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
Gisela Lüscher Jean-Philippe Choisis Philippe Jeanneret Manuel K. Schneider Andy Hector Michaela Arndorfer Katalin Balász András Báldi Debra Bailey Peter Dennis Sebastian Eiter Zoltán Elek Wendy Fjellstad Phillipa K. Gillingham Maximilian Kainz Anikó Kovács-Hostyánszki Kurt-Jürgen Hülsbergen Maurizio Guido Paoletti Susanne Papaja-Hülsbergen Jean-Pierre Sarthou Norman Siebrecht Sebastian Wolfrum Felix HerzogSammendrag
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Forfattere
Safaa Wasof Jonathan Lenoir Per Arild Aarrestad Inger Greve Alsos W. Scott Armbruster Gunnar Austrheim Vegar Bakkestuen Harry John Betteley Birks Kari Anne Bråthen Olivier Broennimann Jörg Brunet Hans Henrik Bruun Carl Johan Dahlberg Martin Diekmann Stefan Dullinger Mats Dynesius Rasmus Ejrnæs Jean-Claude Gegout Bente Jessen Graae John-Arvid Grytnes Antoine Guisan Kristoffer Hylander Ingibjørg Jonsdottir Jutta Kapfer Kari Klanderud Miska Luoto Ann Milbau Mari Moora Bettina Nygaard Arvid Odland Harald Pauli Virve Ravolainen Stefanie Reinhardt Sylvi Marlen Sandvik Fride Høistad Schei James David Mervyn Speed Jens-Christian Svenning Wilfried Thuiller Unn Tveraabak Vigdis Vandvik Liv Guri Velle Risto Virtanen Pascal Vittoz Wolfgang Willner Thomas Wohlgemuth Niklaus E Zimmermann Martin Zobel Guillaume DecocqSammendrag
Aim Previous research on how climatic niches vary across species ranges has focused on a limited number of species, mostly inv asive, and has not, to date, been very conclusive. Here we assess the degree of niche conservatism between distant populations of native alpine plant species that have been separated for thousands of years. Location European Alps and Fennoscandia. Methods Of the studied pool of 888 terrestr ial vascular plant species occurring in both the Alps and Fennoscandia, we used two complementary approaches to test and quantify climatic-niche shifts for 31 species having strictly disjunct populations and 358 species having either a contiguous or a patchy distribution with distant populations. First, we used species distr i- bution modelling to test for a region effect on each species’ climatic niche. Second, we quantified niche overlap and shifts in niche width (i.e. ecological amplitude) and position (i.e. ecological optimum) within a bi-dimensional climatic space. Results Only one species (3%) of the 31 species with str ictly disjunct populations and 58 species (16%) of the 358 species with distant popula- tions showed a region effect on their climatic niche. Niche overlap was higher for species with strictly disjunct populations than for species with distant populations and highest for arctic–alpine species. Climatic niches were, on average, wider and located towards warmer and wetter conditions in the Alps. Main conclusion Climatic niches seem to be generally conserved between populations that are separated between the Alps and Fennoscandia and have probably been so for 10,000–15,000 years. Therefore, the basic assumption of species distribution models that a species’ climatic niche is constant in space and time – at least on time scales 10 4 years or less – seems to be largely valid for arctic–alpine plants.
Sammendrag
Remotely sensed data from airborne laser scanning (ALS) and interferometric synthetic aperture radar (InSAR) can greatly improve the precision of estimates of forest resource parameters such as mean biomass and biomass change per unit area. Field plots are typically used to construct models that relate the variable of interest to explanatory variables derived from the remotely sensed data. The models may then be used in combination with the field plots to provide estimates for a geographical area of interest with corresponding estimates of precision using model-assisted estimators. Previous studies have shown that field plot sizes found suitable for pure field surveys may be sub-optimal for use in combination with remotely sensed data. Plot boundary effects, co-registration problems, and misalignment problems favor larger plots because the relative impact of these effects on the models of relationships may decline by increasing plot size. In a case study in a small boreal forest area in southeastern Norway (852.6 ha) a probability sample of 145 field plots was measured twice over an 11 year period (1998/1999 and 2010). For each plot, field measurements were recorded for two plot sizes (200 m2 and 300/400 m2). Corresponding multitemporal ALS (1999 and 2010) and InSAR data (2000 and 2011) were also available. Biomass for each of the two measurement dates as well as biomass change were modeled for all plot sizes separately using explanatory variables from the ALS and InSAR data, respectively. Biomass change was estimated using model-assisted estimators. Separate estimates were obtained for different methods for estimation of change, like the indirect method (difference between predictions of biomass for each of the two measurement dates) and the direct method (direct prediction of change). Relative efficiency (RE) was calculated by dividing the variance obtained for a pure field-based change estimate by the variance of a corresponding estimate using the model-assisted approach. For ALS, the RE values ranged between 7.5 and 15.0, indicating that approximately 7.5–15.0 as many field plots would be required for a pure field-based estimate to provide the same precision as an ALS-assisted estimate. For InSAR, RE ranged between 1.8 and 2.5. The direct estimation method showed greater REs than the indirect method for both remote sensing technologies. There was clearly a trend of improved RE of the model-assisted estimates by increasing plot size. For ALS and the direct estimation method RE increased from 9.8 for 200 m2 plots to 15.0 for 400 m2 plots. Similar trends of increasing RE with plot size were observed for InSAR. ALS showed on average 3.2–6.0 times greater RE values than InSAR. Because remote sensing can contribute to improved precision of estimates, sample plot size is a prominent design issue in future sample surveys which should be considered with due attention to the great benefits that can be achieved when using remote sensing if the plot size reflects the specific challenges arising from use of remote sensing in the estimation. That is especially the case in the tropics where field resources may be scarce and inaccessibility and poor infrastructure hamper field work.
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Forfattere
Hugo de Boer Hugh Cross Willem J.J.O. de Wilde Brigitta E.E. Duyfjes Barbara GravendeelSammendrag
The tropical cucurbitaceous genus Zehneria as traditionally circumscribed displays much morphological diversity. Recent taxonomic revisions have resulted in its redefinition through both recognition and subsequent lumping of several additional genera. This study utilized plastid and nuclear DNA sequence data to reconstruct a molecular phylogeny of Zehneria and its close relatives in order to test whether these revisions reflected the molecular evolution in this group. The results suggest that Neoachmandra is monophyletic, and that Zehneria in a restricted sense and Neoachmandra accessions form a single monophyletic clade, whereas Pilogyne in its present understanding is polyphyletic. In the light of these results Pilogyne should be merged back into Zehneria from which it was split off earlier.
Forfattere
Laura Zoratti Laura Jaakola Hely Häggman Lara GiongoSammendrag
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Agricultural and Food Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see <a href=http://doi.org/10.1021/acs.jafc.5b02833>http://doi.org/10.1021/acs.jafc.5b02833</a>.
Forfattere
Elke J. van Nieuwenhuijzen Michael F. Sailer Lone Ross Olaf C. G. Adan Peter J. Punt Robert A. SamsonSammendrag
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Forfattere
Eva Brod Anne K. Falk Øgaard Eddy Walther Hansen David Wragg Trond Haraldsen Tore KrogstadSammendrag
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