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.
2017
Authors
Greeley Beck Emil Engelund Thybring Lisbeth Garbrecht Thygesen Callum Aidan Stephen HillAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Shota Masumoto Masaki Uchida Motoaki Tojo Maria-Luz Herrero Akira S. Mori Satoshi ImuraAbstract
In Arctic tundra, plant pathogens have substantial effects on the growth and survival of hosts, and impacts on the carbon balance at the scale of ecological systems. To understand these effects on carbon dynamics across different scales including plant organ, individual, population and ecosystem, we focused on two primary factors: host productivity reduction and carbon consumption by the pathogen. We measured the effect of the pathogen on photosynthetic and respiratory activity in the host. We also measured respiration and the amount of carbon in the pathogen. We constructed a model based on these two factors, and calculated pathogenic effects on the carbon balance at different organismal and ecological scales. We found that carbon was reduced in infected leaves by 118% compared with healthy leaves; the major factor causing this loss was pathogenic carbon consumption. The carbon balance at the population and ecosystem levels decreased by 35% and 20%, respectively, at an infection rate of 30%. This case study provides the first evidence that a host plant can lose more carbon through pathogenic carbon consumption than through a reduction in productivity. Such a pathogenic effect could greatly change ecosystem carbon cycling without decreasing annual productivity.
Authors
Nesrin Colak Anja K. Primetta Kaisu R. Riihinen Laura Jaakola Jiři Grúz Miroslav Strnad Hülya Torun Faik Ahmet AyazAbstract
Bilberries and their products are popular worldwide and represent a very interesting source of dietary antioxidants. Berries of eight different-colored and non-pigmented bilberry (Vaccinium myrtillus L.) samples from Finland were evaluated in terms of antioxidant capacity and total phenolic compounds (range, 220.06 – 3715.21 mg/100 g dw) and total monomeric anthocyanin (range, 206.18 – 867.52 mg/100 g dw) contents. Delphinidin (range, 5915.93–18108.39 μg /g dw) was the major anthocyanin moiety, while sinapic acid was the major phenolic acid in the free form (range, 0.01 – 6.06 μg /g dw), and p-coumaric acid in the ester (range, 26.39 – 110.78 μg /g dw), glycoside (range, 15.83 – 57.73 μg /g dw) and ester-bound (range, 2.32 – 14.20 μg /g dw) forms. The white colored berry samples did not contain any anthocyanins, but the colored berries did contain them. Antioxidant capacity was much higher in colored (pink to blue/black) berry samples than in the white sample, and it was more related to the total phenolic concentration rather than to the anthocyanin concentration. This is the first time that these different-colored berry phenotypes of bilberry (V. myrtillus L.) have been analyzed within the same study.
Abstract
The absorption of anthropogenic CO 2 by the oceans is causing a reduction in the pH of the surface waters termed ocean acidification (OA). This could have substantial effects on marine coastal environments where fleshy (non-calcareous) macroalgae are dominant primary producers and ecosystem engineers. Few OA studies have focused on the early life stages of large macroalgae such as kelps. This study evaluated the effects of seawater pH on the ontogenic development of meiospores of the native kelp Macrocystis pyrifera and the invasive kelp Undaria pinnatifi da , in south-eastern New Zealand. Meiospores of both kelps were released into four seawater pH treatments (pH T 7.20, extreme OA predicted for 2300; pH T 7.65, OA predicted for 2100; pH T 8.01, ambient pH; and pH T 8.40, pre-industrial pH) and cultured for 15 d. Meiospore germination, germling growth rate, and gametophyte size and sex ratio were monitored and measured. Exposure to reduced pH T (7.20 and 7.65) had pos itive effects on germling growth rate and gametophyte size in both M. pyrifera and U. pinnatifida , whereas, higher pH T (8.01 and 8.40) reduced the gametophyte size in both kelps. Sex ratio of gametophytes of both kelps was biased toward females under all pH T treatm ents, except for U. pinnatifida at pH T 7.65. Germling growth rate under OA was significantly higher in M. pyrifera compared to U. pinnatifida but gametophyte development was equal for both kelps under all seawater pH T treatments, indicating that the microscopic stages of the native M. pyrifera and the invasive U. pinnatifida will respond similarly to OA.
Authors
Ryan Bright Edouard Davin Thomas O'Halloran Julia Pongratz Kaiguang Zhao Alessandro CescattiAbstract
Following a land cover and land management change (LCMC), local surface temperature responds to both a change in available energy and a change in the way energy is redistributed by various non-radiative mechanisms. However, the extent to which non-radiative mechanisms contribute to the local direct temperature response for different types of LCMC across the world remains uncertain. Here, we combine extensive records of remote sensing and in situ observation to show that non-radiative mechanisms dominate the local response in most regions for eight of nine common LCMC perturbations. We find that forest cover gains lead to an annual cooling in all regions south of the upper conterminous United States, northern Europe, and Siberia—reinforcing the attractiveness of re-/afforestation as a local mitigation and adaptation measure in these regions. Our results affirm the importance of accounting for non-radiative mechanisms when evaluating local land-based mitigation or adaptation policies.
Authors
K. Marijanusic M. Manojlovic D. Bogdanovic R. Cabilovski Peder LombnæsAbstract
In order to evaluate the mineral composition of forage crops in respect to dairy cow nutrition 40 soil and corresponding plant (alfalfa, grasses and silage corn) samples were collected from 15 locations in Serbia and analyzed for the concentration of macro- (P, K, and Ca) and microelements (Mn, Cu, Zn, Fe, Co, Se, and Mo). On average, the soils were well provided with the studied elements from the aspect of plant nutrition, but the analyzed fodder crops could not secure suffi cient amounts of Cu, Zn, Se, and Ca for dairy cow nutrition. Principal components analysis was applied in order to determine the connection between the concentrations of macro- and microelements in forage crops and their grouping into components responsible for most of the variability in mineral content. The mineral composition of alfalfa was defi ned by three components (Se, Zn, and Cu) which accounted for the largest part of the established variability. The variability of mineral composition of grasses was defi ned by four components (Zn, K, Se, and P) and that of silage corn by the concentrations of Fe, Mn, and K.
Abstract
Today’s modern precision agriculture applications have a huge demand for data with high spatial and temporal resolution. This leads to the need of unmanned aerial vehicles (UAV) as sensor platforms providing both, easy use and a high area coverage. This study shows the successful development of a prototype hybrid UAV for practical applications in precision agriculture. The UAV consists of an off-the-shelf fixed-wing fuselage, which has been enhanced with multi-rotor functionality. It was programmed to perform pre-defined waypoint missions completely autonomously, including vertical take-off, horizontal flight, and vertical landing. The UAV was tested for its return-to-home (RTH) accuracy, power consumption and general flight performance at different wind speeds. The RTH accuracy was 43.7 cm in average, with a root-mean-square error of 39.9 cm. The power consumption raised with an increase in wind speed. An extrapolation of the analysed power consumption to conditions without wind resulted in an estimated 40 km travel range, when we assumed a 25 % safety margin of remaining battery capacity. This translates to a maximal area coverage of 300 ha for a scenario with 18 m/s airspeed, 50 minutes flight time, 120 m AGL altitude, and a desired 70 % of image side-lap and 85 % forward-lap. The ground sample distance with an in-built RGB camera was 3.5 cm, which we consider sufficient for farm-scale mapping missions for most precision agriculture applications.
Authors
N.P. Havill J. Elkinton J.C. Andersen Snorre Hagen Hannah J. Broadley G.J. Boettner A. CacconeAbstract
The European winter moth, Operophtera brumata, is a non-native pest in the Northeastern USA causing defoliation of forest trees and crops such as apples and blueberries. This species is known to hybridize with O. bruceata, the Bruce spanworm, a native species across North America, although it is not known if there are hybrid generations beyond F1. To study winter moth population genetics and hybridization with Bruce spanworm, we developed two sets of genetic markers, single nucleotide polymorphisms (SNPs) and microsatellites, using genomic approaches. Both types of markers were validated using samples from the two species and their hybrids. We identified 1216 SNPs and 24 variable microsatellite loci. From them we developed a subset of 95 species-diagnostic SNPs and ten microsatellite loci that could be used for hybrid identification. We further validated the ten microsatellite loci by screening field collected samples of both species and putative hybrids. In addition to confirming the presence of F1 hybrids reported in previous studies, we found evidence for multi-generation asymmetric hybridization, as suggested by the occurrence of hybrid backcrosses with the winter month, but not with the Bruce spanworm. Laboratory crosses between winter moth females and Bruce spanworm males resulted in a higher proportion of viable eggs than the reciprocal cross, supporting this pattern. We discuss the possible roles of population demographics, sex chromosome genetic incompatibility, and bacterial symbionts as causes of this asymmetrical hybridization and the utility of the developed markers for future studies.
Abstract
No abstract has been registered