses, models may be used. However, models designed for studying the interaction between biodiversity and productivity tend to be structurally different from models for studying the effects of climatic impacts. Here we review the literature on the impacts of climate change on biodiversity and productivity of grasslands. We first discuss the availability of data for model development. Then we analyse strengths and weaknesses of three types of model: ecological, process-based and integrated. We discuss the merits of this model diversity and the scope for merging different model types.
Sammendrag
No abstract has been registered
Forfattere
Ievina SturiteSammendrag
No abstract has been registered
Sammendrag
No abstract has been registered
Sammendrag
Knowledge about the botanical composition of grassland for silage is important regarding composition of seed mixtures, control of weeds, choice of harvest times and feeding strategies. The botanical composition of 185 fields in the mountain regions of southern Norway was examined using the dryweight rank method. The survey shows that the youngest grasslands (age 1 - 3 years) were dominated by the sown species with Phleum pratense L. the species with the highest proportion in the sward. In 4 - 6 year old grasslands, the proportion of sown species was reduced with the exception of Poa pratensis L., and Elytrigia repens L. had the highest proportion of unsown species. The proportion of Festuca pratensis (Huds.) was reduced at the same rate as Phleum pratense L. In grasslands of greater age (> 6 years) Poa pratensis L. and Elytrigia repens L. had the highest occurrence. The content of herbs increased with age, and Ranunculus repens L. and Taraxacum officinale F.H. Wigg were the most frequent species. The average clover content was < 6% of DM yield. The impact of Elytrigia repens L. on forage yield and quality should be further examined due to the high occurrence. Poa pratensis L. or other long-lasting grass species should be included in seed mixtures for this region when the grassland is intended to last more than three years.
Sammendrag
No abstract has been registered
Sammendrag
No abstract has been registered
Sammendrag
In order to establish the relationship between spectral reflectance and grass yield, we used a UAV-based hyperspectral camera and ground-based spectroradiometry to image a number of cultivated grasslands of different age and productivity in northern Norway. In addition, samples were taken to determine biomass and grass species composition. We investigated a number of vegetation indices as well as regression analysis to identify which spectral reflectance features can be used to map crop yield. We found poor relationships between NDVI and yield, but were able to obtain an acceptable relationship using all 15 available bands in the visible-near infrared range. Bands in the near infrared appear to contain most of the information related to yield.