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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

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Abstract

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Abstract

In Europe, over a third of the agricultural area is grass meadows used for livestock grazing and fodder production. Grass meadows provide a food source for wild ungulates causing human-wildlife conflicts due to forage removal. Few experimental studies have quantified biomass loss with enough replicates to determine how surrounding environments influences level of biomass removal. Using an exclosure experiment on 57 grassland meadows over five years at the northwest coast of Norway covering 10 650 km2, we quantified biomass removal by red deer (Cervus elaphus L.) and how environmental factors impacted biomass loss (Study 1). Furthermore, we examined development of biomass loss and crude protein concentration in five fields throughout the growing season (Study 2). The average predicted biomass loss to red deer grazing was 16% for the first harvest, and 7.3% for the second harvest (Study 1). Biomass loss increased with red deer density from 0% at the lowest density (0.6 red deer harvested/km2) to 31% at the highest density (4 red deer harvested/km2). Biomass loss increased from 12% to 32.8% as terrain ruggedness index (TRI) rose from 2.1 to 7.1. Absolute biomass loss increased towards time of grass harvest (Study 2). Crude protein concentration was higher in unfenced plots during the period before first harvest, but not between first and second harvest (Study 2). The quantification of biomass removal at a large spatial scale over several years in this study provides a better understanding of factors causing variation in losses.

Abstract

Female flowering and cone production took place in three Norway spruce progeny tests at ages 17 and 20 years, each planted with full-sib families from a half diallel. The number of cones on individual trees were scored in five classes. More than 50 % of the trees produced cones, and a considerable variation was found among families for the ability to produce cones (precocity) and for the number of clones scored in classes (fruitfulness). Both traits were strongly related to tree heights and diameters at the individual and at the family level. In general, tall trees produced the highest number of cones. However, some families produced many cones even if their average heights were low. In two of the half diallels, estimates of GCA variance components for the number of cones produced had twice the value of the SCA component, indicating additive genetic inheritance of cone production. Heritability estimates of cone scores were 0.10, 0.17 and 0.23, and the genetic correlations between cone production and tree heights were 0.40, 0.50 and 0.35 in the three half-diallels, respectively.