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.
2016
Authors
Carrie Joy Andrew Einar Heegaard Rune Halvorsen Fernando Martinez-Pena Simon Egli Paul M. Kirk Claus Bässler Ulf Büntgen Jorge Aldea Klaus Høiland Lynne Boddy Håvard KauserudAbstract
No abstract has been registered
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No abstract has been registered
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No abstract has been registered
Authors
Krishna Reddy K. Mehreteab Tesfai Andrew Borrell Sekhar Udaya Nagothu Suresh Reddy K. Gurava Reddy K.Abstract
No abstract has been registered
Abstract
The present study aims to develop biologically sound and parsimonious site index models for Norway to predict changes in site index (SI) under different climatic conditions. The models are constructed using data from the Norwegian National Forest Inventory and climate data from the Norwegian meteorological institute. Site index was modeled using the potential modifier functional form, with a potential component (POT) depending on site quality classes and two modifier components (MOD): temperature and moisture. Each of these modifiers was based on a portfolio of candidate variables. The best model for spruce-dominated stands included temperature as modifier (R2 = 0.56). In the case of pine- and deciduous-dominated stands, the best models included both modifiers (R2 = 0.40 and 0.54 for temperature and moisture, respectively). We illustrate the use of the models by analyzing the possible shift in SI for year 2100 under one (RCP4.5) of the benchmark scenarios adopted by the Intergovernmental Panel on Climate Change for its fifth assessment report. The models presented can be valuable for evaluating the effect of climate change scenarios in Norwegian forests.
Authors
Xurong Mei Hongmin Dong Yue Li Nicholas Clarke Daozhi Gong Weiping Hao Yingchun Li Buchun Liu Xin Ma Wei XiongAbstract
No abstract has been registered
Authors
Gudni Thorvaldsson Liv Østrem Linda Öhlund Toroddur Sveinsson Sigridur Dalmannsdottir Rolvur Djurhuus Kenneth Høegh Thordis Anna KristjansdottirAbstract
Eight experiments with cultivars (cvs.) of grass and clover species were established in the Faroe Islands, Greenland, Iceland, Norway and Sweden to evaluate important forage species and cvs. in terms of yield potential, persistence and adaptation to variable climate in the West Nordic countries. Timothy had on average the highest spring cover after three years of trial together with smooth meadow grass (cv. Knut), whereas perennial ryegrass had the lowest spring cover after three years. On average cocksfoot (cv. Laban) and timothy (Grindstad related cvs.) gave the highest yield, 8.85 and 8.71 t ha-1, respectively, and smooth meadow grass and common bent grass the lower yields, 7.52 and 7.30 t ha-1, respectively. The results from these experiments show that we have a wide range of species and cultivars usable in the West Nordic areas. We can meet an increase in temperature to a certain level by moving the more southern species and cvs. farther north, however, our most winter hardy cvs. are still important to maintain.
Abstract
The paper is a mini review on the climatic effects on berry production and berry quality in the Arctic north. Plants in the north are facing short growing seasons with low temperatures and long days with a unique light quality. The winter time is cold but with fluctuating temperatures, especially along the coast. Fluctuating winter temperatures and unstable snow cover is a challenge for the perennials that need to be dormant during winter time. Dormancy is induced in the autumn by a combination of day length and temperature. The wild berries domestic to the Nordic countries are adapted to these growth conditions while many of the commercially important berry species originate from more southern areas. Pre-breeding studies on interactions between genotype and environment are essential in order to develop climatically adapted berry cultivars for northern growth conditions.
Abstract
Grazing is an important management action to conserve biodiversity in semi-natural grasslands but it is important to understand how grazing influences the life-history components and population dynamics of plant species. In this study, we analysed effects of grazing intensity and abandonment on population dynamics of the semi-natural grassland species Knautia arvensis which is an important nectar source for pollinating species and an indicator of biodiversity in agricultural landscapes. We recorded life-history stage, survival, establishment of seedlings and ramets, number of inflorescences and grazing marks on permanently marked individuals in eight populations in mid-Norway for three consecutive years. Matrix modelling was used to estimate population growth rates and elasticities, and life Table response experiments (LTREs) were used to assess the contribution of different life-history components to the observed variation in population growth rates between different management treatments. Generalized linear mixed effects models (GLMMs) were used to investigate the effect of management on vital rates and number of inflorescences as well as damage to K. arvensis individuals. Populations in abandoned grasslands had more inflorescences, a lower proportion of seedlings and a higher proportion of flowering ramets compared to populations in grasslands under high grazing intensity. There were no differences in population growth rates between different grazing intensities. Fecundity however, contributed more to the growth rate in grazed grasslands compared to abandoned grasslands where clonal regeneration contributed the most. Survival of non-flowering rosettes made the largest impact to overall growth rates. Our results indicate that a long life-span and clonal growth buffer the effect of environmental change in abandoned grasslands and that there is a trade-off between fertility and clonal regeneration in K. arvensis populations.
Authors
Jakob GeipelAbstract
No abstract has been registered