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.
2004
Sammendrag
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Sammendrag
Forslag til fôrplaner ved fôring av økologisk sau med 100 % økologisk fôrandel
Forfattere
Karl Thunes John Skartveit Ivar Gjerde Josef Stary Torstein Solhøy Arne Fjellberg Sverre Kobro Sueo Nakahara R. Zur Strassen Gijsbertus Vierbergen Ryszard Szadziewski Daniel V. Hagan William. L. Grogan Jr Terje Jonassen Kjetil Aakra Johannes Anonby Lita Greve Berend Aukema Kai Heller Verner Michelsen Jean-Paul Haenni Alexandr F. Emeljanov Per Douwes Kai Berggren Jutta Franzen R. Henry L. Disney Sabine Prescher Kjell Arne Johanson Boris Mamaev Sigitas Podenas Stig Andersen Stephen D. Gaimari Emilia Narchuk Geir Einar Ellefsen Søli Laszlo Papp Fred Midtgaard Arild Andersen Michael von Tschirnhaus Gerhard Bächli Kjell Magne Olsen Hans A. Olsvik Mihaly Földvari Jan Emil Raastad Lars Ove Hansen Per DjursvollSammendrag
Det er ikke registrert sammendrag
Forfattere
Carl Gunnar Fossdal Øystein Johnsen Nina Elisabeth Nagy R Baumann Jørgen A.B. Mølmann Tore SkrøppaSammendrag
Introduction: Survival and competitive successes of boreal forest trees depend on a balance between exploiting the full growing season and minimising frost injury through proper timing of hardening in autumn and dehardening in spring. Our research indicates that the female parents of Norway spruce adjust these timing events in their progeny according to the prevailing temperature conditions during sexual reproduction. Reproduction in a cold environment advances bud-set and cold acclimation in the autumn and dehardening and flushing in spring, whereas a warm reproductive environment delays these progeny traits by an unknown non-Mendelian mechanism. We are now looking for molecular mechanisms that can explain this “epigenetic” phenomenon. Material and methods: We have performed identical crosses with the same Norway spruce (Picea abies) parent, as discussed by Skrøppa & Johnsen (1994) and Johnsen et al. (1995), in combination with timed temperature treatments during shorter and longer periods from female meiosis, pollen tube growth, syngamy and embryogenesis and tested the progenies for bud-set and frost hardiness. We have followed the transcription of the spruce phytochromes PHYO, PHYP and PHYN and the class IV chitinase PaChi4 using Quantitative Multiplex Real-Time PCR. Results and conclusions: The effect of temperature on Adaptive properties is most likely a response to accumulated heat during embryogenesis and seed maturation. Our first attempt to look for a molecular mechanism has revealed that transcription of PHYO, PHYP and PHYN and the class IV chitinase PaChi4 (relative to alphaTubulin) all show higher transcription levels in progenies born under cold conditions than their full-sibs born under warmer conditions. This result is consistent with preliminary findings that methylation of cytosine in total DNA is higher in progenies reproduce under warm conditions than their colder full-sib counterparts. If these observations are related to methylation or other epigenetic effects, we may explain why progenies with a memory of a past time cold embryogenesis are more sensitive to short days than their full-sibs with a warmer embryonic history.
2003
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Formålet med rapporten er å gi en innføring i fagområdet spredningsøkologi og gi en oversikt over skoglevende arters spredningsevne. Fokus er satt på truete arter og bevaring av biologisk mangfold i skog. Det er også gitt en oversikt over problemstillinger som er aktuelle for videre forskning. Spredningsevne er en grunnleggende og livsviktig egenskap hos biologiske organismer. Spredning kan defineres som mellom-generasjonsforflytning, dvs. den forflytning som skjer av individer fra en generasjon til den neste. I skogbrukssammenheng dreier det seg om i hvilken grad arter greier å omfordele seg i terrenget når deres livsmiljø fjernes for en kortere eller lengre periode. Spredning kan deles inn i to faser: (1) den fysiske forflytningen av spredningsenheter fra opprinnelig til ny lokalitet, og (2) etableringen av spredningsenheten på den nye lokaliteten (realisert spredning). Litteraturgjennomgangen viser at arter med dårlig spredningsevne og/eller dårlig etableringsevne først og fremst synes å forekomme i følgende organismegrupper og skogsmiljøer: Frøplanter i edelløvskog og andre rike vegetasjonstyper. En rekke arter i denne gruppen sprer seg kun over korte avstander og artene bør i stor grad bevares der de er eller i tilstøtende områder. Biller knyttet til død ved og hule trær, først og fremst i rike løvskoger. Flere arter i denne gruppen sprer seg normalt over korte distanser. Viktige tiltak her vil være å gjenskape nytt substrat i nærheten av kjente forekomster. Epifyttisk lav: Det er to hovedgrupper som skiller seg ut, hengelaver (f.eks. huldrestry, mjuktjafs og trådragg) som hovedsakelig vokser på gamle bartrær, og lungenever-samfunnet som vokser på løvtrær i boreal barskog, temperert løvskog og både på bar og løv i kystområder. Enkelte arter har dårlig spredningsevne, mens andre arter har dårlig etableringsevne. Vern av kjerneområder og lukkede hogstformer er viktige tiltak for denne gruppen. Moser i fuktige miljøer: Her finnes det noe fakta, men i hovedsak er det indikasjoner, på at en del arter sprer seg dårlig. Årsaken til dårlig spredningsevne synes å være at noen arter kun sprer seg vegetativt.
Forfattere
Yi He Jixi Gao Haiying Liu Zhengtao Liu Feng Liu Xiaoshan Zhang Jingheng Guo Yanhui Wang He Shang Pengtao Yu Jianhua Zhu Jingjun Han Bin Yao Xiyon Hu Xiaoquan Zhang Min Shao Limin Zeng Lei Jin Lei Duan Quanru Liu Dawei Zhao Dongbao Zhang Shengliang Chen Renjun Xiang Yi Chang Jinhong Zhang Jiahai Luo Zhanyi Zhang Jinsong Xiao Xiaoyu Peng Rolf David Vogt Hans Martin Seip Wenche Aas Kjetil Tørseth Jan Mulder Trine Sogn Odd Eilertsen Tonje Økland Harald Bratli Valter Angell Svein Solberg Tor Myking Espen Lydersen Thorjørn Larssen Dagang TangSammendrag
Sulphur deposition is high at all IMPACTS sites and exceed maximum levels observed in Europe and North-America. Dry deposition equals or exceeds wet deposition. The IMPACTS data, in particular those from the remote Lei Gong Shan site clearly document long-range transport of air pollutants. Due to the actual and future energy combustion and emission strategy in China, the long-range transport of air pollutants may significantly increase with subsequent increased environmental damage in rural and remote areas in China. In addition to sulphur deposition, depositions of reactive nitrogen (nitric acid and ammonia) and calcium are also important and clearly demonstrate that pH alone is not a good indicator for acid deposition. High concentrations of ground level ozone, above critical levels for vegetation and forest, are observed at the Liu Xi He site in Guangdong province. Soil acidification gives rise to high concentrations of toxic aluminium in soil water at several sites. At the Tie Shan Ping site in Chongqing aluminium occurs at a level where long-term harmful effects on trees might be expected. Defoliation and mortality have been severe, however, fairly stable. Insect attacks are apparently a major cause, but enhanced insect attacks might be an indirect effect of health weakening due to acidification. Defoliation has been considerable also in Liu Chong Guan in Guiyang, while the three other catchments had minor defoliation only. High foliar nitrogen concentrations are seen in Lei Gong Shan in Guizhou and Cai Jia Tang in Hunan, accompanied by low P/N-ratios. Statistical tests of vegetation change, so far only implemented in Liu Chong Guan, revealed minor changes in number and abundances of vascular plants, but a significant decline in number of bryophytes. This decline is probably related to climatic year-to-year variations. Data from other catchments and longer time periods are needed to identify vegetation changes related to soil acidification or direct effects of air pollutants. Modelling results from Tie Shan Ping suggest that the currently planned 20% reduction in sulphur emissions is far from sufficient to avoid further acidification. As more data are generated, dose-response relationships, critical load estimates and model predictions will obviously be improved.
Sammendrag
Establishment, survival and height growth of sown and naturally regenerated Picea abies (L.) Karst. seedlings were examined in a 6 yr period in eight stands on bilberry woodland in south- east Norway. Five harvesting treatments (shelterwoods of high, medium and low density, 253/25 m patch-cut, 503/50 m clear-cut) and three scarification alternatives (unscarified, patch scarification, inverting) were combined in a split-plot design. Establishment, survival and plant height after 6 yrs were positively affected by scarification. Significant differences between patch scarification and inverting were not observed, although mortality tended to be lower, and seedlings slightly taller, after patch scarification. Establishment after natural seedfall was least successful on the clear-cut, but more or less equal at the other stand treatments. Height growth increased with decreasing overstorey retention, while there was a tendency towards lower survival on the clear-cuts and patch-cuts. Natural regeneration in the unscarified plots was unsuccessful after 6 yrs, while the different combinations of harvesting and scarification treatments usually gave sufficient regeneration.