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.
2007
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Line Rosef Anne Langerud Ann NorderhaugSammendrag
The response of Deschampsia cespitosa in four different grazing regimes (continuously and rotationally grazed by sheep and continuously and rotationally grazed by cattle) was investigated in two regions Norway. Grazing both by cattle and sheep reduces, to a certain extent, the cover of D. cespitosa, while trampling seems to benefit D. cespitosa, both in terms of distribution and cover, probably due to improved conditions for germination. These two effects are important to consider when restoring abandoned grasslands with D. cespitosa as a dominating species. If the target is to control the species, successful management will depend on an adequate grazing pressure on D. cespitosa at the start of the restoration. At the same time it is important to avoid exposed ground due to damage by trampling.
Forfattere
Leif Jarle AsheimSammendrag
Det er ikke registrert sammendrag
Sammendrag
Model simulations show that an increased frequency in storms and drought periods may result in more frequent and shorter outbreaks of bark beetles. Warmer summers can result in two bark beetle generations per summer instead of one, giving bark beetles the opportunity to attack forests twice in a single year.
Sammendrag
Combinations of covering and fungicide applications were tested on two sweet cherry cultivars; Van during two years (2001 and 2002) and Lapins three years (2001"2003). The following treatments were tested in 2001 and 2002: (i) covering during flowering and from 5 to 6 weeks prior to harvest and throughout harvest, no fungicides applied, (ii) as (i) but fungicides were applied once or twice between the two covering periods, (iii) covered 5 to 6 weeks prior to harvest and throughout harvest, fungicides applied two or three times prior to covering, and (iv) uncovered throughout the season, fungicides applied two or three times in the period from flowering towards harvest. In 2003, the trees were covered only from 5 to 6 weeks prior to harvest and throughout harvest. Both treatments that year received fungicide applications during flowering, but one of the treatments was left unsprayed during the green fruit period prior to covering. Every combination of covering and fungicide applications reduced total fruit decay at harvest significantly compared to a full fungicide programme and no covering. In three of four trials when the trees were covered during flowering and prior to harvest, and fungicide applications were omitted in the green fruit phase between the covering periods, no significant increase in fruit rot occurred compared to treatments where fungicides were applied. However, in one trial there was a significant increase in fruit rot by leaving out one fungicide spray during that intermittent period. Furthermore, if fungicides were only applied during flowering and not on green fruit before covering in 2003, a significant increase in fruit rot occurred. Thus, leaving out fungicide applications during that supposedly less susceptible green fruit period, increased the risk of acquiring fruit rot. Applying fungicides during the green fruit stage significantly reduced the amount of brown rot in four of five trials and anthracnose in one of five trials. No negative effect on fruit quality was found from the extended covering periods. It can be concluded that covering effectively replaced fungicide applications during flowering and prior to harvest.
Sammendrag
Fiskemel og ertemel ble i kombinasjon med korn fôret som isonitrogene og isoenergetiske (NEL) melkekyr i et produksjonsforsøk med høyt (HC) og lavt (LC) kraftfôrnivå. Fiskemel resulterte i en signifikant høyere melkeytelse (kg) med et lavere fettinnhold (HC) sammenlignet med ertemel. Andelene av oljesyre og vaksensyre, CLA (LC), DHA og summen av langkjedete fettsyrer var signifikant høyere og n-6/n-3 forholdet signifikant lavere (HC) i melkefett produsert på fiskemel sammenlignet med ertemel. Melkas sensoriske egenskapeer ble ikke påvirket.
Forfattere
Bert G Drake Tom Powell J. Li R. HinkleSammendrag
these water-gates in response to increased atmospheric CO2 mixing ratio"s, reduces transpiration under most laboratory and short term experimental conditions. Does this imply however, as atmospheric CO2 rises, and plant canopies expand, that evapo-transpiration (ETR), soil moisture content (SMC), and ecosystem water use efficiency (WUE) will increase? To test this question, field experiments have been and still are conducted using open top chambers. We have exposed native species in Florida Scrub to a carbon dioxide mixing ratio of nearly 700 ppmv CO2 for the past ten years and in Chesapeake Bay wetlands for 21 years. As a result of this treatment, in both ecosystems there was an increase in net ecosystem CO2 exchange and leaf area but a reduction of stomatal conductance, stem flow,
Sammendrag
Neozygites floridana is an important natural enemy of the two-spotted spider mite, Tetranychus urticae. Pesticides used in strawberries that might affect the conservation and enhancement of this beneficial fungus were therefore studied. This was done in a laboratory study by letting non-inoculated (healthy) mites and mites inoculated with N. floridana feed on strawberry leaf disks treated with one of the following pesticides: the fungicides tolylfluanid, fenhexamid or cyprodinil + fludioxonil or the acaricide/insecticide/molluscicide methiocarb. The effect of these pesticides on mortality and egg production of T. urticae and on the killing capacity and sporulation of N. floridana were determined. Tolylfluanid increased the mortality of non-inoculated mites (75.3%) compared to the non-inoculated control (27.5%). Methiocarb also killed non-inoculated mites. Fenhexamid did not have any effect on the mortality of non-inoculated mites (19.2%), neither had cyprodinil + fludioxonil (19.1%). Tolylfluanid did not reduce the mortality of mites inoculated with N. floridana (89.3%) compared to the inoculated control (80.0%). Neither did methiocarb, it rather increased the mortality of inoculated mites (93.2%). Fenhexamid did, however, reduce the mortality of inoculated mites (66.7%). The same was true for cyprodinil + fludioxonil (48.7%). In addition, cyprodinil + fludioxonil increased the time to death of inoculated mites (6.69 days) compared to the control (6.10 days), and inhibited sporulation of N. floridana (7.9% sporulation) compared to the control (42.4% sporulation). Tolylfluanid also reduced sporulation of N. floridana (15.5% sporulation). Results from this study indicate that the use of the fungicides tested will potentially reduce the survival and efficacy of the natural enemy N. floridana in the field.
Forfattere
Thomas Hartnik Henning MatthiesenSammendrag
Piling as a foundation technique on cultural layers has the advantage that the amount of excavated material is reduced. On the other hand, piling can have an adverse impact on the preservation of cultural layers in the ground due to physical deterioration and by enhancing biological degradation. The study presented in this report aimed at assessing the effect of piling and associated construction techniques on the environmental conditions in cultural layers that control biological degradation. Physical and chemical investigations in two excavated soil profiles near Hotel Klubben in Tønsberg were performed where piling was used as a foundation technique, and where drillings had earlier indicated a reduced organic content and worse state of preservation of the deposits close to the pile. Environmental conditions were assessed conducting field and laboratory measurements of basic physical and chemical parameters, as well as measurements of redox sensitive parameters. The results of the measurements revealed high oxygen concentrations near the foundation wall of the building where the cultural layers had been exchanged by porous fill masses. While areas that were not affected by oxygen intrusion had iron and sulphate reducing conditions that represent good preservation conditions in cultural layers, redox conditions near the building were aerobic and nitratereducing. These conditions enhance degradation of cultural layers. Oxygen intrusion into the ground is most likely facilitated by coarse material that was refilled next to the building when a girder was built under the foundation walls of the building. This coarse material enables diffusion of air into cultural layers as well as percolation of oxygen rich rain water into the ground . A possible adverse effect of the pile on environmental conditions is totally overshadowed by the effect of the girder and refilling material and could not be detected. It was not possible to investigate the conditions closer than approximately 50 cm from the pile. Nor was it possible to investigate the conditions deeper than 2.2 m beneath the soil surface, and thus this report cannot conclude anything about the conditions and possible impacts outside the investigated area.
Forfattere
Thomas Hartnik Henning MathiessenSammendrag
Det er ikke registrert sammendrag