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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.

2024

To document

Abstract

Ash dieback (ADB) has been threatening populations of European ash (Fraxinus excelsior & F. angustifolia) for more than three decades. Although much knowledge has been gathered in the recent past, practical conservation measures have been mostly implemented at local scale. Since range contraction in both ash species is likely to be exacerbated already in the near future by westward expansion of the emerald ash borer and climate change, systematic conservation frameworks need to be developed to avoid long-term population-genetic consequences and depletion of genomic diversity. In this article, we address the advantages and obstacles of conservation approaches aiming to conserve genetic diversity in situ or ex situ during tree pandemics. We are reviewing 47 studies which were published on ash dieback to unravel three important dimensions of ongoing conservation approaches or perceived conservation problems: i) conservation philosophy (i.e. natural selection, resistance breeding or genetic conservation), ii) the spatial scale (ecosystem, country, continent), and iii) the integration of genetic safety margins in conservation planning. Although nearly equal proportions of the reviewed studies mention breeding or active conservation as possible long-term solutions, only 17 % consider that additional threats exist which may further reduce genetic diversity in both ash species. We also identify and discuss several knowledge gaps and limitations which may have limited the initiation of conservation projects at national and international level so far. Finally, we demonstrate that there is not much time left for filling these gaps, because European-wide forest health monitoring data indicates a significant decline of ash populations in the last 5 years.

To document

Abstract

Wood-decay fungi are adapted to growth under different climate conditions and on various host tree species, but little is known about intraspecific variation in growth, substrate specificity and decay rates under different climatic conditions. Such knowledge is relevant to understand how wood-decay fungi will respond to climate change. Here, we investigate whether populations of the widespread brown-rot fungus Fomitopsis pinicola grow at different rates under different temperatures and water availabilities and whether the decay rate of the two wood substrates, Alnus incana and Picea abies, differs across populations. We isolated 72 cultures from fruit bodies collected in nine geographic localities across Norway, representing different climate conditions and substrates. We conducted in vitro growth experiments to assess the level of intraspecific phenotypic variability in temperature-dependent growth. All populations showed a strong but similar response in mycelial growth rates to different temperatures and water potentials. There were no consistent differences between populations in growth rates across temperatures, but larger variation between populations at the higher temperatures. Similarly, we observed no significant differences in wood decay rates across the nine populations and no signs of substrate specific adaptation to P. abies and A. incana. Our results indicate that local adaptation to different climates or substrates, as revealed by in vitro growth experiments, has to a limited extent, taken place during the few thousand years Fomitopsis pinicola has been present in this area.

Abstract

Species-rich natural and semi-natural ecosystems are under threat owing to land use change. To conserve the biodiversity associated with these ecosystems, we must identify and target conservation efforts towards functionally important species and supporting habitats that create connections between remnant patches in the landscape. Here, we use a multi-layer network approach to identify species that connect a metanetwork of plant–bee interactions in remnant semi-natural grasslands which are biodiversity hotspots in European landscapes. We investigate how these landscape connecting species, and their interactions, persist in their proposed supporting habitat, road verges, across a landscape with high human impact. We identify 11 plant taxa and nine bee species that connect semi-natural grassland patches. We find the beta diversity of these connector species to be low across road verges, indicating a poor contribution of these habitats to the landscape-scale diversity in semi-natural grasslands. We also find a significant influence of the surrounding landscape on the beta diversity of connector species and their interactions with implications for landscape-scale management. Conservation actions targeted toward species with key functional roles as connectors of fragmented ecosystems can provide cost-effective management of the diversity and functioning of threatened ecosystems.