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.
2012
Forfattere
Signe Kynding Borgen Arne Grønlund Olof Andrén Thomas Kätterer Ole Einar Tveito Lars Bakken K PaustianSammendrag
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Sammendrag
The genera Leiopus Audinet-Serville, 1835 and Acanthocinus Dejean, 1821 are redescribed. New morphological differences at the generic level are described, and the importance of genitalia characters in taxonomy at both species and generic level is emphasized. Carinopus subgen. nov. in Leiopus is described from mainland China and Taiwan. Acanthobatesianus subgen. nov. in Acanthocinus is described from China, the Korean peninsula and Japan. Leiopus (Carinopus) campbelli (Gressitt, 1937) comb. nov. is transferred from Acanthocinus, and Acanthocinus (Acanthobatesianus) guttatus (Bates, 1873) comb. nov. from Leiopus. Six new species of Leiopus from China are diagnosed, described, and illustrated: L. nigropunctatus sp. nov., L. flavomaculatus sp. nov., L. ocellatus sp. nov., L. nigrofasciculosus sp. nov., L. holzschuhi sp. nov. and L. multipunctellus sp. nov. Redescriptions of L. kharazii Holzschuh, 1974, L. albivittis albivittis Kraatz, 1879, L. stillatus (Bates, 1884), L. (Carinopus) shibatai Hayashi, 1974, L. (Carinopus) fallaciosus Holzschuh, 1993, L. (Carinopus) campbelli (Gressitt, 1937) comb. nov. and Acanthocinus (Acanthobatesianus) guttatus (Bates, 1873) comb. nov. are added. A key to the generic and subgeneric levels of Leiopus and Acanthocinus, and a dichotomous key to all six new species of Carinopus subgen. nov. (Leiopus str.) from China, are provided.
Sammendrag
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Sammendrag
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Sammendrag
Springs are characterized by consistent thermal and hydrologic conditions, which enable use of spring-inhabiting organisms as sensitive indicators of biogeochemical changes in their catchments. We hypothesized that bryophytes would show a stronger response than vascular plants to changes in spring water quality because submerged bryophytes do not take up compounds from the soil. We analyzed species responses to interannual changes in spring water quality (discharge, water temperature, electrical conductivity, and pH) in 57 forest springs over 4 consecutive years. We calculated interannual turnover in species composition for bryophytes and vascular plants with the Bray–Curtis dissimilarity index. We applied regression analysis to test interannual changes in species composition of the taxonomic groups over time, and we used 2-sided t-tests to compare year-to-year changes in species composition between bryophytes and vascular plants. We used boosted regression tree (BRT) models to quantify the relative importance of different physicochemical variables and Pearson linear correlation to quantify short-term changes in vegetation relative to changes in spring-water pH. For both groups, interannual changes in species composition were significantly positively related to time scale. Bryophytes did not show a significantly stronger response than vascular plants to interannual changes in the environment. Alterations in pH and conductivity explained most of the observed interannual changes in species composition of both groups, whereas changes in water temperature and discharge were less important. However, responses of single species to environmental change may be delayed, resulting in inertia at the community and ecosystem scales. Hence, longer time periods need to be considered for a better understanding of response times of the vegetation of European forest springs to changes in spring water quality.
Sammendrag
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Forfattere
Stein Michael Tomter Patrizia Gasparini Thomas Gschwantner Petra Hennig Gintaras Kulbokas Andrius Kuliesis Heino Polley Nicolas Robert Jacques Rondeux Giovanni Tabacchi Erkki TomppoSammendrag
Estimates of growing stock in European countries vary mainly by using different thresholds for dbh of sample trees, as well as by the inclusion or exclusion of stump and stem top volume. European national forest inventories use dbh thresholds ranging from 0 to 12 cm in estimating the volume of growing stock. COST Action E43 has agreed to a reference definition for growing stock with a dbh threshold of 0 cm. With use of national volume distributions by dbh classes, models for estimating the proportions of growing stock between the national threshold and the 0-cm threshold were constructed. Models for characterizing growing stock distributions were tested, and their predictive abilities were investigated. Similar comparisons were made with respect to the volume of stumps and stem tops. Examples of estimation methods and the resulting percentages of these tree elements of total growing stock are presented.
Sammendrag
Harvest activity directly impacts timber supply, forest conditions, and carbon stock. Forecasts of the harvest activity have traditionally relied on the assumption that harvest is carried out according to forest management guidelines or to maximize forest value. However, these rules are, in practice, seldom applied systematically, which may result in large discrepancies between predicted and actual harvest in short-term forecasts. We present empirical harvest models that predict final felling and thinning based on forest attributes such as site index, stand age, volume, slope, and distance to road. The logistic regression models were developed and fit to Norwegian national forest inventory data and predict harvest with high discriminating power. The models were consistent with expected landowners behavior, that is, areas with high timber value and low harvest cost were more likely to be harvested. We illustrate how the harvest models can be used, in combination with a growth model, to develop a national business-as-usual scenario for forest carbon. The business-as-usual scenario shows a slight increase in national harvest levels and a decrease in carbon sequestration in living trees over the next decade.
Forfattere
Jozef Martinka Karol Balog Tomás Chrebet Emília Hroncová Janka DibdiakovaSammendrag
The presented article deals with the assessment of combined impact of temperature and flow of oxidising atmosphere, its oxygen concentration and heat flux on the ignition time of isotactic polypropylene (PP). The ignition time was determined in a specially adapted hot air Setchkin furnace at temperatures (450 and 600 °C), density of heat flux (12.4 and 26.4 kW m−2), flows of oxidation mixture (6 and 8 L min−1) and volume oxygen concentrations (3, 9, 15, 21, 27, 33, 39, 45 and 50 %). Obtained data allows us to assume that the temperature influence on PP induction period of ignition increases with decreasing flow rate of oxidising atmosphere. At the flow of oxidising mixture equal to 6 L min−1 and temperature of 600 °C, oxygen concentration had only a negligible impact on the the induction period of ignition in the analysed period. From the presented results, the induction period of ignition depends on the temperature and also on the flow rate of oxidising mixture and oxygen concentration in it. In addition, heat flux has a significant influence on the induction period. However, the quantification of the heat flux influence was not possible with the applied experimental device.
Sammendrag
Stand and disturbance dynamics are key processes that need to be assessed along with climate-species interactions if we are to better understand the impacts of climate change on species. In this study we investigated the biotic interactions (competition) between species, the influence of disturbance type, and changes in resource availability (moisture and light) on the response of six tree species to climate change in the northwest region of central British Columbia, Canada. Two ecological models were parameterized, linked together and coupled to climate change scenarios to explore the interactions between: (1) the response of species in the regeneration phase and (2) the role of disturbance, resource availability and competition on determining stand composition and productivity. Climate change was found to reduce soil moisture availability which resulted in a decline in regeneration potential for all species on dry sites and negative to neutral responses on sites with higher water availability. Following fire, stand dynamics and composition were modeled to undergo significant changes under the 2080s climate compared to current climate conditions on dry and mesic sites. Changes in stand dynamics under climate change were marginal following bark beetle disturbances. While significant changes to stand dynamics were found on dry sites, the presented results suggest that the sites with the highest moisture availability maintain the same general stand dynamics and composition following disturbances under climate change. This study highlights the need to consider species response to climate change in interaction with existing stand conditions, disturbance type, competition, resource availability, not just temperature and precipitation.