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.
2013
Authors
Roman Gebauer Daniel Volařík Josef Urban Isabella Børja Nina Elisabeth Nagy Toril Drabløs Eldhuset Paal KrokeneAbstract
Trees must respond to many environmental factors during their development, and light is one of the main stimuli regulating tree growth. Thinning of forest stands by selective tree removal is a common tool in forest management that increases light intensity. However, morphological and anatomical adaptations of individual shoots to the new environmental conditions created by thinning are still poorly understood. In this study, we evaluated shoot morphology (shoot length, needle number, projected leaf area) and anatomy (tracheid lumen area, tracheid number, tracheid dimensions, xylem area, potential hydraulic conductivity) in three Norway spruce (Picea abies/L./Karst.) families exposed to different thinning regimes. We compared shoot characteristics of upper-canopy (i.e. sun-exposed) and lower-canopy (i.e. shaded) current-year shoots in a control plot and a plot thinned to 50 % stand density the previous year. One tree per family was chosen in each treatment, and five shoots were taken per canopy position. We found that upper-canopy shoots in both plots had higher values than lower-canopy shoots for all studied parameters, except lumen roundness and tracheid frequency (i.e. tracheid number per xylem area). Thinning had little effect on shoot morphology and anatomy 1 year after thinning, except for small but significant changes in tracheid dimensions. Needles were more sensitive to altered light conditions, as projected leaf area of shoot, needle number and leaf hydraulic conductivity changed after thinning. Differences between upper- and lower-canopy shoots did not seem to be influenced by thinning and were almost the same in both plots. Our results suggest that lower-canopy shoots require several years to modify their morphology and anatomy to new light conditions following thinning. The slow light adaptation of the lower canopy may be of practical importance in forest management: thinned stands may be predisposed to drought stress because newly exposed shoots experience increased illumination and transpiration after thinning.
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Lampros LamprinakisAbstract
No abstract has been registered
Abstract
Over the past 40 years, a new multidisciplinary field of study has emerged which is characterised by at least two major changes in the way some scientists treat systems. First, it is increasingly accepted that we cannot fully understand the laws that govern a system simply by studying its parts, nor can we fully understand the behaviour of the parts without placing them in the context of the larger system in which they are embedded. This realization, which has arisen as we face the limits of reductionist science, has given rise to the development of new models and methods that facilitate the study of systems across multiple scales of organization. Second, the notions of equilibrium and predictability in natural systems, developed in the 19th Century and continuously pursued until far into the 20th Century, are being rejected in favour of models that embrace variability, diversity, continual change and adaptation as the status quo. Traditional analytical models that assume a stable equilibrium are being replaced by new approaches that facilitate the exploration of a system’s natural range of variation and its possible emergent responses to changing external conditions. The implications of this new field, now known as complexity science, are manifest across disciplines, fundamentally changing the way we study, analyze and perceive natural systems. We provide an overview of complexity science in the context of forest management.
Authors
Zehra Sapci John Morken Roar LinjordetAbstract
No abstract has been registered
Authors
B.J. Schutte B.J. Tomasek A.S. Davis L. Andersson D.L. Benoit A. Cirujeda J. Dekker F. Forcella J.L. Gonzales-Andujar F. Graziani A.J. Murdoch P. Neve I.A. Rasmussen B. Sera J. Salonen F. Tei Kirsten Tørresen J. M. UrbanoAbstract
No abstract has been registered
Authors
Mallikarjuna Rao Kovi Mats Höglind Hans Martin Hanslin Åshild Ergon Byrne Stephen Torben Asp Odd Arne RognliAbstract
No abstract has been registered
Abstract
No abstract has been registered
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.
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.