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.
2025
Authors
Martina Paponov Pembi Sherpa Lama Jörg Ziegler Cathrine Lillo Ivan PaponovAbstract
No abstract has been registered
Abstract
Diverse pedoclimatic zones lead to large variations in soil organic carbon (SOC). Key questions involve how much carbon the soil contains, what is its potential for more storage and whether levels are sufficient to maintain soil structure stability (SSS). We evaluate current SOC levels using ratios of clay/silt fractions to SOC, to identify potential SOC storage areas and to gauge likely SSS status. SOC retention is affected by clay and silt, which protect it from microbial activity. Hassink (1997) used the ratio of clay plus silt <20 µm (fines20) to SOC to indicate this relationship, whilst Dexter et al. (2008) used the ratio of clay to SOC. Jensen et al. (2019) found critical ratios for SSS to be ~10 for clay/SOC and ~20 for fines20/SOC, above which SSS is impaired and below which SOC is less likely to be retained. These ratios appear valid under Norwegian conditions, where greatest declines in SOC have been found in soils with high initial SOC levels and lowest declines in clay soils (Riley & Bakkegard 2008). After 28 years of a cropping system trial in eastern Norway (Riley et al. 2022), equilibrium between SOC gains and losses was at a fines20/SOC ratio of ~18, whilst in the same trial SSS declined sharply in an arable cropping system with a clay/SOC ratio >10, compared to systems with ratios of 6- 8. In western Norway, on grassland soils with generally low fines20/SOC ratios, SOC appears to be declining despite manure inputs, especially in cases with high initial SOC levels (Rittl et al. 2023). To obtain insight into the potential for SOC across Norway, data was used from a study in which SOC and soil texture was analysed on 600 fields in agricultural districts throughout the country. Results are grouped into 13 regions with relatively uniform climate and cropping within each. Greatest proportions of fields with high ratio levels were found in regions around Oslo and east of Oslofjord, with predominantly clay and silty clay loams, where 65% of fields had clay/SOC >10 and 80% had fines20/SOC >20. Proportions of fields with fines20/SOC >20 were somewhat lower west of Oslofjord (65%) and in central Norway (44%), where many soil textures are found, and in an inland region with predominantly silty soils (55%). Proportions of fields with high ratio levels were low in inland regions with loam soil, where 15-20% had clay/SOC >10 and 24% had fines20/SOC >20. All these regions are mainly arable, with some livestock, and mean SOC levels are <3,0%. In the predominantly grassland/livestock regions of southern, western and northern Norway, and in upland areas, the soils are mostly sandy and silty loams, and mean SOC levels are mostly >3,5%. In these regions, the proportion of fields with clay/SOC >10 was below 5% whilst that of fines20/SOC >20 was below 10%. Mean clay/SOC ratios were 1-3 and mean fines20/SOC ratios were 4-10. Arable land has thus greater potential for carbon storage than grassland, whilst at the same time increasing SSS and reducing erosion risk.
Authors
Liping Wei Emiel De Lombaerde Thomas Vanneste Pieter Sanczuk Lander Baeten Jonathan Lenoir Karen De Pauw Kris Verheyen Markus Bernhardt-Römermann Antoine Becker-Scarpitta Jörg Brunet Markéta Chudomelová Guillaume Decocq Martin Diekmann Tomasz Durak Radim Hédl Thilo Heinken Peter J. Horchler Bogdan Jaroszewicz Martin Kopecký Martin Macek František Máliš Tobias Naaf Thomas A. Nagel Anna Orczewska Petr Petřík Kamila Reczyńska Fride Høistad Schei Wolfgang Schmidt Jan Šebesta Alina Stachurska-Swakoń Tibor Standovár Krzysztof Świerkosz Balázs Teleki Hans Van Calster Ondřej Vild Donald M. Waller Monika Wulf Pieter De FrenneAbstract
We face increasing concerns about how the local diversity of native plant communities responds to various drivers of global change, yet often lack comprehensive studies that integrate several components of diversity and the effects of both local and regional drivers of change. We analyzed changes in taxonomic, functional, and phylogenetic diversity across 2681 (semi-)permanent temperate forest understory plots surveyed and resurveyed for all vascular plants over intervals of 15–78 yr, spanning 72 regions distributed across Europe. We quantified temporal changes in these diversity indices and assessed their responses to changes in both local drivers (plot-level overstory cover, indicator values for soil nutrients) and regional shifts in macroclimate and nitrogen deposition. Overall, local changes in taxonomic, functional, and phylogenetic diversity were centered around zero, reflecting – on average – little net change in forest diversity. Observed diversity changes mostly reflected local conditions such as overstory cover change and baseline soil nutrients rather than regional drivers of large-scale change. Changes in phylogenetic diversity correlated positively with changes in taxonomic diversity but negatively with changes in functional diversity. Our findings underscore the importance of local habitat management and multifaceted diversity monitoring for effective biodiversity conservation in temperate forests.
Authors
Martin Nopens Imke Greving Silja Flenner Linnea Hesse Jan Lüdtke Michael Altgen Gerald Koch Johannes Beruda Sabrina Heldner Hannes Köhm Sergej Kaschuro Andrea Olbrich Jakob Benedikt Mietner Fabian Scheckenbach Jördis Sieburg-Rockel Andreas KrauseAbstract
Deep understanding of the structural composition and growth of biological specimens is becoming increasingly important for the development of bio-based and sustainable material systems. Full-field nano-computed tomography is particularly suitable for this purpose as it allows for non-destructive 3D imaging at high spatial resolution. However, most biological samples are functionalized by water and respond sensitively to any changes in climate conditions, specifically relative humidity, by adjusting their material moisture content. To date, only a limited number of tomography instruments offer an in situ climate control option to users. These, however, are limited either by the range of relative humidity states, the long times required to change the climate state, or obstruction or attenuation of the beam. Here, the first fully automatized climate cell for in situ full-field nanotomography is presented. It has been designed, built and integrated at the nanotomography station at the P05 imaging beamline, operated by Hereon at the DESY storage ring PETRA III, Germany. The highly flexible and windowless design allows the humidity dependent swelling and shrinking of lignified plant cell walls to be studied in situ, using phase contrast nanotomography. The concept of this climate chamber can easily be integrated into other setups. It operates in the relative humidity range of 0–90% and can be controlled in a temperature range of 10–50°C. Climate conditions can be adjusted at any time, remotely from the control hutch by using a humidity generator. Results show that the developed setup maintains a stable climate during the entire duration of a tomographic scan at different humidities and does not obstruct the sample or hinder the imaging conditions. During the tomographic investigation the sample remains stable in the flow of the air stream and shows typical cell wall swelling and shrinking behaviour depending on the equilibrium moisture content. This new climate cell is now available to all users of the P05 nanotomography instrument for conditioning samples, serving a wide range of scientific applications.
Authors
Pia Marinček Jing Vir Leong Loic Pittet Ètienne Léveillé-Bourret Tommi Nyman Maria Tomoshevich Evgeny Banaev Li He Elvira Hörandl Martin Volf Natascha D. WagnerAbstract
The spatio-temporal evolution of woody plant lineages in the Holarctic is still understudied, limiting our understanding of evolutionary processes that promote higher diversity at higher latitudes in some lineages, which contradicts the latitudinal gradient hypothesis which predicts higher species richness in the tropics. Shrub willows (Salix subgenus Vetrix) comprise about 350 species of which many are adapted to arctic-alpine ecosystems and thus form an important element across the Holarctic region. In this study, we utilized RAD sequencing to estimate the spatio-temporal evolution of the Vetrix clade based on about 140 species covering most of its morphological and geographical diversity. The resolved phylogeny revealed four lineages: the Pan-Himalayan clade, the North American clade and two clades containing species from Eurasia. Widespread circumpolar species form a hybridogenetic grade between the Eurasian and North American clades. Our results confirm that shrub willows originated in the Tertiary, probably in Asia, and that diversification coincided with the climatic cooling in the Pleistocene. At least two radiations were observed, in the Pan Himalayas and in North America. Speciation was further shaped by migration and dispersal in Eurasia, likely accelerated by the uplift of mountain chains, the closure of the Turgai Strait and expansion of suitable habitats. The dated phylogeny revealed that speciation of arctic lineages predates adaptation to high latitudes, as also evident from the fossil record. Small wind-dispersed seeds enabled shrub willows to colonize the expanding arctic tundra regions in the Miocene and their recolonization after the LGM. Given the high observed number of polyploid species equally distributed in all clades and indications of genetic admixture, we assume that species diversity in shrub willows was additionally increased by hybridization and polyploidization.
Authors
Alejandro Sánchez-Gómez Katrin Bieger Christoph Schürz José Manuel Rodríguez-Castellanos Eugenio Molina-NavarroAbstract
Calibration is essential to ensure hydrological models’ reliability. While performance metrics for simulated variables are often used as the primary indicators of model adequacy, it is equally important to verify that the underlying hydrological processes are realistically represented. This consideration becomes even more critical in complex basins characterized by heterogeneous climatic or geological conditions, where processes variability may necessitate the use of zonal calibration approaches. This study presents a multi-spatial and multi-criteria calibration of a SWAT+ model for the Upper Tagus River basin, a large and geologically diverse catchment. This approach, which includes a sensitivity analysis, has been designed to ensure a realistic simulation of hydrological processes in geologically diverse areas. The daily streamflow simulation performance and its components have been evaluated at 22 gauged areas, as inflows to 12 reservoirs, collectively covering 44 % of the modelled area (all under natural flow regimes). The optimization of the model required a detailed zonation based on geological properties, and a comprehensive validation process, including a fine-tuning, was necessary to obtain a set of parameters resulting in an accurate (considering performance metrics) and realistic (considering the streamflow components) simulation in most of the areas evaluated. The global performance (evaluated aggregating streamflow of the different areas considered) demonstrated a very good daily streamflow simulation performance (NSE > 0.8, PBIAS < 5 %) and an accurate simulation of the daily streamflow components. The developed calibration approach, coded in R, can be effectively applied to other hydrologically complex regions.
Authors
Samuel L. Zelinka Samuel V. Glass Natalia Farkas Emil E. Thybring Michael Altgen Lauri Rautkari Simon Curling Jinzhen Cao Yujiao Wang Tina Künniger Gustav Nyström Christopher Hubert Dreimol Ingo Burgert Mark G. Roper Darren P. Broom Matthew Schwarzkopf Arief Yudhanto Mohammad Subah Gilles Lubineau Maria Fredriksson Wiesław Olek Jerzy Majka Nanna Bjerregaard Pedersen Daniel J. Burnett Armando R. Garcia Frieder Dreisbach Louis Waguespack Jennifer Schott Luis G. Esteban Alberto García‑Iruela Thibaut Colinart Romain Rémond Brahim Mazian Patrick Perré Lukas EmmerichAbstract
Many studies that use an automated sorption balance to determine a water vapor sorption isotherm for wood collect data until the moisture content change is less than or equal to 0.002% min −1 (20 µg g −1 min −1 ). This stop criterion has been claimed to give errors in equilibrium moisture content (EMC) predictions of less than 0.001 g g −1 but over the past 10 years, studies have shown that the actual errors can be greater than 0.01 g g −1 because the measurements are stopped well before equilibrium is reached. Despite the large errors associated with this stop criterion, it remains popular due to the speed at which isotherms can be measured. This paper utilizes data from a worldwide interlaboratory study on automated sorption balances to develop a correction method for estimating EMC of western larch ( Larix occidentalis Nutt.) from the moisture content corresponding to the 20 µg g −1 min −1 criterion. The study uses data from 72 relative humidity absorption steps with hold times of 7–10 days from 21 different laboratories and eight different instrument models. EMC is defined based on the inherent mass stability of automated sorption balances determined in the first part of this interlaboratory study. On average the sorption process is less than 80% complete when the 20 µg g −1 min −1 criterion is reached, resulting in a mean absolute error (MAE) of 0.006 g g −1 . The correction equation for estimating EMC reduces the MAE to 0.001 g g −1 . The analysis presented in this paper, along with the correction equation, can be considered for certain use cases to reduce systematic errors and shorten measurement times.
Authors
Alexey Mikaberidze C. D. Cruz Ayalsew Zerihun Abel Barreto Pieter Simon A Beck Rocío Calderón Carlos Camino Rebecca E. Campbell Stephanie K.L. Delalieux Frédéric Fabre Elin Falla Stuart Fraser Kaitlin M. Gold Carlos Gongora-Canul Frédéric Hamelin Dalphy Ondine Camira Harteveld Cheng Fang Hong Melen Leclerc Da Young Lee Murillo Lobo Anne Katrin Mahlein Emily McLay Paul Melloy Stephen Parnell Uwe Rascher Jack Rich Irene Salotti Samuel Soubeyrand Susan Sprague Antony Surano Sandhya D. Takooree Thomas H. Taylor Suzanne Touzeau Pablo J. Zarco-Tejada Nik J. CunniffeAbstract
No abstract has been registered
Authors
Ludmila Sromek Kevin P. Johnson Mervi Kunnasranta Aqqalu Rosing-Asvid Britt-Marie Bäcklin Aselle Tasmagambetova Adylkhan Tovassarov Olga Rusinek Heather L. Ziel Ana Rubio-García Tommi NymanAbstract
We studied the drivers of population-genetic structuring and genetic diversity in specialist parasites based on whole-genome resequencing data from 82 Echinophthirius horridus seal louse individuals sampled from 12 ecologically and behaviourally different phocine seal species, subspecies and populations across the Holarctic. We found that the main genetic disjunctions in E. horridus lice occur across seal host species and subspecies, with a further level of population subdivision emerging among host individuals within some populations. Endemic and relict landlocked seal (sub)species host the genetically most distinct louse populations, while lice associated with sympatric marine seals show signatures of occasional gene flow across hosts. Within the latter, the most extreme case is seen in the near-panmictic lice associated with northern European grey and harbour seals, which aggregate in shared rookeries and colonies. Although the louse and seal phylogenies were overall statistically significantly congruent, evidence for similar host shifts in the past is reflected in several conflicts in the phylogenetic trees of the lice and their hosts. Population-level mean heterozygosity and theta in seal lice varied considerably, and both measures of genetic variation were statistically significantly related to host population size. Taken together, our results support a non-adaptive model of parasite diversification, in which geographic and behavioural isolation among hosts drives parasite genetic differentiation, and genetic erosion in bottlenecked hosts cascades up to their specialist parasites. Our results provide new insights into processes that generate parasite diversity and trigger parallel losses of genetic diversity in endangered host–parasite systems.
Authors
Vincent Biard Piia Mutka Mairi Young Marja Niemi Tommi Nyman Milaja Nykänen Mervi KunnasrantaAbstract
While social network analysis was originally developed for human sociology studies, it is also a valuable tool for characterizing behavioural aspects in many animal populations. For instance, social network analysis can be used for assessing the transmission of diseases or information within groups. Here, we describe co-occurrences and potential social associations of ringed seals, Pusa hispida saimensis, in Lake Saimaa, Finland, from 2016 to 2022, based on photoidentification data. Throughout seven successive moulting seasons (April to June), we identified 425 individuals, of which 178 had pairwise co-occurrences in altogether 185 dyads. These seals had a variable number of associates (up to 10), and co-occurrences were observed in 1–7 years. In general, observations of pairs or larger groups of seals (up to five individuals) were rare, and mainly occurred in the two most densely populated basins of the lake. Most of the group observations occurred on ice rather than on rocks. Overall, the fragmented nature of the lake system, site fidelity and moulting habitat availability are key factors that probably affect the observed co-occurrences. Most of the dyads were observed during only one year, which may indicate social tolerance while using the same moulting site. However, 21 dyads were observed during multiple moulting seasons, with some at different sites separated by up to 3 km in different years, suggesting the existence of actual long-lasting associations. Our study represents the first description of co-occurrences and potential social associations in the endangered Saimaa ringed seal. These results can be used for designing and implementing mitigation strategies in case of unforeseen and sudden changes in the environment, such as a disease outbreak.