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The European biodiversity and forest strategies rely on forest sustainable management (SFM) to conserve forest biodiversity. However, current sustainability assessments hardly account for direct biodiversity indicators. We focused on forest multi-taxon biodiversity to: i) gather and map the existing information; ii) identify knowledge and research gaps; iii) discuss its research potential. We established a research network to fit data on species, standing trees, lying deadwood and sampling unit description from 34 local datasets across 3591 sampling units. A total of 8724 species were represented, with the share of common and rare species varying across taxonomic classes: some included many species with several rare ones (e.g., Insecta); others (e.g., Bryopsida) were repre sented by few common species. Tree-related structural attributes were sampled in a subset of sampling units (2889; 2356; 2309 and 1388 respectively for diameter, height, deadwood and microhabitats). Overall, multi taxon studies are biased towards mature forests and may underrepresent the species related to other developmental phases. European forest compositional categories were all represented, but beech forests were over represented as compared to thermophilous and boreal forests. Most sampling units (94%) were referred to a habitat type of conservation concern. Existing information may support European conservation and SFM strategies in: (i) methodological harmonization and coordinated monitoring; (ii) definition and testing of SFM indicators and thresholds; (iii) data-driven assessment of the effects of environmental and management drivers on multi-taxon forest biological and functional diversity, (iv) multi-scale forest monitoring integrating in-situ and remotely sensed information.

Although the application of sequencing-by-synthesis techniques to DNA extracted from bones has revolutionized the study of ancient DNA, it has been plagued by large fractions of contaminating environmental DNA. The genetic analyses of hair shafts could be a solution: We present 10 previously unexamined Siberian mammoth (Mammuthus primigenius) mitochondrial genomes, sequenced with up to 48-fold coverage. The observed levels of damage-derived sequencing errors were lower than those observed in previously published frozen bone samples, even though one of the specimens was >50,000 14C years old and another had been stored for 200 years at room temperature. The method therefore sets the stage for molecular-genetic analysis of museum collections.

X-ray computed tomography (CT-) scanning is revolutionizing the study of extinct organisms. Its non-invasive and non-destructive character makes it currently by far the most potent method to allow fossils to be studied in three dimensions and with unprecedented detail. More importantly, and differing from other 3D techniques, CT-scanning looks through and inside objects, revealing hidden structures and characters. Recent innovations in the field of CT-scanning allow obtaining details up to a few micrometers in resolution, and higher quality images of relatively dense materials, like fossils, even when wholly encased in hard sediment (Keklikoglou et al., 2019). In 2016, the Royal Belgian Institute of Natural Sciences (RBINS) acquired two high-end X-ray CT machines: the micro-CT RX EasyTom and the nano-CT XRE-Tescan UniTom. Both scanners are currently nearly full time in use to help accomplishing the gigantic task of the digitization of the RBINS and Royal Museum for Central Africa (RMCA) type collections, the aim of two multi-year Belspo funded projects, DiSSCo-Fed (2018-2023) and DIGIT-4 (2019-2024). With about 300.000 types and 48.000.000 general specimens, 46.000 and 3.000.000 respectively in their paleontology collections, the results of nearly two centuries of intensive collecting and research, these two Belgian Federal Scientific Institutions (FSI’s) are major players in the European framework of scientific research infrastructures for natural history. Digitizing this large number of types, spread across almost the entire Tree of Life, and exhibiting an entire array of differing taphonomies, results in a steadily growing expertise of the RBINS-RMCA micro-CT lab (Brecko et al., 2018). While the newly acquired infrastructure and ongoing digitization projects are primarily oriented towards the digitization of type and figured specimens, these also offer great opportunities for researchers and teachers in various disciplines of paleontology. Targeting on researchers interested in incorporating micro-CT as a technique in their research projects, the current digitization workflow of the RBINS-RMCA micro-CT lab will be presented. While micro-CT offers many advantages, there are also pitfalls and limitations that need to be considered. Based on our expertise, and illustrated by some of our scanning results, important constraints that may block the pathway between your expectations and perfect micro-CT-imaging results that can be fully incorporated into research projects will be presented. Possible effects of some of the most important parameters that may influence the quality of the output, and thus can increase the signal to noise ratio (SNR) will be reviewed, such as the size and shape of the specimen to be scanned, the density of its matrix the specimen is made of or encased in, the presence of certain minerals (e.g. pyrite) and how these may be distributed inside the specimen (e.g. finely disseminated, dense masses or crystals), the best possible resolution in relation to the specimen and preferred output, the time needed to scan a specimen, the choice between machines to be used and their limits and different possible scan settings (e.g. beam power, filters…). Post-processing parameters to be considered are the size of the image stack output (will the computer be able to handle the amount of Gigabytes?), the time needed to render and segment regions of interest and optimize 3D-models, and which format suits best to visualize and export the data (renderings, meshes, videos, virtual sections…). While segmentation may be a time-consuming task, new developments like the incorporation of artificial intelligence (e.g. the Deep Learning function in Dragonfly ORS) offer great potential to reduce the workload in complex segmentation. Many researchers are also teachers. The reason why they may also be particularly interested in the 3D models of the already digitized types that are available on the Virtual Collections platforms of the RBINS (http://virtualcollections.naturalsciences.be/) and RMCA (https://virtualcol.africamuseum.be/). While 3D models are not intended to replace physical specimens, they may become significant teaching aids in both the physical and virtual classroom. In addition, the presence of a steadily growing number of 3D-models and animations of extant animals that are also added to these Virtual Collections, would allow teachers to connect fossils (in general incomplete) with extant (more complete) relatives. Last but not least, while the focus of this communication is largely on micro-CT, some of the many other new techniques that are being tested, used and improved will be highlighted (see e.g. Brecko & Mathys, 2020; Brecko et al., 2014, 2016, 2018; Mathys et al., 2013, 2019 for some examples). Interested in our work, expertise, techniques, equipment, or scans-on-demand? Please do not hesitate to reach out! References Brecko, J., Lefevre, U., Locatelli, C., Van de Gehuchte, E., Van Noten, K., Mathys, A., De Ceukelaire, M., Dekoninck, W., Folie, A., Pauwels, O., Samyn, Y., Meirte, D., Vandenspiegel, D. & Semal, P. 2018. Rediscovering the museum’s treasures: μCT digitisation of the type collection. Poster presented at 6th annual Tomography for Scientific Advancement (ToScA) symposium, Warwick, England, 10-12 Sept 2018. Brecko, J. & Mathys, A., 2020. Handbook of best practice and standards for 2D+ and 3D imaging of natural history collections. European Journal of Taxonomy, 623, 1-115. Brecko, J., Mathys, A., Dekoninck, W., De Ceukelaire, M., VandenSpiegel, D. & Semal, P., 2016. Revealing Invisible Beauty, Ultra Detailed: The Influence of Low-Cost UV Exposure on Natural History Specimens in 2D+ Digitization. PLoS One 11(8):e0161572. Brecko, J., Mathys, A., Dekoninck, W., Leponce, M., Vanden Spiegel, D. & Semal, P., 2014. Focus stacking: Comparing commercial top-end set-ups with a semi-automatic low budget approach. A possible solution for mass digitization of type specimens. Zookeys, 464, 1-23. Keklikoglou, K., Faulwetter, S., Chatzinikolaou, E., Wils, P., Brecko, J., Kvaček, J., Metscher, B. & Arvanitidis, C. 2019. Micro-computed tomography for natural history specimens: a handbook of best practice protocols. European Journal of Taxonomy, 522, 1-55. Mathys, A., Semal, P., Brecko, J. & Van den Spiegel, D., 2019. Improving 3D photogrammetry models through spectral imaging: Tooth enamel as a case study. PLoS One, 14(8): e0220949. Mathys, A., Brecko, J., Di Modica, K., Abrams, G., Bonjean, D. & Semal, P., 2013. Agora 3D. Low cost 3D imaging: a first look for field archaeology. Notae Praehistoricae, 33/2013, 33-42.