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
Forfattere
Endre Hofstad Hansen Terje Gobakken Svein Solberg Annika Kangas Liviu Theodor Ene Ernest William Mauya Erik NæssetSammendrag
Forest inventories based on field sample surveys, supported by auxiliary remotely sensed data, have the potential to provide transparent and confident estimates of forest carbon stocks required in climate change mitigation schemes such as the REDD+ mechanism. The field plot size is of importance for the precision of carbon stock estimates, and better information of the relationship between plot size and precision can be useful in designing future inventories. Precision estimates of forest biomass estimates developed from 30 concentric field plots with sizes of 700, 900, …, 1900 m2, sampled in a Tanzanian rainforest, were assessed in a model-based inference framework. Remotely sensed data from airborne laser scanning (ALS) and interferometric synthetic aperture radio detection and ranging (InSAR) were used as auxiliary information. The findings indicate that larger field plots are relatively more efficient for inventories supported by remotely sensed ALS and InSAR data. A simulation showed that a pure field-based inventory would have to comprise 3.5–6.0 times as many observations for plot sizes of 700–1900 m2 to achieve the same precision as an inventory supported by ALS data.
Forfattere
Thi Ngoc Chi Truong Thi Thuy Anh Tran Tuyet Loan Dang Cao Cuong Pham Duy Le Solveig Kolberg Sekhar Udaya NagothuSammendrag
The objective of this study is to better understand socio-economic and gender-differentiated impacts and perceptions of climate change in rice farms in Southern Viet Nam. Focus group discussions and a household survey of both male and female farmers in 160 households were conducted in four villages of Soc Trang and Tra Vinh provinces. These coastal provinces are located at the mouth of the Mekong delta in southern Viet Nam, an area highly at risk of climate variability and climate change causing exacerbating problems of saline intrusion and drought episodes. The survey found that the farm households heavily relied on rice for their livelihood, and that rice contributed to 79 % of the farmer’s total income. In the last 10 years, 95 % of the Soc Trang households and 89 % of the Tra Vinh province had experienced damage to their livelihoods due to salinity and/or drought. The residents in Soc Trang and Tra Vinh province are mostly Khmer ethnic, followed by Kinh (Vietnamese) people. Most of the households are rice farmers, having their own lands. Husbands are generally the household heads and the landowners, and they little education, but in general more educated than women. Both male and female farmers perceived the existence of climate change and variability and recognized its adverse impacts on crop production, animal husbandry, and fishing, as well as other household activities. Low crop yields, and even occasionally total crop losses were rated as the major impacts, leading to increased debt and food insecurity. Farmers coping strategies included change of rice varieties; leave land fallow during severe drought; change of the cropping pattern; more cash crops; and off-farm work. Women not only did the same tasks as men in farming traditionally but also contributed to seed preparation, replanting, hand weeding, removing off types, drying and sacking. Womens’ workload inn recent years increased more than that of men due to climate variation. It was found that male farmers are more likely than female farmers to adopt technologies that can reduce vulnerability to climate change. These technologies included the use of stress-tolerant crop varieties; planting of early, medium or late varieties to avoid crop loss to variations in presence of drought/salinity; pest and disease management techniques; and development and use of crop varieties resistant to pests and diseases. Both female and male farmers had equal access to credit and money loans in the periods of extreme weather events. Moreover, female farmers tend to spend less money, and they stored food to cover basic needs, while male farmers are used to seek wage labor or migrate. The respondents, especially women, reported a lack of adequate extension and technical information about how to cope with agriculture under climate variability. Thus, in situations of salinity and drought, rice farmers reverted to traditional practices with low rice yield outputs, and the Benefit-Cost Ratio (BCR) varied from 1.2 to 1.6 only. Given the important role of women in rice production , rural extension should not ignore women farmers in the development of the extension programs related to agriculture adaptation and climate change. Moreover, mitigation measures should address the needs of both men and women, and ethnic people living in the areas affected by climate change. Any new adaptation measures have to be simple, help in reducing GHGs, low cost and easily adaptable, since majority of farmers are small or marginal landholders with little education and low investment capacity and the government does not have adequate resources.
Forfattere
Erling Johan Solberg Olav Strand Vebjørn Veiberg Roy Andersen Morten Heim Christer Moe Rolandsen May I. Solem Frode Holmstrøm Per Jordhøy Erlend Birkeland Nilsen Aksel Granhus Rune EriksenSammendrag
Dette er en framdriftsrapport fra Overvåkingsprogrammet for hjortevilt etter de tre første årene i kontraktsperioden 2012–2017. I rapporten gir vi en oversikt og kvalitetsvurdering av data innsamlet i årene 2012–2014 og viser utviklingen i flere sentrale overvåkingsparameter fra de respektive overvåkingsområdene for elg, hjort og villrein. I tillegg gir vi en generell vurdering av bestandsutviklingen på nasjonalt og regionalt nivå samt en grov oversikt over tilstand og utvikling i beitetilbud og beitetrykk på aktuelle trearter. I de tre siste årene har vi stort sett fått inn data med samme omfang og kvalitet som i forrige kontraktsperiode (2007–2011), men med noe variasjon mellom områder. I tillegg er det å merke seg at vi har opprettet 2 nye overvåkingsområder for hjort. Disse er begge opprettet på Østlandet, der hjorten nylig har etablert seg og bestandene er økende. Utviklingen i den samlede tettheten av hjortevilt i Norge er nedadgående. Siden toppåret i 2010, felles det nå færre elg, hjort og rådyr, og den samme utviklingen finner vi i antallet elg, hjort og rådyr som er påkjørt og drept i trafikken. Trenden i bestandstetthet varierer likevel mye mellom bestander og arter. Generelt sett har det vært en økning i antallet villrein, og avskytningen har økt de siste tre årene. Dette skyldes mest at bestandstettheten har økt mye på Hardangervidda. Samlet ser vi likevel ingen dramatiske endringer i bestandstettheten av hjortedyr i Norge. Det meste av bestandsvariasjonen skyldes varierende jakttrykk, og i de aller fleste tilfellene er variasjonen et resultat av en ønsket utvikling. I Norge er ikke elg, hjort eller villrein særlig utsatt for predasjon, og følgelig er det bare unntaksvis at rovdyr har en stor effekt på bestandsdynamikken. Tilsvarende ser vi ikke tegn til tetthetsavhengige responser i overlevelse (utenom jakt) og kalveproduksjon av en slik styrke at disse alene kan føre til bestandsnedgang. Dette betyr likevel ikke at bestandene er upåvirket av tetthetsavhengige effekter. Særlig i hjortebestandene har vi de siste 20 årene sett en kraftig reduksjon i slaktevekter og fruktbarhetsrater i takt med økende bestandstetthet. Dette er mest sannsynlig en respons på økt konkurranse om maten med påfølgende redusert vekst. Tilsvarende ser vi i villreinområdene indikasjoner på at kalveproduksjonen varierer med varierende bestandstetthet, men stor variasjon mellom år gjør det vanskelig å konkludere entydig. I flere av elgområdene har bestandskondisjonen sunket mye de siste 25 årene, selv i områder der bestandene samtidig er redusert. Et presserende spørsmål er derfor om kondisjonsnedgangen på 1990-tallet utelukkende er forårsaket av de høye bestandstetthetene eller om også andre faktorer helt eller delvis ligger til grunn for den manglende positive responsen i bestandskondisjon. For å bedre kunne avklare slike spørsmål har vi igangsatt en mer regulær overvåking av beitegrunnlaget i skogen. Dette gjennomføres som et samarbeid med Landsskogtakseringen ved Norsk institutt for skog og landskap, som i 2 takster (9. takst: 2005–2009, og 10. takst: 2010– 2014), har gjennomført taksering av beitetrykk og beitetilbud i den skogdekte delen av landet. Datamaterialet som er innsamlet så langt synes å være av rimelig høy kvalitet og vi forventer å benytte dette langt mer aktivt i årene som kommer. Spesielt ønsker vi å undersøke hvordan beitetilbud og beitetrykk varierer mellom områder, og i hvilken grad beitetilbud og bestandstetthet i kombinasjon kan forklare den store variasjonen vi ser i elgens bestandskondisjon i Norge. Beitetilbud, beitetrykk, bestandsovervåking, elg, hjort, hjortevilt,hjorteviltforvaltning, Norge, rådyr, villrein, Browse abundance, Browsing pressure, Moose, Norway, Population monitoring, Red deer, Reindeer, Roe deer, Ungulate management
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
There have been intense discussions about reducing fossil energy dependence for many years, indeed there is a vision to have a carbon-neutral energy system in Scandinavia by the year 2050. One way to address this ambition is to increase the use of woody biomass. This places a focus on forest tree breeding, since it is considered to be one of the most effective and environmentally friendly options to increase sustainable biomass production in our forests. In this report we have summarised information about forest tree breeding in Denmark, Finland, Norway and Sweden, covering historic, current and future activities. It includes estimates of realised genetic gain in volume and dry matter production on a regional basis for regeneration materials of different improvement levels, which are available today and will be available in the year 2050. Genetic gains in economic terms are also discussed, and basic breeding and mass propagation principles are described. The report includes the most relevant commercial forest tree species in Scandinavia: Scots pine, Norway spruce, Sitka spruce, Douglas fir, grand fir, birch, poplars, alder, oak and beech. Intensive and long-term breeding is carried out continuously in Sweden and Finland for Scots pine, Norway spruce and to some extent birch, while other species are worked with intermittently. In Norway the interest in breeding has, after a break of some years, now resumed, resulting in the initiation of a new breeding cycle for Norway spruce. The present resources put into breeding in Denmark are small, due to a major change in silvicultural management towards natural regeneration in the State Forests. However, as in all the other Scandinavian countries, there is great potential to increase growth through breeding. Seed from seed orchards is, and will within coming decades, be the main way to supply the forestry with genetically improved plant material. The extra gain in yield that is obtained by using material from existing seed orchards varies among species, but in general it is, on average, 10–15% when compared to local unimproved material. In 2050 it is estimated that this gain will be 20–25% for many species, which is a substantial increase in productivity. The time elapsed from establishment of a seed orchard to the first seed harvest for many species is quite long (10–20 years) and delays the realisation of the genetic improvement efforts. An alternative is to use plants obtained from the vegetative propagation of genetically well-performing seed sources or individuals, which makes it possible to capture the progress from breeding immediately. Utilisation of clones is also a way to reduce the consequences of limited amounts of seed from seed orchards, which for instance, is the case for Norway spruce in southern Sweden. For Norway spruce, using clonal material can immediately deliver a gain of around 25–35% in yield, and it is estimated that by 2050 this figure will have increased to 40%. It should be noted, however, that the use of clonal material may be limited by forest regulations. Future climate change will probably alter the growing conditions in Scandinavia in a way that makes forestry with high productivity exotic species such as Douglas fir, grand fir, Sitka spruce and poplars more attractive. Using several species, instead of the few traditional ones, is a way to spread the risk of an unknown future. In Denmark, several exotic species have been an integrated part of forestry for more than 100 years. Limited breeding work has been performed for these species and the gain in yield is, for instance, estimated to amount to 40% for existing seed orchard material of Sitka spruce compared to unimproved material.
Forfattere
Henrik Vejre Sebastian Eiter Veronica Hernández-Jiménez Frank Lohrberg Isabel Loupa-Ramos Xavier Recasens Dona Pickard Lionella Scazzosi Marian Simon-RojoSammendrag
Det er ikke registrert sammendrag
Forfattere
Marian Simon-Rojo Xavier Recasens Sonia Callau Barbora Duží Sebastian Eiter Veronica Hernández-Jiménez Patricia Kettle Raffaela Laviscio Frank Lohrberg Dona Pickard Lionella Scazzosi Henrik VejreSammendrag
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Sammendrag
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Sammendrag
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Sammendrag
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