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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.

2014

2013

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Abstract

Background: Studies quantifying and comparing the variation and degree of compositional stability of vegetation and what determines this stability are needed to better understand the effects of the projected climate change. Aims: We quantified long-term vegetation changes in different habitats in northern Europe by exploring changes in species co-occurrences and their links to diversity and productivity gradients. Methods: We re-sampled vegetation in 16 arctic, mountain, and mire sites 20 to 90 years after first inventories. A site-specific change in species assemblages (stability) was quantified using species co-occurrences. We tested if the observed changes were significantly greater than would be expected by chance using a randomisation test. Relationships between patterns in vegetation stability and time between surveys, numbers of plots, or species diversity and proxies for productivity were tested using regression analysis. Results: At most sites, changes in species co-occurrences of vascular plants and bryophytes were greater than expected by chance. Observed changes were not found to be related to gradients in productivity or diversity. Conclusions: Changes in species co-occurrences are not strongly linked to diversity or productivity gradients in vegetation, suggesting that other gradients or site-specific factors (e.g. land-use, species interactions) might be more important in controlling recent compositional shifts in vegetation in northern Europe.

Abstract

In this study, a technique based on wireless sensor networks (WSN) for matching mother reindeer to their calves in order to identify the ownership of the calves is presented. This task is currently performed using manual techniques which are stressful on the animals and herders alike. Various potential WSN technologies are considered. RFID technology was given greater interest as it is widely used in animal identification. A method based on Wi-Fi enabled active RFID tags is proposed in this work. This technique entails the temporary attachment of Wi-Fi enabled RFID tags to the necks of the calf and mother reindeers and to monitor the location of those tags using the Wi-Fi network. A detailed discussion of localization algorithms to monitor the location of the tags and to determine the correlation between any pairs of tags which indicate mother and her calf is presented. This work aims to pave the way for the use of wireless sensor networks for the purpose of matching mother reindeer to their calves and for other matching purposes in animal welfare and industry.