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
Kathrin Seidel Johannes Kahl Flavio Paoletti Inés Birlouez-Aragone Nicolaas Busscher Ursula Kretzschmar Marjo Särkka-Tirkkonen Randi Seljåsen Fiorella Sinesio Torfinn Torp Irene BaiamonteAbstract
No abstract has been registered
Abstract
Seasonal time-courses of flower bud initiation and differentiation were monitored during two growing seasons (2011 and 2012) in 19 black currant cultivars of distant geographic origin, grown in the field at a South Norwegian locality (60°40’N, 10°52’E; 250 m asl). For comparison, the time-courses of shoot elongation growth in 15 of the same cultivars were also monitored during the 2012 growing season.The results revealed widely different seasonal timings of growth cessation and floral initiation in cultivars of different latitudinal origin. High latitude cultivars originating from crosses and selections of local, wild black currant populations from the Kola peninsula and Swedish Lapland were particularly early and had ceased growing and had initiated floral primordia by mid-June.This was approx. 5 – 6 weeks earlier than any of the other cultivars from lower latitudes. However, these also varied in their earliness of growth cessation and flower initiation in relation to their latitudinal origin. Many cultivars bred and selected in Southern Scandinavia, Scotland, and Poland did not cease growing and initiate floral primordia until late August, 9 weeks after the early, highlatitude cultivars. Overall, the 19 cultivars constituted a typical latitudinal cline in their photoperiodically controlled timing of growth and flowering responses. The high-latitude Russian cultivars ‘Imandra’ and ‘Murmanschanka’ represent valuable additions to the limited diversity of the available black currant gene-pool, and may be of particular use for breeding cultivars adapted to the sub-Arctic environment.
Abstract
In cases where sap flow is measured in trees and cross-sectional sapwood is not uniformly distributed, as in stems of diseased trees, an additional method may refine the sap flow measurements. If the studied trees are felled, the modified differential translucence method (MDT) for quantifying sapwood distribution in cross-sectional area may be compared with sap flow measurements. We studied sap flow by the heat field deformation method (HFD) in 12 Norway spruce trees with visible dieback symptoms and 12 without symptoms. Later, all sample trees were felled and analysed by MDT method. Results from MDT described well the differences and abnormalities which were also detected by HFD at any depth of the sapwood. Sap flow for whole tree (SF1) was calculated in accordance with radial and circumferential variation of sap flow density detected by HFD (based on average sap flow radial profiles). Other sapwood disturbances in parts not covered by HFD measurements were later corrected by MDT and refined total sap flow (SF2) was calculated. Relative differences between SF1and SF2 reached an interval from -0.21 to 0.41 for symptomatic trees and from -0.15 to 0.29 for non-symptomatic trees. The majority of the non-symptomatic trees had the relative difference close to zero. The theoretical use of single-point sensors for sap flow measurement was compared with the proportions of three wood types in a line 2 cm below the vascular cambium (a-sapwood, b-borders sapwood/heartwood or embolism, c-heartwood or embolism). The variability across wood types in the chosen line in the symptomatic trees was high and therefore quantifying the sap flow by the single point method was not possible.
Abstract
Originally, Trypophloeus dejevi (Stark, 1936) was described from Sakhalin Island in the Far East of Russia, and it remained undetected in Europe until 2009, when one Swedish specimen was found in the collection of the late Lars Huggert. This specimen was sampled in Northern Sweden in Torne Lappmark: Årosjokk, 67°52’ N/19°22’E, in 1968. In 2010, the species was found in five new localities in the same area. Here we present T. dejevi, recorded in 2012 as a new species to Norway and Finland. In Norway, galleries with beetles were found in Salix myrsinifolia Salisbury and in Finland Salix glauca L. was the observed host tree. Both are common willow species in Northern Fennoscandia. The distribution of the beetle within trunks of living Salix combined with a low population-density may be an explanation to why T. dejevi has been overlooked until now.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Ghislain Tchoromi Tepa-Yotto Trond Hofsvang I. Godonou May SæthreAbstract
No abstract has been registered
Abstract
Information on tree species effects on soil organic carbon (SOC) stocks is scattered and there have been few attempts to synthesize results for forest floor and mineral soil C pools. We reviewed and synthesized current knowledge of tree species effects on SOC stocks in temperate and boreal forests based on common garden, retrospective paired stand and retrospective single-tree studies. There was evidence of consistent tree species effects on SOC stocks. Effects were clearest for forest floor C stocks (23 of 24 studies) with consistent differences for tree genera common to European and North American temperate and boreal forests. Support for generalization of tree species effects on mineral soil C stocks was more limited, but significant effects were found in 13 of 22 studies that measured mineral soil C. Proportional differences in forest floor and mineral soil C stocks among tree species suggested that C stocks can be increased by 200–500% in forest floors and by 40–50% in top mineral soil by tree species change. However, these proportional differences within forest floors and mineral soils are not always additive: the C distribution between forest floor and mineral soil rather than total C stock tends to differ among tree species within temperate forests. This suggests that some species may be better engineers for sequestration of C in stable form in the mineral soil, but it is unclear whether the key mechanism is root litter input or macrofauna activity. Tree species effects on SOC in targeted experiments were most consistent with results from large-scale inventories for forest floor C stocks whereas mineral soil C stocks appeared to be stronger influenced by soil type or climate than by tree species at regional or national scales. Although little studied, there are indications that higher tree species diversity could lead to higher SOC stocks but the role of tree species diversity per se vs. species identity effects needs to be disentangled in rigorous experimental designs. For targeted use of tree species to sequester soil C we must identify the processes related to C input and output, particularly belowground, that control SOC stock differences. We should also study forms and stability of C along with bulk C stocks to assess whether certain broadleaves store C in more stable form. Joint cooperation is needed to support syntheses and process-oriented work on tree species and SOC, e.g. through an international network of common garden experiments.
Authors
Sarah Hale John Jensen Lena Jakob Patryk Oleszczuk Thomas Hartnik Thomas Henriksen Gudny Okkenhaug Vegard Martinsen Gerard CornelissenAbstract
The aim of the present study was to evaluate the secondary ecotoxicological effects of soil amendment materials that can be added to contaminated soils in order to sequester harmful pollutants. To this end, a nonpolluted agricultural soil was amended with 0.5, 2, and 5% of the following four amendments: powder activated carbon (PAC), granular activated carbon, corn stover biochar, and ferric oxyhydroxide powder, which have previously been proven to sequester pollutants in soil. The resulting immediate effects (i.e., without aging the mixtures before carrying out tests) on the springtail Folsomia candida, the earthworm species Aporectodea caliginosa and Eisenia fetida, the marine bacteria Vibrio f ischeri, a suite of ten prokaryotic species, and a eukaryote (the yeast species Pichia anomalia) were investigated. Reproduction of F. candida was significantly increased compared to the unamended soil when 2% biochar was added to it. None of the treatments caused a negative effect on reproduction. All amendments had a deleterious effect on the growth of A. caliginosa when compared to the unamended soil, except the 0.5% amendment of biochar. In avoidance tests, E. fetida preferred biochar compared to all other amendments including the unamended soil. All amendments reduced the inhibition of luminescence to V. f ischeri, i.e., were beneficial for the bacteria, with PAC showing the greatest improvement. The effects of the amendments on the suite of prokaryotic species and the eukaryote were variable, but overall the 2% biochar dose provided the most frequent positive effect on growth. It is concluded that the four soil amendments had variable but never strongly deleterious effects on the bacteria and invertebrates studied here during the respective recommended experimental test periods.
Authors
Pedro A. Alviola IV Rodolfo M. Jr. Nayga Michael R. Thomsen Zhongyi WangAbstract
No abstract has been registered