Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2015
Abstract
Remotely sensed data from airborne laser scanning (ALS) and interferometric synthetic aperture radar (InSAR) can greatly improve the precision of estimates of forest resource parameters such as mean biomass and biomass change per unit area. Field plots are typically used to construct models that relate the variable of interest to explanatory variables derived from the remotely sensed data. The models may then be used in combination with the field plots to provide estimates for a geographical area of interest with corresponding estimates of precision using model-assisted estimators. Previous studies have shown that field plot sizes found suitable for pure field surveys may be sub-optimal for use in combination with remotely sensed data. Plot boundary effects, co-registration problems, and misalignment problems favor larger plots because the relative impact of these effects on the models of relationships may decline by increasing plot size. In a case study in a small boreal forest area in southeastern Norway (852.6 ha) a probability sample of 145 field plots was measured twice over an 11 year period (1998/1999 and 2010). For each plot, field measurements were recorded for two plot sizes (200 m2 and 300/400 m2). Corresponding multitemporal ALS (1999 and 2010) and InSAR data (2000 and 2011) were also available. Biomass for each of the two measurement dates as well as biomass change were modeled for all plot sizes separately using explanatory variables from the ALS and InSAR data, respectively. Biomass change was estimated using model-assisted estimators. Separate estimates were obtained for different methods for estimation of change, like the indirect method (difference between predictions of biomass for each of the two measurement dates) and the direct method (direct prediction of change). Relative efficiency (RE) was calculated by dividing the variance obtained for a pure field-based change estimate by the variance of a corresponding estimate using the model-assisted approach. For ALS, the RE values ranged between 7.5 and 15.0, indicating that approximately 7.5–15.0 as many field plots would be required for a pure field-based estimate to provide the same precision as an ALS-assisted estimate. For InSAR, RE ranged between 1.8 and 2.5. The direct estimation method showed greater REs than the indirect method for both remote sensing technologies. There was clearly a trend of improved RE of the model-assisted estimates by increasing plot size. For ALS and the direct estimation method RE increased from 9.8 for 200 m2 plots to 15.0 for 400 m2 plots. Similar trends of increasing RE with plot size were observed for InSAR. ALS showed on average 3.2–6.0 times greater RE values than InSAR. Because remote sensing can contribute to improved precision of estimates, sample plot size is a prominent design issue in future sample surveys which should be considered with due attention to the great benefits that can be achieved when using remote sensing if the plot size reflects the specific challenges arising from use of remote sensing in the estimation. That is especially the case in the tropics where field resources may be scarce and inaccessibility and poor infrastructure hamper field work.
Authors
Jon Swenson Ole-Gunnar Støen Inger Hansen Henrik Andren Jens Persson Håkan Sand Camilla Wikenros Barbara Zimmermann John Odden Audun Stien Bjørnar Ytrehus Oddmund Kleven Henrik Brøseth Jonas Kindberg Jenny Mattisson Erling Johan Solberg Erlend Birkeland Nilsen Torgeir Nygård Karl-Otto JacobsenEditors
John Durrus Linnell Torkild TveraaAbstract
Miljødirektoratet har bestilt denne rapporten for å identifisere kunnskapshull vedrørende rovvilt (gaupe, brunbjørn, ulv, jerv og kongeørn) i Skandinavia, med særlig fokus på situasjonen i Norge. Over 20 forskere fra ulike institusjoner i Norge og Sverige har bidratt til prosessen. Arbeidet har primært fokusert på naturvitenskapelige problemstillinger. De siste 30 årene har det vært gjennomført en omfattende forskning på store rovdyr i Skandinavia. Særlig har det vært gjennomført mange feltbaserte studier som har samlet inn demografiske data og atferdsdata gjennom bruk av telemetribaserte metoder. Parallelt har det vært en stor innsats på bestandsovervåking både ved bruk av tradisjonelle overvåkingsmetoder og genetiske analyser. I tillegg har det vært en betydelig forskningsinnsats på rovvilt innen andre disipliner. Forskningen har bidratt til et stort antall vitenskapelige publikasjoner – over 650 publikasjoner har kommet ut siden 1987, og det utgis nå rundt 50 publikasjoner i året. Den generelle biologien til disse artene er nå godt kjent og det finnes en god del kvantitative data for mange demografiske parametre, atferd og predator-byttedyrsammenhenger. Følgelig er de gjenstående kunnskapshullene fragmentert, spredt og varierer mellom artene. Kunnskap om demografi og områdebruk kommer fra et begrenset antall studieområder over begrensede tidsrom. Det er derfor til dels ukjent hvordan disse variablene varierer med endringer i bestandsstørrelse, klimatiske forhold og landskap. Et annet spørsmål er hvilke effekter den store avskytingen av rovdyr i Skandinavia har på atferdsmessige og demografiske parametre. Mesteparten av eksisterende kunnskap er knyttet til voksne individer. Vi har identifisert en rekke kunnskapshull knyttet til atferd og overlevelse hos juvenile – fra fødsel, gjennom spredningsfasen og fram til uavhengighet. Det er videre et behov for å forstå hvordan forskjellen i forvaltningsregime mellom Norge og Sverige påvirker våre felles rovviltbestander. Generelle trekk ved predasjonen på byttedyr er godt beskrevet. Det er imidlertid mange ubesvarte spørsmål knyttet til betydningen av romlig variasjon og byttedyrenes bevegelse (spredning og migrasjon) på predator-byttedyrdynamikken. Tilsvarende er det en del ubesvarte spørsmål knyttet til interaksjoner (f. eks. åtselspising / kleptoparasittisme) mellom store rovdyr, og hvordan disse påvirker byttedyrene. Alle feltstudiene har vært gjennomført i flerbrukslandskap som utnyttes både til skogbruk, jakt, friluftsliv og husdyrbeite. Den menneskelige aktiviteten kan ha stor innvirkning på store rovdyrs økologi og bør undersøkes. Eksempler på dette er effekten av skogsdrift på bjørn og betydningen av et stadig økende veinett på alle artene, inkludert interaksjonen med deres byttedyr. Innen temaene dyrehelse er det mange kunnskapshull å tette. Økt fokus på dyrevelferd, og klimaendringer som forventes å påvirke utbredelsen av parasitter og sykdommer, understreker behovet for å undersøke disse forholdene. Rovvilt, kunnskapsoversikt, kunnskapsbehov, rovvilt-beitedyr-konflikter, sau, tamrein, bjørn, gaupe, jerv, kongeørn, ulv, Large carnivores, Knowledge status, Knowledge needs, Carnivore - livestock conflict, Sheep, Semi-domestic reindeer, Brown bear, Eurasian Lynx, Golden Eagle, Wolverine, Wolf
Authors
K.A. Alexander D. Angel S. Freeman D. Israel J. Johansen D. Kletou Marte Meland D. Pecorino Celine Rebours M. Rousou M. Shorten T. PottsAbstract
Research into stakeholder perceptions of conventional aquaculture has focused upon issues such as risk, impact on other users of marine space, and the factors influencing consumers. However, some of these issues may become redundant with new aquaculture practices such as Integrated Multi-trophic Aquaculture (IMTA). For practices such as IMTA to realise their potential they must be socially acceptable and this may depend on satisfying key stakeholders. This study used in-depth interviews to identify potential concerns of stakeholders as well as perceived benefits in relation to the development of IMTA to a commercial level of production. A total of 44 interviews were conducted across 12 stakeholder groups in six countries: Cyprus, Ireland, Israel, Italy, Norway and Scotland. Levels of awareness and understanding of IMTA were mixed across stakeholder groups and across countries. Concerns were raised including: spatial location issues, food safety and disease. Perceived benefits of IMTA included: waste utilisation, minimisation of impacts to the benthos and the filtering of sea lice larvae. Also recognised as important was the creation of new income streams. The results showed that some issues/ benefits were more important in certain countries. Risks to the environment, risks arising from governance and risks to the industry itself were raised, but stakeholders felt that these sources of risk could be addressed by research studies, education and changes to legislation. Stakeholders also believed that IMTA could contribute to improving the image of the aquaculture industry. For IMTA to successfully move forward from pilot scale to commercial scale development, it is imperative that the issues raised in this study form priorities for reform and action.
Authors
Leif Sundheim Trond RafossAbstract
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Abstract
BACKGROUND Plants grown at different latitudes experience differences in light spectral composition. Broccoli (Brassica oleracea L. var italica) plants were grown in climate-controlled chambers under supplemental wavelengths (red, far-red, red + far-red or blue) from light-emitting diodes (LEDs). The light treatments were combined with two cold climate temperatures (12 and 15 °C) during broccoli head formation to investigate the effects on morphology and content of health- and sensory-related compounds: glucosinolates, flavonols, ascorbic acid and soluble sugars. RESULTS Supplemental far-red and red + far-red light led to elongated plants and the lowest total glucosinolate content in broccoli florets. The content of quercetin was highest with supplemental red light. Vitamin C was not significantly affected by the light treatments, but 12 °C gave a higher content than 15 °C. CONCLUSION The effects of supplemental red and far-red light suggest an involvement of phytochromes in the regulation of glucosinolates and flavonols. A shift in red:far-red ratio could cause changes in their content besides altering the morphology. The sugar and vitamin C content appears to be unaffected by these light conditions. Supplemental blue light had little effect on plant morphology and content of the health- and sensory related compounds.
Authors
Siv Aarnes Alexander Kopatz Hans Geir Eiken Julia Schregel Paul Eric Aspholm Tuomo Ollila Olga Makarova Natalia Polikarpova Vladimir Chizhov Sergey Ogurtcov Snorre HagenAbstract
The trans-border brown bear population of Pasvik-Inari-Pechenga (Norway-Finland-Russia) has been monitored using genetic analyses of feces collection since 2005. In addition, in 2007 and 2011, hair traps were systematically placed out in the area to collect hairs for genetic analysis, to more precisely determine the minimum numbers of bears in the area. In 2015, we repeated this hair trap study, using the exact same methodology as in 2007 and 2011, to make a direct comparison of the results from all the 3 study years. Brown bear DNA was detected in 158 of 209 hair samples (76%) obtained from hair traps in 2015 and for 136 of these samples, a complete DNA profile could be determined. We identified 26 different bears in 2015, 17 females and 9 males. We detected 16 bears in Norway, 5 bears in Finland and 9 bears in Russia. Thirteen of these 26 bears were previously unknown, 7 were detected in Norway, 2 in Finland and 4 in Russia. A comparison to the results from 2007 and 2011 showed that we detected more bears in hair traps in 2015 (26 bears) than in 2007 (24 bears) and 2011 (20 bears). We observed an increase in the total yield of hair samples in the traps in 2015 (209 samples) compared to 2007 (196 samples) and 2011 (88 samples). Four (16%) and seven (35%) of the bears caught in hair traps in 2007 and in 2011, respectively, were also recaptured in 2015. Additional samples (scats and hair) collected opportunistically in the field within the Russian and Finnish parts of the study area in 2015 detected 4 male bears and 1 female bear in the Russian part leading to a total of 14 bears identified in Russia, of which 8 bears were detected for the first time. Additional scat and hair samples from the field in Norway were not included in our study and comparisons between the systematic hair-trapping and opportunistic sampling in the field were not performed. However, the results indicate that both methods combined are currently the optimal approach to monitor brown bear numbers in an area.
Authors
Stephan Arnold Geoffrey Smith Gerard Hazeu Barbara Kosztra Christoph Perger Gebhard Banko Tomas Soukup Geir-Harald Strand Nuria V. Sanz Michael BockAbstract
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Abstract
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Authors
Andreja Kutnar Callum Aidan Stephen HillAbstract
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Authors
Lars Olav BrandsæterAbstract
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